diff options
| author | Nicholas Piggin <npiggin@gmail.com> | 2020-10-07 18:06:05 +1000 |
|---|---|---|
| committer | Michael Ellerman <mpe@ellerman.id.au> | 2020-10-08 12:50:52 +1100 |
| commit | 792254a77201453d9a77479e63dc216ad90462d2 (patch) | |
| tree | 705bc1471240d76c54be84a457c51fb18e9439ff /arch/powerpc/kernel/entry_64.S | |
| parent | 09b791d95559ef82542063333ecaa2ac9d57118e (diff) | |
| download | linux-792254a77201453d9a77479e63dc216ad90462d2.tar.gz | |
powerpc/security: Fix link stack flush instruction
The inline execution path for the hardware assisted branch flush
instruction failed to set CTR to the correct value before bcctr,
causing a crash when the feature is enabled.
Fixes: 4d24e21cc694 ("powerpc/security: Allow for processors that flush the link stack using the special bcctr")
Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20201007080605.64423-1-npiggin@gmail.com
Diffstat (limited to 'arch/powerpc/kernel/entry_64.S')
| -rw-r--r-- | arch/powerpc/kernel/entry_64.S | 8 |
1 files changed, 6 insertions, 2 deletions
diff --git a/arch/powerpc/kernel/entry_64.S b/arch/powerpc/kernel/entry_64.S index 733e40eba4ebe3..2f3846192ec7df 100644 --- a/arch/powerpc/kernel/entry_64.S +++ b/arch/powerpc/kernel/entry_64.S @@ -430,7 +430,11 @@ _ASM_NOKPROBE_SYMBOL(save_nvgprs); #define FLUSH_COUNT_CACHE \ 1: nop; \ - patch_site 1b, patch__call_flush_branch_caches + patch_site 1b, patch__call_flush_branch_caches1; \ +1: nop; \ + patch_site 1b, patch__call_flush_branch_caches2; \ +1: nop; \ + patch_site 1b, patch__call_flush_branch_caches3 .macro nops number .rept \number @@ -512,7 +516,7 @@ _GLOBAL(_switch) kuap_check_amr r9, r10 - FLUSH_COUNT_CACHE + FLUSH_COUNT_CACHE /* Clobbers r9, ctr */ /* * On SMP kernels, care must be taken because a task may be |