From: Theodore Ts'o <tytso@mit.edu>
Date: Tue, 14 Nov 2006 05:34:34 +0000 (-0500)
Subject: Fix type punning bugs in ext2fs_get_mem() and ext2fs_free_mem()
X-Git-Tag: E2FSPROGS-1_40-WIP-1114~5
X-Git-Url: https://git.whamcloud.com/gitweb?a=commitdiff_plain;h=2694f31946f0c168cc8d098f3970f0ae08d94e7b;p=tools%2Fe2fsprogs.git

Fix type punning bugs in ext2fs_get_mem() and ext2fs_free_mem()

This was causing dumpe2fs to crash on the ARM platform when examining
the badblocks list.

Also reverts an incorrect fix made by changeset 38078f692c20

Addresses Debian Bug: #397044
---

diff --git a/lib/ext2fs/ChangeLog b/lib/ext2fs/ChangeLog
index 4a15a4f..30fda66 100644
--- a/lib/ext2fs/ChangeLog
+++ b/lib/ext2fs/ChangeLog
@@ -1,3 +1,9 @@
+2006-11-14  Theodore Tso  <tytso@mit.edu>
+
+	* ext2fs.h (ext2fs_get_mem, ext2fs_free_mem): Avoid type punning
+		which causes problems on the ARM processor.  (Addresses
+		Debian Bug: #397044)
+
 2006-11-12  Theodore Tso  <tytso@mit.edu>
 
 	* ext2_fs.h (EXT2_FLAG_SOFTSUPP_FEATURES), openfs.c
@@ -8,15 +14,6 @@
 	* ext3_extents.h, ext2fs.h: Check in ext4 extent headers into the
 		source tree, in preparation for adding full extent support.
 
-	* badblocks.c (make_u32_list): Add workaround for GCC bug (ARM,
-		gcc version 4.1.1-17).  The inline function involved is
-		used all over the e2fsprogs sources, so hopefully this bug
-		won't hit us in other places, but with this one change the
-		e2fsprogs regression test suite is passing, so we'll cross
-		our fingers, report the GCC bug, and hope that it doesn't
-		cause any data corruption/loss.  (Addresses Debian Bug:
-		#397044; Gcc bug reported as Debian Bug #398316)
-
 	* unix_io.c (unix_flush): Allow offsets greater than 2G.
 		(Addresses SourceForge Bug #1547922)
 
diff --git a/lib/ext2fs/badblocks.c b/lib/ext2fs/badblocks.c
index 42e33bf..50e6336 100644
--- a/lib/ext2fs/badblocks.c
+++ b/lib/ext2fs/badblocks.c
@@ -26,10 +26,6 @@
 #include "ext2_fs.h"
 #include "ext2fsP.h"
 
-#ifdef __arm__
-#define BUGGY_ARM_GCC
-#endif
-
 /*
  * Helper function for making a badblocks list
  */
@@ -46,19 +42,11 @@ static errcode_t make_u32_list(int size, int num, __u32 *list,
 	bb->magic = EXT2_ET_MAGIC_BADBLOCKS_LIST;
 	bb->size = size ? size : 10;
 	bb->num = num;
-#ifdef BUGGY_ARM_GCC
-	bb->list = malloc(bb->size * sizeof(blk_t));
-	if (!bb->list) {
-		free(bb);
-		return EXT2_ET_NO_MEMORY;
-	}
-#else
 	retval = ext2fs_get_mem(bb->size * sizeof(blk_t), &bb->list);
-	if (!bb->list) {
+	if (retval) {
 		ext2fs_free_mem(&bb);
 		return retval;
 	}
-#endif
 	if (list)
 		memcpy(bb->list, list, bb->size * sizeof(blk_t));
 	else
diff --git a/lib/ext2fs/ext2fs.h b/lib/ext2fs/ext2fs.h
index f4214c2..0889cec 100644
--- a/lib/ext2fs/ext2fs.h
+++ b/lib/ext2fs/ext2fs.h
@@ -1007,11 +1007,12 @@ extern unsigned int ext2fs_div_ceil(unsigned int a, unsigned int b);
  */
 _INLINE_ errcode_t ext2fs_get_mem(unsigned long size, void *ptr)
 {
-	void **pp = (void **)ptr;
+	void *pp;
 
-	*pp = malloc(size);
-	if (!*pp)
+	pp = malloc(size);
+	if (!pp)
 		return EXT2_ET_NO_MEMORY;
+	memcpy(ptr, &pp, sizeof (pp));
 	return 0;
 }
 
@@ -1020,10 +1021,12 @@ _INLINE_ errcode_t ext2fs_get_mem(unsigned long size, void *ptr)
  */
 _INLINE_ errcode_t ext2fs_free_mem(void *ptr)
 {
-	void **pp = (void **)ptr;
+	void *p;
 
-	free(*pp);
-	*pp = 0;
+	memcpy(&p, ptr, sizeof(p));
+	free(p);
+	p = 0;
+	memcpy(ptr, &p, sizeof(p));
 	return 0;
 }
 	
@@ -1037,11 +1040,11 @@ _INLINE_ errcode_t ext2fs_resize_mem(unsigned long EXT2FS_ATTR((unused)) old_siz
 
 	/* Use "memcpy" for pointer assignments here to avoid problems
 	 * with C99 strict type aliasing rules. */
-	memcpy(&p, ptr, sizeof (p));
+	memcpy(&p, ptr, sizeof(p));
 	p = realloc(p, size);
 	if (!p)
 		return EXT2_ET_NO_MEMORY;
-	memcpy(ptr, &p, sizeof (p));
+	memcpy(ptr, &p, sizeof(p));
 	return 0;
 }
 #endif	/* Custom memory routines */