diff options
Diffstat (limited to 'sysdeps/unix/sysv/linux/dl-osinfo.h')
| -rw-r--r-- | sysdeps/unix/sysv/linux/dl-osinfo.h | 226 |
1 files changed, 163 insertions, 63 deletions
diff --git a/sysdeps/unix/sysv/linux/dl-osinfo.h b/sysdeps/unix/sysv/linux/dl-osinfo.h index abc67fcdcf..3c93218dfc 100644 --- a/sysdeps/unix/sysv/linux/dl-osinfo.h +++ b/sysdeps/unix/sysv/linux/dl-osinfo.h @@ -1,5 +1,5 @@ -/* Operating system specific code for generic dynamic loader functions. - Copyright (C) 2000, 2001, 2002, 2004 Free Software Foundation, Inc. +/* Operating system specific code for generic dynamic loader functions. Linux. + Copyright (C) 2000,2001,2002,2004,2005,2006 Free Software Foundation, Inc. This file is part of the GNU C Library. The GNU C Library is free software; you can redistribute it and/or @@ -18,10 +18,14 @@ 02111-1307 USA. */ #include <string.h> +#include <errno.h> #include <fcntl.h> -#include <sys/sysctl.h> #include <sys/utsname.h> -#include "kernel-features.h" +#include <kernel-features.h> +#include <dl-sysdep.h> +#include <stdint.h> +#include <hp-timing.h> +#include <endian.h> #ifndef MIN # define MIN(a,b) (((a)<(b))?(a):(b)) @@ -39,71 +43,167 @@ dl_fatal (const char *str) } #endif +static inline int __attribute__ ((always_inline)) +_dl_discover_osversion (void) +{ +#if (defined NEED_DL_SYSINFO || defined NEED_DL_SYSINFO_DSO) && defined SHARED + if (GLRO(dl_sysinfo_map) != NULL) + { + /* If the kernel-supplied DSO contains a note indicating the kernel's + version, we don't need to call uname or parse any strings. */ + + static const struct + { + ElfW(Word) vendorlen; + ElfW(Word) datalen; + ElfW(Word) type; + char vendor[8]; + } expected_note = { sizeof "Linux", sizeof (ElfW(Word)), 0, "Linux" }; + const ElfW(Phdr) *const phdr = GLRO(dl_sysinfo_map)->l_phdr; + const ElfW(Word) phnum = GLRO(dl_sysinfo_map)->l_phnum; + for (uint_fast16_t i = 0; i < phnum; ++i) + if (phdr[i].p_type == PT_NOTE) + { + const ElfW(Addr) start = (phdr[i].p_vaddr + + GLRO(dl_sysinfo_map)->l_addr); + const struct + { + ElfW(Word) vendorlen; + ElfW(Word) datalen; + ElfW(Word) type; + } *note = (const void *) start; + while ((ElfW(Addr)) (note + 1) - start < phdr[i].p_memsz) + { + if (!memcmp (note, &expected_note, sizeof expected_note)) + return *(const ElfW(Word) *) ((const void *) note + + sizeof expected_note); +#define ROUND(len) (((len) + sizeof (ElfW(Word)) - 1) & -sizeof (ElfW(Word))) + note = ((const void *) (note + 1) + + ROUND (note->vendorlen) + ROUND (note->datalen)); + } + } + } +#endif + + char bufmem[64]; + char *buf = bufmem; + unsigned int version; + int parts; + char *cp; + struct utsname uts; + + /* Try the uname system call. */ + if (__uname (&uts)) + { + /* This was not successful. Now try reading the /proc filesystem. */ + int fd = __open ("/proc/sys/kernel/osrelease", O_RDONLY); + if (fd < 0) + return -1; + ssize_t reslen = __read (fd, bufmem, sizeof (bufmem)); + __close (fd); + if (reslen <= 0) + /* This also didn't work. We give up since we cannot + make sure the library can actually work. */ + return -1; + buf[MIN (reslen, (ssize_t) sizeof (bufmem) - 1)] = '\0'; + } + else + buf = uts.release; + + /* Now convert it into a number. The string consists of at most + three parts. */ + version = 0; + parts = 0; + cp = buf; + while ((*cp >= '0') && (*cp <= '9')) + { + unsigned int here = *cp++ - '0'; + + while ((*cp >= '0') && (*cp <= '9')) + { + here *= 10; + here += *cp++ - '0'; + } -#define