root/sapi/phpdbg/phpdbg_sigsafe.c

DEFINITIONS

1. zend_mm_mem_alloc
2. zend_mm_mem_free
3. phpdbg_set_sigsafe_mem
4. phpdbg_original_heap_sigsafe_mem
5. phpdbg_clear_sigsafe_mem
6. phpdbg_active_sigsafe_mem

   1 #include "phpdbg_sigsafe.h"
   2 #include "phpdbg.h"
   3 
   4 ZEND_EXTERN_MODULE_GLOBALS(phpdbg)
   5 
   6 #define STR(x) #x
   7 #define EXP_STR(x) STR(x)
   8 
   9 static void* zend_mm_mem_alloc(zend_mm_storage *storage, size_t size, size_t alignment) {
  10 
  11         if (EXPECTED(size <= PHPDBG_SIGSAFE_MEM_SIZE && !PHPDBG_G(sigsafe_mem).allocated)) {
  12                 PHPDBG_G(sigsafe_mem).allocated = 1;
  13                 return (void *) (((size_t) PHPDBG_G(sigsafe_mem).mem & ~(alignment - 1)) + alignment);
  14         }
  15 
  16         quiet_write(PHPDBG_G(io)[PHPDBG_STDERR].fd, ZEND_STRL("Tried to allocate more than " EXP_STR(PHPDBG_SIGSAFE_MEM_SIZE) " bytes from stack memory in signal handler ... bailing out of signal handler\n"));
  17 
  18         if (*EG(bailout)) {
  19                 LONGJMP(*EG(bailout), FAILURE);
  20         }
  21 
  22         quiet_write(PHPDBG_G(io)[PHPDBG_STDERR].fd, ZEND_STRL("Bailed out without a bailout address in signal handler!\n"));
  23 
  24         return NULL;
  25 }
  26 
  27 static void zend_mm_mem_free(zend_mm_storage *storage, void *ptr, size_t size) {
  28 }
  29 
  30 void phpdbg_set_sigsafe_mem(char *buffer) {
  31         phpdbg_signal_safe_mem *mem = &PHPDBG_G(sigsafe_mem);
  32         const zend_mm_handlers phpdbg_handlers = {
  33                 zend_mm_mem_alloc,
  34                 zend_mm_mem_free,
  35                 NULL,
  36                 NULL,
  37         };
  38 
  39         mem->mem = buffer;
  40         mem->allocated = 0;
  41 
  42         mem->heap = zend_mm_startup_ex(&phpdbg_handlers, NULL, 0);
  43 
  44         mem->old_heap = zend_mm_set_heap(mem->heap);
  45 }
  46 
  47 zend_mm_heap *phpdbg_original_heap_sigsafe_mem(void) {
  48         return PHPDBG_G(sigsafe_mem).old_heap;
  49 }
  50 
  51 void phpdbg_clear_sigsafe_mem(void) {
  52         zend_mm_set_heap(phpdbg_original_heap_sigsafe_mem());
  53         PHPDBG_G(sigsafe_mem).mem = NULL;
  54 }
  55 
  56 zend_bool phpdbg_active_sigsafe_mem(void) {
  57         return !!PHPDBG_G(sigsafe_mem).mem;
  58 }
  59