Minki/linux
1
0
Fork 1
mirror of https://github.com/torvalds/linux.git synced 2024-11-23 12:42:02 +00:00
Code Issues Packages Projects Releases Wiki Activity
20045f0155
linux/arch/powerpc
History
Michael Ellerman 20045f0155 powerpc/64s/radix: Don't warn on copros in radix__tlb_flush() 
Sachin reported a warning when running the inject-ra-err selftest:

  # selftests: powerpc/mce: inject-ra-err
  Disabling lock debugging due to kernel taint
  MCE: CPU19: machine check (Severe)  Real address Load/Store (foreign/control memory) [Not recovered]
  MCE: CPU19: PID: 5254 Comm: inject-ra-err NIP: [0000000010000e48]
  MCE: CPU19: Initiator CPU
  MCE: CPU19: Unknown
  ------------[ cut here ]------------
  WARNING: CPU: 19 PID: 5254 at arch/powerpc/mm/book3s64/radix_tlb.c:1221 radix__tlb_flush+0x160/0x180
  CPU: 19 PID: 5254 Comm: inject-ra-err Kdump: loaded Tainted: G   M        E      6.6.0-rc3-00055-g9ed22ae6be81 #4
  Hardware name: IBM,9080-HEX POWER10 (raw) 0x800200 0xf000006 of:IBM,FW1030.20 (NH1030_058) hv:phyp pSeries
  ...
  NIP radix__tlb_flush+0x160/0x180
  LR  radix__tlb_flush+0x104/0x180
  Call Trace:
    radix__tlb_flush+0xf4/0x180 (unreliable)
    tlb_finish_mmu+0x15c/0x1e0
    exit_mmap+0x1a0/0x510
    __mmput+0x60/0x1e0
    exit_mm+0xdc/0x170
    do_exit+0x2bc/0x5a0
    do_group_exit+0x4c/0xc0
    sys_exit_group+0x28/0x30
    system_call_exception+0x138/0x330
    system_call_vectored_common+0x15c/0x2ec

And bisected it to commit e43c0a0c3c ("powerpc/64s/radix: combine
final TLB flush and lazy tlb mm shootdown IPIs"), which added a warning
in radix__tlb_flush() if mm->context.copros is still elevated.

However it's possible for the copros count to be elevated if a process
exits without first closing file descriptors that are associated with a
copro, eg. VAS.

If the process exits with a VAS file still open, the release callback
is queued up for exit_task_work() via:
  exit_files()
    put_files_struct()
      close_files()
        filp_close()
          fput()

And called via:
  exit_task_work()
    ____fput()
      __fput()
        file->f_op->release(inode, file)
          coproc_release()
            vas_user_win_ops->close_win()
              vas_deallocate_window()
                mm_context_remove_vas_window()
                  mm_context_remove_copro()

But that is after exit_mm() has been called from do_exit() and triggered
the warning.

Fix it by dropping the warning, and always calling __flush_all_mm().

In the normal case of no copros, that will result in a call to
_tlbiel_pid(mm->context.id, RIC_FLUSH_ALL) just as the current code
does.

If the copros count is elevated then it will cause a global flush, which
should flush translations from any copros. Note that the process table
entry was cleared in arch_exit_mmap(), so copros should not be able to
fetch any new translations.

Fixes: e43c0a0c3c ("powerpc/64s/radix: combine final TLB flush and lazy tlb mm shootdown IPIs")
Reported-by: Sachin Sant <sachinp@linux.ibm.com>
Closes: https://lore.kernel.org/all/A8E52547-4BF1-47CE-8AEA-BC5A9D7E3567@linux.ibm.com/
Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Tested-by: Sachin Sant <sachinp@linux.ibm.com>
Link: https://msgid.link/20231017121527.1574104-1-mpe@ellerman.id.au
2023-10-18 09:45:52 +11:00
..
boot powerpc: dts: add missing space before { 2023-08-25 08:39:30 +10:00
configs Kbuild updates for v6.6 2023-09-05 11:01:47 -07:00
crypto This push fixes a random config build failure on powerpc. 2023-09-01 15:39:25 -07:00
include powerpc/64e: Fix wrong test in __ptep_test_and_clear_young() 2023-10-09 22:37:31 +11:00
kernel powerpc/47x: Fix 47x syscall return crash 2023-10-11 09:31:26 +11:00
kexec powerpc: Move DMA64_PROPNAME define to a header 2023-08-18 17:03:15 +10:00
kvm powerpc updates for 6.6 2023-08-31 12:43:10 -07:00
lib powerpc: Drop zalloc_maybe_bootmem() 2023-08-24 22:33:16 +10:00
math-emu powerpc/math-emu: Inhibit W=1 warnings 2022-09-08 11:11:18 +10:00
mm powerpc/64s/radix: Don't warn on copros in radix__tlb_flush() 2023-10-18 09:45:52 +11:00
net powerpc/bpf: populate extable entries only during the last pass 2023-05-15 15:40:31 +10:00
perf powerpc/perf/hv-24x7: Update domain value check 2023-09-18 12:23:47 +10:00
platforms powerpc/pseries: Remove unused r0 in the hcall tracing code 2023-09-30 22:52:18 +10:00
purgatory powerpc/purgatory: remove PGO flags 2023-06-12 11:31:50 -07:00
sysdev TTY/Serial driver changes for 6.6-rc1 2023-09-01 09:38:00 -07:00
tools powerpc/ftrace: Add support for -fpatchable-function-entry 2023-08-22 00:09:06 +10:00
xmon TTY/Serial driver changes for 6.6-rc1 2023-09-01 09:38:00 -07:00
Kbuild
Kconfig powerpc/mm: Allow ARCH_FORCE_MAX_ORDER up to 12 2023-10-15 20:55:03 +11:00
Kconfig.debug powerpc: allow PPC_EARLY_DEBUG_CPM only when SERIAL_CPM=y 2023-07-03 16:07:55 +10:00
Makefile powerpc/64s: Move CPU -mtune options into Kconfig 2023-08-25 08:39:29 +10:00
Makefile.postlink kbuild: remove --include-dir MAKEFLAG from top Makefile 2023-02-05 18:51:22 +09:00