Commit Graph

6 Commits

Author SHA1 Message Date
Rusty Russell ad6561dffa module: trim exception table on init free.
It's theoretically possible that there are exception table entries
which point into the (freed) init text of modules.  These could cause
future problems if other modules get loaded into that memory and cause
an exception as we'd see the wrong fixup.  The only case I know of is
kvm-intel.ko (when CONFIG_CC_OPTIMIZE_FOR_SIZE=n).

Amerigo fixed this long-standing FIXME in the x86 version, but this
patch is more general.

This implements trim_init_extable(); most archs are simple since they
use the standard lib/extable.c sort code.  Alpha and IA64 use relative
addresses in their fixups, so thier trimming is a slight variation.

Sparc32 is unique; it doesn't seem to define ARCH_HAS_SORT_EXTABLE,
yet it defines its own sort_extable() which overrides the one in lib.
It doesn't sort, so we have to mark deleted entries instead of
actually trimming them.

Inspired-by: Amerigo Wang <amwang@redhat.com>
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
Cc: linux-alpha@vger.kernel.org
Cc: sparclinux@vger.kernel.org
Cc: linux-ia64@vger.kernel.org
2009-06-12 21:47:04 +09:30
Eric Dumazet 15ae02baf0 lib/extable.c: remove an expensive integer divide in search_extable()
Actual code let compiler generates idiv instruction on x86.

Using a right shift is OK here and readable as well.

Before patch
   10:   57                      push   %edi
   11:   56                      push   %esi
   12:   89 d6                   mov    %edx,%esi
   14:   53                      push   %ebx
   15:   89 c3                   mov    %eax,%ebx
   17:   eb 22                   jmp    3b <search_extable+0x2b>
   19:   89 f0                   mov    %esi,%eax
   1b:   ba 02 00 00 00          mov    $0x2,%edx
   20:   29 d8                   sub    %ebx,%eax
   22:   89 d7                   mov    %edx,%edi
   24:   c1 f8 03                sar    $0x3,%eax
   27:   99                      cltd
   28:   f7 ff                   idiv   %edi
   2a:   8d 04 c3                lea    (%ebx,%eax,8),%eax
   2d:   39 08                   cmp    %ecx,(%eax)
...

After patch

00000010 <search_extable>:
   10:   53                      push   %ebx
   11:   89 c3                   mov    %eax,%ebx
   13:   eb 18                   jmp    2d <search_extable+0x1d>
   15:   89 d0                   mov    %edx,%eax
   17:   29 d8                   sub    %ebx,%eax
   19:   c1 f8 04                sar    $0x4,%eax
   1c:   8d 04 c3                lea    (%ebx,%eax,8),%eax
   1f:   39 08                   cmp    %ecx,(%eax)
...

Signed-off-by: Eric Dumazet <dada1@cosmosbay.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-02-06 10:41:08 -08:00
Jörn Engel 6ab3d5624e Remove obsolete #include <linux/config.h>
Signed-off-by: Jörn Engel <joern@wohnheim.fh-wedel.de>
Signed-off-by: Adrian Bunk <bunk@stusta.de>
2006-06-30 19:25:36 +02:00
Jon Mason 2ef9481e66 [PATCH] powerpc: trivial: modify comments to refer to new location of files
This patch removes all self references and fixes references to files
in the now defunct arch/ppc64 tree.  I think this accomplises
everything wanted, though there might be a few references I missed.

Signed-off-by: Jon Mason <jdmason@us.ibm.com>
Signed-off-by: Paul Mackerras <paulus@samba.org>
2006-02-10 16:53:51 +11:00
Nicolas Pitre c4dd0e4c63 [PATCH] extable: remove needless declaration
They aren't used anywhere in that file.

Signed-off-by: Nicolas Pitre <nico@cam.org>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-10-30 17:37:26 -08:00
Linus Torvalds 1da177e4c3 Linux-2.6.12-rc2
Initial git repository build. I'm not bothering with the full history,
even though we have it. We can create a separate "historical" git
archive of that later if we want to, and in the meantime it's about
3.2GB when imported into git - space that would just make the early
git days unnecessarily complicated, when we don't have a lot of good
infrastructure for it.

Let it rip!
2005-04-16 15:20:36 -07:00