The IA32 Emulation support can be either removed from the kernel, disabled by default or disabled at runtime. The x86/ptrace_syscall selftest crashes for all of above thus is_32bit_syscall_supported() helper is added to skip int80 syscalls if they are not supported.
Signed-off-by: Slawomir Rosek srosek@google.com --- tools/testing/selftests/x86/ptrace_syscall.c | 20 ++++++++++++++++++-- 1 file changed, 18 insertions(+), 2 deletions(-)
diff --git a/tools/testing/selftests/x86/ptrace_syscall.c b/tools/testing/selftests/x86/ptrace_syscall.c index 360ec88d5432..6c19bea485c6 100644 --- a/tools/testing/selftests/x86/ptrace_syscall.c +++ b/tools/testing/selftests/x86/ptrace_syscall.c @@ -51,6 +51,18 @@ extern void sys32_helper(struct syscall_args32 *, void *); extern void int80_and_ret(void); #endif
+static bool is_32bit_syscall_supported(void) +{ +#ifdef __x86_64__ + return system("((zcat /proc/config.gz | grep CONFIG_IA32_EMULATION=y) &&" + "((test -z $(zcat /proc/config.gz | grep CONFIG_IA32_EMULATION_DEFAULT_DISABLED=y)) || (grep ia32_emulation=true /proc/cmdline)) &&" + "(test -z $(grep ia32_emulation=false /proc/cmdline))) >/dev/null 2>&1" + ) == 0; +#else + return true; +#endif +} + /* * Helper to invoke int80 with controlled regs and capture the final regs. */ @@ -389,8 +401,12 @@ static void test_restart_under_ptrace(void)
int main() { - printf("[RUN]\tCheck int80 return regs\n"); - test_sys32_regs(do_full_int80); + if (is_32bit_syscall_supported()) { + printf("[RUN]\tCheck int80 return regs\n"); + test_sys32_regs(do_full_int80); + } else { + printf("[SKIP]\t32bit syscall support is not available\n"); + }
#if defined(__i386__) && (!defined(__GLIBC__) || __GLIBC__ > 2 || __GLIBC_MINOR__ >= 16) vsyscall32 = (void *)getauxval(AT_SYSINFO);