On Wed, Jul 25, 2007 at 12:21:49PM +0530, Srinivasa Ds wrote: > > When I was testing kprobes on x86_64 and I come across the below error > message > on latest 2.6.23-rc1 kernel. > ========================================== > 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 > > ====================================================== > > This indicates that vunmap() is not receving the page-aligned address in > text_poke(). So the below attached patch will address this issue. Please let > me know your comments. > > Signed-off-by: Srinivasa DS <[EMAIL PROTECTED]> > Signed-off-by: Suzuki K P <[EMAIL PROTECTED]> > > > 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 > 11:45:53.000000000 +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(addr-(((unsigned long)oaddr) % PAGE_SIZE)); It is appropriate to use PAGE_MASK rather than doing all this, as shown below.
vunmap((u8 *)((unsigned long)addr & PAGE_MASK)); Thanks Prasanna -- Prasanna S.P. Linux Technology Center India Software Labs, IBM Bangalore Email: [EMAIL PROTECTED] Ph: 91-80-41776329 - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [EMAIL PROTECTED] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/