Every in-kernel use of this function defined it to KERNEL_DS (either as
an actual define, or as an inline function). It's an entirely
historical artifact, and long long long ago used to actually read the
segment selector valueof '%ds' on x86.
Which in the kernel is always KERNEL_DS.
Inspired by a patch from Jann Horn that just did this for a very small
subset of users (the ones in fs/), along with Al who suggested a script.
I then just took it to the logical extreme and removed all the remaining
gunk.
Roughly scripted with
git grep -l '(get_ds())' -- :^tools/ | xargs sed -i 's/(get_ds())/(KERNEL_DS)/'
git grep -lw 'get_ds' -- :^tools/ | xargs sed -i '/^#define get_ds()/d'
plus manual fixups to remove a few unusual usage patterns, the couple of
inline function cases and to fix up a comment that had become stale.
The 'get_ds()' function remains in an x86 kvm selftest, since in user
space it actually does something relevant.
Inspired-by: Jann Horn <jannh@google.com>
Inspired-by: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Nobody has actually used the type (VERIFY_READ vs VERIFY_WRITE) argument
of the user address range verification function since we got rid of the
old racy i386-only code to walk page tables by hand.
It existed because the original 80386 would not honor the write protect
bit when in kernel mode, so you had to do COW by hand before doing any
user access. But we haven't supported that in a long time, and these
days the 'type' argument is a purely historical artifact.
A discussion about extending 'user_access_begin()' to do the range
checking resulted this patch, because there is no way we're going to
move the old VERIFY_xyz interface to that model. And it's best done at
the end of the merge window when I've done most of my merges, so let's
just get this done once and for all.
This patch was mostly done with a sed-script, with manual fix-ups for
the cases that weren't of the trivial 'access_ok(VERIFY_xyz' form.
There were a couple of notable cases:
- csky still had the old "verify_area()" name as an alias.
- the iter_iov code had magical hardcoded knowledge of the actual
values of VERIFY_{READ,WRITE} (not that they mattered, since nothing
really used it)
- microblaze used the type argument for a debug printout
but other than those oddities this should be a total no-op patch.
I tried to fix up all architectures, did fairly extensive grepping for
access_ok() uses, and the changes are trivial, but I may have missed
something. Any missed conversion should be trivially fixable, though.
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Pull uacess-unaligned removal from Al Viro:
"That stuff had just one user, and an exotic one, at that - binfmt_flat
on arm and m68k"
* 'work.uaccess-unaligned' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs:
kill {__,}{get,put}_user_unaligned()
binfmt_flat: flat_{get,put}_addr_from_rp() should be able to fail
for one thing, the last argument is always __access_mask and had been such
since 2.4.0-test3pre8; for another, it can bloody well be a static inline -
-O2 or -Os, __builtin_constant_p() propagates through static inline calls.
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
kernelci.org reports tons of build warnings for linux-next:
35 WARNING: "memcpy" [fs/fat/msdos.ko] has no CRC!
35 WARNING: "__copy_user" [fs/fat/fat.ko] has no CRC!
32 WARNING: EXPORT symbol "memset" [vmlinux] version generation failed, symbol will not be versioned.
32 WARNING: EXPORT symbol "copy_page" [vmlinux] version generation failed, symbol will not be versioned.
32 WARNING: EXPORT symbol "clear_page" [vmlinux] version generation failed, symbol will not be versioned.
32 WARNING: EXPORT symbol "__strncpy_from_user_nocheck_asm" [vmlinux] version generation failed, symbol will not be versioned.
The problem here is mainly the missing asm/asm-prototypes.h header file
that is supposed to include the prototypes for each symbol that is exported
from an assembler file.
A second problem is that the asm/uaccess.h header contains some but not
all the necessary declarations for the user access helpers.
Finally, the vdso build is broken once we add asm/asm-prototypes.h, so
we have to fix this at the same time by changing the vdso header. My
approach here is to just not look for exported symbols in the VDSO
assembler files, as the symbols cannot be exported anyway.
