[tip:tracing/core] x86: expand irq-off region in text_poke()

From: Masami Hiramatsu
Date: Tue Mar 10 2009 - 17:58:31 EST


Commit-ID: 7cf49427042400d40bdc80b5c3399b6b5945afa8
Gitweb: http://git.kernel.org/tip/7cf49427042400d40bdc80b5c3399b6b5945afa8
Author: "Masami Hiramatsu" <mhiramat@xxxxxxxxxx>
AuthorDate: Mon, 9 Mar 2009 12:40:40 -0400
Commit: Ingo Molnar <mingo@xxxxxxx>
CommitDate: Tue, 10 Mar 2009 16:24:23 +0100

x86: expand irq-off region in text_poke()

Expand irq-off region to cover fixmap using code and cache synchronizing.

Signed-off-by: Masami Hiramatsu <mhiramat@xxxxxxxxxx>
LKML-Reference: <49B54688.8090403@xxxxxxxxxx>
Signed-off-by: Ingo Molnar <mingo@xxxxxxx>


---
arch/x86/kernel/alternative.c | 4 ++--
1 files changed, 2 insertions(+), 2 deletions(-)

diff --git a/arch/x86/kernel/alternative.c b/arch/x86/kernel/alternative.c
index 2d903b7..f576587 100644
--- a/arch/x86/kernel/alternative.c
+++ b/arch/x86/kernel/alternative.c
@@ -526,13 +526,12 @@ void *__kprobes text_poke(void *addr, const void *opcode, size_t len)
pages[1] = virt_to_page(addr + PAGE_SIZE);
}
BUG_ON(!pages[0]);
+ local_irq_save(flags);
set_fixmap(FIX_TEXT_POKE0, page_to_phys(pages[0]));
if (pages[1])
set_fixmap(FIX_TEXT_POKE1, page_to_phys(pages[1]));
vaddr = (char *)fix_to_virt(FIX_TEXT_POKE0);
- local_irq_save(flags);
memcpy(&vaddr[(unsigned long)addr & ~PAGE_MASK], opcode, len);
- local_irq_restore(flags);
clear_fixmap(FIX_TEXT_POKE0);
if (pages[1])
clear_fixmap(FIX_TEXT_POKE1);
@@ -542,5 +541,6 @@ void *__kprobes text_poke(void *addr, const void *opcode, size_t len)
that causes hangs on some VIA CPUs. */
for (i = 0; i < len; i++)
BUG_ON(((char *)addr)[i] != ((char *)opcode)[i]);
+ local_irq_restore(flags);
return addr;
}
--
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