diff options
| author | Dominik Brodowski <linux@dominikbrodowski.net> | 2018-02-11 14:10:10 +0300 |
|---|---|---|
| committer | Ingo Molnar <mingo@kernel.org> | 2018-02-13 11:04:55 +0300 |
| commit | 198ee8e17502da2634f7366395db1d77630e0219 (patch) | |
| tree | 3fb8542c88da183c08bbe2fb54964b31bcd97c22 /tools/testing | |
| parent | b498c261107461d5c42140dfddd05df83d8ca078 (diff) | |
| download | linux-198ee8e17502da2634f7366395db1d77630e0219.tar.xz | |
selftests/x86: Fix vDSO selftest segfault for vsyscall=none
The vDSO selftest tries to execute a vsyscall unconditionally, even if it
is not present on the test system (e.g. if booted with vsyscall=none or
with CONFIG_LEGACY_VSYSCALL_NONE=y set. Fix this by copying (and tweaking)
the vsyscall check from test_vsyscall.c
Signed-off-by: Dominik Brodowski <linux@dominikbrodowski.net>
Cc: Andrew Lutomirski <luto@kernel.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: linux-kselftest@vger.kernel.org
Cc: shuah@kernel.org
Link: http://lkml.kernel.org/r/20180211111013.16888-3-linux@dominikbrodowski.net
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Diffstat (limited to 'tools/testing')
| -rw-r--r-- | tools/testing/selftests/x86/test_vdso.c | 50 |
1 files changed, 43 insertions, 7 deletions
diff --git a/tools/testing/selftests/x86/test_vdso.c b/tools/testing/selftests/x86/test_vdso.c index 29973cde06d3..558c8207e7b9 100644 --- a/tools/testing/selftests/x86/test_vdso.c +++ b/tools/testing/selftests/x86/test_vdso.c @@ -28,18 +28,52 @@ int nerrs = 0; +typedef long (*getcpu_t)(unsigned *, unsigned *, void *); + +getcpu_t vgetcpu; +getcpu_t vdso_getcpu; + +static void *vsyscall_getcpu(void) +{ #ifdef __x86_64__ -# define VSYS(x) (x) + FILE *maps; + char line[128]; + bool found = false; + + maps = fopen("/proc/self/maps", "r"); + if (!maps) /* might still be present, but ignore it here, as we test vDSO not vsyscall */ + return NULL; + + while (fgets(line, sizeof(line), maps)) { + char r, x; + void *start, *end; + char name[128]; + if (sscanf(line, "%p-%p %c-%cp %*x %*x:%*x %*u %s", + &start, &end, &r, &x, name) != 5) + continue; + + if (strcmp(name, "[vsyscall]")) + continue; + + /* assume entries are OK, as we test vDSO here not vsyscall */ + found = true; + break; + } + + fclose(maps); + + if (!found) { + printf("Warning: failed to find vsyscall getcpu\n"); + return NULL; + } + return (void *) (0xffffffffff600800); #else -# define VSYS(x) 0 + return NULL; #endif +} -typedef long (*getcpu_t)(unsigned *, unsigned *, void *); - -const getcpu_t vgetcpu = (getcpu_t)VSYS(0xffffffffff600800); -getcpu_t vdso_getcpu; -void fill_function_pointers() +static void fill_function_pointers() { void *vdso = dlopen("linux-vdso.so.1", RTLD_LAZY | RTLD_LOCAL | RTLD_NOLOAD); @@ -54,6 +88,8 @@ void fill_function_pointers() vdso_getcpu = (getcpu_t)dlsym(vdso, "__vdso_getcpu"); if (!vdso_getcpu) printf("Warning: failed to find getcpu in vDSO\n"); + + vgetcpu = (getcpu_t) vsyscall_getcpu(); } static long sys_getcpu(unsigned * cpu, unsigned * node, |