Commit Graph

22640 Commits

Author SHA1 Message Date
Tony Ambardar
34ceafa62f powerpc: fix EDEADLOCK redefinition error in uapi/asm/errno.h
commit 7de21e679e6a789f3729e8402bc440b623a28eae upstream.

A few archs like powerpc have different errno.h values for macros
EDEADLOCK and EDEADLK. In code including both libc and linux versions of
errno.h, this can result in multiple definitions of EDEADLOCK in the
include chain. Definitions to the same value (e.g. seen with mips) do
not raise warnings, but on powerpc there are redefinitions changing the
value, which raise warnings and errors (if using "-Werror").

Guard against these redefinitions to avoid build errors like the following,
first seen cross-compiling libbpf v5.8.9 for powerpc using GCC 8.4.0 with
musl 1.1.24:

  In file included from ../../arch/powerpc/include/uapi/asm/errno.h:5,
                   from ../../include/linux/err.h:8,
                   from libbpf.c:29:
  ../../include/uapi/asm-generic/errno.h:40: error: "EDEADLOCK" redefined [-Werror]
   #define EDEADLOCK EDEADLK

  In file included from toolchain-powerpc_8540_gcc-8.4.0_musl/include/errno.h:10,
                   from libbpf.c:26:
  toolchain-powerpc_8540_gcc-8.4.0_musl/include/bits/errno.h:58: note: this is the location of the previous definition
   #define EDEADLOCK       58

  cc1: all warnings being treated as errors

Cc: Stable <stable@vger.kernel.org>
Reported-by: Rosen Penev <rosenp@gmail.com>
Signed-off-by: Tony Ambardar <Tony.Ambardar@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20200917135437.1238787-1-Tony.Ambardar@gmail.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-05-11 14:47:35 +02:00
Christophe Leroy
0bdcaebb12 powerpc/32: Fix boot failure with CONFIG_STACKPROTECTOR
commit f5668260b872e89b8d3942a8b7d4278aa9c2c981 upstream.

Commit 7c95d8893f ("powerpc: Change calling convention for
create_branch() et. al.") complexified the frame of function
do_feature_fixups(), leading to GCC setting up a stack
guard when CONFIG_STACKPROTECTOR is selected.

The problem is that do_feature_fixups() is called very early
while 'current' in r2 is not set up yet and the code is still
not at the final address used at link time.

So, like other instrumentation, stack protection needs to be
deactivated for feature-fixups.c and code-patching.c

Fixes: 7c95d8893f ("powerpc: Change calling convention for create_branch() et. al.")
Cc: stable@vger.kernel.org # v5.8+
Reported-by: Jonathan Neuschaefer <j.neuschaefer@gmx.net>
Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
Tested-by: Jonathan Neuschaefer <j.neuschaefer@gmx.net>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/b688fe82927b330349d9e44553363fa451ea4d95.1619715114.git.christophe.leroy@csgroup.eu
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-05-11 14:47:35 +02:00
Sourabh Jain
f2aa64979e powerpc/kexec_file: Use current CPU info while setting up FDT
commit 40c753993e3aad51a12c21233486e2037417a4d6 upstream.

kexec_file_load() uses initial_boot_params in setting up the device tree
for the kernel to be loaded. Though initial_boot_params holds info about
CPUs at the time of boot, it doesn't account for hot added CPUs.

So, kexec'ing with kexec_file_load() syscall leaves the kexec'ed kernel
with inaccurate CPU info.

If kdump kernel is loaded with kexec_file_load() syscall and the system
crashes on a hot added CPU, the capture kernel hangs failing to identify
the boot CPU, with no output.

To avoid this from happening, extract current CPU info from of_root
device node and use it for setting up the fdt in kexec_file_load case.

Fixes: 6ecd0163d3 ("powerpc/kexec_file: Add appropriate regions for memory reserve map")
Cc: stable@vger.kernel.org # v5.9+
Signed-off-by: Sourabh Jain <sourabhjain@linux.ibm.com>
Reviewed-by: Hari Bathini <hbathini@linux.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20210429060256.199714-1-sourabhjain@linux.ibm.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-05-11 14:47:35 +02:00
Mahesh Salgaonkar
481fee8295 powerpc/eeh: Fix EEH handling for hugepages in ioremap space.
commit 5ae5bc12d0728db60a0aa9b62160ffc038875f1a upstream.

During the EEH MMIO error checking, the current implementation fails to map
the (virtual) MMIO address back to the pci device on radix with hugepage
mappings for I/O. This results into failure to dispatch EEH event with no
recovery even when EEH capability has been enabled on the device.

eeh_check_failure(token)		# token = virtual MMIO address
  addr = eeh_token_to_phys(token);
  edev = eeh_addr_cache_get_dev(addr);
  if (!edev)
	return 0;
  eeh_dev_check_failure(edev);	<= Dispatch the EEH event

In case of hugepage mappings, eeh_token_to_phys() has a bug in virt -> phys
translation that results in wrong physical address, which is then passed to
eeh_addr_cache_get_dev() to match it against cached pci I/O address ranges
to get to a PCI device. Hence, it fails to find a match and the EEH event
never gets dispatched leaving the device in failed state.

The commit 3343962068 ("powerpc/eeh: Handle hugepages in ioremap space")
introduced following logic to translate virt to phys for hugepage mappings:

eeh_token_to_phys():
+	pa = pte_pfn(*ptep);
+
+	/* On radix we can do hugepage mappings for io, so handle that */
+       if (hugepage_shift) {
+               pa <<= hugepage_shift;			<= This is wrong
+               pa |= token & ((1ul << hugepage_shift) - 1);
+       }

This patch fixes the virt -> phys translation in eeh_token_to_phys()
function.

  $ cat /sys/kernel/debug/powerpc/eeh_address_cache
  mem addr range [0x0000040080000000-0x00000400807fffff]: 0030:01:00.1
  mem addr range [0x0000040080800000-0x0000040080ffffff]: 0030:01:00.1
  mem addr range [0x0000040081000000-0x00000400817fffff]: 0030:01:00.0
  mem addr range [0x0000040081800000-0x0000040081ffffff]: 0030:01:00.0
  mem addr range [0x0000040082000000-0x000004008207ffff]: 0030:01:00.1
  mem addr range [0x0000040082080000-0x00000400820fffff]: 0030:01:00.0
  mem addr range [0x0000040082100000-0x000004008210ffff]: 0030:01:00.1
  mem addr range [0x0000040082110000-0x000004008211ffff]: 0030:01:00.0

Above is the list of cached io address ranges of pci 0030:01:00.<fn>.

Before this patch:

Tracing 'arg1' of function eeh_addr_cache_get_dev() during error injection
clearly shows that 'addr=' contains wrong physical address:

   kworker/u16:0-7       [001] ....   108.883775: eeh_addr_cache_get_dev:
	   (eeh_addr_cache_get_dev+0xc/0xf0) addr=0x80103000a510

dmesg shows no EEH recovery messages:

  [  108.563768] bnx2x: [bnx2x_timer:5801(eth2)]MFW seems hanged: drv_pulse (0x9ae) != mcp_pulse (0x7fff)
  [  108.563788] bnx2x: [bnx2x_hw_stats_update:870(eth2)]NIG timer max (4294967295)
  [  108.883788] bnx2x: [bnx2x_acquire_hw_lock:2013(eth1)]lock_status 0xffffffff  resource_bit 0x1
  [  108.884407] bnx2x 0030:01:00.0 eth1: MDC/MDIO access timeout
  [  108.884976] bnx2x 0030:01:00.0 eth1: MDC/MDIO access timeout
  <..>

After this patch:

eeh_addr_cache_get_dev() trace shows correct physical address:

  <idle>-0       [001] ..s.  1043.123828: eeh_addr_cache_get_dev:
	  (eeh_addr_cache_get_dev+0xc/0xf0) addr=0x40080bc7cd8

dmesg logs shows EEH recovery getting triggerred:

  [  964.323980] bnx2x: [bnx2x_timer:5801(eth2)]MFW seems hanged: drv_pulse (0x746f) != mcp_pulse (0x7fff)
  [  964.323991] EEH: Recovering PHB#30-PE#10000
  [  964.324002] EEH: PE location: N/A, PHB location: N/A
  [  964.324006] EEH: Frozen PHB#30-PE#10000 detected
  <..>

Fixes: 3343962068 ("powerpc/eeh: Handle hugepages in ioremap space")
Cc: stable@vger.kernel.org # v5.3+
Reported-by: Dominic DeMarco <ddemarc@us.ibm.com>
Signed-off-by: Mahesh Salgaonkar <mahesh@linux.ibm.com>
Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/161821396263.48361.2796709239866588652.stgit@jupiter
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-05-11 14:47:35 +02:00
Nicholas Piggin
293c30ce25 powerpc/powernv: Enable HAIL (HV AIL) for ISA v3.1 processors
commit 49c1d07fd04f54eb588c4a1dfcedc8d22c5ffd50 upstream.

Starting with ISA v3.1, LPCR[AIL] no longer controls the interrupt
mode for HV=1 interrupts. Instead, a new LPCR[HAIL] bit is defined
which behaves like AIL=3 for HV interrupts when set.

Set HAIL on bare metal to give us mmu-on interrupts and improve
performance.

This also fixes an scv bug: we don't implement scv real mode (AIL=0)
vectors because they are at an inconvenient location, so we just
disable scv support when AIL can not be set. However powernv assumes
that LPCR[AIL] will enable AIL mode so it enables scv support despite
HV interrupts being AIL=0, which causes scv interrupts to go off into
the weeds.

Fixes: 7fa95f9ada ("powerpc/64s: system call support for scv/rfscv instructions")
Cc: stable@vger.kernel.org # v5.9+
Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20210402024124.545826-1-npiggin@gmail.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-05-11 14:47:35 +02:00
Michael Ellerman
75e967a04d powerpc/4xx: Fix build errors from mfdcr()
[ Upstream commit eead089311f4d935ab5d1d8fbb0c42ad44699ada ]

lkp reported a build error in fsp2.o:

  CC      arch/powerpc/platforms/44x/fsp2.o
  {standard input}:577: Error: unsupported relocation against base

Which comes from:

  pr_err("GESR0: 0x%08x\n", mfdcr(base + PLB4OPB_GESR0));

Where our mfdcr() macro is stringifying "base + PLB4OPB_GESR0", and
passing that to the assembler, which obviously doesn't work.

