user/sven/linux.git/lib/extable.c, branch v3.3.4

module: trim exception table on init free.

2009-06-12T12:17:04Z

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 Signed-off-by: Rusty Russell Cc: linux-alpha@vger.kernel.org Cc: sparclinux@vger.kernel.org Cc: linux-ia64@vger.kernel.org

lib/extable.c: remove an expensive integer divide in search_extable()

2008-02-06T18:41:08Z

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 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 : 10: 53 push %ebx 11: 89 c3 mov %eax,%ebx 13: eb 18 jmp 2d 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 Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

Remove obsolete #include

2006-06-30T17:25:36Z

Signed-off-by: Jörn Engel Signed-off-by: Adrian Bunk

[PATCH] powerpc: trivial: modify comments to refer to new location of files

2006-02-10T05:53:51Z

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 Signed-off-by: Paul Mackerras

[PATCH] extable: remove needless declaration

2005-10-31T01:37:26Z

They aren't used anywhere in that file. Signed-off-by: Nicolas Pitre Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

[PATCH] ia64 extable sorting fix

2005-03-10T12:20:45Z

Fix a goofup from the recent sort consolidation patches. - Subtractions in comparison functions could overflow the return type for 64-bit pointers. Make it right again. - Add missing size arg to ia64 extable swap function. Signed-off-by: Matt Mackall Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

[PATCH] lib/sort: Replace insertion sort in exception tables

2005-03-08T02:05:40Z

Replace exception table insertion sort with lib/sort Signed-off-by: Matt Mackall Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

[PATCH] do not use shared extable code for ia64

2004-01-20T11:17:40Z

From: Jes Sorensen The new sort_extable and shared search_extable code doesn't work on ia64. I have introduced two new #defines that archs can define to avoid the common code being built. ARCH_HAS_SEARCH_EXTABLE and ARCH_HAS_SORT_EXTABLE.

[PATCH] exception table search fix

2004-01-20T11:16:20Z

The exception table search code currently fails if addresses differ by more than 2G. This is only a problem when using the 4g/4g address space split, but it's more robust this way. Also, shuffle the comparison order n there so the least likely case comes last.

[PATCH] sort exception tables

2004-01-19T13:49:29Z

This patch arranges for the exception tables to be sorted on most architectures. It sorts the main kernel exception table on startup and the module exception tables when they get loaded. The main table is sorted reasonably early - just after kmem_cache_init - but that could be moved even earlier if necessary. There is now a lib/extable.c which includes the sort_extable() function from arch/ppc/mm/extable.c and the search_extable() function from arch/i386/mm/extable.c, which had been copied to many architectures. On many architectures, arch/$(ARCH)/mm/extable.c became empty and so I have removed it. There are four architectures which do things differently from i386: alpha, ia64, sparc and sparc64. Alpha and ia64 store the offset from the offset from the exception table entry to the instruction, and sparc and sparc64 have range entries in the table. For those architectures I have added empty sort_extable functions. The maintainers for those architectures can implement something better if they care to. As it is they are no worse off than before. Although it is a moderately sizable patch, it ends up with a net reduction of 377 lines in the size of the kernel source. :) I have tested this on x86 and ppc with a module that uses __get_user in an init function, deliberately laid out to get the exception table out of order, and it works (whereas it oopsed without this patch).