Fixes: 576a2f0c5c ("MIPS: Export memcpy & memset functions alongside their definitions")
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: James Hogan <james.hogan@imgtec.com>
Cc: Maciej W. Rozycki <macro@imgtec.com>
Cc: linux-mips@linux-mips.org
Cc: linux-kernel@vger.kernel.org
Patchwork: https://patchwork.linux-mips.org/patch/15038/
Patchwork: https://patchwork.linux-mips.org/patch/15069/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
Pull MIPS updates from Ralf Baechle:
"This is the main MIPS pull request for 4.9:
MIPS core arch code:
- traps: 64bit kernels should read CP0_EBase 64bit
- traps: Convert ebase to KSEG0
- c-r4k: Drop bc_wback_inv() from icache flush
- c-r4k: Split user/kernel flush_icache_range()
- cacheflush: Use __flush_icache_user_range()
- uprobes: Flush icache via kernel address
- KVM: Use __local_flush_icache_user_range()
- c-r4k: Fix flush_icache_range() for EVA
- Fix -mabi=64 build of vdso.lds
- VDSO: Drop duplicated -I*/-E* aflags
- tracing: move insn_has_delay_slot to a shared header
- tracing: disable uprobe/kprobe on compact branch instructions
- ptrace: Fix regs_return_value for kernel context
- Squash lines for simple wrapper functions
- Move identification of VP(E) into proc.c from smp-mt.c
- Add definitions of SYNC barrierstype values
- traps: Ensure full EBase is written
- tlb-r4k: If there are wired entries, don't use TLBINVF
- Sanitise coherentio semantics
- dma-default: Don't check hw_coherentio if device is non-coherent
- Support per-device DMA coherence
- Adjust MIPS64 CAC_BASE to reflect Config.K0
- Support generating Flattened Image Trees (.itb)
- generic: Introduce generic DT-based board support
- generic: Convert SEAD-3 to a generic board
- Enable hardened usercopy
- Don't specify STACKPROTECTOR in defconfigs
Octeon:
- Delete dead code and files across the platform.
- Change to use all memory into use by default.
- Rename upper case variables in setup code to lowercase.
- Delete legacy hack for broken bootloaders.
- Leave maintaining the link state to the actual ethernet/PHY drivers.
- Add DTS for D-Link DSR-500N.
- Fix PCI interrupt routing on D-Link DSR-500N.
Pistachio:
- Remove ANDROID_TIMED_OUTPUT from defconfig
TX39xx:
- Move GPIO setup from .mem_setup() to .arch_init()
- Convert to Common Clock Framework
TX49xx:
- Move GPIO setup from .mem_setup() to .arch_init()
- Convert to Common Clock Framework
txx9wdt:
- Add missing clock (un)prepare calls for CCF
BMIPS:
- Add PW, GPIO SDHCI and NAND device node names
- Support APPENDED_DTB
- Add missing bcm97435svmb to DT_NONE
- Rename bcm96358nb4ser to bcm6358-neufbox4-sercom
- Add DT examples for BCM63268, BCM3368 and BCM6362
- Add support for BCM3368 and BCM6362
PCI
- Reduce stack frame usage
- Use struct list_head lists
- Support for CONFIG_PCI_DOMAINS_GENERIC
- Make pcibios_set_cache_line_size an initcall
- Inline pcibios_assign_all_busses
- Split pci.c into pci.c & pci-legacy.c
- Introduce CONFIG_PCI_DRIVERS_LEGACY
- Support generic drivers
CPC
- Convert bare 'unsigned' to 'unsigned int'
- Avoid lock when MIPS CM >= 3 is present
GIC:
- Delete unused file smp-gic.c
mt7620:
- Delete unnecessary assignment for the field "owner" from PCI
BCM63xx:
- Let clk_disable() return immediately if clk is NULL
pm-cps:
- Change FSB workaround to CPU blacklist
- Update comments on barrier instructions
- Use MIPS standard lightweight ordering barrier
- Use MIPS standard completion barrier
- Remove selection of sync types
- Add MIPSr6 CPU support
- Support CM3 changes to Coherence Enable Register
SMP:
- Wrap call to mips_cpc_lock_other in mips_cm_lock_other
- Introduce mechanism for freeing and allocating IPIs
cpuidle:
- cpuidle-cps: Enable use with MIPSr6 CPUs.