The mfdcr() macro already checks that the argument is constant using
__builtin_constant_p(), and if not calls the out-of-line version of
mfdcr(). But in this case GCC is smart enough to notice that "base +
PLB4OPB_GESR0" will be constant, even though it's not something we can
immediately stringify into a register number.

Segher pointed out that passing the register number to the inline asm
as a constant would be better, and in fact it fixes the build error,
presumably because it gives GCC a chance to resolve the value.

While we're at it, change mtdcr() similarly.

Reported-by: kernel test robot <lkp@intel.com>
Suggested-by: Segher Boessenkool <segher@kernel.crashing.org>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Acked-by: Feng Tang <feng.tang@intel.com>
Link: https://lore.kernel.org/r/20210218123058.748882-1-mpe@ellerman.id.au
Signed-off-by: Sasha Levin <sashal@kernel.org>
2021-03-30 14:31:47 +02:00
Christophe Leroy
5a62d6d7af powerpc: Force inlining of cpu_has_feature() to avoid build failure
commit eed5fae00593ab9d261a0c1ffc1bdb786a87a55a upstream.

The code relies on constant folding of cpu_has_feature() based
on possible and always true values as defined per
CPU_FTRS_ALWAYS and CPU_FTRS_POSSIBLE.

Build failure is encountered with for instance
book3e_all_defconfig on kisskb in the AMDGPU driver which uses
cpu_has_feature(CPU_FTR_VSX_COMP) to decide whether calling
kernel_enable_vsx() or not.

The failure is due to cpu_has_feature() not being inlined with
that configuration with gcc 4.9.

In the same way as commit acdad8fb4a15 ("powerpc: Force inlining of
mmu_has_feature to fix build failure"), for inlining of
cpu_has_feature().

Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/b231dfa040ce4cc37f702f5c3a595fdeabfe0462.1615378209.git.christophe.leroy@csgroup.eu
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-03-25 09:04:14 +01:00
Sandipan Das
41d4c889b2 powerpc/sstep: Fix darn emulation
[ Upstream commit 22b89ba178dd0a66a26699ead014a3e73ff8e044 ]

Commit 8813ff49607e ("powerpc/sstep: Check instruction validity
against ISA version before emulation") introduced a proper way to skip
unknown instructions. This makes sure that the same is used for the
darn instruction when the range selection bits have a reserved value.

Fixes: a23987ef26 ("powerpc: sstep: Add support for darn instruction")
Signed-off-by: Sandipan Das <sandipan@linux.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20210204080744.135785-2-sandipan@linux.ibm.com
Signed-off-by: Sasha Levin <sashal@kernel.org>
2021-03-25 09:04:12 +01:00
Sandipan Das
8a335142f1 powerpc/sstep: Fix load-store and update emulation
[ Upstream commit bbda4b6c7d7c7f79da71f95c92a5d76be22c3efd ]

The Power ISA says that the fixed-point load and update instructions
must neither use R0 for the base address (RA) nor have the
destination (RT) and the base address (RA) as the same register.
Similarly, for fixed-point stores and floating-point loads and stores,
the instruction is invalid when R0 is used as the base address (RA).

This is applicable to the following instructions.
  * Load Byte and Zero with Update (lbzu)
  * Load Byte and Zero with Update Indexed (lbzux)
  * Load Halfword and Zero with Update (lhzu)
  * Load Halfword and Zero with Update Indexed (lhzux)
  * Load Halfword Algebraic with Update (lhau)
  * Load Halfword Algebraic with Update Indexed (lhaux)
  * Load Word and Zero with Update (lwzu)
  * Load Word and Zero with Update Indexed (lwzux)
  * Load Word Algebraic with Update Indexed (lwaux)
  * Load Doubleword with Update (ldu)
  * Load Doubleword with Update Indexed (ldux)
  * Load Floating Single with Update (lfsu)
  * Load Floating Single with Update Indexed (lfsux)
  * Load Floating Double with Update (lfdu)
  * Load Floating Double with Update Indexed (lfdux)
  * Store Byte with Update (stbu)
  * Store Byte with Update Indexed (stbux)
  * Store Halfword with Update (sthu)
  * Store Halfword with Update Indexed (sthux)
  * Store Word with Update (stwu)
  * Store Word with Update Indexed (stwux)
  * Store Doubleword with Update (stdu)
  * Store Doubleword with Update Indexed (stdux)
  * Store Floating Single with Update (stfsu)
  * Store Floating Single with Update Indexed (stfsux)
  * Store Floating Double with Update (stfdu)
  * Store Floating Double with Update Indexed (stfdux)

E.g. the following behaviour is observed for an invalid load and
update instruction having RA = RT.

While a userspace program having an instruction word like 0xe9ce0001,
i.e. ldu r14, 0(r14), runs without getting receiving a SIGILL on a
Power system (observed on P8 and P9), the outcome of executing that
instruction word varies and its behaviour can be considered to be
undefined.

Attaching an uprobe at that instruction's address results in emulation
which currently performs the load as well as writes the effective
address back to the base register. This might not match the outcome
from hardware.

To remove any inconsistencies, this adds additional checks for the
aforementioned instructions to make sure that the emulation
infrastructure treats them as unknown. The kernel can then fallback to
executing such instructions on hardware.

Fixes: 0016a4cf55 ("powerpc: Emulate most Book I instructions in emulate_step()")
Signed-off-by: Sandipan Das <sandipan@linux.ibm.com>
Reviewed-by: Naveen N. Rao <naveen.n.rao@linux.vnet.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20210204080744.135785-1-sandipan@linux.ibm.com
Signed-off-by: Sasha Levin <sashal@kernel.org>
2021-03-25 09:04:12 +01:00
Christophe Leroy
0e4750f69c powerpc: Fix missing declaration of [en/dis]able_kernel_vsx()
commit bd73758803c2eedc037c2268b65a19542a832594 upstream.

Add stub instances of enable_kernel_vsx() and disable_kernel_vsx()
when CONFIG_VSX is not set, to avoid following build failure.

  CC [M]  drivers/gpu/drm/amd/amdgpu/../display/dc/calcs/dcn_calcs.o
  In file included from ./drivers/gpu/drm/amd/amdgpu/../display/dc/dm_services_types.h:29,
                   from ./drivers/gpu/drm/amd/amdgpu/../display/dc/dm_services.h:37,
                   from drivers/gpu/drm/amd/amdgpu/../display/dc/calcs/dcn_calcs.c:27:
  drivers/gpu/drm/amd/amdgpu/../display/dc/calcs/dcn_calcs.c: In function 'dcn_bw_apply_registry_override':
  ./drivers/gpu/drm/amd/amdgpu/../display/dc/os_types.h:64:3: error: implicit declaration of function 'enable_kernel_vsx'; did you mean 'enable_kernel_fp'? [-Werror=implicit-function-declaration]
     64 |   enable_kernel_vsx(); \
        |   ^~~~~~~~~~~~~~~~~
  drivers/gpu/drm/amd/amdgpu/../display/dc/calcs/dcn_calcs.c:640:2: note: in expansion of macro 'DC_FP_START'
    640 |  DC_FP_START();
        |  ^~~~~~~~~~~
  ./drivers/gpu/drm/amd/amdgpu/../display/dc/os_types.h:75:3: error: implicit declaration of function 'disable_kernel_vsx'; did you mean 'disable_kernel_fp'? [-Werror=implicit-function-declaration]
     75 |   disable_kernel_vsx(); \
        |   ^~~~~~~~~~~~~~~~~~
  drivers/gpu/drm/amd/amdgpu/../display/dc/calcs/dcn_calcs.c:676:2: note: in expansion of macro 'DC_FP_END'
    676 |  DC_FP_END();
        |  ^~~~~~~~~
  cc1: some warnings being treated as errors
  make[5]: *** [drivers/gpu/drm/amd/amdgpu/../display/dc/calcs/dcn_calcs.o] Error 1

This works because the caller is checking if VSX is available using
cpu_has_feature():

  #define DC_FP_START() { \
  	if (cpu_has_feature(CPU_FTR_VSX_COMP)) { \
  		preempt_disable(); \
  		enable_kernel_vsx(); \
  	} else if (cpu_has_feature(CPU_FTR_ALTIVEC_COMP)) { \
  		preempt_disable(); \
  		enable_kernel_altivec(); \
  	} else if (!cpu_has_feature(CPU_FTR_FPU_UNAVAILABLE)) { \
  		preempt_disable(); \
  		enable_kernel_fp(); \
  	} \

When CONFIG_VSX is not selected, cpu_has_feature(CPU_FTR_VSX_COMP)
constant folds to 'false' so the call to enable_kernel_vsx() is
discarded and the build succeeds.

Fixes: 16a9dea110 ("amdgpu: Enable initial DCN support on POWER")
Cc: stable@vger.kernel.org # v5.6+
Reported-by: Geert Uytterhoeven <geert@linux-m68k.org>
Reported-by: kernel test robot <lkp@intel.com>
Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
[mpe: Incorporate some discussion comments into the change log]
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/8d7d285a027e9d21f5ff7f850fa71a2655b0c4af.1615279170.git.christophe.leroy@csgroup.eu
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-03-17 17:06:35 +01:00
Nicholas Piggin
1f372e8956 powerpc: Fix inverted SET_FULL_REGS bitop
commit 73ac79881804eed2e9d76ecdd1018037f8510cb1 upstream.

This bit operation was inverted and set the low bit rather than
cleared it, breaking the ability to ptrace non-volatile GPRs after
exec. Fix.

Only affects 64e and 32-bit.

