linux_dsm_epyc7002/arch/powerpc/kernel
Cyril Bur 78a3e8889b powerpc: signals: Discard transaction state from signal frames
Userspace can begin and suspend a transaction within the signal
handler which means they might enter sys_rt_sigreturn() with the
processor in suspended state.

sys_rt_sigreturn() wants to restore process context (which may have
been in a transaction before signal delivery). To do this it must
restore TM SPRS. To achieve this, any transaction initiated within the
signal frame must be discarded in order to be able to restore TM SPRs
as TM SPRs can only be manipulated non-transactionally..
>From the PowerPC ISA:
  TM Bad Thing Exception [Category: Transactional Memory]
   An attempt is made to execute a mtspr targeting a TM register in
   other than Non-transactional state.

Not doing so results in a TM Bad Thing:
[12045.221359] Kernel BUG at c000000000050a40 [verbose debug info unavailable]
[12045.221470] Unexpected TM Bad Thing exception at c000000000050a40 (msr 0x201033)
[12045.221540] Oops: Unrecoverable exception, sig: 6 [#1]
[12045.221586] SMP NR_CPUS=2048 NUMA PowerNV
[12045.221634] Modules linked in: xt_CHECKSUM iptable_mangle ipt_MASQUERADE
 nf_nat_masquerade_ipv4 iptable_nat nf_nat_ipv4 nf_nat nf_conntrack_ipv4 nf_defrag_ipv4
 xt_conntrack nf_conntrack ipt_REJECT nf_reject_ipv4 xt_tcpudp bridge stp llc ebtable_filter
 ebtables ip6table_filter ip6_tables iptable_filter ip_tables x_tables kvm_hv kvm
 uio_pdrv_genirq ipmi_powernv uio powernv_rng ipmi_msghandler autofs4 ses enclosure
 scsi_transport_sas bnx2x ipr mdio libcrc32c
[12045.222167] CPU: 68 PID: 6178 Comm: sigreturnpanic Not tainted 4.7.0 #34
[12045.222224] task: c0000000fce38600 ti: c0000000fceb4000 task.ti: c0000000fceb4000
[12045.222293] NIP: c000000000050a40 LR: c0000000000163bc CTR: 0000000000000000
[12045.222361] REGS: c0000000fceb7ac0 TRAP: 0700   Not tainted (4.7.0)
[12045.222418] MSR: 9000000300201033 <SF,HV,ME,IR,DR,RI,LE,TM[SE]> CR: 28444280  XER: 20000000
[12045.222625] CFAR: c0000000000163b8 SOFTE: 0 PACATMSCRATCH: 900000014280f033
GPR00: 01100000b8000001 c0000000fceb7d40 c00000000139c100 c0000000fce390d0
GPR04: 900000034280f033 0000000000000000 0000000000000000 0000000000000000
GPR08: 0000000000000000 b000000000001033 0000000000000001 0000000000000000
GPR12: 0000000000000000 c000000002926400 0000000000000000 0000000000000000
GPR16: 0000000000000000 0000000000000000 0000000000000000 0000000000000000
GPR20: 0000000000000000 0000000000000000 0000000000000000 0000000000000000
GPR24: 0000000000000000 00003ffff98cadd0 00003ffff98cb470 0000000000000000
GPR28: 900000034280f033 c0000000fceb7ea0 0000000000000001 c0000000fce390d0
[12045.223535] NIP [c000000000050a40] tm_restore_sprs+0xc/0x1c
[12045.223584] LR [c0000000000163bc] tm_recheckpoint+0x5c/0xa0
[12045.223630] Call Trace:
[12045.223655] [c0000000fceb7d80] [c000000000026e74] sys_rt_sigreturn+0x494/0x6c0
[12045.223738] [c0000000fceb7e30] [c0000000000092e0] system_call+0x38/0x108
[12045.223806] Instruction dump:
[12045.223841] 7c800164 4e800020 7c0022a6 f80304a8 7c0222a6 f80304b0 7c0122a6 f80304b8
[12045.223955] 4e800020 e80304a8 7c0023a6 e80304b0 <7c0223a6> e80304b8 7c0123a6 4e800020
[12045.224074] ---[ end trace cb8002ee240bae76 ]---

It isn't clear exactly if there is really a use case for userspace
returning with a suspended transaction, however, doing so doesn't (on
its own) constitute a bad frame. As such, this patch simply discards
the transactional state of the context calling the sigreturn and
continues.

