e2fsprogs: fix type-punning warnings

PATCH In review Eric Sandeen 3 participants 5 messages Dec 14, 2010 – Dec 16, 2010

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Eric Sandeen

author

2010-12-14 19:00 UTC #0 lore raw

PATCH 1/1 e2fsprogs: fix type-punning warnings

Flags used during RHEL/Fedora builds lead to a couple type-punning warnings:

recovery.c: In function 'do_one_pass':
recovery.c:539: warning: dereferencing type-punned pointer will break strict-aliasing rules ./csum.c: In function 'print_csum':
./csum.c:170: warning: dereferencing type-punned pointer will break strict-aliasing rules

The two changes below fix this up.

Note that the csum test binary output changes slightly, but this does not break any tests.

Signed-off-by Eric Sandeen <[email protected]>

---

e2fsck/recovery.c +4 -2

index 8e40575..cac9294 100644
@@ -536,8 +536,10 @@ static int do_one_pass(journal_t *journal,
 					memcpy(nbh->b_data, obh->b_data,
 							journal->j_blocksize);
 					if (flags & JFS_FLAG_ESCAPE) {
-						*((__be32 *)nbh->b_data) =
-						cpu_to_be32(JFS_MAGIC_NUMBER);
+						journal_header_t *header;
+
+						header = (journal_header_t *) &nbh->b_data[0];
+						header->h_magic = cpu_to_be32(JFS_MAGIC_NUMBER);
 					}
 
 					BUFFER_TRACE(nbh, "marking dirty");

lib/ext2fs/Makefile.in +1 -1

index a71d12c..1024c10 100644
@@ -317,7 +317,7 @@ tst_extents: $(srcdir)/extent.c extent_dbg.c $(DEBUG_OBJS) $(DEPLIBSS) \
 tst_csum: csum.c $(STATIC_LIBEXT2FS) $(DEPLIBCOM_ERR)
 	$(E) "	LD $@"
 	$(Q) $(CC) -o tst_csum $(srcdir)/csum.c -DDEBUG \
-		$(ALL_CFLAGS) $(STATIC_LIBEXT2FS) $(LIBCOM_ERR)
+		$(ALL_CFLAGS) $(STATIC_LIBEXT2FS) $(LIBCOM_ERR) $(LIBE2P)
 
 mkjournal: mkjournal.c $(STATIC_LIBEXT2FS) $(DEPLIBCOM_ERR)
 	$(E) "	LD $@"

lib/ext2fs/csum.c +3 -3

index 58ebd23..2b6b364 100644
@@ -166,9 +166,9 @@ void print_csum(const char *msg, ext2_filsys fs, dgrp_t group)
 	crc2 = ext2fs_crc16(crc1, &swabgroup, sizeof(swabgroup));
 	crc3 = ext2fs_crc16(crc2, desc,
 			    offsetof(struct ext2_group_desc, bg_checksum));
-	printf("%s: UUID %016Lx%016Lx(%04x), grp %u(%04x): %04x=%04x\n",
-	       msg, *(long long *)&sb->s_uuid, *(long long *)&sb->s_uuid[8],
-	       crc1, group, crc2, crc3, ext2fs_group_desc_csum(fs, group));
+	printf("%s: UUID %s(%04x), grp %u(%04x): %04x=%04x\n",
+	       msg, e2p_uuid2str(sb->s_uuid), crc1, group, crc2,crc3,
+	       ext2fs_group_desc_csum(fs, group));
 }
 
 unsigned char sb_uuid[16] = { 0x4f, 0x25, 0xe8, 0xcf, 0xe7, 0x97, 0x48, 0x23,

Edward Shishkin

Acked-by on v1 1/1

2010-12-15 18:54 UTC #1 lore raw

Quoted 8 lines · Eric Sandeen

Flags used during RHEL/Fedora builds lead to a couple type-punning warnings:
recovery.c: In function 'do_one_pass':
recovery.c:539: warning: dereferencing type-punned pointer will break strict-aliasing rules ./csum.c: In function 'print_csum':
./csum.c:170: warning: dereferencing type-punned pointer will break strict-aliasing rules

Quoted 7 lines

The two changes below fix this up.
Note that the csum test binary output changes slightly, but this does not break any tests.
Signed-off-by Eric Sandeen <[email protected]>

Acked-by Edward Shishkin <[email protected]>

Quoted 54 lines

---

e2fsck/recovery.c +4 -2

index 8e40575..cac9294 100644
@@ -536,8 +536,10 @@ static int do_one_pass(journal_t *journal,
 					memcpy(nbh->b_data, obh->b_data,
 							journal->j_blocksize);
 					if (flags & JFS_FLAG_ESCAPE) {
-						*((__be32 *)nbh->b_data) =
-						cpu_to_be32(JFS_MAGIC_NUMBER);
+						journal_header_t *header;
+
+						header = (journal_header_t *) &nbh->b_data[0];
+						header->h_magic = cpu_to_be32(JFS_MAGIC_NUMBER);
 					}
 