Fixes: feb9df3462 ("powerpc/64s: Always has full regs, so remove remnant checks")
Cc: stable@vger.kernel.org # v5.8+
Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20210308085530.3191843-1-npiggin@gmail.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-03-17 17:06:35 +01:00
Naveen N. Rao
9776812ee8 powerpc/64s: Fix instruction encoding for lis in ppc_function_entry()
commit cea15316ceee2d4a51dfdecd79e08a438135416c upstream.

'lis r2,N' is 'addis r2,0,N' and the instruction encoding in the macro
LIS_R2 is incorrect (it currently maps to 'addis r0,r2,N'). Fix the
same.

Fixes: c71b7eff42 ("powerpc: Add ABIv2 support to ppc_function_entry")
Cc: stable@vger.kernel.org # v3.16+
Reported-by: Jiri Olsa <jolsa@redhat.com>
Signed-off-by: Naveen N. Rao <naveen.n.rao@linux.vnet.ibm.com>
Acked-by: Segher Boessenkool <segher@kernel.crashing.org>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20210304020411.16796-1-naveen.n.rao@linux.vnet.ibm.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-03-17 17:06:35 +01:00
Daniel Axtens
372734dc18 powerpc/64s/exception: Clean up a missed SRR specifier
[ Upstream commit c080a173301ffc62cb6c76308c803c7fee05517a ]

Nick's patch cleaning up the SRR specifiers in exception-64s.S missed
a single instance of EXC_HV_OR_STD. Clean that up.

Caught by clang's integrated assembler.

Fixes: 3f7fbd97d0 ("powerpc/64s/exception: Clean up SRR specifiers")
Signed-off-by: Daniel Axtens <dja@axtens.net>
Acked-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20210225031006.1204774-2-dja@axtens.net
Signed-off-by: Sasha Levin <sashal@kernel.org>
2021-03-17 17:06:34 +01:00
Michael Ellerman
adc631d87e powerpc/64: Fix stack trace not displaying final frame
[ Upstream commit e3de1e291fa58a1ab0f471a4b458eff2514e4b5f ]

In commit bf13718bc57a ("powerpc: show registers when unwinding
interrupt frames") we changed our stack dumping logic to show the full
registers whenever we find an interrupt frame on the stack.

However we didn't notice that on 64-bit this doesn't show the final
frame, ie. the interrupt that brought us in from userspace, whereas on
32-bit it does.

That is due to confusion about the size of that last frame. The code
in show_stack() calls validate_sp(), passing it STACK_INT_FRAME_SIZE
to check the sp is at least that far below the top of the stack.

However on 64-bit that size is too large for the final frame, because
it includes the red zone, but we don't allocate a red zone for the
first frame.

So add a new define that encodes the correct size for 32-bit and
64-bit, and use it in show_stack().

This results in the full trace being shown on 64-bit, eg:

  sysrq: Trigger a crash
  Kernel panic - not syncing: sysrq triggered crash
  CPU: 0 PID: 83 Comm: sh Not tainted 5.11.0-rc2-gcc-8.2.0-00188-g571abcb96b10-dirty #649
  Call Trace:
  [c00000000a1c3ac0] [c000000000897b70] dump_stack+0xc4/0x114 (unreliable)
  [c00000000a1c3b00] [c00000000014334c] panic+0x178/0x41c
  [c00000000a1c3ba0] [c00000000094e600] sysrq_handle_crash+0x40/0x50
  [c00000000a1c3c00] [c00000000094ef98] __handle_sysrq+0xd8/0x210
  [c00000000a1c3ca0] [c00000000094f820] write_sysrq_trigger+0x100/0x188
  [c00000000a1c3ce0] [c0000000005559dc] proc_reg_write+0x10c/0x1b0
  [c00000000a1c3d10] [c000000000479950] vfs_write+0xf0/0x360
  [c00000000a1c3d60] [c000000000479d9c] ksys_write+0x7c/0x140
  [c00000000a1c3db0] [c00000000002bf5c] system_call_exception+0x19c/0x2c0
  [c00000000a1c3e10] [c00000000000d35c] system_call_common+0xec/0x278
  --- interrupt: c00 at 0x7fff9fbab428
  NIP:  00007fff9fbab428 LR: 000000001000b724 CTR: 0000000000000000
  REGS: c00000000a1c3e80 TRAP: 0c00   Not tainted  (5.11.0-rc2-gcc-8.2.0-00188-g571abcb96b10-dirty)
  MSR:  900000000280f033 <SF,HV,VEC,VSX,EE,PR,FP,ME,IR,DR,RI,LE>  CR: 22002884  XER: 00000000
  IRQMASK: 0
  GPR00: 0000000000000004 00007fffc3cb8960 00007fff9fc59900 0000000000000001
  GPR04: 000000002a4b32d0 0000000000000002 0000000000000063 0000000000000063
  GPR08: 000000002a4b32d0 0000000000000000 0000000000000000 0000000000000000
  GPR12: 0000000000000000 00007fff9fcca9a0 0000000000000000 0000000000000000
  GPR16: 0000000000000000 0000000000000000 0000000000000000 00000000100b8fd0
  GPR20: 000000002a4b3485 00000000100b8f90 0000000000000000 0000000000000000
  GPR24: 000000002a4b0440 00000000100e77b8 0000000000000020 000000002a4b32d0
  GPR28: 0000000000000001 0000000000000002 000000002a4b32d0 0000000000000001
  NIP [00007fff9fbab428] 0x7fff9fbab428
  LR [000000001000b724] 0x1000b724
  --- interrupt: c00

Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20210209141627.2898485-1-mpe@ellerman.id.au
Signed-off-by: Sasha Levin <sashal@kernel.org>
2021-03-17 17:06:24 +01:00
Athira Rajeev
eb5a9ee32c powerpc/perf: Record counter overflow always if SAMPLE_IP is unset
[ Upstream commit d137845c973147a22622cc76c7b0bc16f6206323 ]

While sampling for marked events, currently we record the sample only
if the SIAR valid bit of Sampled Instruction Event Register (SIER) is
set. SIAR_VALID bit is used for fetching the instruction address from
Sampled Instruction Address Register(SIAR). But there are some
usecases, where the user is interested only in the PMU stats at each
counter overflow and the exact IP of the overflow event is not
required. Dropping SIAR invalid samples will fail to record some of
the counter overflows in such cases.

Example of such usecase is dumping the PMU stats (event counts) after
some regular amount of instructions/events from the userspace (ex: via
ptrace). Here counter overflow is indicated to userspace via signal
handler, and captured by monitoring and enabling I/O signaling on the
event file descriptor. In these cases, we expect to get
sample/overflow indication after each specified sample_period.

Perf event attribute will not have PERF_SAMPLE_IP set in the
sample_type if exact IP of the overflow event is not requested. So
while profiling if SAMPLE_IP is not set, just record the counter
overflow irrespective of SIAR_VALID check.

Suggested-by: Michael Ellerman <mpe@ellerman.id.au>
Signed-off-by: Athira Rajeev <atrajeev@linux.vnet.ibm.com>
[mpe: Reflow comment and if formatting]
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/1612516492-1428-1-git-send-email-atrajeev@linux.vnet.ibm.com
Signed-off-by: Sasha Levin <sashal@kernel.org>
2021-03-17 17:06:23 +01:00
Nicholas Piggin
87e443255d powerpc: improve handling of unrecoverable system reset
[ Upstream commit 11cb0a25f71818ca7ab4856548ecfd83c169aa4d ]

If an unrecoverable system reset hits in process context, the system
does not have to panic. Similar to machine check, call nmi_exit()
before die().

Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20210130130852.2952424-26-npiggin@gmail.com
Signed-off-by: Sasha Levin <sashal@kernel.org>
2021-03-17 17:06:23 +01:00
Oliver O'Halloran
912237ec34 powerpc/pci: Add ppc_md.discover_phbs()
[ Upstream commit 5537fcb319d016ce387f818dd774179bc03217f5 ]

On many powerpc platforms the discovery and initalisation of
pci_controllers (PHBs) happens inside of setup_arch(). This is very early
in boot (pre-initcalls) and means that we're initialising the PHB long
before many basic kernel services (slab allocator, debugfs, a real ioremap)
are available.

On PowerNV this causes an additional problem since we map the PHB registers
with ioremap(). As of commit d538aadc27 ("powerpc/ioremap: warn on early
use of ioremap()") a warning is printed because we're using the "incorrect"
API to setup and MMIO mapping in searly boot. The kernel does provide
early_ioremap(), but that is not intended to create long-lived MMIO
mappings and a seperate warning is printed by generic code if
early_ioremap() mappings are "leaked."

This is all fixable with dumb hacks like using early_ioremap() to setup
the initial mapping then replacing it with a real ioremap later on in
boot, but it does raise the question: Why the hell are we setting up the
PHB's this early in boot?

The old and wise claim it's due to "hysterical rasins." Aside from amused
grapes there doesn't appear to be any real reason to maintain the current
behaviour. Already most of the newer embedded platforms perform PHB
discovery in an arch_initcall and between the end of setup_arch() and the
start of initcalls none of the generic kernel code does anything PCI
related. On powerpc scanning PHBs occurs in a subsys_initcall so it should
be possible to move the PHB discovery to a core, postcore or arch initcall.

This patch adds the ppc_md.discover_phbs hook and a core_initcall stub that
calls it. The core_initcalls are the earliest to be called so this will
any possibly issues with dependency between initcalls. This isn't just an
academic issue either since on pseries and PowerNV EEH init occurs in an
arch_initcall and depends on the pci_controllers being available, similarly
the creation of pci_dns occurs at core_initcall_sync (i.e. between core and
postcore initcalls). These problems need to be addressed seperately.

Reported-by: kernel test robot <lkp@intel.com>
Signed-off-by: Oliver O'Halloran <oohall@gmail.com>
[mpe: Make discover_phbs() static]
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20201103043523.916109-1-oohall@gmail.com
Signed-off-by: Sasha Levin <sashal@kernel.org>
2021-03-17 17:06:23 +01:00
Christophe Leroy
aa1258d914 powerpc/603: Fix protection of user pages mapped with PROT_NONE
commit c119565a15a628efdfa51352f9f6c5186e506a1c upstream.

