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(unexec): Use mmap/munmap to allocate buffers

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instead of malloc/free.
This commit is contained in:
Gerd Moellmann
2001-11-10 11:40:04 +00:00
parent dbe3a58a44
commit 86928dfb6f
2 changed files with 19 additions and 18 deletions
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5
src/ChangeLog
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@@ -1,3 +1,8 @@
2001-11-10 Gerd Moellmann <gerd@gnu.org>
* unexelf.c (unexec): Use mmap/munmap to allocate buffers
instead of malloc/free.
2001-11-09 Pavel Jan,Bm(Bk <Pavel@Janik.cz>
* xfaces.c (merge_face_vectors): Use braces to follow GNU

32
src/unexelf.c
View File

@@ -668,6 +668,7 @@ unexec (new_name, old_name, data_start, bss_start, entry_address)
int old_data_index, new_data2_index;
int old_mdebug_index;
struct stat stat_buf;
int old_file_size;
/* Open the old file, allocate a buffer of the right size, and read
in the file contents. */
@@ -680,16 +681,16 @@ unexec (new_name, old_name, data_start, bss_start, entry_address)
if (fstat (old_file, &stat_buf) == -1)
fatal ("Can't fstat (%s): errno %d\n", old_name, errno);
old_base = malloc (stat_buf.st_size);
if (old_base == 0)
/* We cannot use malloc here because that may use sbrk. If it does,
we'd dump our temporary buffers with Emacs, and we'd have to be
extra careful to use the correct value of sbrk(0) after
allocating all buffers in the code below, which we aren't. */
old_file_size = stat_buf.st_size;
old_base = mmap (NULL, old_file_size, PROT_READ | PROT_WRITE,
MAP_ANON | MAP_PRIVATE, -1, 0);
if (old_base == (caddr_t) -1)
fatal ("Can't allocate buffer for %s\n", old_name);
#ifdef DEBUG
fprintf (stderr, "%s: malloc(%d) -> %x\n", old_name, stat_buf.st_size,
old_base);
#endif
if (read (old_file, old_base, stat_buf.st_size) != stat_buf.st_size)
fatal ("Didn't read all of %s: errno %d\n", old_name, errno);
@@ -774,16 +775,11 @@ unexec (new_name, old_name, data_start, bss_start, entry_address)
if (ftruncate (new_file, new_file_size))
fatal ("Can't ftruncate (%s): errno %d\n", new_name, errno);
new_base = malloc (new_file_size);
if (new_base == 0)
new_base = mmap (NULL, new_file_size, PROT_READ | PROT_WRITE,
MAP_ANON | MAP_PRIVATE, -1, 0);
if (new_base == (caddr_t) -1)
fatal ("Can't allocate buffer for %s\n", old_name);
#ifdef DEBUG
fprintf (stderr, "%s: malloc(%d) -> %x\n", new_name, new_file_size
new_base);
#endif
new_file_h = (ElfW(Ehdr) *) new_base;
new_program_h = (ElfW(Phdr) *) ((byte *) new_base + old_file_h->e_phoff);
new_section_h = (ElfW(Shdr) *)
@@ -1202,8 +1198,8 @@ unexec (new_name, old_name, data_start, bss_start, entry_address)
fatal ("Didn't write %d bytes to %s: errno %d\n",
new_file_size, new_base, errno);
free (old_base);
free (new_base);
munmap (old_base, old_file_size);
munmap (new_base, new_file_size);
/* Close the files and make the new file executable. */