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authorAdhemerval Zanella <adhemerval.zanella@linaro.org>2019-11-29 10:44:59 -0300
committerAdhemerval Zanella <adhemerval.zanella@linaro.org>2020-01-03 11:22:07 -0300
commit1bdda52fe92fd01b424cd6fbb63e3df96a95015c (patch)
treed25214e63bf5c96ab48c11ec0df28b5d96ca99da /sysdeps/unix/sysv/linux/libc-vdso.h
parent57013650f7e796428ac2c0b7512757e99327bfc9 (diff)
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elf: Move vDSO setup to rtld (BZ#24967)
This patch moves the vDSO setup from libc to loader code, just after the vDSO link_map setup. For static case the initialization is moved to _dl_non_dynamic_init instead. Instead of using the mangled pointer, the vDSO data is set as attribute_relro (on _rtld_global_ro for shared or _dl_vdso_* for static). It is read-only even with partial relro. It fixes BZ#24967 now that the vDSO pointer is setup earlier than malloc interposition is called. Also, vDSO calls should not be a problem for static dlopen as indicated by BZ#20802. The vDSO pointer would be zero-initialized and the syscall will be issued instead. Checked on x86_64-linux-gnu, i686-linux-gnu, aarch64-linux-gnu, arm-linux-gnueabihf, powerpc64le-linux-gnu, powerpc64-linux-gnu, powerpc-linux-gnu, s390x-linux-gnu, sparc64-linux-gnu, and sparcv9-linux-gnu. I also run some tests on mips. Reviewed-by: Siddhesh Poyarekar <siddhesh@sourceware.org>
Diffstat (limited to 'sysdeps/unix/sysv/linux/libc-vdso.h')
-rw-r--r--sysdeps/unix/sysv/linux/libc-vdso.h30
1 files changed, 1 insertions, 29 deletions
diff --git a/sysdeps/unix/sysv/linux/libc-vdso.h b/sysdeps/unix/sysv/linux/libc-vdso.h
index 1d7af16be8..31ceafe9d8 100644
--- a/sysdeps/unix/sysv/linux/libc-vdso.h
+++ b/sysdeps/unix/sysv/linux/libc-vdso.h
@@ -19,37 +19,9 @@
#ifndef _LIBC_VDSO_H
#define _LIBC_VDSO_H
-#define VDSO_SYMBOL(__name) __vdso_##__name
-
/* Adjust the return IFUNC value from a vDSO symbol accordingly required
by the ELFv1 ABI. It is used by the architecture to create an ODP
entry since the kernel vDSO does not provide it. */
-#ifndef VDSO_IFUNC_RET
-# define VDSO_IFUNC_RET(__value) (__value)
-#endif
+#define VDSO_IFUNC_RET(__value) (__value)
-#ifdef HAVE_CLOCK_GETTIME_VSYSCALL
-extern int (*VDSO_SYMBOL(clock_gettime)) (clockid_t, struct timespec *)
- attribute_hidden;
-#endif
-#ifdef HAVE_CLOCK_GETTIME64_VSYSCALL
-extern int (*VDSO_SYMBOL(clock_gettime64)) (clockid_t, struct __timespec64 *)
- attribute_hidden;
-#endif
-#ifdef HAVE_CLOCK_GETRES_VSYSCALL
-extern int (*VDSO_SYMBOL(clock_getres)) (clockid_t, struct timespec *)
- attribute_hidden;
#endif
-#ifdef HAVE_GETTIMEOFDAY_VSYSCALL
-extern int (*VDSO_SYMBOL (gettimeofday)) (struct timeval *, void *)
- attribute_hidden;
-#endif
-#ifdef HAVE_GETCPU_VSYSCALL
-extern long int (*VDSO_SYMBOL(getcpu)) (unsigned *, unsigned *, void *)
- attribute_hidden;
-#endif
-#ifdef HAVE_TIME_VSYSCALL
-extern time_t (*VDSO_SYMBOL(time)) (time_t *) attribute_hidden;
-#endif
-
-#endif /* _LIBC_VDSO_H */