On book3s/32, page protection is defined by the PP bits in the PTE
which provide the following protection depending on the access
keys defined in the matching segment register:
- PP 00 means RW with key 0 and N/A with key 1.
- PP 01 means RW with key 0 and RO with key 1.
- PP 10 means RW with both key 0 and key 1.
- PP 11 means RO with both key 0 and key 1.

Since the implementation of kernel userspace access protection,
PP bits have been set as follows:
- PP00 for pages without _PAGE_USER
- PP01 for pages with _PAGE_USER and _PAGE_RW
- PP11 for pages with _PAGE_USER and without _PAGE_RW

For kernelspace segments, kernel accesses are performed with key 0
and user accesses are performed with key 1. As PP00 is used for
non _PAGE_USER pages, user can't access kernel pages not flagged
_PAGE_USER while kernel can.

For userspace segments, both kernel and user accesses are performed
with key 0, therefore pages not flagged _PAGE_USER are still
accessible to the user.

This shouldn't be an issue, because userspace is expected to be
accessible to the user. But unlike most other architectures, powerpc
implements PROT_NONE protection by removing _PAGE_USER flag instead of
flagging the page as not valid. This means that pages in userspace
that are not flagged _PAGE_USER shall remain inaccessible.

To get the expected behaviour, just mimic other architectures in the
TLB miss handler by checking _PAGE_USER permission on userspace
accesses as if it was the _PAGE_PRESENT bit.

Note that this problem only is only for 603 cores. The 604+ have
an hash table, and hash_page() function already implement the
verification of _PAGE_USER permission on userspace pages.

Fixes: f342adca3a ("powerpc/32s: Prepare Kernel Userspace Access Protection")
Cc: stable@vger.kernel.org # v5.2+
Reported-by: Christoph Plattner <christoph.plattner@thalesgroup.com>
Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/4a0c6e3bb8f0c162457bf54d9bc6fd8d7b55129f.1612160907.git.christophe.leroy@csgroup.eu
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-03-17 17:06:13 +01:00
Greg Kurz
a9c55f22a0 powerpc/pseries: Don't enforce MSI affinity with kdump
commit f9619d5e5174867536b7e558683bc4408eab833f upstream.

Depending on the number of online CPUs in the original kernel, it is
likely for CPU #0 to be offline in a kdump kernel. The associated IRQs
in the affinity mappings provided by irq_create_affinity_masks() are
thus not started by irq_startup(), as per-design with managed IRQs.

This can be a problem with multi-queue block devices driven by blk-mq :
such a non-started IRQ is very likely paired with the single queue
enforced by blk-mq during kdump (see blk_mq_alloc_tag_set()). This
causes the device to remain silent and likely hangs the guest at
some point.

This is a regression caused by commit 9ea69a55b3 ("powerpc/pseries:
Pass MSI affinity to irq_create_mapping()"). Note that this only happens
with the XIVE interrupt controller because XICS has a workaround to bypass
affinity, which is activated during kdump with the "noirqdistrib" kernel
parameter.

The issue comes from a combination of factors:
- discrepancy between the number of queues detected by the multi-queue
  block driver, that was used to create the MSI vectors, and the single
  queue mode enforced later on by blk-mq because of kdump (i.e. keeping
  all queues fixes the issue)
- CPU#0 offline (i.e. kdump always succeed with CPU#0)

Given that I couldn't reproduce on x86, which seems to always have CPU#0
online even during kdump, I'm not sure where this should be fixed. Hence
going for another approach : fine-grained affinity is for performance
and we don't really care about that during kdump. Simply revert to the
previous working behavior of ignoring affinity masks in this case only.

Fixes: 9ea69a55b3 ("powerpc/pseries: Pass MSI affinity to irq_create_mapping()")
Cc: stable@vger.kernel.org # v5.10+
Signed-off-by: Greg Kurz <groug@kaod.org>
Reviewed-by: Laurent Vivier <lvivier@redhat.com>
Reviewed-by: Cédric Le Goater <clg@kaod.org>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20210215094506.1196119-1-groug@kaod.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-03-17 17:06:10 +01:00
Athira Rajeev
ac022fbee6 powerpc/perf: Fix handling of privilege level checks in perf interrupt context
commit 5ae5fbd2107959b68ac69a8b75412208663aea88 upstream.

Running "perf mem record" in powerpc platforms with selinux enabled
resulted in soft lockup's. Below call-trace was seen in the logs:

  CPU: 58 PID: 3751 Comm: sssd_nss Not tainted 5.11.0-rc7+ #2
  NIP:  c000000000dff3d4 LR: c000000000dff3d0 CTR: 0000000000000000
  REGS: c000007fffab7d60 TRAP: 0100   Not tainted  (5.11.0-rc7+)
  ...
  NIP _raw_spin_lock_irqsave+0x94/0x120
  LR  _raw_spin_lock_irqsave+0x90/0x120
  Call Trace:
    0xc00000000fd47260 (unreliable)
    skb_queue_tail+0x3c/0x90
    audit_log_end+0x6c/0x180
    common_lsm_audit+0xb0/0xe0
    slow_avc_audit+0xa4/0x110
    avc_has_perm+0x1c4/0x260
    selinux_perf_event_open+0x74/0xd0
    security_perf_event_open+0x68/0xc0
    record_and_restart+0x6e8/0x7f0
    perf_event_interrupt+0x22c/0x560
    performance_monitor_exception0x4c/0x60
    performance_monitor_common_virt+0x1c8/0x1d0
  interrupt: f00 at _raw_spin_lock_irqsave+0x38/0x120
  NIP:  c000000000dff378 LR: c000000000b5fbbc CTR: c0000000007d47f0
  REGS: c00000000fd47860 TRAP: 0f00   Not tainted  (5.11.0-rc7+)
  ...
  NIP _raw_spin_lock_irqsave+0x38/0x120
  LR  skb_queue_tail+0x3c/0x90
  interrupt: f00
    0x38 (unreliable)
    0xc00000000aae6200
    audit_log_end+0x6c/0x180
    audit_log_exit+0x344/0xf80
    __audit_syscall_exit+0x2c0/0x320
    do_syscall_trace_leave+0x148/0x200
    syscall_exit_prepare+0x324/0x390
    system_call_common+0xfc/0x27c

The above trace shows that while the CPU was handling a performance
monitor exception, there was a call to security_perf_event_open()
function. In powerpc core-book3s, this function is called from
perf_allow_kernel() check during recording of data address in the
sample via perf_get_data_addr().

Commit da97e18458 ("perf_event: Add support for LSM and SELinux
checks") introduced security enhancements to perf. As part of this
commit, the new security hook for perf_event_open() was added in all
places where perf paranoid check was previously used. In powerpc
core-book3s code, originally had paranoid checks in
perf_get_data_addr() and power_pmu_bhrb_read(). So
perf_paranoid_kernel() checks were replaced with perf_allow_kernel()
in these PMU helper functions as well.

The intention of paranoid checks in core-book3s was to verify
privilege access before capturing some of the sample data. Along with
paranoid checks, perf_allow_kernel() also does a
security_perf_event_open(). Since these functions are accessed while
recording a sample, we end up calling selinux_perf_event_open() in PMI
context. Some of the security functions use spinlock like
sidtab_sid2str_put(). If a perf interrupt hits under a spin lock and
if we end up in calling selinux hook functions in PMI handler, this
could cause a dead lock.

Since the purpose of this security hook is to control access to
perf_event_open(), it is not right to call this in interrupt context.

The paranoid checks in powerpc core-book3s were done at interrupt time
which is also not correct.

Reference commits:
  Commit cd1231d703 ("powerpc/perf: Prevent kernel address leak via perf_get_data_addr()")
  Commit bb19af8160 ("powerpc/perf: Prevent kernel address leak to userspace via BHRB buffer")

We only allow creation of events that have already passed the
privilege checks in perf_event_open(). So these paranoid checks are
not needed at event time. As a fix, patch uses
'event->attr.exclude_kernel' check to prevent exposing kernel address
for userspace only sampling.

Fixes: cd1231d703 ("powerpc/perf: Prevent kernel address leak via perf_get_data_addr()")
Cc: stable@vger.kernel.org # v4.17+
Suggested-by: Michael Ellerman <mpe@ellerman.id.au>
Signed-off-by: Athira Rajeev <atrajeev@linux.vnet.ibm.com>
Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/1614247839-1428-1-git-send-email-atrajeev@linux.vnet.ibm.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-03-17 17:06:10 +01:00
Ananth N Mavinakayanahalli
686fa5a0c6 powerpc/sstep: Fix incorrect return from analyze_instr()
commit 718aae916fa6619c57c348beaedd675835cf1aa1 upstream.

We currently just percolate the return value from analyze_instr()
to the caller of emulate_step(), especially if it is a -1.

For one particular case (opcode = 4) for instructions that aren't
currently emulated, we are returning 'should not be single-stepped'
while we should have returned 0 which says 'did not emulate, may
have to single-step'.

Fixes: 930d6288a2 ("powerpc: sstep: Add support for maddhd, maddhdu, maddld instructions")
Signed-off-by: Ananth N Mavinakayanahalli <ananth@linux.ibm.com>
Suggested-by: Michael Ellerman <mpe@ellerman.id.au>
Tested-by: Naveen N. Rao <naveen.n.rao@linux.vnet.ibm.com>
Reviewed-by: Sandipan Das <sandipan@linux.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/161157999039.64773.14950289716779364766.stgit@thinktux.local
Signed-off-by: Naveen N. Rao <naveen.n.rao@linux.vnet.ibm.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-03-07 12:34:16 +01:00
Ananth N Mavinakayanahalli
20d323c8cf powerpc/sstep: Check instruction validity against ISA version before emulation
commit 8813ff49607eab3caaf40fe8929b0ce7dc68e85f upstream.

