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Diffstat (limited to 'REORG.TODO/elf/dl-minimal.c')
| -rw-r--r-- | REORG.TODO/elf/dl-minimal.c | 380 |
1 files changed, 380 insertions, 0 deletions
diff --git a/REORG.TODO/elf/dl-minimal.c b/REORG.TODO/elf/dl-minimal.c new file mode 100644 index 0000000000..1a35baff2e --- /dev/null +++ b/REORG.TODO/elf/dl-minimal.c @@ -0,0 +1,380 @@ +/* Minimal replacements for basic facilities used in the dynamic linker. + Copyright (C) 1995-2017 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, see + <http://www.gnu.org/licenses/>. */ + +#include <errno.h> +#include <limits.h> +#include <stdio.h> +#include <string.h> +#include <tls.h> +#include <unistd.h> +#include <sys/mman.h> +#include <sys/param.h> +#include <sys/types.h> +#include <ldsodefs.h> +#include <_itoa.h> +#include <malloc/malloc-internal.h> + +#include <assert.h> + +/* Minimal malloc allocator for used during initial link. After the + initial link, a full malloc implementation is interposed, either + the one in libc, or a different one supplied by the user through + interposition. */ + +static void *alloc_ptr, *alloc_end, *alloc_last_block; + +/* Declarations of global functions. */ +extern void weak_function free (void *ptr); +extern void * weak_function realloc (void *ptr, size_t n); +extern unsigned long int weak_function __strtoul_internal (const char *nptr, + char **endptr, + int base, + int group); +extern unsigned long int weak_function strtoul (const char *nptr, + char **endptr, int base); + + +/* Allocate an aligned memory block. */ +void * weak_function +malloc (size_t n) +{ + if (alloc_end == 0) + { + /* Consume any unused space in the last page of our data segment. */ + extern int _end attribute_hidden; + alloc_ptr = &_end; + alloc_end = (void *) 0 + (((alloc_ptr - (void *) 0) + + GLRO(dl_pagesize) - 1) + & ~(GLRO(dl_pagesize) - 1)); + } + + /* Make sure the allocation pointer is ideally aligned. */ + alloc_ptr = (void *) 0 + (((alloc_ptr - (void *) 0) + MALLOC_ALIGNMENT - 1) + & ~(MALLOC_ALIGNMENT - 1)); + + if (alloc_ptr + n >= alloc_end || n >= -(uintptr_t) alloc_ptr) + { + /* Insufficient space left; allocate another page plus one extra + page to reduce number of mmap calls. */ + caddr_t page; + size_t nup = (n + GLRO(dl_pagesize) - 1) & ~(GLRO(dl_pagesize) - 1); + if (__glibc_unlikely (nup == 0 && n != 0)) + return NULL; + nup += GLRO(dl_pagesize); + page = __mmap (0, nup, PROT_READ|PROT_WRITE, + MAP_ANON|MAP_PRIVATE, -1, 0); + if (page == MAP_FAILED) + return NULL; + if (page != alloc_end) + alloc_ptr = page; + alloc_end = page + nup; + } + + alloc_last_block = (void *) alloc_ptr; + alloc_ptr += n; + return alloc_last_block; +} + +/* We use this function occasionally since the real implementation may + be optimized when it can assume the memory it returns already is + set to NUL. */ +void * weak_function +calloc (size_t nmemb, size_t size) +{ + /* New memory from the trivial malloc above is always already cleared. + (We make sure that's true in the rare occasion it might not be, + by clearing memory in free, below.) */ + size_t bytes = nmemb * size; + +#define HALF_SIZE_T (((size_t) 1) << (8 * sizeof (size_t) / 2)) + if (__builtin_expect ((nmemb | size) >= HALF_SIZE_T, 0) + && size != 0 && bytes / size != nmemb) + return NULL; + + return malloc (bytes); +} + +/* This will rarely be called. */ +void weak_function +free (void *ptr) +{ + /* We can free only the last block allocated. */ + if (ptr == alloc_last_block) + { + /* Since this is rare, we clear the freed block here + so that calloc can presume malloc returns cleared memory. */ + memset (alloc_last_block, '\0', alloc_ptr - alloc_last_block); + alloc_ptr = alloc_last_block; + } +} + +/* This is only called with the most recent block returned by malloc. */ +void * weak_function +realloc (void *ptr, size_t n) +{ + if (ptr == NULL) + return malloc (n); + assert (ptr == alloc_last_block); + size_t old_size = alloc_ptr - alloc_last_block; + alloc_ptr = alloc_last_block; + void *new = malloc (n); + return new != ptr ? memcpy (new, ptr, old_size) : new; +} + +/* Avoid signal frobnication in setjmp/longjmp. Keeps things smaller. */ + +#include <setjmp.h> + +int weak_function +__sigjmp_save (sigjmp_buf env, int savemask __attribute__ ((unused))) +{ + env[0].