From aff37336ea0e27a5cbc61b42b63d28a9d74b1498 Mon Sep 17 00:00:00 2001 From: Sam Steingold Date: Mon, 19 Nov 2001 15:13:45 +0000 Subject: [PATCH] [!defined MAP_ANON]: Define MAP_ANON to MAP_ANONYMOUS if defined, 0 otherwise. (MAP_FAILED): Define if not defined and use it for testing mmap failure. (unexec) [!MAP_ANON]: Use /dev/zero as file to map. --- src/ChangeLog | 8 ++++++++ src/unexelf.c | 36 ++++++++++++++++++++++++++++++++---- 2 files changed, 40 insertions(+), 4 deletions(-) diff --git a/src/ChangeLog b/src/ChangeLog index 991c7648689..f7c5a5895df 100644 --- a/src/ChangeLog +++ b/src/ChangeLog @@ -1,3 +1,11 @@ +2001-11-14 Andreas Schwab + + * unexelf.c [!defined MAP_ANON]: Define MAP_ANON to MAP_ANONYMOUS + if defined, 0 otherwise. + (MAP_FAILED): Define if not defined and use it for testing mmap + failure. + (unexec) [!MAP_ANON]: Use /dev/zero as file to map. + 2001-11-19 Richard M. Stallman * indent.c (current_column_1): Fix handling of scan_bytes for mb chars. diff --git a/src/unexelf.c b/src/unexelf.c index 5b0b3704266..32fdbc77cba 100644 --- a/src/unexelf.c +++ b/src/unexelf.c @@ -434,6 +434,18 @@ extern void fatal (char *, ...); #include /* for HDRR declaration */ #endif /* __sgi */ +#ifndef MAP_ANON +#ifdef MAP_ANONYMOUS +#define MAP_ANON MAP_ANONYMOUS +#else +#define MAP_ANON 0 +#endif +#endif + +#ifndef MAP_FAILED +#define MAP_FAILED ((void *) -1) +#endif + #if defined (__alpha__) && !defined (__NetBSD__) && !defined (__OpenBSD__) /* Declare COFF debugging symbol table. This used to be in /usr/include/sym.h, but this file is no longer included in Red Hat @@ -649,6 +661,12 @@ unexec (new_name, old_name, data_start, bss_start, entry_address) /* Pointers to the base of the image of the two files. */ caddr_t old_base, new_base; +#if MAP_ANON == 0 + int mmap_fd; +#else +# define mmap_fd -1 +#endif + /* Pointers to the file, program and section headers for the old and new files. */ ElfW(Ehdr) *old_file_h, *new_file_h; @@ -681,14 +699,20 @@ 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); +#if MAP_ANON == 0 + mmap_fd = open ("/dev/zero", O_RDONLY); + if (mmap_fd < 0) + fatal ("Can't open /dev/zero for reading: errno %d\n", errno); +#endif + /* 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) + MAP_ANON | MAP_PRIVATE, mmap_fd, 0); + if (old_base == MAP_FAILED) fatal ("Can't allocate buffer for %s\n", old_name); if (read (old_file, old_base, stat_buf.st_size) != stat_buf.st_size) @@ -776,8 +800,8 @@ unexec (new_name, old_name, data_start, bss_start, entry_address) fatal ("Can't ftruncate (%s): errno %d\n", new_name, errno); new_base = mmap (NULL, new_file_size, PROT_READ | PROT_WRITE, - MAP_ANON | MAP_PRIVATE, -1, 0); - if (new_base == (caddr_t) -1) + MAP_ANON | MAP_PRIVATE, mmap_fd, 0); + if (new_base == MAP_FAILED) fatal ("Can't allocate buffer for %s\n", old_name); new_file_h = (ElfW(Ehdr) *) new_base; @@ -1203,6 +1227,10 @@ unexec (new_name, old_name, data_start, bss_start, entry_address) /* Close the files and make the new file executable. */ +#if MAP_ANON == 0 + close (mmap_fd); +#endif + if (close (old_file)) fatal ("Can't close (%s): errno %d\n", old_name, errno); -- 2.39.2