SEAD3:
- Rewrite to use DT and generic kernel feature.
USB:
- host: ehci-sead3: Remove SEAD-3 EHCI code
FBDEV:
- cobalt_lcdfb: Drop SEAD3 support
dt-bindings:
- Document a binding for simple ASCII LCDs
auxdisplay:
- img-ascii-lcd: driver for simple ASCII LCD displays
irqchip i8259:
- i8259: Add domain before mapping parent irq
- i8259: Allow platforms to override poll function
- i8259: Remove unused i8259A_irq_pending
Malta:
- Rewrite to use DT
of/platform:
- Probe "isa" busses by default
CM:
- Print CM error reports upon bus errors
Module:
- Migrate exception table users off module.h and onto extable.h
- Make various drivers explicitly non-modular:
- Audit and remove any unnecessary uses of module.h
mailmap:
- Canonicalize to Qais' current email address.
Documentation:
- MIPS supports HAVE_REGS_AND_STACK_ACCESS_API
Loongson1C:
- Add CPU support for Loongson1C
- Add board support
- Add defconfig
- Add RTC support for Loongson1C board
All this except one Documentation fix has sat in linux-next and has
survived Imagination's automated build test system"
* 'upstream' of git://git.linux-mips.org/pub/scm/ralf/upstream-linus: (127 commits)
Documentation: MIPS supports HAVE_REGS_AND_STACK_ACCESS_API
MIPS: ptrace: Fix regs_return_value for kernel context
MIPS: VDSO: Drop duplicated -I*/-E* aflags
MIPS: Fix -mabi=64 build of vdso.lds
MIPS: Enable hardened usercopy
MIPS: generic: Convert SEAD-3 to a generic board
MIPS: generic: Introduce generic DT-based board support
MIPS: Support generating Flattened Image Trees (.itb)
MIPS: Adjust MIPS64 CAC_BASE to reflect Config.K0
MIPS: Print CM error reports upon bus errors
MIPS: Support per-device DMA coherence
MIPS: dma-default: Don't check hw_coherentio if device is non-coherent
MIPS: Sanitise coherentio semantics
MIPS: PCI: Support generic drivers
MIPS: PCI: Introduce CONFIG_PCI_DRIVERS_LEGACY
MIPS: PCI: Split pci.c into pci.c & pci-legacy.c
MIPS: PCI: Inline pcibios_assign_all_busses
MIPS: PCI: Make pcibios_set_cache_line_size an initcall
MIPS: PCI: Support for CONFIG_PCI_DOMAINS_GENERIC
MIPS: PCI: Use struct list_head lists
...
more victims of indirect include chains - au1200fb
lasat/picvue_proc and watchdog/ath79_wdt
... as well as tb0219, spotted by Sudip Mukherjee
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
The use of config_enabled() against config options is ambiguous. In
practical terms, config_enabled() is equivalent to IS_BUILTIN(), but the
author might have used it for the meaning of IS_ENABLED(). Using
IS_ENABLED(), IS_BUILTIN(), IS_MODULE() etc. makes the intention
clearer.
This commit replaces config_enabled() with IS_ENABLED() where possible.
This commit is only touching bool config options.
I noticed two cases where config_enabled() is used against a tristate
option:
- config_enabled(CONFIG_HWMON)
[ drivers/net/wireless/ath/ath10k/thermal.c ]
- config_enabled(CONFIG_BACKLIGHT_CLASS_DEVICE)
[ drivers/gpu/drm/gma500/opregion.c ]
I did not touch them because they should be converted to IS_BUILTIN()
in order to keep the logic, but I was not sure it was the authors'
intention.