__mask_was_saved = 0; + return 0; +} + +/* Define our own version of the internal function used by strerror. We + only provide the messages for some common errors. This avoids pulling + in the whole error list. */ + +char * weak_function +__strerror_r (int errnum, char *buf, size_t buflen) +{ + char *msg; + + switch (errnum) + { + case ENOMEM: + msg = (char *) "Cannot allocate memory"; + break; + case EINVAL: + msg = (char *) "Invalid argument"; + break; + case ENOENT: + msg = (char *) "No such file or directory"; + break; + case EPERM: + msg = (char *) "Operation not permitted"; + break; + case EIO: + msg = (char *) "Input/output error"; + break; + case EACCES: + msg = (char *) "Permission denied"; + break; + default: + /* No need to check buffer size, all calls in the dynamic linker + provide enough space. */ + buf[buflen - 1] = '\0'; + msg = _itoa (errnum, buf + buflen - 1, 10, 0); + msg = memcpy (msg - (sizeof ("Error ") - 1), "Error ", + sizeof ("Error ") - 1); + break; + } + + return msg; +} + +void +__libc_fatal (const char *message) +{ + _dl_fatal_printf ("%s", message); +} +rtld_hidden_def (__libc_fatal) + +void +__attribute__ ((noreturn)) +__chk_fail (void) +{ + _exit (127); +} +rtld_hidden_def (__chk_fail) + +#ifndef NDEBUG +/* Define (weakly) our own assert failure function which doesn't use stdio. + If we are linked into the user program (-ldl), the normal __assert_fail + defn can override this one. */ + +void weak_function +__assert_fail (const char *assertion, + const char *file, unsigned int line, const char *function) +{ + _dl_fatal_printf ("\ +Inconsistency detected by ld.so: %s: %u: %s%sAssertion `%s' failed!\n", + file, line, function ?: "", function ? ": " : "", + assertion); + +} +rtld_hidden_weak (__assert_fail) + +void weak_function +__assert_perror_fail (int errnum, + const char *file, unsigned int line, + const char *function) +{ + char errbuf[400]; + _dl_fatal_printf ("\ +Inconsistency detected by ld.so: %s: %u: %s%sUnexpected error: %s.\n", + file, line, function ?: "", function ? ": " : "", + __strerror_r (errnum, errbuf, sizeof errbuf)); + +} +rtld_hidden_weak (__assert_perror_fail) +#endif + +unsigned long int weak_function +__strtoul_internal (const char *nptr, char **endptr, int base, int group) +{ + unsigned long int result = 0; + long int sign = 1; + unsigned max_digit; + + while (*nptr == ' ' || *nptr == '\t') + ++nptr; + + if (*nptr == '-') + { + sign = -1; + ++nptr; + } + else if (*nptr == '+') + ++nptr; + + if (*nptr < '0' || *nptr > '9') + { + if (endptr != NULL) + *endptr = (char *) nptr; + return 0UL; + } + + assert (base == 0); + base = 10; + max_digit = 9; + if (*nptr == '0') + { + if (nptr[1] == 'x' || nptr[1] == 'X') + { + base = 16; + nptr += 2; + } + else + { + base = 8; + max_digit = 7; + } + } + + while (1) + { + unsigned long int digval; + if (*nptr >= '0' && *nptr <= '0' + max_digit) + digval = *nptr - '0'; + else if (base == 16) + { + if (*nptr >= 'a' && *nptr <= 'f') + digval = *nptr - 'a' + 10; + else if (*nptr >= 'A' && *nptr <= 'F') + digval = *nptr - 'A' + 10; + else + break; + } + else + break; + + if (result > ULONG_MAX / base + || (result == ULONG_MAX / base && digval > ULONG_MAX % base)) + { + errno = ERANGE; + if (endptr != NULL) + *endptr = (char *) nptr; + return ULONG_MAX; + } + result *= base; + result += digval; + ++nptr; + } + + if (endptr != NULL) + *endptr = (char *) nptr; + return result * sign; +} + + +#undef _itoa +/* We always use _itoa instead of _itoa_word in ld.so since the former + also has to be present and it is never about speed when these + functions are used. */ +char * +_itoa (unsigned long long int value, char *buflim, unsigned int base, + int upper_case) +{ + assert (! upper_case); + + do + *--buflim = _itoa_lower_digits[value % base]; + while ((value /= base) != 0); + + return buflim; +} + +/* The '_itoa_lower_digits' variable in libc.so is able to handle bases + up to 36. We don't need this here. */ +const char _itoa_lower_digits[16] = "0123456789abcdef"; +rtld_hidden_data_def (_itoa_lower_digits) + +/* The following is not a complete strsep implementation. It cannot + handle empty delimiter strings. But this isn't necessary for the + execution of ld.so. */ +#undef strsep +#undef __strsep +char * +__strsep (char **stringp, const char *delim) +{ + char *begin; + + assert (delim[0] != '\0'); + + begin = *stringp; + if (begin != NULL) + { + char *end = begin; + + while (*end != '\0' || (end = NULL)) + { + const char *dp = delim; + + do + if (*dp == *end) + break; + while (*++dp != '\0'); + + if (*dp != '\0') + { + *end++ = '\0'; + break; + } + + ++end; + } + + *stringp = end; + } + + return begin; +} +weak_alias (__strsep, strsep) +strong_alias (__strsep, __strsep_g) |