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authorUlrich Drepper <drepper@redhat.com>2005-12-14 08:43:25 +0000
committerUlrich Drepper <drepper@redhat.com>2005-12-14 08:43:25 +0000
commitb6ab06cef4670e02756bcdd4d2c33a49369a4346 (patch)
treeb30743eb9728d890d1519f62b2d1f2b96f62547a /elf/dl-sysdep.c
parentd1dc39a44e339f9c48baa3854fffb3d68c73c8fa (diff)
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2005-12-13 Ulrich Drepper <drepper@redhat.com>
Diffstat (limited to 'elf/dl-sysdep.c')
-rw-r--r--elf/dl-sysdep.c590
1 files changed, 590 insertions, 0 deletions
diff --git a/elf/dl-sysdep.c b/elf/dl-sysdep.c
new file mode 100644
index 0000000..985e2b8
--- /dev/null
+++ b/elf/dl-sysdep.c
@@ -0,0 +1,590 @@
+/* Operating system support for run-time dynamic linker. Generic Unix version.
+ Copyright (C) 1995-1998, 2000-2003, 2004, 2005 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
+ modify it under the terms of the GNU Lesser General Public
+ License as published by the Free Software Foundation; either
+ version 2.1 of the License, or (at your option) any later version.
+
+ The GNU C Library is distributed in the hope that it will be useful,
+ but WITHOUT ANY WARRANTY; without even the implied warranty of
+ MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
+ Lesser General Public License for more details.
+
+ You should have received a copy of the GNU Lesser General Public
+ License along with the GNU C Library; if not, write to the Free
+ Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
+ 02111-1307 USA. */
+
+#include <assert.h>
+#include <elf.h>
+#include <errno.h>
+#include <fcntl.h>
+#include <libintl.h>
+#include <stdlib.h>
+#include <string.h>
+#include <unistd.h>
+#include <sys/types.h>
+#include <sys/stat.h>
+#include <sys/mman.h>
+#include <ldsodefs.h>
+#include <stdio-common/_itoa.h>
+#include <fpu_control.h>
+
+#include <entry.h>
+#include <dl-machine.h>
+#include <dl-procinfo.h>
+#include <dl-osinfo.h>
+#include <hp-timing.h>
+#include <tls.h>
+
+#ifdef _DL_FIRST_PLATFORM
+# define _DL_FIRST_EXTRA (_DL_FIRST_PLATFORM + _DL_PLATFORMS_COUNT)
+#else
+# define _DL_FIRST_EXTRA _DL_HWCAP_COUNT
+#endif
+
+extern char **_environ attribute_hidden;
+extern void _end attribute_hidden;
+
+/* Protect SUID program against misuse of file descriptors. */
+extern void __libc_check_standard_fds (void);
+
+#ifdef NEED_DL_BASE_ADDR
+ElfW(Addr) _dl_base_addr;
+#endif
+int __libc_enable_secure attribute_relro = 0;
+INTVARDEF(__libc_enable_secure)
+int __libc_multiple_libcs = 0; /* Defining this here avoids the inclusion
+ of init-first. */
+/* This variable contains the lowest stack address ever used. */
+void *__libc_stack_end attribute_relro = NULL;
+rtld_hidden_data_def(__libc_stack_end)
+static ElfW(auxv_t) *_dl_auxv attribute_relro;
+
+#ifndef DL_FIND_ARG_COMPONENTS
+# define DL_FIND_ARG_COMPONENTS(cookie, argc, argv, envp, auxp) \
+ do { \
+ void **_tmp; \
+ (argc) = *(long int *) cookie; \
+ (argv) = (char **) ((long int *) cookie + 1); \