Link: http://lkml.kernel.org/r/1465215656-20569-1-git-send-email-yamada.masahiro@socionext.com
Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
Acked-by: Kees Cook <keescook@chromium.org>
Cc: Stas Sergeev <stsp@list.ru>
Cc: Matt Redfearn <matt.redfearn@imgtec.com>
Cc: Joshua Kinard <kumba@gentoo.org>
Cc: Jiri Slaby <jslaby@suse.com>
Cc: Bjorn Helgaas <bhelgaas@google.com>
Cc: Borislav Petkov <bp@suse.de>
Cc: Markos Chandras <markos.chandras@imgtec.com>
Cc: "Dmitry V. Levin" <ldv@altlinux.org>
Cc: yu-cheng yu <yu-cheng.yu@intel.com>
Cc: James Hogan <james.hogan@imgtec.com>
Cc: Brian Gerst <brgerst@gmail.com>
Cc: Johannes Berg <johannes@sipsolutions.net>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Will Drewry <wad@chromium.org>
Cc: Nikolay Martynov <mar.kolya@gmail.com>
Cc: Huacai Chen <chenhc@lemote.com>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Daniel Borkmann <daniel@iogearbox.net>
Cc: Leonid Yegoshin <Leonid.Yegoshin@imgtec.com>
Cc: Rafal Milecki <zajec5@gmail.com>
Cc: James Cowgill <James.Cowgill@imgtec.com>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Ralf Baechle <ralf@linux-mips.org>
Cc: Alex Smith <alex.smith@imgtec.com>
Cc: Adam Buchbinder <adam.buchbinder@gmail.com>
Cc: Qais Yousef <qais.yousef@imgtec.com>
Cc: Jiang Liu <jiang.liu@linux.intel.com>
Cc: Mikko Rapeli <mikko.rapeli@iki.fi>
Cc: Paul Gortmaker <paul.gortmaker@windriver.com>
Cc: Denys Vlasenko <dvlasenk@redhat.com>
Cc: Brian Norris <computersforpeace@gmail.com>
Cc: Hidehiro Kawai <hidehiro.kawai.ez@hitachi.com>
Cc: "Luis R. Rodriguez" <mcgrof@do-not-panic.com>
Cc: Andy Lutomirski <luto@amacapital.net>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: "Kirill A. Shutemov" <kirill.shutemov@linux.intel.com>
Cc: Roland McGrath <roland@hack.frob.com>
Cc: Paul Burton <paul.burton@imgtec.com>
Cc: Kalle Valo <kvalo@qca.qualcomm.com>
Cc: Viresh Kumar <viresh.kumar@linaro.org>
Cc: Tony Wu <tung7970@gmail.com>
Cc: Huaitong Han <huaitong.han@intel.com>
Cc: Sumit Semwal <sumit.semwal@linaro.org>
Cc: Alexei Starovoitov <ast@kernel.org>
Cc: Juergen Gross <jgross@suse.com>
Cc: Jason Cooper <jason@lakedaemon.net>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Andrea Gelmini <andrea.gelmini@gelma.net>
Cc: David Woodhouse <dwmw2@infradead.org>
Cc: Marc Zyngier <marc.zyngier@arm.com>
Cc: Rabin Vincent <rabin@rab.in>
Cc: "Maciej W. Rozycki" <macro@imgtec.com>
Cc: David Daney <david.daney@cavium.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
__clear_user() (and clear_user() which uses it), always access the user
mode address space, which results in EVA store instructions when EVA is
enabled even if the current user address limit is KERNEL_DS.
Fix this by adding a new symbol __bzero_kernel for the normal kernel
address space bzero in EVA mode, and call that from __clear_user() if
eva_kernel_access().