Reported-by: Laurent Dufour <ldufour@linux.vnet.ibm.com>
Signed-off-by: Cyril Bur <cyrilbur@gmail.com>
Tested-by: Laurent Dufour <ldufour@linux.vnet.ibm.com>
Reviewed-by: Laurent Dufour <ldufour@linux.vnet.ibm.com>
Acked-by: Simon Guo <wei.guo.simon@gmail.com>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2016-08-29 12:48:40 +10:00
..
vdso32 powerpc/vdso: Fix build rules to rebuild vdsos correctly 2016-08-10 23:04:12 +10:00
vdso64 powerpc/vdso: Fix build rules to rebuild vdsos correctly 2016-08-10 23:04:12 +10:00
.gitignore
align.c powerpc: Move cpu_has_feature() to a separate file 2016-08-01 11:15:03 +10:00
asm-offsets.c powerpc/8xx: Force VIRT_IMMR_BASE to be a positive number 2016-07-09 03:26:53 -05:00
audit.c
btext.c powerpc/mm: Use a helper for finding pte bits mapping I/O area 2016-05-01 18:32:32 +10:00
cacheinfo.c powerpc: Fix missing L2 cache size in /sys/devices/system/cpu 2015-04-11 20:49:28 +10:00
cacheinfo.h
compat_audit.c
cpu_setup_6xx.S powerpc: Various typo fixes 2016-06-14 13:58:26 +10:00
cpu_setup_44x.S
cpu_setup_fsl_booke.S powerpc/cache: add cache flush operation for various e500 2016-03-04 23:44:51 -06:00
cpu_setup_pa6t.S
cpu_setup_power.S powerpc/irq: Add support for HV virtualization interrupts 2016-07-17 16:42:44 +10:00
cpu_setup_ppc970.S
cputable.c powerpc: Add option to use jump label for mmu_has_feature() 2016-08-01 11:15:06 +10:00
crash_dump.c powerpc: Remove superfluous bootmem includes 2014-11-10 09:59:26 +11:00
crash.c powerpc/crash: Rearrange loop condition to avoid out of bounds array access 2016-07-14 20:26:22 +10:00
dbell.c powerpc/powernv: Fixes for hypervisor doorbell handling 2015-03-20 14:51:53 +11:00
dma-iommu.c dma-mapping: use unsigned long for dma_attrs 2016-08-04 08:50:07 -04:00
dma-swiotlb.c powerpc/iommu: Support "hybrid" iommu/direct DMA ops for coherent_mask < dma_mask 2015-07-13 10:10:55 +10:00
dma.c dma-mapping: use unsigned long for dma_attrs 2016-08-04 08:50:07 -04:00
eeh_cache.c powerpc/eeh: Fix pr_debug()s in eeh_cache.c 2016-07-08 22:09:50 +10:00
eeh_dev.c powerpc/pci: Delay populating pdn 2016-06-21 15:30:56 +10:00
eeh_driver.c powerpc fixes for 4.7 #5 2016-07-15 14:57:47 +10:00
eeh_event.c powerpc: sparse: static-ify some things 2016-04-12 21:05:18 +10:00
eeh_pe.c powerpc/eeh: fix misleading indentation 2016-04-27 09:19:37 +10:00
eeh_sysfs.c powerpc/eeh: Fix PE state format 2014-11-27 09:32:58 +11:00
eeh.c powerpc/eeh: Switch to conventional PCI address output in EEH log 2016-08-09 16:52:03 +10:00
entry_32.S powerpc32: provide VIRT_CPU_ACCOUNTING 2016-07-09 01:43:50 -05:00
entry_64.S powerpc/tm: do not use r13 for tabort_syscall 2016-08-29 12:47:56 +10:00
epapr_hcalls.S
epapr_paravirt.c Merge branch 'next' of git://git.kernel.org/pub/scm/linux/kernel/git/benh/powerpc 2014-06-10 18:54:22 -07:00