+ (envp) = (argv) + (argc) + 1; \
+ for (_tmp = (void **) (envp); *_tmp; ++_tmp) \
+ continue; \
+ (auxp) = (void *) ++_tmp; \
+ } while (0)
+#endif
+
+#ifndef DL_STACK_END
+# define DL_STACK_END(cookie) ((void *) (cookie))
+#endif
+
+ElfW(Addr)
+_dl_sysdep_start (void **start_argptr,
+ void (*dl_main) (const ElfW(Phdr) *phdr, ElfW(Word) phnum,
+ ElfW(Addr) *user_entry))
+{
+ const ElfW(Phdr) *phdr = NULL;
+ ElfW(Word) phnum = 0;
+ ElfW(Addr) user_entry;
+ ElfW(auxv_t) *av;
+#ifdef HAVE_AUX_SECURE
+# define set_seen(tag) (tag) /* Evaluate for the side effects. */
+# define set_seen_secure() ((void) 0)
+#else
+ uid_t uid = 0;
+ gid_t gid = 0;
+ unsigned int seen = 0;
+# define set_seen_secure() (seen = -1)
+# ifdef HAVE_AUX_XID
+# define set_seen(tag) (tag) /* Evaluate for the side effects. */
+# else
+# define M(type) (1 << (type))
+# define set_seen(tag) seen |= M ((tag)->a_type)
+# endif
+#endif
+#ifdef NEED_DL_SYSINFO
+ uintptr_t new_sysinfo = 0;
+#endif
+
+ __libc_stack_end = DL_STACK_END (start_argptr);
+ DL_FIND_ARG_COMPONENTS (start_argptr, _dl_argc, INTUSE(_dl_argv), _environ,
+ _dl_auxv);
+
+ user_entry = (ElfW(Addr)) ENTRY_POINT;
+ GLRO(dl_platform) = NULL; /* Default to nothing known about the platform. */
+
+ for (av = _dl_auxv; av->a_type != AT_NULL; set_seen (av++))
+ switch (av->a_type)
+ {
+ case AT_PHDR:
+ phdr = (void *) av->a_un.a_val;
+ break;
+ case AT_PHNUM:
+ phnum = av->a_un.a_val;
+ break;
+ case AT_PAGESZ:
+ GLRO(dl_pagesize) = av->a_un.a_val;
+ break;
+ case AT_ENTRY:
+ user_entry = av->a_un.a_val;
+ break;
+#ifdef NEED_DL_BASE_ADDR
+ case AT_BASE:
+ _dl_base_addr = av->a_un.a_val;
+ break;
+#endif
+#ifndef HAVE_AUX_SECURE
+ case AT_UID:
+ case AT_EUID:
+ uid ^= av->a_un.a_val;
+ break;
+ case AT_GID:
+ case AT_EGID:
+ gid ^= av->a_un.a_val;
+ break;
+#endif
+ case AT_SECURE:
+#ifndef HAVE_AUX_SECURE
+ seen = -1;
+#endif
+ INTUSE(__libc_enable_secure) = av->a_un.a_val;
+ break;
+ case AT_PLATFORM:
+ GLRO(dl_platform) = (void *) av->a_un.a_val;
+ break;
+ case AT_HWCAP:
+ GLRO(dl_hwcap) = (unsigned long int) av->a_un.a_val;
+ break;
+ case AT_CLKTCK:
+ GLRO(dl_clktck) = av->a_un.a_val;
+ break;
+ case AT_FPUCW:
+ GLRO(dl_fpu_control) = av->a_un.a_val;
+ break;
+#ifdef NEED_DL_SYSINFO
+ case AT_SYSINFO:
+ new_sysinfo = av->a_un.a_val;
+ break;
+#endif
+#if defined NEED_DL_SYSINFO || defined NEED_DL_SYSINFO_DSO
+ case AT_SYSINFO_EHDR:
+ GLRO(dl_sysinfo_dso) = (void *) av->a_un.a_val;
+ break;
+#endif
+#ifdef DL_PLATFORM_AUXV
+ DL_PLATFORM_AUXV
+#endif
+ }
+
+#ifndef HAVE_AUX_SECURE
+ if (seen != -1)
+ {
+ /* Fill in the values we have not gotten from the kernel through the
+ auxiliary vector. */
+# ifndef HAVE_AUX_XID
+# define SEE(UID, var, uid) \
+ if ((seen & M (AT_##UID)) == 0) var ^= __get##uid ()
+ SEE (UID, uid, uid);
+ SEE (EUID, uid, euid);
+ SEE (GID, gid, gid);
+ SEE (EGID, gid, egid);
+# endif
+
+ /* If one of the two pairs of IDs does not match this is a setuid
+ or setgid run. */
+ INTUSE(__libc_enable_secure) = uid | gid;
