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| author | Nicholas Piggin <npiggin@gmail.com> | 2020-02-26 03:35:35 +1000 |
|---|---|---|
| committer | Michael Ellerman <mpe@ellerman.id.au> | 2020-04-01 13:42:13 +1100 |
| commit | 993c670a4dfb2bded39d96f11df763c657d15a41 (patch) | |
| tree | 55469336d404d428bd3d49a25b44f98eb6cd4774 /arch/powerpc/kernel/entry_64.S | |
| parent | 68b34588e2027f699a3c034235f21cd19356b2e6 (diff) | |
| download | linux-993c670a4dfb2bded39d96f11df763c657d15a41.tar.gz | |
powerpc/64/syscall: Zero volatile registers when returning
Kernel addresses and potentially other sensitive data could be leaked
in volatile registers after a syscall.
Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20200225173541.1549955-27-npiggin@gmail.com
Diffstat (limited to 'arch/powerpc/kernel/entry_64.S')
| -rw-r--r-- | arch/powerpc/kernel/entry_64.S | 13 |
1 files changed, 13 insertions, 0 deletions
diff --git a/arch/powerpc/kernel/entry_64.S b/arch/powerpc/kernel/entry_64.S index 5f70830b5ae46f..29949bbe857b30 100644 --- a/arch/powerpc/kernel/entry_64.S +++ b/arch/powerpc/kernel/entry_64.S @@ -141,6 +141,19 @@ END_FTR_SECTION_IFCLR(CPU_FTR_STCX_CHECKS_ADDRESS) cmpdi r3,0 bne .Lsyscall_restore_regs + /* Zero volatile regs that may contain sensitive kernel data */ + li r0,0 + li r4,0 + li r5,0 + li r6,0 + li r7,0 + li r8,0 + li r9,0 + li r10,0 + li r11,0 + li r12,0 + mtctr r0 + mtspr SPRN_XER,r0 .Lsyscall_restore_regs_cont: BEGIN_FTR_SECTION |