exceptions-64e.S powerpc32: provide VIRT_CPU_ACCOUNTING 2016-07-09 01:43:50 -05:00
exceptions-64s.S powerpc/pseries: PACA save area fix for MCE vs MCE 2016-08-22 11:09:33 +10:00
fadump.c powerpc/fadump: Fix build error introduced by recent cleanup 2016-07-05 23:49:46 +10:00
firmware.c
fpu.S powerpc: Add the ability to save FPU without giving it up 2016-03-02 23:34:49 +11:00
fsl_booke_entry_mapping.S powerpc/fsl: Force coherent memory on e500mc derivatives 2015-08-07 23:00:01 -05:00
ftrace.c powerpc/ftrace: Separate the heuristics for checking call sites 2016-07-21 20:10:37 +10:00
head_8xx.S powerpc/8xx: add CONFIG_PIN_TLB_IMMR 2016-07-09 02:02:48 -05:00
head_32.S
head_40x.S powerpc: Remove check for CONFIG_SERIAL_TEXT_DEBUG 2014-06-11 16:31:21 +10:00
head_44x.S powerpc: Fix misspellings in comments. 2016-03-01 19:27:20 +11:00
head_64.S powerpc/64: Move the content of setup_system() to setup_arch() 2016-07-21 19:14:29 +10:00
head_booke.h
head_fsl_booke.S powerpc/cache: add cache flush operation for various e500 2016-03-04 23:44:51 -06:00
hw_breakpoint.c powerpc/hw_breakpoint: Fix oops when destroying hw_breakpoint event 2016-03-03 22:06:08 +11:00
ibmebus.c dma-mapping: use unsigned long for dma_attrs 2016-08-04 08:50:07 -04:00
idle_6xx.S
idle_book3e.S powerpc: No need to use dot symbols when branching to a function 2014-04-23 10:05:16 +10:00
idle_book3s.S powerpc/powernv: Move IDLE_STATE_ENTER_SEQ macro to cpuidle.h 2016-08-09 14:50:20 +10:00
idle_e500.S powerpc/e500mc: Remove dead L2 flushing code in idle_e500.S 2015-06-02 21:37:19 -05:00
idle_power4.S powerpc: No need to use dot symbols when branching to a function 2014-04-23 10:05:16 +10:00
idle.c
io-workarounds.c powerpc/mm: Differentiate between hugetlb and THP during page walk 2015-10-12 15:30:09 +11:00
io.c
iomap.c powerpc: add io{read,write}64 accessors 2016-05-31 16:41:52 +08:00
iommu.c dma-mapping: use unsigned long for dma_attrs 2016-08-04 08:50:07 -04:00
irq.c powerpc: Move cpu_has_feature() to a separate file 2016-08-01 11:15:03 +10:00
isa-bridge.c powerpc/mm: Use a helper for finding pte bits mapping I/O area 2016-05-01 18:32:32 +10:00
jump_label.c jump_label: Rename JUMP_LABEL_{EN,DIS}ABLE to JUMP_LABEL_{JMP,NOP} 2015-08-03 11:34:12 +02:00
kgdb.c powerpc: Fix kgdb on little endian ppc64le 2016-02-18 00:03:26 +11:00
kprobes.c powerpc: migrate exception table users off module.h and onto extable.h 2016-08-22 11:09:33 +10:00
kvm_emul.S
kvm.c powerpc: Remove redundant breaks 2015-08-06 15:10:20 +10:00
l2cr_6xx.S
legacy_serial.c powerpc: make of_device_ids const 2014-09-25 23:14:46 +10:00
machine_kexec_32.c
machine_kexec_64.c powerpc/mm: Move hash table ops to a separate structure 2016-07-21 18:59:09 +10:00
