This is the mail archive of the
systemtap@sourceware.org
mailing list for the systemtap project.
Re: [RFC] [PATCH] To vunmap correct address in text_poke()(kprobes)
- From: Srinivasa Ds <srinivasa at in dot ibm dot com>
- To: prasanna at in dot ibm dot com, linux-kernel at vger dot kernel dot org, Andrew Morton <akpm at linux-foundation dot org>, anil dot s dot keshavamurthy at intel dot com, jkenisto at us dot ibm dot com, systemtap at sources dot redhat dot com, ak at suse dot de
- Cc: suzuki at in dot ibm dot com
- Date: Wed, 25 Jul 2007 20:51:50 +0530
- Subject: Re: [RFC] [PATCH] To vunmap correct address in text_poke()(kprobes)
- Organization: IBM
- References: <200707251221.49827.srinivasa@in.ibm.com> <20070725141117.GA7254@in.ibm.com>
Resending patch according to Prasanna's suggestion, CC'ing Andi Kleen.
Hit this issue when testing kprobes on x86_64 systems. We need to align
vunmap() address to a page boundary in text_poke(). Patch below
==============================
Trying to vfree() bad address (ffffc20002233199)
WARNING: at mm/vmalloc.c:330 __vunmap()
Call Trace:
[<ffffffff8023d199>] sys_gettimeofday+0x0/0x62
[<ffffffff8047636c>] text_poke+0x119/0x124
[<ffffffff80476b42>] arch_arm_kprobe+0x1c/0x21
[<ffffffff80477cfd>] __register_kprobe+0x28a/0x2ed
[<ffffffff8815a039>] :gettimeofday:kprobe_init+0x39/0x65
[<ffffffff8025b5cf>] sys_init_module+0x1626/0x1788
[<ffffffff802aaf12>] dput+0x3f/0xfa
[<ffffffff8026bf91>] audit_syscall_entry+0x141/0x174
[<ffffffff8020bee5>] tracesys+0xdc/0xe1
========================================
Signed-off-by: Srinivasa DS <srinivasa@in.ibm.com>
Signed-off-by: Suzuki K P <suzuki@in.ibm.com>
Signed-off-by: Prasanna S Panchamukhi <prasanna@in.ibm.com>
Index: linux-2.6.23-rc1/arch/i386/kernel/alternative.c
===================================================================
--- linux-2.6.23-rc1.orig/arch/i386/kernel/alternative.c 2007-07-23
02:11:00.000000000 +0530
+++ linux-2.6.23-rc1/arch/i386/kernel/alternative.c 2007-07-25
20:27:13.000000000 +0530
@@ -447,5 +447,5 @@ void __kprobes text_poke(void *oaddr, un
if (cpu_has_clflush)
asm("clflush (%0) " :: "r" (oaddr) : "memory");
if (addr != oaddr)
- vunmap(addr);
+ vunmap((u8 *)((unsigned long)addr & PAGE_MASK));
}