We currently unconditionally try to emulate newer instructions on older
Power versions that could cause issues. Gate it.

Fixes: 350779a29f ("powerpc: Handle most loads and stores in instruction emulation code")
Signed-off-by: Ananth N Mavinakayanahalli <ananth@linux.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/161157995977.64773.13794501093457185080.stgit@thinktux.local
[Dropped a few missing hunks for the backport to v5.10]
Signed-off-by: Naveen N. Rao <naveen.n.rao@linux.vnet.ibm.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-03-07 12:34:15 +01:00
Christophe Leroy
01b487b67c powerpc/32s: Add missing call to kuep_lock on syscall entry
commit 57fdfbce89137ae85cd5cef48be168040a47dd13 upstream.

Userspace Execution protection and fast syscall entry were implemented
independently from each other and were both merged in kernel 5.2,
leading to syscall entry missing userspace execution protection.

On syscall entry, execution of user space memory must be
locked in the same way as on exception entry.

Fixes: b86fb88855 ("powerpc/32: implement fast entry for syscalls on non BOOKE")
Cc: stable@vger.kernel.org
Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/c65e105b63aaf74f91a14f845bc77192350b84a6.1612796617.git.christophe.leroy@csgroup.eu
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-03-04 11:38:40 +01:00
Hari Bathini
402d31bdcd powerpc/kexec_file: fix FDT size estimation for kdump kernel
commit 2377c92e37fe97bc5b365f55cf60f56dfc4849f5 upstream.

On systems with large amount of memory, loading kdump kernel through
kexec_file_load syscall may fail with the below error:

    "Failed to update fdt with linux,drconf-usable-memory property"

This happens because the size estimation for kdump kernel's FDT does
not account for the additional space needed to setup usable memory
properties. Fix it by accounting for the space needed to include
linux,usable-memory & linux,drconf-usable-memory properties while
estimating kdump kernel's FDT size.

Fixes: 6ecd0163d3 ("powerpc/kexec_file: Add appropriate regions for memory reserve map")
Cc: stable@vger.kernel.org # v5.9+
Signed-off-by: Hari Bathini <hbathini@linux.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/161243826811.119001.14083048209224609814.stgit@hbathini
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-03-04 11:38:39 +01:00
Christophe Leroy
c0ec202951 powerpc/32: Preserve cr1 in exception prolog stack check to fix build error
commit 3642eb21256a317ac14e9ed560242c6d20cf06d9 upstream.

THREAD_ALIGN_SHIFT = THREAD_SHIFT + 1 = PAGE_SHIFT + 1
Maximum PAGE_SHIFT is 18 for 256k pages so
THREAD_ALIGN_SHIFT is 19 at the maximum.

No need to clobber cr1, it can be preserved when moving r1
into CR when we check stack overflow.

This reduces the number of instructions in Machine Check Exception
prolog and fixes a build failure reported by the kernel test robot
on v5.10 stable when building with RTAS + VMAP_STACK + KVM. That
build failure is due to too many instructions in the prolog hence
not fitting between 0x200 and 0x300. Allthough the problem doesn't
show up in mainline, it is still worth the change.

Fixes: 98bf2d3f4970 ("powerpc/32s: Fix RTAS machine check with VMAP stack")
Cc: stable@vger.kernel.org
Reported-by: kernel test robot <lkp@intel.com>
Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/5ae4d545e3ac58e133d2599e0deb88843cb494fc.1612768623.git.christophe.leroy@csgroup.eu
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-03-04 11:38:39 +01:00
Cédric Le Goater
6f7e5b49f6 powerpc/prom: Fix "ibm,arch-vec-5-platform-support" scan
commit ed5b00a05c2ae95b59adc3442f45944ec632e794 upstream.

The "ibm,arch-vec-5-platform-support" property is a list of pairs of
bytes representing the options and values supported by the platform
firmware. At boot time, Linux scans this list and activates the
available features it recognizes : Radix and XIVE.

A recent change modified the number of entries to loop on and 8 bytes,
4 pairs of { options, values } entries are always scanned. This is
fine on KVM but not on PowerVM which can advertises less. As a
consequence on this platform, Linux reads extra entries pointing to
random data, interprets these as available features and tries to
activate them, leading to a firmware crash in
ibm,client-architecture-support.

Fix that by using the property length of "ibm,arch-vec-5-platform-support".

Fixes: ab91239942 ("powerpc/prom: Remove VLA in prom_check_platform_support()")
Cc: stable@vger.kernel.org # v4.20+
Signed-off-by: Cédric Le Goater <clg@kaod.org>
Reviewed-by: Fabiano Rosas <farosas@linux.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20210122075029.797013-1-clg@kaod.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-03-04 11:38:35 +01:00
Alexey Kardashevskiy
f5f08edae1 powerpc/kuap: Restore AMR after replaying soft interrupts
[ Upstream commit 60a707d0c99aff4eadb7fd334c5fd21df386723e ]

Since de78a9c42a ("powerpc: Add a framework for Kernel Userspace
Access Protection"), user access helpers call user_{read|write}_access_{begin|end}
when user space access is allowed.

Commit 890274c2dc ("powerpc/64s: Implement KUAP for Radix MMU") made
the mentioned helpers program a AMR special register to allow such
access for a short period of time, most of the time AMR is expected to
block user memory access by the kernel.

Since the code accesses the user space memory, unsafe_get_user() calls
might_fault() which calls arch_local_irq_restore() if either
CONFIG_PROVE_LOCKING or CONFIG_DEBUG_ATOMIC_SLEEP is enabled.
arch_local_irq_restore() then attempts to replay pending soft
interrupts as KUAP regions have hardware interrupts enabled.

If a pending interrupt happens to do user access (performance
interrupts do that), it enables access for a short period of time so
after returning from the replay, the user access state remains blocked
and if a user page fault happens - "Bug: Read fault blocked by AMR!"
appears and SIGSEGV is sent.

An example trace:
  Bug: Read fault blocked by AMR!
  WARNING: CPU: 0 PID: 1603 at /home/aik/p/kernel/arch/powerpc/include/asm/book3s/64/kup-radix.h:145
  CPU: 0 PID: 1603 Comm: amr Not tainted 5.10.0-rc6_v5.10-rc6_a+fstn1 #24
  NIP:  c00000000009ece8 LR: c00000000009ece4 CTR: 0000000000000000
  REGS: c00000000dc63560 TRAP: 0700   Not tainted  (5.10.0-rc6_v5.10-rc6_a+fstn1)
  MSR:  8000000000021033 <SF,ME,IR,DR,RI,LE>  CR: 28002888  XER: 20040000
  CFAR: c0000000001fa928 IRQMASK: 1
  GPR00: c00000000009ece4 c00000000dc637f0 c000000002397600 000000000000001f
  GPR04: c0000000020eb318 0000000000000000 c00000000dc63494 0000000000000027
  GPR08: c00000007fe4de68 c00000000dfe9180 0000000000000000 0000000000000001
  GPR12: 0000000000002000 c0000000030a0000 0000000000000000 0000000000000000
  GPR16: 0000000000000000 0000000000000000 0000000000000000 bfffffffffffffff
  GPR20: 0000000000000000 c0000000134a4020 c0000000019c2218 0000000000000fe0
  GPR24: 0000000000000000 0000000000000000 c00000000d106200 0000000040000000
  GPR28: 0000000000000000 0000000000000300 c00000000dc63910 c000000001946730
  NIP __do_page_fault+0xb38/0xde0
  LR  __do_page_fault+0xb34/0xde0
  Call Trace:
    __do_page_fault+0xb34/0xde0 (unreliable)
    handle_page_fault+0x10/0x2c
  --- interrupt: 300 at strncpy_from_user+0x290/0x440
      LR = strncpy_from_user+0x284/0x440
    strncpy_from_user+0x2f0/0x440 (unreliable)
    getname_flags+0x88/0x2c0
    do_sys_openat2+0x2d4/0x5f0
    do_sys_open+0xcc/0x140
    system_call_exception+0x160/0x240
    system_call_common+0xf0/0x27c

To fix it save/restore the AMR when replaying interrupts, and also
add a check if AMR was not blocked prior to replaying interrupts.

Originally found by syzkaller.

Fixes: 890274c2dc ("powerpc/64s: Implement KUAP for Radix MMU")
Signed-off-by: Alexey Kardashevskiy <aik@ozlabs.ru>
Reviewed-by: Nicholas Piggin <npiggin@gmail.com>
[mpe: Use normal commit citation format and add full oops log to
      change log, move kuap_check_amr() into the restore routine to
      avoid warnings about unreconciled IRQ state]
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20210202091541.36499-1-aik@ozlabs.ru
Signed-off-by: Sasha Levin <sashal@kernel.org>
2021-03-04 11:38:06 +01:00
Alexey Kardashevskiy
97ab82462a powerpc/uaccess: Avoid might_fault() when user access is enabled
[ Upstream commit 7d506ca97b665b95e698a53697dad99fae813c1a ]

The amount of code executed with enabled user space access (unlocked
KUAP) should be minimal. However with CONFIG_PROVE_LOCKING or
CONFIG_DEBUG_ATOMIC_SLEEP enabled, might_fault() calls into various
parts of the kernel, and may even end up replaying interrupts which in
turn may access user space and forget to restore the KUAP state.

The problem places are:
  1. strncpy_from_user (and similar) which unlock KUAP and call
     unsafe_get_user -> __get_user_allowed -> __get_user_nocheck()
     with do_allow=false to skip KUAP as the caller took care of it.
  2. __unsafe_put_user_goto() which is called with unlocked KUAP.

eg:
  WARNING: CPU: 30 PID: 1 at arch/powerpc/include/asm/book3s/64/kup.h:324 arch_local_irq_restore+0x160/0x190
  NIP arch_local_irq_restore+0x160/0x190
  LR  lock_is_held_type+0x140/0x200
  Call Trace:
    0xc00000007f392ff8 (unreliable)
    ___might_sleep+0x180/0x320
    __might_fault+0x50/0xe0
    filldir64+0x2d0/0x5d0
    call_filldir+0xc8/0x180
    ext4_readdir+0x948/0xb40
    iterate_dir+0x1ec/0x240
    sys_getdents64+0x80/0x290
    system_call_exception+0x160/0x280
    system_call_common+0xf0/0x27c

Change __get_user_nocheck() to look at `do_allow` to decide whether to
skip might_fault(). Since strncpy_from_user/etc call might_fault()
anyway before unlocking KUAP, there should be no visible change.