Signed-off-by: James Hogan <james.hogan@imgtec.com>
Cc: Markos Chandras <markos.chandras@imgtec.com>
Cc: Paul Burton <paul.burton@imgtec.com>
Cc: Leonid Yegoshin <leonid.yegoshin@imgtec.com>
Cc: linux-mips@linux-mips.org
Patchwork: https://patchwork.linux-mips.org/patch/10844/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
When EVA is in use, __copy_from_user() was unconditionally using the EVA
instructions to read the user address space, however this can also be
used for kernel access. If the address isn't a valid user address it
will cause an address error or TLB exception, and if it is then user
memory may be read instead of kernel memory.
For example in the following stack trace from Linux v3.10 (changes since
then will prevent this particular one still happening) kernel_sendmsg()
set the user address limit to KERNEL_DS, and tcp_sendmsg() goes on to
use __copy_from_user() with a kernel address in KSeg0.
[<8002d434>] __copy_fromuser_common+0x10c/0x254
[<805710e0>] tcp_sendmsg+0x5f4/0xf00
[<804e8e3c>] sock_sendmsg+0x78/0xa0
[<804e8f28>] kernel_sendmsg+0x24/0x38
[<804ee0f8>] sock_no_sendpage+0x70/0x7c
[<8017c820>] pipe_to_sendpage+0x80/0x98
[<8017c6b0>] splice_from_pipe_feed+0xa8/0x198
[<8017cc54>] __splice_from_pipe+0x4c/0x8c
[<8017e844>] splice_from_pipe+0x58/0x78
[<8017e884>] generic_splice_sendpage+0x20/0x2c
[<8017d690>] do_splice_from+0xb4/0x110
[<8017d710>] direct_splice_actor+0x24/0x30
[<8017d394>] splice_direct_to_actor+0xd8/0x208
[<8017d51c>] do_splice_direct+0x58/0x7c
[<8014eaf4>] do_sendfile+0x1dc/0x39c
[<8014f82c>] SyS_sendfile+0x90/0xf8
Add the eva_kernel_access() check in __copy_from_user() like the one in
copy_from_user().
Signed-off-by: James Hogan <james.hogan@imgtec.com>
Cc: Markos Chandras <markos.chandras@imgtec.com>
Cc: Paul Burton <paul.burton@imgtec.com>
Cc: Leonid Yegoshin <leonid.yegoshin@imgtec.com>
Cc: linux-mips@linux-mips.org
Patchwork: https://patchwork.linux-mips.org/patch/10843/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
The strlen_user() function calls __strlen_kernel_asm in both branches of
the eva_kernel_access() conditional. For EVA it should be calling
__strlen_user_eva for user accesses, otherwise it will load from the
kernel address space instead of the user address space, and the access
checking will likely be ineffective at preventing it due to EVA's
overlapping user and kernel address spaces.
This was found after extending the test_user_copy module to cover user
string access functions, which gave the following error with EVA:
test_user_copy: illegal strlen_user passed
Fortunately the use of strlen_user() has been all but eradicated from
the mainline kernel, so only out of tree modules could be affected.
Fixes: e3a9b07a9c ("MIPS: asm: uaccess: Add EVA support for str*_user operations")
Signed-off-by: James Hogan <james.hogan@imgtec.com>
Cc: Markos Chandras <markos.chandras@imgtec.com>
Cc: Paul Burton <paul.burton@imgtec.com>
Cc: Leonid Yegoshin <leonid.yegoshin@imgtec.com>
Cc: linux-mips@linux-mips.org
Cc: <stable@vger.kernel.org> # 3.15.x-
Patchwork: https://patchwork.linux-mips.org/patch/10842/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
Pull MIPS updates from Ralf Baechle:
- Improvements to the tlb_dump code
- KVM fixes
- Add support for appended DTB
- Minor improvements to the R12000 support
- Minor improvements to the R12000 support
- Various platform improvments for BCM47xx
- The usual pile of minor cleanups
- A number of BPF fixes and improvments
- Some improvments to the support for R3000 and DECstations
- Some improvments to the ATH79 platform support
- A major patchset for the JZ4740 SOC adding support for the CI20 platform
- Add support for the Pistachio SOC
- Minor BMIPS/BCM63xx platform support improvments.
