From 4e56fdbce36cc1d2bbd853589809b4f7ad634fc3 Mon Sep 17 00:00:00 2001 From: Ulrich Drepper Date: Fri, 19 Jan 2001 05:16:45 +0000 Subject: Update. * sysdeps/generic/dl-sysdep.c (_dl_sysdep_start): If HAVE_AUX_XID is defined don't look whether the AT_*ID values were set. If HAVE_AUX_PAGESIZE is defined don't look whether the pagesize is set. (_dl_show_auxv): Rewrite to avoid switch statement. * sysdeps/unix/sysv/linux/kernel-features.h: Define __ASSUME_AT_PAGESIZE for kernel >= 2.4.1. * sysdeps/unix/sysv/linux/ldsodefs.h: Define HAVE_AUX_XID. Define HAVE_AUX_PAGESIZE if __ASSUME_AT_PAGESIZE is defined. --- sysdeps/generic/dl-sysdep.c | 142 ++++++++++++------------------ sysdeps/unix/sysv/linux/kernel-features.h | 8 +- sysdeps/unix/sysv/linux/ldsodefs.h | 12 +++ 3 files changed, 77 insertions(+), 85 deletions(-) (limited to 'sysdeps') diff --git a/sysdeps/generic/dl-sysdep.c b/sysdeps/generic/dl-sysdep.c index 2b01878cfe..9807e6bc10 100644 --- a/sysdeps/generic/dl-sysdep.c +++ b/sysdeps/generic/dl-sysdep.c @@ -17,6 +17,7 @@ write to the Free Software Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA. */ +#include #include #include #include @@ -87,7 +88,10 @@ _dl_sysdep_start (void **start_argptr, uid_t euid = 0; gid_t gid = 0; gid_t egid = 0; - unsigned int seen; +#ifndef HAVE_AUX_X + unsigned int seen = 0; +# define M(type) (1 << (type)) +#endif DL_FIND_ARG_COMPONENTS (start_argptr, _dl_argc, _dl_argv, _environ, _dl_auxv); @@ -95,9 +99,6 @@ _dl_sysdep_start (void **start_argptr, user_entry = (ElfW(Addr)) &ENTRY_POINT; _dl_platform = NULL; /* Default to nothing known about the platform. */ - seen = 0; -#define M(type) (1 << (type)) - for (av = _dl_auxv; av->a_type != AT_NULL; seen |= M ((++av)->a_type)) switch (av->a_type) { @@ -149,16 +150,20 @@ _dl_sysdep_start (void **start_argptr, /* Linux doesn't provide us with any of these values on the stack when the dynamic linker is run directly as a program. */ -#define SEE(UID, uid) if ((seen & M (AT_##UID)) == 0) uid = __get##uid () +#ifndef HAVE_AUX_XID +# define SEE(UID, uid) if ((seen & M (AT_##UID)) == 0) uid = __get##uid () SEE (UID, uid); SEE (GID, gid); SEE (EUID, euid); SEE (EGID, egid); +#endif __libc_enable_secure = uid != euid || gid != egid; +#ifndef HAVE_AUX_PAGESIZE if (_dl_pagesize == 0) _dl_pagesize = __getpagesize (); +#endif #ifdef DL_SYSDEP_INIT DL_SYSDEP_INIT; @@ -206,87 +211,56 @@ _dl_show_auxv (void) /* Terminate string. */ buf[63] = '\0'; + /* The following code assumes that the AT_* values are encoded + starting from 0 with AT_NULL, 1 for AT_IGNORE, and all other values + close by (otherwise the array will be too large). In case we have + to support a platform where these requirements are not fulfilled + some alternative implementation has to be used. */ for (av = _dl_auxv; av->a_type != AT_NULL; ++av) - switch (av->a_type) + { + static const struct { - case AT_PHDR: - _dl_sysdep_message ("AT_PHDR: 0x", - _itoa_word (av->a_un.a_val, buf + sizeof buf - 1, - 16, 0), - "\n", NULL); - break; - case AT_PHNUM: - _dl_sysdep_message ("AT_PHNUM: ", - _itoa_word (av->a_un.a_val, buf + sizeof buf - 1, - 10, 0), - "\n", NULL); - break; - case AT_PAGESZ: - _dl_sysdep_message ("AT_PAGESZ: ", - _itoa_word (av->a_un.a_val, buf + sizeof buf - 1, - 10, 0), - "\n", NULL); - break; - case AT_ENTRY: - _dl_sysdep_message ("AT_ENTRY: 0x", - _itoa_word (av->a_un.a_val, buf + sizeof buf - 1, - 16, 0), - "\n", NULL); - break; - case AT_BASE: - _dl_sysdep_message ("AT_BASE: 0x", - _itoa_word (av->a_un.a_val, buf + sizeof buf - 1, - 16, 0), - "\n", NULL); - break; - case AT_UID: - _dl_sysdep_message ("AT_UID: ", - _itoa_word (av->a_un.a_val, buf + sizeof buf - 1, - 10, 0), - "\n", NULL); - break; - case AT_GID: - _dl_sysdep_message ("AT_GID: ", - _itoa_word (av->a_un.a_val, buf + sizeof buf - 1, - 10, 0), - "\n", NULL); - break; - case