Drop might_fault() in __unsafe_put_user_goto() as it is only called
from unsafe_put_user(), which already has KUAP unlocked.

Since keeping might_fault() is still desirable for debugging, add
calls to it in user_[read|write]_access_begin(). That also allows us
to drop the is_kernel_addr() test, because there should be no code
using user_[read|write]_access_begin() in order to access a kernel
address.

Fixes: de78a9c42a ("powerpc: Add a framework for Kernel Userspace Access Protection")
Signed-off-by: Alexey Kardashevskiy <aik@ozlabs.ru>
[mpe: Combine with related patch from myself, merge change logs]
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20210204121612.32721-1-aik@ozlabs.ru
Signed-off-by: Sasha Levin <sashal@kernel.org>
2021-03-04 11:38:06 +01:00
Christophe Leroy
e87684f927 powerpc/8xx: Fix software emulation interrupt
[ Upstream commit 903178d0ce6bb30ef80a3604ab9ee2b57869fbc9 ]

For unimplemented instructions or unimplemented SPRs, the 8xx triggers
a "Software Emulation Exception" (0x1000). That interrupt doesn't set
reason bits in SRR1 as the "Program Check Exception" does.

Go through emulation_assist_interrupt() to set REASON_ILLEGAL.

Fixes: fbbcc3bb13 ("powerpc/8xx: Remove SoftwareEmulation()")
Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/ad782af87a222efc79cfb06079b0fd23d4224eaf.1612515180.git.christophe.leroy@csgroup.eu
Signed-off-by: Sasha Levin <sashal@kernel.org>
2021-03-04 11:38:05 +01:00
Nathan Lynch
c035dcae0b powerpc/pseries/dlpar: handle ibm, configure-connector delay status
[ Upstream commit 768d70e19ba525debd571b36e6d0ab19956c63d7 ]

dlpar_configure_connector() has two problems in its handling of
ibm,configure-connector's return status:

1. When the status is -2 (busy, call again), we call
   ibm,configure-connector again immediately without checking whether
   to schedule, which can result in monopolizing the CPU.
2. Extended delay status (9900..9905) goes completely unhandled,
   causing the configuration to unnecessarily terminate.

Fix both of these issues by using rtas_busy_delay().

Fixes: ab519a011c ("powerpc/pseries: Kernel DLPAR Infrastructure")
Signed-off-by: Nathan Lynch <nathanl@linux.ibm.com>
Reviewed-by: Tyrel Datwyler <tyreld@linux.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20210107025900.410369-1-nathanl@linux.ibm.com
Signed-off-by: Sasha Levin <sashal@kernel.org>
2021-03-04 11:38:04 +01:00
Pingfan Liu
99e7c8d157 powerpc/time: Enable sched clock for irqtime
[ Upstream commit b709e32ef570b8b91dfbcb63cffac4324c87799f ]

When CONFIG_IRQ_TIME_ACCOUNTING and CONFIG_VIRT_CPU_ACCOUNTING_GEN, powerpc
does not enable "sched_clock_irqtime" and can not utilize irq time
accounting.

Like x86, powerpc does not use the sched_clock_register() interface. So it
needs an dedicated call to enable_sched_clock_irqtime() to enable irq time
accounting.

Fixes: 518470fe96 ("powerpc: Add HAVE_IRQ_TIME_ACCOUNTING")
Signed-off-by: Pingfan Liu <kernelfans@gmail.com>
[mpe: Add fixes tag]
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/1603349479-26185-1-git-send-email-kernelfans@gmail.com
Signed-off-by: Sasha Levin <sashal@kernel.org>
2021-03-04 11:38:01 +01:00
Christophe Leroy
f6ba4a84b9 powerpc/47x: Disable 256k page size
[ Upstream commit 910a0cb6d259736a0c86e795d4c2f42af8d0d775 ]

PPC47x_TLBE_SIZE isn't defined for 256k pages, leading to a build
break if 256k pages is selected.

So change the kconfig so that 256k pages can't be selected for 47x.

Fixes: e7f75ad01d ("powerpc/47x: Base ppc476 support")
Reported-by: kernel test robot <lkp@intel.com>
Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
[mpe: Expand change log to mention build break]
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/2fed79b1154c872194f98bac4422c23918325e61.1611128938.git.christophe.leroy@csgroup.eu
Signed-off-by: Sasha Levin <sashal@kernel.org>
2021-03-04 11:38:01 +01:00
Cédric Le Goater
6b83da9b1e KVM: PPC: Make the VMX instruction emulation routines static
[ Upstream commit 9236f57a9e51c72ce426ccd2e53e123de7196a0f ]

These are only used locally. It fixes these W=1 compile errors :

../arch/powerpc/kvm/powerpc.c:1521:5: error: no previous prototype for ‘kvmppc_get_vmx_dword’ [-Werror=missing-prototypes]
 1521 | int kvmppc_get_vmx_dword(struct kvm_vcpu *vcpu, int index, u64 *val)
      |     ^~~~~~~~~~~~~~~~~~~~
../arch/powerpc/kvm/powerpc.c:1539:5: error: no previous prototype for ‘kvmppc_get_vmx_word’ [-Werror=missing-prototypes]
 1539 | int kvmppc_get_vmx_word(struct kvm_vcpu *vcpu, int index, u64 *val)
      |     ^~~~~~~~~~~~~~~~~~~
../arch/powerpc/kvm/powerpc.c:1557:5: error: no previous prototype for ‘kvmppc_get_vmx_hword’ [-Werror=missing-prototypes]
 1557 | int kvmppc_get_vmx_hword(struct kvm_vcpu *vcpu, int index, u64 *val)
      |     ^~~~~~~~~~~~~~~~~~~~
../arch/powerpc/kvm/powerpc.c:1575:5: error: no previous prototype for ‘kvmppc_get_vmx_byte’ [-Werror=missing-prototypes]
 1575 | int kvmppc_get_vmx_byte(struct kvm_vcpu *vcpu, int index, u64 *val)
      |     ^~~~~~~~~~~~~~~~~~~

Fixes: acc9eb9305 ("KVM: PPC: Reimplement LOAD_VMX/STORE_VMX instruction mmio emulation with analyse_instr() input")
Signed-off-by: Cédric Le Goater <clg@kaod.org>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20210104143206.695198-19-clg@kaod.org
Signed-off-by: Sasha Levin <sashal@kernel.org>
2021-03-04 11:38:01 +01:00
Raoni Fassina Firmino
7f546959b3 powerpc/64/signal: Fix regression in __kernel_sigtramp_rt64() semantics
commit 24321ac668e452a4942598533d267805f291fdc9 upstream.

Commit 0138ba5783 ("powerpc/64/signal: Balance return predictor
stack in signal trampoline") changed __kernel_sigtramp_rt64() VDSO and
trampoline code, and introduced a regression in the way glibc's
backtrace()[1] detects the signal-handler stack frame. Apart from the
practical implications, __kernel_sigtramp_rt64() was a VDSO function
with the semantics that it is a function you can call from userspace
to end a signal handling. Now this semantics are no longer valid.

I believe the aforementioned change affects all releases since 5.9.

This patch tries to fix both the semantics and practical aspect of
__kernel_sigtramp_rt64() returning it to the previous code, whilst
keeping the intended behaviour of 0138ba5783 by adding a new symbol
to serve as the jump target from the kernel to the trampoline. Now the
trampoline has two parts, a new entry point and the old return point.

[1] https://lists.ozlabs.org/pipermail/linuxppc-dev/2021-January/223194.html

Fixes: 0138ba5783 ("powerpc/64/signal: Balance return predictor stack in signal trampoline")
Cc: stable@vger.kernel.org # v5.9+
Signed-off-by: Raoni Fassina Firmino <raoni@linux.ibm.com>
Acked-by: Nicholas Piggin <npiggin@gmail.com>
[mpe: Minor tweaks to change log formatting, add stable tag]
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20210201200505.iz46ubcizipnkcxe@work-tp
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-02-13 13:55:02 +01:00
Nicholas Piggin
ae02c0008c powerpc/64s: prevent recursive replay_soft_interrupts causing superfluous interrupt
[ Upstream commit 4025c784c573cab7e3f84746cc82b8033923ec62 ]

When an asynchronous interrupt calls irq_exit, it checks for softirqs
that may have been created, and runs them. Running softirqs enables
local irqs, which can replay pending interrupts causing recursion in
replay_soft_interrupts. This abridged trace shows how this can occur:

! NIP replay_soft_interrupts
  LR  interrupt_exit_kernel_prepare
  Call Trace:
    interrupt_exit_kernel_prepare (unreliable)
    interrupt_return
  --- interrupt: ea0 at __rb_reserve_next
  NIP __rb_reserve_next
  LR __rb_reserve_next
  Call Trace:
    ring_buffer_lock_reserve
    trace_function
    function_trace_call
    ftrace_call
    __do_softirq
    irq_exit
    timer_interrupt
!   replay_soft_interrupts
    interrupt_exit_kernel_prepare
    interrupt_return
  --- interrupt: ea0 at arch_local_irq_restore

This can not be prevented easily, because softirqs must not block hard
irqs, so it has to be dealt with.

The recursion is bounded by design in the softirq code because softirq
replay disables softirqs and loops around again to check for new
softirqs created while it ran, so that's not a problem.

However it does mess up interrupt replay state, causing superfluous
interrupts when the second replay_soft_interrupts clears a pending
interrupt, leaving it still set in the first call in the 'happened'
local variable.

Fix this by not caching a copy of irqs_happened across interrupt
handler calls.