machine_kexec.c powerpc: Update of_remove_property() call sites to remove null checking 2016-05-11 21:54:04 +10:00
Makefile powerpc: move hmi.c to arch/powerpc/kvm/ 2016-08-22 11:09:33 +10:00
mce_power.c powerpc/mm/radix: Fix CONFIG_PPC_MMU_STD_64 typo 2016-05-11 21:53:59 +10:00
mce.c powerpc/book3s: Fix MCE console messages for unrecoverable MCE. 2016-08-09 19:46:54 +10:00
misc_32.S powerpc/32: Get rid of sub_reloc_offset() 2016-06-14 13:58:26 +10:00
misc_64.S powerpc/mm: Move hash table ops to a separate structure 2016-07-21 18:59:09 +10:00
misc.S powerpc: Rename __get_SP() to current_stack_pointer() 2014-10-15 11:23:20 +11:00
module_32.c powerpc/module: Only try to generate the ftrace_caller() stub once 2016-03-07 14:53:53 +11:00
module_64.c powerpc/modules: Never restore r2 for a mprofile-kernel style mcount() call 2016-07-21 20:10:42 +10:00
module.c powerpc/module: Only try to generate the ftrace_caller() stub once 2016-03-07 14:53:53 +11:00
msi.c powerpc: Remove MSI-related PCI controller ops from ppc_md 2015-06-02 11:47:45 +10:00
nvram_64.c pstore: add lzo/lz4 compression support 2016-06-02 10:59:31 -07:00
of_platform.c powerpc/eeh: Do probe on pci_dn 2015-03-24 13:15:52 +11:00
paca.c powerpc/mm: Convert early cpu/mmu feature check to use the new helpers 2016-08-01 11:15:01 +10:00
pci_32.c powerpc: Remove more traces of bootmem 2014-11-19 21:41:51 +11:00
pci_64.c powerpc fixes for 4.7 #5 2016-07-15 14:57:47 +10:00
pci_dn.c powerpc/pci: Fix build with PCI_IOV=y and EEH=n 2016-07-07 16:33:27 +10:00
pci_of_scan.c PCI/MSI: Initialize MSI capability for all architectures 2015-11-24 17:45:18 -06:00
pci-common.c powerpc/pseries: use pci_host_bridge.release_fn() to kfree(phb) 2016-08-22 11:09:33 +10:00
pci-hotplug.c powerpc/pci: Don't scan empty slot 2016-05-11 21:54:26 +10:00
pmc.c
ppc32.h
ppc_ksyms_32.c powerpc32: Remove clear_pages() and define clear_page() inline 2016-03-11 17:20:11 -06:00
ppc_ksyms.c powerpc32: move xxxxx_dcache_range() functions inline 2016-03-11 17:20:12 -06:00
ppc_save_regs.S
proc_powerpc.c
process.c powerpc/ptrace: Fix coredump since ptrace TM changes 2016-08-10 16:34:20 +10:00
prom_init_check.sh powerpc: Simplify symbol check in prom_init_check.sh 2014-09-25 23:14:46 +10:00
prom_init.c powerpc/prom: Fix sub-processor option passed to ibm, client-architecture-support 2016-08-22 11:09:33 +10:00
prom_parse.c
prom.c powerpc/mm: Make MMU_FTR_RADIX a MMU family feature 2016-08-01 11:14:57 +10:00
ptrace32.c
ptrace.c powerpc/ptrace: Fix coredump since ptrace TM changes 2016-08-10 16:34:20 +10:00
reloc_32.S
reloc_64.S powerpc: Align p_dyn, p_rela and p_st symbols 2014-03-07 13:50:19 +11:00
rtas_flash.c powerpc: Fix endianness of flash_block_list in rtas_flash 2014-07-28 11:30:54 +10:00
rtas_pci.c powerpc: move find_and_init_phbs() to pSeries specific code 2015-04-11 20:49:09 +10:00
