From: Jordan Niethe jniethe5@gmail.com
[ Upstream commit db96221a683342fd4775fd820a4d5376cd2f2ed0 ]
The signal handler in the alignment handler self test has the ability to jump over the instruction that triggered the signal. It does this by incrementing the PT_NIP in the user context by 4. If it were a prefixed instruction this will mean that the suffix is then executed which is incorrect. Instead check if the major opcode indicates a prefixed instruction (e.g. it is 1) and if so increment PT_NIP by 8.
If ISA v3.1 is not available treat it as a word instruction even if the major opcode is 1.
Fixes: 620a6473df36 ("selftests/powerpc: Add prefixed loads/stores to alignment_handler test") Signed-off-by: Jordan Niethe jniethe5@gmail.com [mpe: Fix 32-bit build, rename haveprefixes to prefixes_enabled] Signed-off-by: Michael Ellerman mpe@ellerman.id.au Link: https://lore.kernel.org/r/20200824131231.14008-1-jniethe5@gmail.com Signed-off-by: Sasha Levin sashal@kernel.org --- .../selftests/powerpc/alignment/alignment_handler.c | 10 +++++++++- 1 file changed, 9 insertions(+), 1 deletion(-)
diff --git a/tools/testing/selftests/powerpc/alignment/alignment_handler.c b/tools/testing/selftests/powerpc/alignment/alignment_handler.c index 55ef15184057d..386bca731e581 100644 --- a/tools/testing/selftests/powerpc/alignment/alignment_handler.c +++ b/tools/testing/selftests/powerpc/alignment/alignment_handler.c @@ -64,6 +64,7 @@ int bufsize; int debug; int testing; volatile int gotsig; +bool prefixes_enabled; char *cipath = "/dev/fb0"; long cioffset;
@@ -77,7 +78,12 @@ void sighandler(int sig, siginfo_t *info, void *ctx) } gotsig = sig; #ifdef __powerpc64__ - ucp->uc_mcontext.gp_regs[PT_NIP] += 4; + if (prefixes_enabled) { + u32 inst = *(u32 *)ucp->uc_mcontext.gp_regs[PT_NIP]; + ucp->uc_mcontext.gp_regs[PT_NIP] += ((inst >> 26 == 1) ? 8 : 4); + } else { + ucp->uc_mcontext.gp_regs[PT_NIP] += 4; + } #else ucp->uc_mcontext.uc_regs->gregs[PT_NIP] += 4; #endif @@ -648,6 +654,8 @@ int main(int argc, char *argv[]) exit(1); }
+ prefixes_enabled = have_hwcap2(PPC_FEATURE2_ARCH_3_1); + rc |= test_harness(test_alignment_handler_vsx_206, "test_alignment_handler_vsx_206"); rc |= test_harness(test_alignment_handler_vsx_207,