linux_dsm_epyc7002/arch
Max Filippov 2958b66694 xtensa: enable coprocessors that are being flushed
coprocessor_flush_all may be called from a context of a thread that is
different from the thread being flushed. In that case contents of the
cpenable special register may not match ti->cpenable of the target
thread, resulting in unhandled coprocessor exception in the kernel
context.
Set cpenable special register to the ti->cpenable of the target register
for the duration of the flush and restore it afterwards.
This fixes the following crash caused by coprocessor register inspection
in native gdb:

  (gdb) p/x $w0
  Illegal instruction in kernel: sig: 9 [#1] PREEMPT
  Call Trace:
    ___might_sleep+0x184/0x1a4
    __might_sleep+0x41/0xac
    exit_signals+0x14/0x218
    do_exit+0xc9/0x8b8
    die+0x99/0xa0
    do_illegal_instruction+0x18/0x6c
    common_exception+0x77/0x77
    coprocessor_flush+0x16/0x3c
    arch_ptrace+0x46c/0x674
    sys_ptrace+0x2ce/0x3b4
    system_call+0x54/0x80
    common_exception+0x77/0x77
  note: gdb[100] exited with preempt_count 1
  Killed

Cc: stable@vger.kernel.org
Signed-off-by: Max Filippov <jcmvbkbc@gmail.com>
2018-11-26 18:37:47 -08:00
..
alpha TTY/Serial fixes for 4.20-rc2 2018-11-10 13:32:14 -06:00
arc mm: remove include/linux/bootmem.h 2018-10-31 08:54:16 -07:00
arm Merge branch 'spectre' of git://git.armlinux.org.uk/~rmk/linux-arm 2018-11-18 10:45:09 -08:00
arm64 arm64: cpufeature: Fix mismerge of CONFIG_ARM64_SSBD block 2018-11-23 18:44:16 +00:00
c6x c6x changes for 4.20 2018-10-31 15:39:25 -07:00
csky csky: dtb Kbuild fixup patches for linux-4.20-rc1 2018-11-01 09:04:30 -07:00
h8300 mm: remove include/linux/bootmem.h 2018-10-31 08:54:16 -07:00
hexagon mm: remove include/linux/bootmem.h 2018-10-31 08:54:16 -07:00
ia64 memblock: stop using implicit alignment to SMP_CACHE_BYTES 2018-10-31 08:54:16 -07:00
m68k s390 updates for 4.20-rc2 2018-11-09 06:30:44 -06:00
microblaze s390 updates for 4.20-rc2 2018-11-09 06:30:44 -06:00
mips MIPS: Loongson3,SGI-IP27: Simplify max_low_pfn calculation 2018-11-15 15:42:15 -08:00
nds32 s390 updates for 4.20-rc2 2018-11-09 06:30:44 -06:00
nios2 mm: remove include/linux/bootmem.h 2018-10-31 08:54:16 -07:00
openrisc mm: remove include/linux/bootmem.h 2018-10-31 08:54:16 -07:00
parisc Merge branch 'parisc-4.20-3' of git://git.kernel.org/pub/scm/linux/kernel/git/deller/parisc-linux 2018-11-14 13:42:41 -06:00
powerpc powerpc/64: Fix kernel stack 16-byte alignment 2018-11-15 14:48:43 +11:00
riscv RISC-V: recognize S/U mode bits in print_isa 2018-11-20 05:19:28 -08:00
s390 s390 updates for 4.20-rc2 2018-11-09 06:30:44 -06:00
sh mm: remove include/linux/bootmem.h 2018-10-31 08:54:16 -07:00
sparc Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/sparc 2018-11-01 09:07:04 -07:00
um for-linus-20181109 2018-11-09 16:31:51 -06:00
unicore32 memblock: stop using implicit alignment to SMP_CACHE_BYTES 2018-10-31 08:54:16 -07:00
x86 perf/x86/intel/uncore: Support CoffeeLake 8th CBOX 2018-11-12 05:03:26 +01:00
xtensa xtensa: enable coprocessors that are being flushed 2018-11-26 18:37:47 -08:00
.gitignore
Kconfig New gcc plugin: stackleak 2018-11-01 11:46:27 -07:00