 					BUFFER_TRACE(nbh, "marking dirty");

lib/ext2fs/Makefile.in +1 -1

index a71d12c..1024c10 100644
@@ -317,7 +317,7 @@ tst_extents: $(srcdir)/extent.c extent_dbg.c $(DEBUG_OBJS) $(DEPLIBSS) \
 tst_csum: csum.c $(STATIC_LIBEXT2FS) $(DEPLIBCOM_ERR)
 	$(E) "	LD $@"
 	$(Q) $(CC) -o tst_csum $(srcdir)/csum.c -DDEBUG \
-		$(ALL_CFLAGS) $(STATIC_LIBEXT2FS) $(LIBCOM_ERR)
+		$(ALL_CFLAGS) $(STATIC_LIBEXT2FS) $(LIBCOM_ERR) $(LIBE2P)
 
 mkjournal: mkjournal.c $(STATIC_LIBEXT2FS) $(DEPLIBCOM_ERR)
 	$(E) "	LD $@"

lib/ext2fs/csum.c +3 -4

index 58ebd23..2b6b364 100644
@@ -166,9 +166,9 @@ void print_csum(const char *msg, ext2_filsys fs, dgrp_t group)
 	crc2 = ext2fs_crc16(crc1, &swabgroup, sizeof(swabgroup));
 	crc3 = ext2fs_crc16(crc2, desc,
 			    offsetof(struct ext2_group_desc, bg_checksum));
-	printf("%s: UUID %016Lx%016Lx(%04x), grp %u(%04x): %04x=%04x\n",
-	       msg, *(long long *)&sb->s_uuid, *(long long *)&sb->s_uuid[8],
-	       crc1, group, crc2, crc3, ext2fs_group_desc_csum(fs, group));
+	printf("%s: UUID %s(%04x), grp %u(%04x): %04x=%04x\n",
+	       msg, e2p_uuid2str(sb->s_uuid), crc1, group, crc2,crc3,
+	       ext2fs_group_desc_csum(fs, group));
 }
 
 unsigned char sb_uuid[16] = { 0x4f, 0x25, 0xe8, 0xcf, 0xe7, 0x97, 0x48, 0x23,
--

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Ted Ts'o

2010-12-15 23:09 UTC #2 lore raw

In reply to Eric Sandeen

Quoted 8 lines · Eric Sandeen

Flags used during RHEL/Fedora builds lead to a couple type-punning warnings:
recovery.c: In function 'do_one_pass':
recovery.c:539: warning: dereferencing type-punned pointer will break strict-aliasing rules ./csum.c: In function 'print_csum':
./csum.c:170: warning: dereferencing type-punned pointer will break strict-aliasing rules

Quoted 6 lines

The two changes below fix this up.
Note that the csum test binary output changes slightly, but this does not break any tests.
Signed-off-by Eric Sandeen <[email protected]>

Thanks, applied. There's also a bone-headed big-endian compile bug which means I'll be doing an e2fsprogs 1.41.14 shortly.

- Ted

Eric Sandeen

author

2010-12-16 20:39 UTC #3 lore raw

Quoted 14 lines · Ted Ts'o

Quoted 13 lines · Eric Sandeen
Flags used during RHEL/Fedora builds lead to a couple type-punning warnings:
recovery.c: In function 'do_one_pass':
recovery.c:539: warning: dereferencing type-punned pointer will break strict-aliasing rules ./csum.c: In function 'print_csum':
./csum.c:170: warning: dereferencing type-punned pointer will break strict-aliasing rules
The two changes below fix this up.
Note that the csum test binary output changes slightly, but this does not break any tests.

Quoted 6 lines

Quoted 1 line
Signed-off-by Eric Sandeen <[email protected]>
Thanks, applied. There's also a bone-headed big-endian compile bug which means I'll be doing an e2fsprogs 1.41.14 shortly.
- Ted

Hm this may need an include of the e2p.h header as well, if built in a pristine buildroot...

lib/ext2fs/csum.c +1 -0

@@ -17,6 +17,7 @@
 #include "ext2_fs.h"
 #include "ext2fs.h"
 #include "crc16.h"
+#include "e2p/e2p.h"
 #include <assert.h>
 
 #ifndef offsetof

Sorry about that,
-Eric

Ted Ts'o

2010-12-16 22:15 UTC #4 lore raw

Quoted 2 lines · Eric Sandeen

Hm this may need an include of the e2p.h header as well, if built in a pristine buildroot...

Actually we only need it if we are building tst_csum (i.e., if #DEBUG is defined). So I'll apply it under #ifdef DEBUG, and then add a dependency for tst_csum in the Makefile.

Thanks for pointing this out.

- Ted