+ }
+#endif
+
+#ifndef HAVE_AUX_PAGESIZE
+ if (GLRO(dl_pagesize) == 0)
+ GLRO(dl_pagesize) = __getpagesize ();
+#endif
+
+#if defined NEED_DL_SYSINFO
+ /* Only set the sysinfo value if we also have the vsyscall DSO. */
+ if (GLRO(dl_sysinfo_dso) != 0 && new_sysinfo)
+ GLRO(dl_sysinfo) = new_sysinfo;
+#endif
+
+#ifdef DL_SYSDEP_INIT
+ DL_SYSDEP_INIT;
+#endif
+
+#ifdef DL_PLATFORM_INIT
+ DL_PLATFORM_INIT;
+#endif
+
+ /* Determine the length of the platform name. */
+ if (GLRO(dl_platform) != NULL)
+ GLRO(dl_platformlen) = strlen (GLRO(dl_platform));
+
+ if (__sbrk (0) == &_end)
+ /* The dynamic linker was run as a program, and so the initial break
+ starts just after our bss, at &_end. The malloc in dl-minimal.c
+ will consume the rest of this page, so tell the kernel to move the
+ break up that far. When the user program examines its break, it
+ will see this new value and not clobber our data. */
+ __sbrk (GLRO(dl_pagesize)
+ - ((&_end - (void *) 0) & (GLRO(dl_pagesize) - 1)));
+
+ /* If this is a SUID program we make sure that FDs 0, 1, and 2 are
+ allocated. If necessary we are doing it ourself. If it is not
+ possible we stop the program. */
+ if (__builtin_expect (INTUSE(__libc_enable_secure), 0))
+ __libc_check_standard_fds ();
+
+ (*dl_main) (phdr, phnum, &user_entry);
+ return user_entry;
+}
+
+void
+internal_function
+_dl_sysdep_start_cleanup (void)
+{
+}
+
+void
+internal_function
+_dl_show_auxv (void)
+{
+ char buf[64];
+ ElfW(auxv_t) *av;
+
+ /* 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)
+ {
+ static const struct
+ {
+ const char label[20];
+ enum { unknown = 0, dec, hex, str, ignore } 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 },
+ [AT_DCACHEBSIZE - 2] = { "AT_DCACHEBSIZE: 0x", hex },
+ [AT_ICACHEBSIZE - 2] = { "AT_ICACHEBSIZE: 0x", hex },
+ [AT_UCACHEBSIZE - 2] = { "AT_UCACHEBSIZE: 0x", hex },
+ [AT_IGNOREPPC - 2] = { "AT_IGNOREPPC", ignore },
+ [AT_SECURE - 2] = { "AT_SECURE: ", dec },
+ [AT_SYSINFO - 2] = { "AT_SYSINFO: 0x", hex },
+ [AT_SYSINFO_EHDR - 2] = { "AT_SYSINFO_EHDR: 0x", hex },
+ };
+ unsigned int idx = (unsigned int) (av->a_type - 2);
+
+ if ((unsigned int) av->a_type < 2u || auxvars[idx].form == ignore)
+ continue;
+
+ assert (AT_NULL == 0);
+ assert (AT_IGNORE == 1);
+
+ if (av->a_type == AT_HWCAP)
+ {
+ /* This is handled special. */
+ if (_dl_procinfo (av->a_un.a_val) == 0)
+ continue;
+ }
+
+ if (idx < sizeof (auxvars) / sizeof (auxvars[0])
+ && auxvars[idx].form != unknown)
+ {
+ const char *val = (char *) av->a_un.a_val;
+
+ if (__builtin_expect (auxvars[idx].form, dec) == dec)
+ val = _itoa ((unsigned long int) av->a_un.a_val,
+ buf + sizeof buf - 1, 10, 0);
+ else if (__builtin_expect (auxvars[idx].form, hex) == hex)
+ val = _itoa ((unsigned long int) av->a_un.a_val,
+ buf + sizeof buf - 1, 16, 0);
+
+ _dl_printf ("%s%s\n", auxvars[idx].label, val);
+
+ continue;
+ }
+
+ /* Unknown value: print a generic line. */
+ char buf2[17];
+ buf[sizeof (buf2) - 1] = '\0';
+ const char *val2 = _itoa ((unsigned long int) av->a_un.a_val,
