| Message ID | 20230509091600.70994-2-npiggin@gmail.com (mailing list archive) |
|---|---|
| State | Accepted |
| Commit | 61d7ebe0376e2640ba77be16e186b1a6c77eb3f7 |
| Headers | show |
| Series | [1/2] powerpc/pseries: Fix hcall tracepoints with JUMP_LABEL=n | 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_sparse | success | Successfully ran 4 jobs. |
| snowpatch_ozlabs/github-powerpc_kernel_qemu | success | Successfully ran 24 jobs. |
| snowpatch_ozlabs/github-powerpc_clang | success | Successfully ran 6 jobs. |
diff --git a/arch/powerpc/platforms/pseries/hvCall.S b/arch/powerpc/platforms/pseries/hvCall.S index ca0674b0b683..bae45b358a09 100644 --- a/arch/powerpc/platforms/pseries/hvCall.S +++ b/arch/powerpc/platforms/pseries/hvCall.S @@ -92,7 +92,6 @@ BEGIN_FTR_SECTION; \ END_FTR_SECTION(0, 1); \ LOAD_REG_ADDR(r12, hcall_tracepoint_refcount) ; \ ld r12,0(r12); \ - std r12,32(r1); \ cmpdi r12,0; \ bne- LABEL; \ 1:
When JUMP_LABEL=n, the tracepoint refcount test in the pre-call stores the refcount value to the stack, so the same value can be used for the post-call (presumably to avoid racing with the value concurrently changing). On little-endian (ELFv2) that might have just worked by luck, because 32(r1) is STK_PARAM(R3) there and so the value save gets clobbered by the tracing code when it's non-zero, but fortunately r3 is the hcall number and 0 is an invalid hcall number so it should get clobbered by another non-zero value. In any case, commit cc1adb5f32557 ("powerpc/pseries: Use jump labels for hcall tracepoints") removed the code that actually used the value stored, so now it's just dead code. It's fragile to be storing to the stack like this, and confusing. Better remove it. Signed-off-by: Nicholas Piggin <npiggin@gmail.com> --- arch/powerpc/platforms/pseries/hvCall.S | 1 - 1 file changed, 1 deletion(-)