rtas-proc.c powerpc: Various typo fixes 2016-06-14 13:58:26 +10:00
rtas-rtc.c
rtas.c powerpc: Make ppc_md.{halt, restart} __noreturn 2016-07-14 21:12:06 +10:00
rtasd.c powerpc/pseries: start rtasd before PCI probing 2016-07-08 19:22:15 +10:00
setup_32.c powerpc/32: Fix crash during static key init 2016-08-10 19:41:58 +10:00
setup_64.c powerpc/32: Fix crash during static key init 2016-08-10 19:41:58 +10:00
setup-common.c powerpc: Move cpu_has_feature() to a separate file 2016-08-01 11:15:03 +10:00
setup.h powerpc: Merge 32-bit and 64-bit setup_arch() 2016-07-21 19:17:46 +10:00
signal_32.c powerpc: signals: Discard transaction state from signal frames 2016-08-29 12:48:40 +10:00
signal_64.c powerpc: signals: Discard transaction state from signal frames 2016-08-29 12:48:40 +10:00
signal.c powerpc: Fix misspellings in comments. 2016-03-01 19:27:20 +11:00
signal.h powerpc: Fix misspellings in comments. 2016-03-01 19:27:20 +11:00
smp-tbsync.c
smp.c powerpc, hotplug: Avoid to touch non-existent cpumasks. 2016-08-22 11:09:33 +10:00
stacktrace.c powerpc: Implement save_stack_trace_regs() to enable kprobe stack tracing 2016-01-11 14:27:28 +11:00
suspend.c nosave: consolidate __nosave_{begin,end} in <asm/sections.h> 2014-10-09 22:26:04 -04:00
swsusp_32.S
swsusp_64.c
swsusp_asm64.S
swsusp_booke.S
swsusp.c powerpc/mm: Abstraction for switch_mmu_context() 2016-05-01 18:33:04 +10:00
sys_ppc32.c
syscalls.c powerpc: Add a proper syscall for switching endianness 2015-03-28 22:03:40 +11:00
sysfs.c powerpc/sparse: make some things static 2016-06-16 22:23:11 +10:00
systbl_chk.c powerpc: Standardise on NR_syscalls rather than __NR_syscalls. 2015-11-26 22:11:17 +11:00
systbl_chk.sh powerpc: Standardise on NR_syscalls rather than __NR_syscalls. 2015-11-26 22:11:17 +11:00
systbl.S powerpc: Add a proper syscall for switching endianness 2015-03-28 22:03:40 +11:00
tau_6xx.c
time.c RTC for 4.8 2016-08-05 09:48:22 -04:00
tm.S powerpc/tm: Fix stack pointer corruption in __tm_recheckpoint() 2016-07-15 15:00:18 +10:00
trace_clock.c powerpc/ftrace: add powerpc timebase as a trace clock source 2015-08-06 16:36:23 +10:00
traps.c powerpc: migrate exception table users off module.h and onto extable.h 2016-08-22 11:09:33 +10:00
udbg_16550.c powerpc: Fix bad NULL pointer check in udbg_uart_getc_poll() 2014-11-12 13:47:20 +11:00
udbg.c powerpc: Remove the celleb support 2015-04-07 17:15:13 +10:00
uprobes.c
vdso.c powerpc/vdso: Add missing include file 2016-08-09 16:52:00 +10:00
vecemu.c
vector.S powerpc: Improve comment explaining why we modify VRSAVE 2016-07-26 14:16:19 +10:00
vio.c dma-mapping: use unsigned long for dma_attrs 2016-08-04 08:50:07 -04:00
vmlinux.lds.S powerpc/32: Remove RELOCATABLE_PPC32 2016-07-19 20:17:07 +10:00