[patch] Patch to fix alignment issue in nsUrlClassifierEntry

nsUrlClassifierEntry-alignment.patch (text/plain), 2.14 KB, created by Friedrich Oslage (RETIRED) on 2009-03-30 23:10:16 UTC

mId in nsUrlClassifierEntry needs to be 8-byte aligned in order to be
accessable. For some reason it's only 4-byte aligned, though gcc should know
that long long needs to be 8-byte aligned on sparc, it's 4-byte even with
__attribute__ ((aligned(8))) specified.

This patch adds a dummy and uses the packed attribute to force the correct
alignment.

For reference: lots of gdb output:

Program received signal SIGBUS, Bus error.
[Switching to Thread 0xf194fb90 (LWP 21159)]
nsTArray<nsUrlClassifierEntry>::AppendElements (this=0xf194ed88, count=1)
    at nsUrlClassifierDBService.cpp:292
292	    , mAddChunkId(0)
Current language:  auto; currently c++
(gdb) info frame
Stack level 0, frame at 0xf194ec48:
 pc = 0xf742e5e8
    in nsTArray<nsUrlClassifierEntry>::AppendElements(unsigned int)
    (nsUrlClassifierDBService.cpp:292); saved pc 0xf7425448
 called by frame at 0xf194ecb8
 source language c++.
 Arglist at 0xf194ec48, args: this=0xf194ed88, count=1
 Locals at 0xf194ec48, Previous frame's sp in fp
 Saved registers:
  l0 at 0xf194ec48, l1 at 0xf194ec4c, l2 at 0xf194ec50, l3 at 0xf194ec54,
  l4 at 0xf194ec58, l5 at 0xf194ec5c, l6 at 0xf194ec60, l7 at 0xf194ec64,
  i0 at 0xf194ec68, i1 at 0xf194ec6c, i2 at 0xf194ec70, i3 at 0xf194ec74,
  i4 at 0xf194ec78, i5 at 0xf194ec7c, fp at 0xf194ec80, i7 at 0xf194ec84
(gdb) disass $pc $pc+4
Dump of assembler code from 0xf742e5e8 to 0xf742e5ec:
0xf742e5e8 <_ZN8nsTArrayI20nsUrlClassifierEntryE14AppendElementsEj+112>:	std  %o4, [ %g1 ]
End of assembler dump.
(gdb) info register $o4
o4             0xffffffff	-1
(gdb) info register $g1
g1             0xf194ed94	-241898092

diff --git a/toolkit/components/url-classifier/src/nsUrlClassifierDBService.cpp b/toolkit/components/url-classifier/src/nsUrlClassifierDBService.cpp
index adee847..88784ac 100644
--- a/toolkit/components/url-classifier/src/nsUrlClassifierDBService.cpp
+++ b/toolkit/components/url-classifier/src/nsUrlClassifierDBService.cpp
@@ -332,7 +332,9 @@ public:
             (mHaveComplete && mCompleteHash < entry.mCompleteHash));
   }
 
-  PRInt64 mId;
+  char __dummy_to_make_mid_aligned[4];
+
+  PRInt64 mId __attribute__ ((packed));
 
   nsUrlClassifierDomainHash mKey;