This is a note to let you know that I've just added the patch titled
selftests/x86: Fix vDSO selftest segfault for vsyscall=none
to the 4.15-stable tree which can be found at: http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git%3Ba=su...
The filename of the patch is: selftests-x86-fix-vdso-selftest-segfault-for-vsyscall-none.patch and it can be found in the queue-4.15 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree, please let stable@vger.kernel.org know about it.
From 198ee8e17502da2634f7366395db1d77630e0219 Mon Sep 17 00:00:00 2001
From: Dominik Brodowski linux@dominikbrodowski.net Date: Sun, 11 Feb 2018 12:10:10 +0100 Subject: selftests/x86: Fix vDSO selftest segfault for vsyscall=none
From: Dominik Brodowski linux@dominikbrodowski.net
commit 198ee8e17502da2634f7366395db1d77630e0219 upstream.
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 Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org
--- tools/testing/selftests/x86/test_vdso.c | 50 +++++++++++++++++++++++++++----- 1 file changed, 43 insertions(+), 7 deletions(-)
--- 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,
Patches currently in stable-queue which might be from linux@dominikbrodowski.net are
queue-4.15/selftests-x86-fix-build-bug-caused-by-the-5lvl-test-which-has-been-moved-to-the-vm-directory.patch queue-4.15/x86-entry-64-interleave-xor-register-clearing-with-push-instructions.patch queue-4.15/x86-entry-64-merge-the-pop_c_regs-and-pop_extra_regs-macros-into-a-single-pop_regs-macro.patch queue-4.15/x86-entry-64-remove-the-unused-icebp-macro.patch queue-4.15/x86-entry-64-use-push_and_clean_regs-in-more-cases.patch queue-4.15/selftests-x86-disable-tests-requiring-32-bit-support-on-pure-64-bit-systems.patch queue-4.15/x86-entry-64-fix-paranoid_entry-frame-pointer-warning.patch queue-4.15/x86-entry-64-merge-save_c_regs-and-save_extra_regs-remove-unused-extensions.patch queue-4.15/selftests-x86-do-not-rely-on-int-0x80-in-single_step_syscall.c.patch queue-4.15/selftests-x86-fix-vdso-selftest-segfault-for-vsyscall-none.patch queue-4.15/x86-entry-64-indent-push_and_clear_regs-and-pop_regs-properly.patch queue-4.15/selftests-x86-clean-up-and-document-sscanf-usage.patch queue-4.15/selftests-x86-do-not-rely-on-int-0x80-in-test_mremap_vdso.c.patch queue-4.15/x86-entry-64-get-rid-of-the-alloc_pt_gpregs_on_stack-and-save_and_clear_regs-macros.patch queue-4.15/x86-entry-64-introduce-the-push_and_clean_regs-macro.patch