Fixes: 3282a3da25 ("powerpc/64: Implement soft interrupt replay in C")
Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20210123061244.2076145-1-npiggin@gmail.com
Signed-off-by: Sasha Levin <sashal@kernel.org>
2021-02-03 23:28:46 +01:00
Nicholas Piggin
062dea906b powerpc/64s: fix scv entry fallback flush vs interrupt
commit 08685be7761d69914f08c3d6211c543a385a5b9c upstream.

The L1D flush fallback functions are not recoverable vs interrupts,
yet the scv entry flush runs with MSR[EE]=1. This can result in a
timer (soft-NMI) or MCE or SRESET interrupt hitting here and overwriting
the EXRFI save area, which ends up corrupting userspace registers for
scv return.

Fix this by disabling RI and EE for the scv entry fallback flush.

Fixes: f79643787e ("powerpc/64s: flush L1D on kernel entry")
Cc: stable@vger.kernel.org # 5.9+ which also have flush L1D patch backport
Reported-by: Tulio Magno Quites Machado Filho <tuliom@linux.ibm.com>
Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20210111062408.287092-1-npiggin@gmail.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-01-27 11:55:12 +01:00
Ariel Marcovitch
29c95dc43f powerpc: Fix alignment bug within the init sections
[ Upstream commit 2225a8dda263edc35a0e8b858fe2945cf6240fde ]

This is a bug that causes early crashes in builds with an .exit.text
section smaller than a page and an .init.text section that ends in the
beginning of a physical page (this is kinda random, which might
explain why this wasn't really encountered before).

The init sections are ordered like this:
  .init.text
  .exit.text
  .init.data

Currently, these sections aren't page aligned.

Because the init code might become read-only at runtime and because
the .init.text section can potentially reside on the same physical
page as .init.data, the beginning of .init.data might be mapped
read-only along with .init.text.

Then when the kernel tries to modify a variable in .init.data (like
kthreadd_done, used in kernel_init()) the kernel panics.

To avoid this, make _einittext page aligned and also align .exit.text
to make sure .init.data is always seperated from the text segments.

Fixes: 060ef9d89d ("powerpc32: PAGE_EXEC required for inittext")
Signed-off-by: Ariel Marcovitch <ariel.marcovitch@gmail.com>
Reviewed-by: Christophe Leroy <christophe.leroy@csgroup.eu>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20210102201156.10805-1-ariel.marcovitch@gmail.com
Signed-off-by: Sasha Levin <sashal@kernel.org>
2021-01-27 11:55:07 +01:00
Youling Tang
3f46eda5df powerpc: Use the common INIT_DATA_SECTION macro in vmlinux.lds.S
[ Upstream commit fdcfeaba38e5b183045f5b079af94f97658eabe6 ]

Use the common INIT_DATA_SECTION rule for the linker script in an effort
to regularize the linker script.

Signed-off-by: Youling Tang <tangyouling@loongson.cn>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/1604487550-20040-1-git-send-email-tangyouling@loongson.cn
Signed-off-by: Sasha Levin <sashal@kernel.org>
2021-01-27 11:55:07 +01:00
Christophe Leroy
bca9ca5a60 powerpc/32s: Fix RTAS machine check with VMAP stack
[ Upstream commit 98bf2d3f4970179c702ef64db658e0553bc6ef3a ]

When we have VMAP stack, exception prolog 1 sets r1, not r11.

When it is not an RTAS machine check, don't trash r1 because it is
needed by prolog 1.

Fixes: da7bb43ab9 ("powerpc/32: Fix vmap stack - Properly set r1 before activating MMU")
Fixes: d2e006036082 ("powerpc/32: Use SPRN_SPRG_SCRATCH2 in exception prologs")
Cc: stable@vger.kernel.org # v5.10+
Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
[mpe: Squash in fixup for RTAS machine check from Christophe]
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/bc77d61d1c18940e456a2dee464f1e2eda65a3f0.1608621048.git.christophe.leroy@csgroup.eu
Signed-off-by: Sasha Levin <sashal@kernel.org>
2021-01-17 14:16:52 +01:00
Nathan Chancellor
cb5a170e97 powerpc: Handle .text.{hot,unlikely}.* in linker script
commit 3ce47d95b7346dcafd9bed3556a8d072cb2b8571 upstream.

Commit eff8728fe6 ("vmlinux.lds.h: Add PGO and AutoFDO input
sections") added ".text.unlikely.*" and ".text.hot.*" due to an LLVM
change [1].

After another LLVM change [2], these sections are seen in some PowerPC
builds, where there is a orphan section warning then build failure:

$ make -skj"$(nproc)" \
       ARCH=powerpc CROSS_COMPILE=powerpc64le-linux-gnu- LLVM=1 O=out \
       distclean powernv_defconfig zImage.epapr
ld.lld: warning: kernel/built-in.a(panic.o):(.text.unlikely.) is being placed in '.text.unlikely.'
...
ld.lld: warning: address (0xc000000000009314) of section .text is not a multiple of alignment (256)
...
ERROR: start_text address is c000000000009400, should be c000000000008000
ERROR: try to enable LD_HEAD_STUB_CATCH config option
ERROR: see comments in arch/powerpc/tools/head_check.sh
...

Explicitly handle these sections like in the main linker script so
there is no more build failure.

[1]: https://reviews.llvm.org/D79600
[2]: https://reviews.llvm.org/D92493

Fixes: 83a092cf95 ("powerpc: Link warning for orphan sections")
Cc: stable@vger.kernel.org
Signed-off-by: Nathan Chancellor <natechancellor@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://github.com/ClangBuiltLinux/linux/issues/1218
Link: https://lore.kernel.org/r/20210104205952.1399409-1-natechancellor@gmail.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-01-12 20:18:17 +01:00
Randy Dunlap
2179bae04b local64.h: make <asm/local64.h> mandatory
[ Upstream commit 87dbc209ea04645fd2351981f09eff5d23f8e2e9 ]

Make <asm-generic/local64.h> mandatory in include/asm-generic/Kbuild and
remove all arch/*/include/asm/local64.h arch-specific files since they
only #include <asm-generic/local64.h>.

This fixes build errors on arch/c6x/ and arch/nios2/ for
block/blk-iocost.c.

Build-tested on 21 of 25 arch-es.  (tools problems on the others)

Yes, we could even rename <asm-generic/local64.h> to
<linux/local64.h> and change all #includes to use
<linux/local64.h> instead.

Link: https://lkml.kernel.org/r/20201227024446.17018-1-rdunlap@infradead.org
Signed-off-by: Randy Dunlap <rdunlap@infradead.org>
Suggested-by: Christoph Hellwig <hch@infradead.org>
Reviewed-by: Masahiro Yamada <masahiroy@kernel.org>
Cc: Jens Axboe <axboe@kernel.dk>
Cc: Ley Foon Tan <ley.foon.tan@intel.com>
Cc: Mark Salter <msalter@redhat.com>
Cc: Aurelien Jacquiot <jacquiot.aurelien@gmail.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2021-01-12 20:18:16 +01:00
Nicholas Piggin
b1e155ccc8 powerpc/64: irq replay remove decrementer overflow check
[ Upstream commit 59d512e4374b2d8a6ad341475dc94c4a4bdec7d3 ]

This is way to catch some cases of decrementer overflow, when the
decrementer has underflowed an odd number of times, while MSR[EE] was
disabled.

With a typical small decrementer, a timer that fires when MSR[EE] is
disabled will be "lost" if MSR[EE] remains disabled for between 4.3 and
8.6 seconds after the timer expires. In any case, the decrementer
interrupt would be taken at 8.6 seconds and the timer would be found at
that point.

So this check is for catching extreme latency events, and it prevents
those latencies from being a further few seconds long.  It's not obvious
this is a good tradeoff. This is already a watchdog magnitude event and
that situation is not improved a significantly with this check. For
large decrementers, it's useless.

Therefore remove this check, which avoids a mftb when enabling hard
disabled interrupts (e.g., when enabling after coming from hardware
interrupt handlers). Perhaps more importantly, it also removes the
clunky MSR[EE] vs PACA_IRQ_HARD_DIS incoherency in soft-interrupt replay
which simplifies the code.

Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20201107014336.2337337-1-npiggin@gmail.com
Signed-off-by: Sasha Levin <sashal@kernel.org>
2021-01-06 14:56:54 +01:00
Qinglang Miao
498d90690f powerpc: sysdev: add missing iounmap() on error in mpic_msgr_probe()
[ Upstream commit ffa1797040c5da391859a9556be7b735acbe1242 ]

I noticed that iounmap() of msgr_block_addr before return from
mpic_msgr_probe() in the error handling case is missing. So use
devm_ioremap() instead of just ioremap() when remapping the message
register block, so the mapping will be automatically released on
probe failure.

Signed-off-by: Qinglang Miao <miaoqinglang@huawei.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20201028091551.136400-1-miaoqinglang@huawei.com
Signed-off-by: Sasha Levin <sashal@kernel.org>
2021-01-06 14:56:53 +01:00
David Hildenbrand
cd2eda58ea powerpc/powernv/memtrace: Fix crashing the kernel when enabling concurrently
commit d6718941a2767fb383e105d257d2105fe4f15f0e upstream.

It's very easy to crash the kernel right now by simply trying to
enable memtrace concurrently, hammering on the "enable" interface

loop.sh:
  #!/bin/bash

  dmesg --console-off

  while true; do
          echo 0x40000000 > /sys/kernel/debug/powerpc/memtrace/enable
  done

[root@localhost ~]# loop.sh &
[root@localhost ~]# loop.sh &

Resulting quickly in a kernel crash. Let's properly protect using a
mutex.

Fixes: 9d5171a8f2 ("powerpc/powernv: Enable removal of memory for in memory tracing")
Cc: stable@vger.kernel.org# v4.14+
Signed-off-by: David Hildenbrand <david@redhat.com>
Reviewed-by: Oscar Salvador <osalvador@suse.de>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20201111145322.15793-3-david@redhat.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-12-30 11:54:16 +01:00
David Hildenbrand
4b8dcb006e powerpc/powernv/memtrace: Don't leak kernel memory to user space
commit c74cf7a3d59a21b290fe0468f5b470d0b8ee37df upstream.

