Re: ftrace introduces instability into kernel 2.6.27(-rc2,-rc3)
From: Scott Wood
Date: Mon Aug 18 2008 - 13:52:42 EST
Mathieu Desnoyers wrote:
asm volatile (
"1: lwz %1, 0(%2)\n"
" cmpw %1, %5\n"
" bne 2f\n"
" stwu %3, 0(%2)\n"
"2:\n"
".section .fixup, \"ax\"\n"
"3: li %0, 1\n"
" b 2b\n"
".previous\n"
".section __ex_table,\"a\"\n"
_ASM_ALIGN "\n"
_ASM_PTR "1b, 3b\n"
".previous"
: "=r"(faulted), "=r"(replaced)
: "r"(ip), "r"(new),
"0"(faulted), "r"(old)
: "memory");
Some (most likely unrelated) nits in the above inline asm:
Should use a "b" constraint for %2, or you could get r0. Or, use an "m"
constraint with %U2%X2 after the lwz/stw. Why stwu with an offset of
zero, BTW?
%1 also needs to be an early clobber.
-Scott
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