- Avoid "SYNC 0" as memory barrier when unlocking spinlocks
- Add support for the XWR-1750 board.
- Paul's __cpuinit/__cpuinitdata cleanups.
- New Malta CPU board support large memory so enable ZONE_DMA32.
* 'upstream' of git://git.linux-mips.org/pub/scm/ralf/upstream-linus: (131 commits)
MIPS: spinlock: Adjust arch_spin_lock back-off time
MIPS: asmmacro: Ensure 64-bit FP registers are used with MSA
MIPS: BCM47xx: Simplify handling SPROM revisions
MIPS: Cobalt Don't use module_init in non-modular MTD registration.
MIPS: BCM47xx: Move NVRAM driver to the drivers/firmware/
MIPS: use for_each_sg()
MIPS: BCM47xx: Don't select BCMA_HOST_PCI
MIPS: BCM47xx: Add helper variable for storing NVRAM length
MIPS: IRQ/IP27: Move IRQ allocation API to platform code.
MIPS: Replace smp_mb with release barrier function in unlocks.
MIPS: i8259: DT support
MIPS: Malta: Basic DT plumbing
MIPS: include errno.h for ENODEV in mips-cm.h
MIPS: Define GCR_GIC_STATUS register fields
MIPS: BPF: Introduce BPF ASM helpers
MIPS: BPF: Use BPF register names to describe the ABI
MIPS: BPF: Move register definition to the BPF header
MIPS: net: BPF: Replace RSIZE with SZREG
MIPS: BPF: Free up some callee-saved registers
MIPS: Xtalk: Update xwidget.h with known Xtalk device numbers
...
Commits ac1d8590d3 (MIPS: asm: uaccess: Use EVA instructions
wrappers), 05c6516005 (MIPS: asm: uaccess: Add EVA support to
copy_{in, to,from}_user) & e3a9b07a9c (MIPS: asm: uaccess: Add EVA
support for str*_user operations) added checks to various user memory
access functions & macros in order to determine whether to perform
standard memory accesses or their EVA userspace equivalents. In kernels
built without support for EVA these checks are entirely redundant. Avoid
emitting them & allow the compiler to optimise out the EVA userspace
code in such kernels by checking config_enabled(CONFIG_EVA).
This reduces the size of a malta_defconfig kernel built using GCC 4.9.2
by approximately 33KB (from 5995072 to 5962304 bytes).
Signed-off-by: Paul Burton <paul.burton@imgtec.com>
Cc: Markos Chandras <markos.chandras@imgtec.com>
Cc: Ralf Baechle <ralf@linux-mips.org>
Cc: linux-kernel@vger.kernel.org
Cc: linux-mips@linux-mips.org
Patchwork: http://patchwork.linux-mips.org/patch/10165/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
When EVA is turned on and prefetching is being used in memcpy.S,
the v1 register is being used as a helper register to the PREFE
instruction. However, v1 ($3) was not in the clobber list, which
means that the compiler did not preserve it across function calls,
and that could corrupt the value of the register leading to all
sorts of userland crashes. We fix this problem by using the
DADDI_SCRATCH macro to define the clobbered register when
CONFIG_EVA && CONFIG_CPU_HAS_PREFETCH are enabled.
Signed-off-by: Markos Chandras <markos.chandras@imgtec.com>
Cc: <stable@vger.kernel.org> # v3.15+
Cc: linux-mips@linux-mips.org
Patchwork: https://patchwork.linux-mips.org/patch/8510/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
The str*_user functions are used to securely access NULL terminated
strings from userland. Therefore, it's necessary to use the appropriate
EVA function. However, if the string is in kernel space, then the normal
instructions are being used to access it. The __str*_kernel_asm and
__str*_user_asm symbols are the same for non-EVA mode so there is no
functional change for the non-EVA kernels.
