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| author |   Masami Hiramatsu <mhiramat@redhat.com> | 2010-02-25 08:34:38 -0500 |
|---|---|---|
| committer |   Ingo Molnar <mingo@elte.hu> | 2010-02-25 17:49:26 +0100 |
| commit | 3d55cc8a058ee96291d6d45b1e35121b9920eca3 (patch) | |
| tree | 716a79a900c013082f02de127e1fae784997ce49 /arch/x86/include/asm/alternative.h | |
| parent | kprobes/x86: Cleanup save/restore registers (diff) | |
| download | linux-dev-3d55cc8a058ee96291d6d45b1e35121b9920eca3.tar.xz linux-dev-3d55cc8a058ee96291d6d45b1e35121b9920eca3.zip | |
x86: Add text_poke_smp for SMP cross modifying code
Add generic text_poke_smp for SMP which uses stop_machine()
to synchronize modifying code.
This stop_machine() method is officially described at "7.1.3
Handling Self- and Cross-Modifying Code" on the intel's
software developer's manual 3A.
Since stop_machine() can't protect code against NMI/MCE, this
function can not modify those handlers. And also, this function
is basically for modifying multibyte-single-instruction. For
modifying multibyte-multi-instructions, we need another special
trap & detour code.
This code originaly comes from immediate values with
stop_machine() version. Thanks Jason and Mathieu!
Signed-off-by: Masami Hiramatsu <mhiramat@redhat.com>
Cc: systemtap <systemtap@sources.redhat.com>
Cc: DLE <dle-develop@lists.sourceforge.net>
Cc: Mathieu Desnoyers <compudj@krystal.dyndns.org>
Cc: Ananth N Mavinakayanahalli <ananth@in.ibm.com>
Cc: Jim Keniston <jkenisto@us.ibm.com>
Cc: Srikar Dronamraju <srikar@linux.vnet.ibm.com>
Cc: Christoph Hellwig <hch@infradead.org>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Anders Kaseorg <andersk@ksplice.com>
Cc: Tim Abbott <tabbott@ksplice.com>
Cc: Andi Kleen <andi@firstfloor.org>
Cc: Jason Baron <jbaron@redhat.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Ananth N Mavinakayanahalli <ananth@in.ibm.com>
LKML-Reference: <20100225133438.6725.80273.stgit@localhost6.localdomain6>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Diffstat (limited to 'arch/x86/include/asm/alternative.h')
| -rw-r--r-- | arch/x86/include/asm/alternative.h | 4 |
1 files changed, 3 insertions, 1 deletions
diff --git a/arch/x86/include/asm/alternative.h b/arch/x86/include/asm/alternative.h index ac80b7d70014..643d6ab3588b 100644 --- a/arch/x86/include/asm/alternative.h +++ b/arch/x86/include/asm/alternative.h @@ -160,10 +160,12 @@ static inline void apply_paravirt(struct paravirt_patch_site *start, * invalid instruction possible) or if the instructions are changed from a * consistent state to another consistent state atomically. * More care must be taken when modifying code in the SMP case because of - * Intel's errata. + * Intel's errata. text_poke_smp() takes care that errata, but still + * doesn't support NMI/MCE handler code modifying. * On the local CPU you need to be protected again NMI or MCE handlers seeing an * inconsistent instruction while you patch. */ extern void *text_poke(void *addr, const void *opcode, size_t len); +extern void *text_poke_smp(void *addr, const void *opcode, size_t len); #endif /* _ASM_X86_ALTERNATIVE_H */ |