DL_SYSDEP_OSCHECK(FATAL) \ + ++parts; + version <<= 8; + version |= here; + + if (*cp++ != '.') + /* Another part following? */ + break; + } + + if (parts < 3) + version <<= 8 * (3 - parts); + + return version; +} + +#define DL_SYSDEP_OSCHECK(FATAL) \ do { \ - /* Test whether the kernel is new enough. This test is only \ - performed if the library is not compiled to run on all \ - kernels. */ \ - if (__LINUX_KERNEL_VERSION > 0) \ - { \ - char bufmem[64]; \ - char *buf = bufmem; \ - unsigned int version; \ - int parts; \ - char *cp; \ - struct utsname uts; \ - \ - /* Try the uname syscall */ \ - if (__uname (&uts)) \ - { \ - /* This was not successful. Now try reading the /proc \ - filesystem. */ \ - ssize_t reslen; \ - int fd = __open ("/proc/sys/kernel/osrelease", O_RDONLY); \ - if (fd == -1 \ - || (reslen = __read (fd, bufmem, sizeof (bufmem))) <= 0) \ - /* This also didn't work. We give up since we cannot \ - make sure the library can actually work. */ \ - FATAL ("FATAL: cannot determine kernel version\n"); \ - __close (fd); \ - buf[MIN (reslen, (ssize_t) sizeof (bufmem) - 1)] = '\0'; \ - } \ - else \ - buf = uts.release; \ + /* Test whether the kernel is new enough. This test is only performed \ + if the library is not compiled to run on all kernels. */ \ \ - /* Now convert it into a number. The string consists of at most \ - three parts. */ \ - version = 0; \ - parts = 0; \ - cp = buf; \ - while ((*cp >= '0') && (*cp <= '9')) \ - { \ - unsigned int here = *cp++ - '0'; \ - \ - while ((*cp >= '0') && (*cp <= '9')) \ - { \ - here *= 10; \ - here += *cp++ - '0'; \ - } \ - \ - ++parts; \ - version <<= 8; \ - version |= here; \ - \ - if (*cp++ != '.') \ - /* Another part following? */ \ - break; \ - } \ - \ - if (parts < 3) \ - version <<= 8 * (3 - parts); \ + int version = _dl_discover_osversion (); \ + if (__builtin_expect (version >= 0, 1)) \ + { \ + if (__builtin_expect (GLRO(dl_osversion) == 0, 1) \ + || GLRO(dl_osversion) > version) \ + GLRO(dl_osversion) = version; \ \ /* Now we can test with the required version. */ \ - if (version < __LINUX_KERNEL_VERSION) \ + if (__LINUX_KERNEL_VERSION > 0 && version < __LINUX_KERNEL_VERSION) \ /* Not sufficent. */ \ FATAL ("FATAL: kernel too old\n"); \ - \ - GLRO(dl_osversion) = version; \ } \ + else if (__LINUX_KERNEL_VERSION > 0) \ + FATAL ("FATAL: cannot determine kernel version\n"); \ } while (0) + +static inline uintptr_t __attribute__ ((always_inline)) +_dl_setup_stack_chk_guard (void) +{ + uintptr_t ret; +#ifdef ENABLE_STACKGUARD_RANDOMIZE + int fd = __open ("/dev/urandom", O_RDONLY); + if (fd >= 0) + { + ssize_t reslen = __read (fd, &ret, sizeof (ret)); + __close (fd); + if (reslen == (ssize_t) sizeof (ret)) + return ret; + } +#endif + ret = 0; + unsigned char *p = (unsigned char *) &ret; + p[sizeof (ret) - 1] = 255; + p[sizeof (ret) - 2] = '\n'; +#ifdef HP_TIMING_NOW + hp_timing_t hpt; + HP_TIMING_NOW (hpt); + hpt = (hpt & 0xffff) << 8; + ret ^= hpt; +#endif + uintptr_t stk; + /* Avoid GCC being too smart. */ + asm ("" : "=r" (stk) : "r" (p)); + stk &= 0x7ffff0; +#if __BYTE_ORDER == __LITTLE_ENDIAN + stk <<= (__WORDSIZE - 23); +#elif __WORDSIZE == 64 + stk <<= 31; +#endif + ret ^= stk; + /* Avoid GCC being too smart. */ + p = (unsigned char *) &errno; + asm ("" : "=r" (stk) : "r" (p)); + stk &= 0x7fff00; +#if __BYTE_ORDER == __LITTLE_ENDIAN + stk <<= (__WORDSIZE - 29); +#else + stk >>= 8; +#endif + ret ^= stk; + return ret; +} |