Messages in this thread Patch in this message | | | Date | Wed, 22 Aug 2012 13:03:48 +0300 | From | Avi Kivity <> | Subject | [PATCH] x86, alternative: fix p6 nops on non-modular kernels |
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On 08/22/2012 12:54 PM, Avi Kivity wrote: > On 08/21/2012 12:28 PM, Tomas Racek wrote: >> >> http://fi.muni.cz/~xracek/debian2.img.bz2 >> >> Other things are the same. >> >> The runtest.sh sets environment for xfstests and runs test 285 which I wrote and and which should test if FS sends discard requests only on free sectors: >> 285: >> 1. Create loop device and FS on it. >> 2. Populate it with some garbage. >> 3. Get free sectors from FS. >> 4. Run fstrim and look for discard requests via blk tracer. >> 5. Compare free sectors to discard requests. >> >> The test itself can have some issues but I'm pretty sure it shouldn't crash the system. ;-) > > Does the following patch help? >
It's obvious that it should. You're running a non-modular kernel, and those nops are discarded (probably a leftover from the days patching was a boot-only activity), so the kernel patched garbage over its own code.
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From: Avi Kivity <avi@redhat.com> Date: Wed, 22 Aug 2012 12:58:18 +0300 Subject: [PATCH] x86, alternative: fix p6 nops on non-modular kernels
Probably a leftover from the early days of self-patching, p6nops are marked __initconst_or_module, which causes them to be discarded in a non-modular kernel. If something later triggers patching, it will overwrite kernel code with garbage.
Reported-by: Tomas Racek <tracek@redhat.com> Signed-off-by: Avi Kivity <avi@redhat.com>
diff --git a/arch/x86/kernel/alternative.c b/arch/x86/kernel/alternative.c index afb7ff7..ced4534 100644 --- a/arch/x86/kernel/alternative.c +++ b/arch/x86/kernel/alternative.c @@ -165,7 +165,7 @@ static int __init setup_noreplace_paravirt(char *str) #endif #ifdef P6_NOP1 -static const unsigned char __initconst_or_module p6nops[] = +static const unsigned char p6nops[] = { P6_NOP1, P6_NOP2,
-- error compiling committee.c: too many arguments to function
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