+ buf2 + sizeof buf2 - 1, 16, 0);
+ const char *val = _itoa ((unsigned long int) av->a_type,
+ buf + sizeof buf - 1, 16, 0);
+ _dl_printf ("AT_??? (0x%s): 0x%s\n", val, val2);
+ }
+}
+
+
+/* Return an array of useful/necessary hardware capability names. */
+const struct r_strlenpair *
+internal_function
+_dl_important_hwcaps (const char *platform, size_t platform_len, size_t *sz,
+ size_t *max_capstrlen)
+{
+ /* Determine how many important bits are set. */
+ uint64_t masked = GLRO(dl_hwcap) & GLRO(dl_hwcap_mask);
+ size_t cnt = platform != NULL;
+ size_t n, m;
+ size_t total;
+ struct r_strlenpair *temp;
+ struct r_strlenpair *result;
+ struct r_strlenpair *rp;
+ char *cp;
+
+ /* Count the number of bits set in the masked value. */
+ for (n = 0; (~((1ULL << n) - 1) & masked) != 0; ++n)
+ if ((masked & (1ULL << n)) != 0)
+ ++cnt;
+
+#if (defined NEED_DL_SYSINFO || defined NEED_DL_SYSINFO_DSO) && defined SHARED
+ /* The system-supplied DSO can contain a note of type 2, vendor "GNU".
+ This gives us a list of names to treat as fake hwcap bits. */
+
+ const char *dsocaps = NULL;
+ size_t dsocapslen = 0;
+ if (GLRO(dl_sysinfo_map) != NULL)
+ {
+ 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)
+ {
+#define ROUND(len) (((len) + sizeof (ElfW(Word)) - 1) & -sizeof (ElfW(Word)))
+ if (note->type == 2
+ && note->vendorlen == sizeof "GNU"
+ && !memcmp ((note + 1), "GNU", sizeof "GNU")
+ && note->datalen > 2 * sizeof (ElfW(Word)) + 2)
+ {
+ const ElfW(Word) *p = ((const void *) (note + 1)
+ + ROUND (sizeof "GNU"));
+ cnt += *p++;
+ ++p; /* Skip mask word. */
+ dsocaps = (const char *) p;
+ dsocapslen = note->datalen - sizeof *p * 2;
+ break;
+ }
+ note = ((const void *) (note + 1)
+ + ROUND (note->vendorlen) + ROUND (note->datalen));
+ }
+ if (dsocaps != NULL)
+ break;
+ }
+ }
+#endif
+
+#ifdef USE_TLS
+ /* For TLS enabled builds always add 'tls'. */
+ ++cnt;
+#else
+ if (cnt == 0)
+ {
+ /* If we no have platform name and no important capability we only
+ have the base directory to search. */
+ result = (struct r_strlenpair *) malloc (sizeof (*result));
+ if (result == NULL)
+ goto no_memory;
+
+ result[0].str = (char *) result; /* Does not really matter. */
+ result[0].len = 0;
+
+ *sz = 1;
+ return result;
+ }
+#endif
+
+ /* Create temporary data structure to generate result table. */
+ temp = (struct r_strlenpair *) alloca (cnt * sizeof (*temp));
+ m = 0;
+#if defined NEED_DL_SYSINFO || defined NEED_DL_SYSINFO_DSO
+ if (dsocaps != NULL)
+ {
+ const ElfW(Word) mask = ((const ElfW(Word) *) dsocaps)[-1];
+ GLRO(dl_hwcap) |= (uint64_t) mask << _DL_FIRST_EXTRA;
+ size_t len;
+ for (const char *p = dsocaps; p < dsocaps + dsocapslen; p += len + 1)
+ {
+ uint_fast8_t bit = *p++;
+ len = strlen (p);
+
+ /* Skip entries that are not enabled in the mask word. */
+ if (__builtin_expect (mask & ((ElfW(Word)) 1 << bit), 1))
+ {
+ temp[m].str = p;
+ temp[m].len = len;
+ ++m;
+ }
+ else
+ --cnt;
+ }
+ }
+#endif
+ for (n = 0; masked != 0; ++n)