We currently leak kernel memory to user space, because memory
offlining doesn't do any implicit clearing of memory and we are
missing explicit clearing of memory.

Let's keep it simple and clear pages before removing the linear
mapping.

Reproduced in QEMU/TCG with 10 GiB of main memory:
  [root@localhost ~]# dd obs=9G if=/dev/urandom of=/dev/null
  [... wait until "free -m" used counter no longer changes and cancel]
  19665802+0 records in
  1+0 records out
  9663676416 bytes (9.7 GB, 9.0 GiB) copied, 135.548 s, 71.3 MB/s
  [root@localhost ~]# cat /sys/devices/system/memory/block_size_bytes
  40000000
  [root@localhost ~]# echo 0x40000000 > /sys/kernel/debug/powerpc/memtrace/enable
  [  402.978663][ T1086] page:000000001bc4bc74 refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x24900
  [  402.980063][ T1086] flags: 0x7ffff000001000(reserved)
  [  402.980415][ T1086] raw: 007ffff000001000 c00c000000924008 c00c000000924008 0000000000000000
  [  402.980627][ T1086] raw: 0000000000000000 0000000000000000 00000001ffffffff 0000000000000000
  [  402.980845][ T1086] page dumped because: unmovable page
  [  402.989608][ T1086] Offlined Pages 16384
  [  403.324155][ T1086] memtrace: Allocated trace memory on node 0 at 0x0000000200000000

Before this patch:
  [root@localhost ~]# hexdump -C /sys/kernel/debug/powerpc/memtrace/00000000/trace  | head
  00000000  c8 25 72 51 4d 26 36 c5  5c c2 56 15 d5 1a cd 10  |.%rQM&6.\.V.....|
  00000010  19 b9 50 b2 cb e3 60 b8  ec 0a f3 ec 4b 3c 39 f0  |..P...`.....K<9.|$
  00000020  4e 5a 4c cf bd 26 19 ff  37 79 13 67 24 b7 b8 57  |NZL..&..7y.g$..W|$
  00000030  98 3e f5 be 6f 14 6a bd  a4 52 bc 6e e9 e0 c1 5d  |.>..o.j..R.n...]|$
  00000040  76 b3 ae b5 88 d7 da e3  64 23 85 2c 10 88 07 b6  |v.......d#.,....|$
  00000050  9a d8 91 de f7 50 27 69  2e 64 9c 6f d3 19 45 79  |.....P'i.d.o..Ey|$
  00000060  6a 6f 8a 61 71 19 1f c7  f1 df 28 26 ca 0f 84 55  |jo.aq.....(&...U|$
  00000070  01 3f be e4 e2 e1 da ff  7b 8c 8e 32 37 b4 24 53  |.?......{..27.$S|$
  00000080  1b 70 30 45 56 e6 8c c4  0e b5 4c fb 9f dd 88 06  |.p0EV.....L.....|$
  00000090  ef c4 18 79 f1 60 b1 5c  79 59 4d f4 36 d7 4a 5c  |...y.`.\yYM.6.J\|$

After this patch:
  [root@localhost ~]# hexdump -C /sys/kernel/debug/powerpc/memtrace/00000000/trace  | head
  00000000  00 00 00 00 00 00 00 00  00 00 00 00 00 00 00 00  |................|
  *
  40000000

Fixes: 9d5171a8f2 ("powerpc/powernv: Enable removal of memory for in memory tracing")
Cc: stable@vger.kernel.org # v4.14+
Reported-by: Michael Ellerman <mpe@ellerman.id.au>
Signed-off-by: David Hildenbrand <david@redhat.com>
Reviewed-by: Oscar Salvador <osalvador@suse.de>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20201111145322.15793-2-david@redhat.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-12-30 11:54:16 +01:00
Alexey Kardashevskiy
8fe4bee4c0 powerpc/powernv/npu: Do not attempt NPU2 setup on POWER8NVL NPU
commit b1198a88230f2ce50c271e22b82a8b8610b2eea9 upstream.

We execute certain NPU2 setup code (such as mapping an LPID to a device
in NPU2) unconditionally if an Nvlink bridge is detected. However this
cannot succeed on POWER8NVL machines and errors appear in dmesg. This is
harmless as skiboot returns an error and the only place we check it is
vfio-pci but that code does not get called on P8+ either.

This adds a check if pnv_npu2_xxx helpers are called on a machine with
NPU2 which initializes pnv_phb::npu in pnv_npu2_init();
pnv_phb::npu==NULL on POWER8/NVL (Naples).

While at this, fix NULL derefencing in pnv_npu_peers_take_ownership/
pnv_npu_peers_release_ownership which occurs when GPUs on mentioned P8s
cause EEH which happens if "vfio-pci" disables devices using
the D3 power state; the vfio-pci's disable_idle_d3 module parameter
controls this and must be set on Naples. The EEH handling clears
the entire pnv_ioda_pe struct in pnv_ioda_free_pe() hence
the NULL derefencing. We cannot recover from that but at least we stop
crashing.

Tested on
- POWER9 pvr=004e1201, Ubuntu 19.04 host, Ubuntu 18.04 vm,
  NVIDIA GV100 10de:1db1 driver 418.39
- POWER8 pvr=004c0100, RHEL 7.6 host, Ubuntu 16.10 vm,
  NVIDIA P100 10de:15f9 driver 396.47

Fixes: 1b785611e1 ("powerpc/powernv/npu: Add release_ownership hook")
Cc: stable@vger.kernel.org # 5.0
Signed-off-by: Alexey Kardashevskiy <aik@ozlabs.ru>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20201122073828.15446-1-aik@ozlabs.ru
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-12-30 11:54:16 +01:00
Christophe Leroy
600ebd0434 powerpc/mm: Fix verification of MMU_FTR_TYPE_44x
commit 17179aeb9d34cc81e1a4ae3f85e5b12b13a1f8d0 upstream.

MMU_FTR_TYPE_44x cannot be checked by cpu_has_feature()

Use mmu_has_feature() instead

Fixes: 23eb7f560a ("powerpc: Convert flush_icache_range & friends to C")
Cc: stable@vger.kernel.org
Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/ceede82fadf37f3b8275e61fcf8cf29a3e2ec7fe.1602351011.git.christophe.leroy@csgroup.eu
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-12-30 11:54:16 +01:00
Christophe Leroy
a8b871dfac powerpc/8xx: Fix early debug when SMC1 is relocated
commit 1e78f723d6a52966bfe3804209dbf404fdc9d3bb upstream.

When SMC1 is relocated and early debug is selected, the
board hangs is ppc_md.setup_arch(). This is because ones
the microcode has been loaded and SMC1 relocated, early
debug writes in the weed.

To allow smooth continuation, the SMC1 parameter RAM set up
by the bootloader have to be copied into the new location.

Fixes: 43db76f418 ("powerpc/8xx: Add microcode patch to move SMC parameter RAM.")
Cc: stable@vger.kernel.org
Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/b2f71f39eca543f1e4ec06596f09a8b12235c701.1607076683.git.christophe.leroy@csgroup.eu
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-12-30 11:54:16 +01:00
Christophe Leroy
8bc125f596 powerpc/xmon: Change printk() to pr_cont()
commit 7c6c86b36a36dd4a13d30bba07718e767aa2e7a1 upstream.

Since some time now, printk() adds carriage return, leading to
unusable xmon output if there is no udbg backend available:

  [   54.288722] sysrq: Entering xmon
  [   54.292209] Vector: 0  at [cace3d2c]
  [   54.292274]     pc:
  [   54.292331] c0023650
  [   54.292468] : xmon+0x28/0x58
  [   54.292519]
  [   54.292574]     lr:
  [   54.292630] c0023724
  [   54.292749] : sysrq_handle_xmon+0xa4/0xfc
  [   54.292801]
  [   54.292867]     sp: cace3de8
  [   54.292931]    msr: 9032
  [   54.292999]   current = 0xc28d0000
  [   54.293072]     pid   = 377, comm = sh
  [   54.293157] Linux version 5.10.0-rc6-s3k-dev-01364-gedf13f0ccd76-dirty (root@po17688vm.idsi0.si.c-s.fr) (powerpc64-linux-gcc (GCC) 10.1.0, GNU ld (GNU Binutils) 2.34) #4211 PREEMPT Fri Dec 4 09:32:11 UTC 2020
  [   54.293287] enter ? for help
  [   54.293470] [cace3de8]
  [   54.293532] c0023724
  [   54.293654]  sysrq_handle_xmon+0xa4/0xfc
  [   54.293711]  (unreliable)
  ...
  [   54.296002]
  [   54.296159] --- Exception: c01 (System Call) at
  [   54.296217] 0fd4e784
  [   54.296303]
  [   54.296375] SP (7fca6ff0) is in userspace
  [   54.296431] mon>
  [   54.296484]  <no input ...>

Use pr_cont() instead.

Fixes: 4bcc595ccd ("printk: reinstate KERN_CONT for printing continuation lines")
Cc: stable@vger.kernel.org # v4.9+
Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
[mpe: Mention that it only happens when udbg is not available]
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/c8a6ec704416ecd5ff2bd26213c9bc026bdd19de.1607077340.git.christophe.leroy@csgroup.eu
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-12-30 11:54:16 +01:00
Christophe Leroy
2ae45223e4 powerpc/feature: Add CPU_FTR_NOEXECUTE to G2_LE
commit 197493af414ee22427be3343637ac290a791925a upstream.

G2_LE has a 603 core, add CPU_FTR_NOEXECUTE.

Fixes: 385e89d5b2 ("powerpc/mm: add exec protection on powerpc 603")
Cc: stable@vger.kernel.org
Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/39a530ee41d83f49747ab3af8e39c056450b9b4d.1602489653.git.christophe.leroy@csgroup.eu
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-12-30 11:54:16 +01:00