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| author | Andi Kleen <ak@suse.de> | 2007-08-10 22:31:03 +0200 |
|---|---|---|
| committer | Linus Torvalds <torvalds@woody.linux-foundation.org> | 2007-08-11 15:58:13 -0700 |
| commit | ab144f5ec64c42218a555ec1dbde6b60cf2982d6 (patch) | |
| tree | e3a4532e1db116e87060c9b18f4cfbf6258fdba3 /include/asm-i386 | |
| parent | d3f3c9346979bfa074c64eac5fc3ed5bba4f40ed (diff) | |
| download | linux-3.10-ab144f5ec64c42218a555ec1dbde6b60cf2982d6.tar.gz linux-3.10-ab144f5ec64c42218a555ec1dbde6b60cf2982d6.tar.bz2 linux-3.10-ab144f5ec64c42218a555ec1dbde6b60cf2982d6.zip | |
i386: Make patching more robust, fix paravirt issue
Commit 19d36ccdc34f5ed444f8a6af0cbfdb6790eb1177 "x86: Fix alternatives
and kprobes to remap write-protected kernel text" uses code which is
being patched for patching.
In particular, paravirt_ops does patching in two stages: first it
calls paravirt_ops.patch, then it fills any remaining instructions
with nop_out(). nop_out calls text_poke() which calls
lookup_address() which calls pgd_val() (aka paravirt_ops.pgd_val):
that call site is one of the places we patch.
If we always do patching as one single call to text_poke(), we only
need make sure we're not patching the memcpy in text_poke itself.
This means the prototype to paravirt_ops.patch needs to change, to
marshal the new code into a buffer rather than patching in place as it
does now. It also means all patching goes through text_poke(), which
is known to be safe (apply_alternatives is also changed to make a
single patch).
AK: fix compilation on x86-64 (bad rusty!)
AK: fix boot on x86-64 (sigh)
AK: merged with other patches
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
Signed-off-by: Andi Kleen <ak@suse.de>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'include/asm-i386')
| -rw-r--r-- | include/asm-i386/paravirt.h | 16 |
1 files changed, 10 insertions, 6 deletions
diff --git a/include/asm-i386/paravirt.h b/include/asm-i386/paravirt.h index 7df88be2dd9..9fa3fa9e62d 100644 --- a/include/asm-i386/paravirt.h +++ b/include/asm-i386/paravirt.h @@ -47,7 +47,8 @@ struct paravirt_ops * The patch function should return the number of bytes of code * generated, as we nop pad the rest in generic code. */ - unsigned (*patch)(u8 type, u16 clobber, void *firstinsn, unsigned len); + unsigned (*patch)(u8 type, u16 clobber, void *insnbuf, + unsigned long addr, unsigned len); /* Basic arch-specific setup */ void (*arch_setup)(void); @@ -253,13 +254,16 @@ extern struct paravirt_ops paravirt_ops; unsigned paravirt_patch_nop(void); unsigned paravirt_patch_ignore(unsigned len); -unsigned paravirt_patch_call(void *target, u16 tgt_clobbers, - void *site, u16 site_clobbers, +unsigned paravirt_patch_call(void *insnbuf, + const void *target, u16 tgt_clobbers, + unsigned long addr, u16 site_clobbers, unsigned len); -unsigned paravirt_patch_jmp(void *target, void *site, unsigned len); -unsigned paravirt_patch_default(u8 type, u16 clobbers, void *site, unsigned len); +unsigned paravirt_patch_jmp(const void *target, void *insnbuf, + unsigned long addr, unsigned len); +unsigned paravirt_patch_default(u8 type, u16 clobbers, void *insnbuf, + unsigned long addr, unsigned len); -unsigned paravirt_patch_insns(void *site, unsigned len, +unsigned paravirt_patch_insns(void *insnbuf, unsigned len, const char *start, const char *end); int paravirt_disable_iospace(void); |