diff options
| author |   Chang S. Bae <chang.seok.bae@intel.com> | 2020-05-28 16:14:02 -0400 |
|---|---|---|
| committer |   Thomas Gleixner <tglx@linutronix.de> | 2020-06-18 15:47:07 +0200 |
| commit | 5e7ec8578fa3dada50c50f5b234fa8d154b76349 (patch) | |
| tree | 0407472ec5427172839114e37fcb812b19478a2b /tools/testing/selftests/x86 | |
| parent | selftests/x86/fsgsbase: Test GS selector on ptracer-induced GS base write (diff) | |
| download | linux-dev-5e7ec8578fa3dada50c50f5b234fa8d154b76349.tar.xz linux-dev-5e7ec8578fa3dada50c50f5b234fa8d154b76349.zip | |
selftests/x86/fsgsbase: Test ptracer-induced GS base write with FSGSBASE
This validates that GS selector and base are independently preserved in
ptrace commands.
Suggested-by: Andy Lutomirski <luto@kernel.org>
Signed-off-by: Chang S. Bae <chang.seok.bae@intel.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Tony Luck <tony.luck@intel.com>
Link: https://lkml.kernel.org/r/20200528201402.1708239-17-sashal@kernel.org
Diffstat (limited to 'tools/testing/selftests/x86')
| -rw-r--r-- | tools/testing/selftests/x86/fsgsbase.c | 11 |
1 files changed, 9 insertions, 2 deletions
diff --git a/tools/testing/selftests/x86/fsgsbase.c b/tools/testing/selftests/x86/fsgsbase.c index 950a48b2e366..9a4349813a30 100644 --- a/tools/testing/selftests/x86/fsgsbase.c +++ b/tools/testing/selftests/x86/fsgsbase.c @@ -465,7 +465,7 @@ static void test_ptrace_write_gsbase(void) wait(&status); if (WSTOPSIG(status) == SIGTRAP) { - unsigned long gs; + unsigned long gs, base; unsigned long gs_offset = USER_REGS_OFFSET(gs); unsigned long base_offset = USER_REGS_OFFSET(gs_base); @@ -481,6 +481,7 @@ static void test_ptrace_write_gsbase(void) err(1, "PTRACE_POKEUSER"); gs = ptrace(PTRACE_PEEKUSER, child, gs_offset, NULL); + base = ptrace(PTRACE_PEEKUSER, child, base_offset, NULL); /* * In a non-FSGSBASE system, the nonzero selector will load @@ -501,8 +502,14 @@ static void test_ptrace_write_gsbase(void) */ if (gs == 0) printf("\tNote: this is expected behavior on older kernels.\n"); + } else if (have_fsgsbase && (base != 0xFF)) { + nerrs++; + printf("[FAIL]\tGSBASE changed to %lx\n", base); } else { - printf("[OK]\tGS remained 0x%hx\n", *shared_scratch); + printf("[OK]\tGS remained 0x%hx", *shared_scratch); + if (have_fsgsbase) + printf(" and GSBASE changed to 0xFF"); + printf("\n"); } } |