AT_EUID: - _dl_sysdep_message ("AT_EUID: ", - _itoa_word (av->a_un.a_val, buf + sizeof buf - 1, - 10, 0), - "\n", NULL); - break; - case AT_EGID: - _dl_sysdep_message ("AT_EGID: ", - _itoa_word (av->a_un.a_val, buf + sizeof buf - 1, - 10, 0), - "\n", NULL); - break; - case AT_PLATFORM: - _dl_sysdep_message ("AT_PLATFORM: ", av->a_un.a_ptr, "\n", NULL); - break; - case AT_HWCAP: - _dl_hwcap = av->a_un.a_val; - if (_dl_procinfo (_dl_hwcap) < 0) - _dl_sysdep_message ("AT_HWCAP: ", - _itoa_word (_dl_hwcap, buf + sizeof buf - 1, - 16, 0), - "\n", NULL); - break; - case AT_CLKTCK: - _dl_sysdep_message ("AT_CLKTCK: ", - _itoa_word (av->a_un.a_val, buf + sizeof buf - 1, - 10, 0), - "\n", NULL); - break; - case AT_FPUCW: - _dl_sysdep_message ("AT_FPUCW: ", - _itoa_word (av->a_un.a_val, buf + sizeof buf - 1, - 10, 0), - "\n", NULL); - break; - } + const char label[16]; + enum { dec, hex, str } form; + } auxvars[] = + { + [AT_EXECFD - 2] = { "AT_EXECFD: ", dec }, + [AT_PHDR - 2] = { "AT_PHDR: 0x", hex }, + [AT_PHENT - 2] = { "AT_PHENT: ", dec }, + [AT_PHNUM - 2] = { "AT_PHNUM: ", dec }, + [AT_PAGESZ - 2] = { "AT_PAGESZ: ", dec }, + [AT_BASE - 2] = { "AT_BASE: 0x", hex }, + [AT_FLAGS - 2] = { "AT_FLAGS: 0x", hex }, + [AT_ENTRY - 2] = { "AT_ENTRY: 0x", hex }, + [AT_NOTELF - 2] = { "AT_NOTELF: ", hex }, + [AT_UID - 2] = { "AT_UID: ", dec }, + [AT_EUID - 2] = { "AT_EUID: ", dec }, + [AT_GID - 2] = { "AT_GID: ", dec }, + [AT_EGID - 2] = { "AT_EGID: ", dec }, + [AT_PLATFORM - 2] = { "AT_PLATFORM: ", str }, + [AT_HWCAP - 2] = { "AT_HWCAP: ", hex }, + [AT_CLKTCK - 2] = { "AT_CLKTCK: ", dec }, + [AT_FPUCW - 2] = { "AT_FPUCW: ", hex } + }; + unsigned int idx = (unsigned int) (av->a_type - 2); + + assert (AT_NULL == 0); + assert (AT_IGNORE == 1); + if (idx < sizeof (auxvars) / sizeof (auxvars[0])) + { + if (av->a_type != AT_HWCAP || _dl_procinfo (av->a_un.a_val) < 0) + { + const char *val = av->a_un.a_ptr; + + if (__builtin_expect (auxvars[idx].form, dec) == dec) + val = _itoa_word (av->a_un.a_val, buf + sizeof buf - 1, 10, 0); + else if (__builtin_expect (auxvars[idx].form, hex) == hex) + val = _itoa_word (av->a_un.a_val, buf + sizeof buf - 1, 16, 0); + + _dl_sysdep_message (auxvars[idx].label, val, "\n", NULL); + } + } + } } diff --git a/sysdeps/unix/sysv/linux/kernel-features.h b/sysdeps/unix/sysv/linux/kernel-features.h index 563a7e911e..bbbae67839 100644 --- a/sysdeps/unix/sysv/linux/kernel-features.h +++ b/sysdeps/unix/sysv/linux/kernel-features.h @@ -1,6 +1,6 @@ /* Set flags signalling availability of kernel features based on given kernel version number. - Copyright (C) 1999, 2000 Free Software Foundation, Inc. + Copyright (C) 1999, 2000, 2001 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 @@ -157,3 +157,9 @@ #if __LINUX_KERNEL_VERSION >= 131939 # define __ASSUME_O_DIRECTORY 1 #endif + +/* Starting with one of the 2.4.0 pre-releases the Linux kernel passes + up the page size information. */ +#if __LINUX_KERNEL_VERSION >= 132097 +# define __ASSUME_AT_PAGESIZE 1 +#endif diff --git a/sysdeps/unix/sysv/linux/ldsodefs.h b/sysdeps/unix/sysv/linux/ldsodefs.h index 1bfe6c38af..b495e555c0 100644 --- a/sysdeps/unix/sysv/linux/ldsodefs.h +++ b/sysdeps/unix/sysv/linux/ldsodefs.h @@ -19,6 +19,8 @@ #ifndef _LDSODEFS_H +#include "kernel-features.h" + /* Get the real definitions. */ #include_next @@ -30,4 +32,14 @@ /* Used by static binaries to check the auxiliary vector. */ extern void _dl_aux_init (ElfW(auxv_t) *av) internal_function; +/* We can assume that the kernel always provides the AT_UID, AT_EUID, + AT_GID, and AT_EGID values in the auxiliary vector. */ +#define HAVE_AUX_XID + +/* Starting with one of the 2.4.0 pre-releases the Linux kernel passes + up the page size information. */ +#if __ASSUME_AT_PAGESIZE +# define HAVE_AUX_PAGESIZE +#endif + #endif /* ldsodefs.h */ -- cgit v1.2.3