+ if ((masked & (1ULL << n)) != 0)
+ {
+ temp[m].str = _dl_hwcap_string (n);
+ temp[m].len = strlen (temp[m].str);
+ masked ^= 1ULL << n;
+ ++m;
+ }
+ if (platform != NULL)
+ {
+ temp[m].str = platform;
+ temp[m].len = platform_len;
+ ++m;
+ }
+#ifdef USE_TLS
+ temp[m].str = "tls";
+ temp[m].len = 3;
+ ++m;
+#endif
+ assert (m == cnt);
+
+ /* Determine the total size of all strings together. */
+ if (cnt == 1)
+ total = temp[0].len + 1;
+ else
+ {
+ total = (1UL << (cnt - 2)) * (temp[0].len + temp[cnt - 1].len + 2);
+ for (n = 1; n + 1 < cnt; ++n)
+ total += (1UL << (cnt - 3)) * (temp[n].len + 1);
+ }
+
+ /* The result structure: we use a very compressed way to store the
+ various combinations of capability names. */
+ *sz = 1 << cnt;
+ result = (struct r_strlenpair *) malloc (*sz * sizeof (*result) + total);
+ if (result == NULL)
+ {
+#ifndef USE_TLS
+ no_memory:
+#endif
+ _dl_signal_error (ENOMEM, NULL, NULL,
+ N_("cannot create capability list"));
+ }
+
+ if (cnt == 1)
+ {
+ result[0].str = (char *) (result + *sz);
+ result[0].len = temp[0].len + 1;
+ result[1].str = (char *) (result + *sz);
+ result[1].len = 0;
+ cp = __mempcpy ((char *) (result + *sz), temp[0].str, temp[0].len);
+ *cp = '/';
+ *sz = 2;
+ *max_capstrlen = result[0].len;
+
+ return result;
+ }
+
+ /* Fill in the information. This follows the following scheme
+ (indeces from TEMP for four strings):
+ entry #0: 0, 1, 2, 3 binary: 1111
+ #1: 0, 1, 3 1101
+ #2: 0, 2, 3 1011
+ #3: 0, 3 1001
+ This allows the representation of all possible combinations of
+ capability names in the string. First generate the strings. */
+ result[1].str = result[0].str = cp = (char *) (result + *sz);
+#define add(idx) \
+ cp = __mempcpy (__mempcpy (cp, temp[idx].str, temp[idx].len), "/", 1);
+ if (cnt == 2)
+ {
+ add (1);
+ add (0);
+ }
+ else
+ {
+ n = 1 << (cnt - 1);
+ do
+ {
+ n -= 2;
+
+ /* We always add the last string. */
+ add (cnt - 1);
+
+ /* Add the strings which have the bit set in N. */
+ for (m = cnt - 2; m > 0; --m)
+ if ((n & (1 << m)) != 0)
+ add (m);
+
+ /* Always add the first string. */
+ add (0);
+ }
+ while (n != 0);
+ }
+#undef add
+
+ /* Now we are ready to install the string pointers and length. */
+ for (n = 0; n < (1UL << cnt); ++n)
+ result[n].len = 0;
+ n = cnt;
+ do
+ {
+ size_t mask = 1 << --n;
+
+ rp = result;
+ for (m = 1 << cnt; m > 0; ++rp)
+ if ((--m & mask) != 0)
+ rp->len += temp[n].len + 1;
+ }
+ while (n != 0);
+
+ /* The first half of the strings all include the first string. */
+ n = (1 << cnt) - 2;
+ rp = &result[2];
+ while (n != (1UL << (cnt - 1)))
+ {
+ if ((--n & 1) != 0)
+ rp[0].str = rp[-2].str + rp[-2].len;
+ else
+ rp[0].str = rp[-1].str;
+ ++rp;
+ }
+
+ /* The second half starts right after the first part of the string of
+ the corresponding entry in the first half. */
+ do
+ {
+ rp[0].str = rp[-(1 << (cnt - 1))].str + temp[cnt - 1].len + 1;
+ ++rp;
+ }
+ while (--n != 0);
+
+ /* The maximum string length. */
+ *max_capstrlen = result[0].len;
+
+ return result;
+}