| Message ID | ce30364fb7ccda489272af4a1612b6aa147e1d23.1637227521.git.christophe.leroy@csgroup.eu (mailing list archive) |
|---|---|
| State | Accepted |
| Headers | show |
| Series | powerpc/32: Fix hardlockup on vmap stack overflow | expand |
| Context | Check | Description |
|---|---|---|
| snowpatch_ozlabs/github-powerpc_ppctests | success | Successfully ran 8 jobs. |
| snowpatch_ozlabs/github-powerpc_selftests | success | Successfully ran 8 jobs. |
| snowpatch_ozlabs/github-powerpc_clang | success | Successfully ran 7 jobs. |
| snowpatch_ozlabs/github-powerpc_sparse | success | Successfully ran 4 jobs. |
| snowpatch_ozlabs/github-powerpc_kernel_qemu | success | Successfully ran 24 jobs. |
On Thu, 18 Nov 2021 10:39:53 +0100, Christophe Leroy wrote: > Since the commit c118c7303ad5 ("powerpc/32: Fix vmap stack - Do not > activate MMU before reading task struct") a vmap stack overflow > results in a hard lockup. This is because emergency_ctx is still > addressed with its virtual address allthough data MMU is not active > anymore at that time. > > Fix it by using a physical address instead. > > [...] Applied to powerpc/fixes. [1/1] powerpc/32: Fix hardlockup on vmap stack overflow https://git.kernel.org/powerpc/c/5bb60ea611db1e04814426ed4bd1c95d1487678e cheers
diff --git a/arch/powerpc/kernel/head_32.h b/arch/powerpc/kernel/head_32.h index 6b1ec9e3541b..349c4a820231 100644 --- a/arch/powerpc/kernel/head_32.h +++ b/arch/powerpc/kernel/head_32.h @@ -202,11 +202,11 @@ _ASM_NOKPROBE_SYMBOL(\name\()_virt) mfspr r1, SPRN_SPRG_THREAD lwz r1, TASK_CPU - THREAD(r1) slwi r1, r1, 3 - addis r1, r1, emergency_ctx@ha + addis r1, r1, emergency_ctx-PAGE_OFFSET@ha #else - lis r1, emergency_ctx@ha + lis r1, emergency_ctx-PAGE_OFFSET@ha #endif - lwz r1, emergency_ctx@l(r1) + lwz r1, emergency_ctx-PAGE_OFFSET@l(r1) addi r1, r1, THREAD_SIZE - INT_FRAME_SIZE EXCEPTION_PROLOG_2 0 vmap_stack_overflow prepare_transfer_to_handler
Since the commit c118c7303ad5 ("powerpc/32: Fix vmap stack - Do not activate MMU before reading task struct") a vmap stack overflow results in a hard lockup. This is because emergency_ctx is still addressed with its virtual address allthough data MMU is not active anymore at that time. Fix it by using a physical address instead. Fixes: c118c7303ad5 ("powerpc/32: Fix vmap stack - Do not activate MMU before reading task struct") Cc: stable@vger.kernel.org Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu> --- arch/powerpc/kernel/head_32.h | 6 +++--- 1 file changed, 3 insertions(+), 3 deletions(-)