From ab144f5ec64c42218a555ec1dbde6b60cf2982d6 Mon Sep 17 00:00:00 2001 From: Andi Kleen Date: Fri, 10 Aug 2007 22:31:03 +0200 Subject: 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 Signed-off-by: Andi Kleen Signed-off-by: Linus Torvalds --- include/asm-i386/paravirt.h | 16 ++++++++++------ 1 file changed, 10 insertions(+), 6 deletions(-) (limited to 'include/asm-i386') diff --git a/include/asm-i386/paravirt.h b/include/asm-i386/paravirt.h index 7df88be2dd9e..9fa3fa9e62d1 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); -- cgit v1.2.3-59-g8ed1b