Signed-off-by: Markos Chandras <markos.chandras@imgtec.com>
Use the EVA specific functions from memcpy.S to perform
userspace operations. When get_fs() == get_ds() the usual load/store
instructions are used because the destination address is located in
the kernel address space region. Otherwise, the EVA specifc load/store
instructions are used which will go through th TLB to perform the virtual
to physical translation for the userspace address.
Signed-off-by: Markos Chandras <markos.chandras@imgtec.com>
The {get,put}_user_asm functions can be used to load data from
kernel or the user address space so rename them to avoid
confusion.
Signed-off-by: Markos Chandras <markos.chandras@imgtec.com>
Use the EVA instruction wrappers from asm.h to perform
read/write operations from userland.
Signed-off-by: Markos Chandras <markos.chandras@imgtec.com>
ulb, ulh, ulw are macros which emulate unaligned access for MIPS.
However, no such macros exist for EVA mode, so the only way to do
EVA unaligned accesses is in the ADE exception handler. As a result
of which, disable these macros for EVA.
Signed-off-by: Leonid Yegoshin <Leonid.Yegoshin@imgtec.com>
Signed-off-by: Markos Chandras <markos.chandras@imgtec.com>
Similar to __get_user_* functions, move common code to
__put_user_*_common so it can be shared among similar users.
Signed-off-by: Markos Chandras <markos.chandras@imgtec.com>
In preparation for EVA support, an instruction argument is needed
for the __get_user_asm{,_ll32} functions to allow instruction overrides in
EVA mode. Even though EVA only works for MIPS 32-bit, both codepaths are
changed (32-bit and 64-bit) for consistency reasons.
Signed-off-by: Markos Chandras <markos.chandras@imgtec.com>
Partially revert commit e0c14a260d66ba35935600d6435940a566fe806b
and turn off LL/SC when building a pure microMIPS kernel. This is
a temporary fix until the cmpxchg assembly macro functions are
re-written to not use the HI/LO registers in address calculations.
Also add .insn in selected user access functions which would
otherwise produce ISA mode jump incompatibilities. This is also a
temporary fix.
Signed-off-by: Steven J. Hill <Steven.Hill@imgtec.com>
Having received another series of whitespace patches I decided to do this
once and for all rather than dealing with this kind of patches trickling
in forever.
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
We can save the 451 lines of code that comprise memcpy-inatomic.S at the
expense of a single instruction in the memcpy prolog. We also use an
additional register (t6), so this may cause increased register pressure in
some places as well. But I think the reduced maintenance burden, of not
having two nearly identical implementations, makes it worth it.
Signed-off-by: David Daney <david.daney@cavium.com>
Cc: linux-mips@linux-mips.org
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
The TASK_SIZE macro should reflect the size of a user process virtual
address space. Previously for 64-bit kernels, this was not the case.
The immediate cause of pain was in
hugetlbfs/inode.c:hugetlb_get_unmapped_area() where 32-bit processes
trying to mmap a huge page would be served a page with an address
outside of the 32-bit address range. But there are other uses of
TASK_SIZE in the kernel as well that would like an accurate value.
The new definition is nice because it now makes TASK_SIZE and
TASK_SIZE_OF() yield the same value for any given process.
For 32-bit kernels there should be no change, although I did factor
out some code in asm/processor.h that became identical for the 32-bit and
64-bit cases.
__UA_LIMIT is now set to ~((1 << SEGBITS) - 1) for 64-bit kernels.
This should eliminate the possibility of getting a
AddressErrorException in the kernel for addresses that pass the
access_ok() test.
With the patch applied, I can still run o32, n32 and n64 processes,
and have an o32 shell fork/exec both n32 and n64 processes.
Signed-off-by: David Daney <ddaney@caviumnetworks.com>
To: linux-mips@linux-mips.org
Patchwork: https://patchwork.linux-mips.org/patch/1701/
The type of the second argument of access_ok should be (void __user *).
The unnecessary conversion of the clear_user address argument was causing
sparse to emit warnings on the __chk_user_ptr check.
Signed-off-by: Wu Zhangjin <wuzhangjin@gmail.com>
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
