diff options
Diffstat (limited to 'tools/testing/selftests/x86')
| -rw-r--r-- | tools/testing/selftests/x86/mov_ss_trap.c | 3 | ||||
| -rw-r--r-- | tools/testing/selftests/x86/sigreturn.c | 13 |
2 files changed, 15 insertions, 1 deletions
diff --git a/tools/testing/selftests/x86/mov_ss_trap.c b/tools/testing/selftests/x86/mov_ss_trap.c index 3c3a022654f3..6da0ac3f0135 100644 --- a/tools/testing/selftests/x86/mov_ss_trap.c +++ b/tools/testing/selftests/x86/mov_ss_trap.c @@ -257,7 +257,8 @@ int main() err(1, "sigaltstack"); sethandler(SIGSEGV, handle_and_longjmp, SA_RESETHAND | SA_ONSTACK); nr = SYS_getpid; - asm volatile ("mov %[ss], %%ss; SYSENTER" : "+a" (nr) + /* Clear EBP first to make sure we segfault cleanly. */ + asm volatile ("xorl %%ebp, %%ebp; mov %[ss], %%ss; SYSENTER" : "+a" (nr) : [ss] "m" (ss) : "flags", "rcx" #ifdef __x86_64__ , "r11" diff --git a/tools/testing/selftests/x86/sigreturn.c b/tools/testing/selftests/x86/sigreturn.c index 3e49a7873f3e..57c4f67f16ef 100644 --- a/tools/testing/selftests/x86/sigreturn.c +++ b/tools/testing/selftests/x86/sigreturn.c @@ -451,6 +451,19 @@ static void sigusr1(int sig, siginfo_t *info, void *ctx_void) ctx->uc_mcontext.gregs[REG_SP] = (unsigned long)0x8badf00d5aadc0deULL; ctx->uc_mcontext.gregs[REG_CX] = 0; +#ifdef __i386__ + /* + * Make sure the kernel doesn't inadvertently use DS or ES-relative + * accesses in a region where user DS or ES is loaded. + * + * Skip this for 64-bit builds because long mode doesn't care about + * DS and ES and skipping it increases test coverage a little bit, + * since 64-bit kernels can still run the 32-bit build. + */ + ctx->uc_mcontext.gregs[REG_DS] = 0; + ctx->uc_mcontext.gregs[REG_ES] = 0; +#endif + memcpy(&requested_regs, &ctx->uc_mcontext.gregs, sizeof(gregset_t)); requested_regs[REG_CX] = *ssptr(ctx); /* The asm code does this. */ |