On Wed, Aug 21, 2002 at 08:48:44PM +1000, Rusty Russell wrote:
> In message <20020821140155.A987@in.ibm.com> you write:
> > No. Don't do this. When a trap occurs in kernel space, the
>
> Sorry Vamsi: I'll have more faith in your code next time, I promise.
>
Thanks :-). But, I think you forgot to apply my incremental patch.
Here it is:
Thanks again,
Vamsi.
-- Vamsi Krishna S. Linux Technology Center, IBM Software Lab, Bangalore. Ph: +91 80 5044959 Internet: vamsi@in.ibm.com-- diff -u 31-dp/arch/i386/kernel/entry.S 31-dp/arch/i386/kernel/entry.S --- 31-dp/arch/i386/kernel/entry.S 2002-08-21 11:20:18.000000000 +0530 +++ 31-dp/arch/i386/kernel/entry.S 2002-08-21 12:10:30.000000000 +0530 @@ -430,7 +430,7 @@ jmp ret_from_exception ENTRY(debug) - pushl %eax + pushl $-1 # mark this as an int SAVE_ALL movl %esp,%edx pushl $0 @@ -452,7 +452,7 @@ RESTORE_ALL ENTRY(int3) - pushl %eax + pushl $-1 # mark this as an int SAVE_ALL movl %esp,%edx pushl $0 diff -u 31-dp/arch/i386/kernel/kprobes.c 31-dp/arch/i386/kernel/kprobes.c --- 31-dp/arch/i386/kernel/kprobes.c 2002-08-21 11:20:18.000000000 +0530 +++ 31-dp/arch/i386/kernel/kprobes.c 2002-08-21 12:09:50.000000000 +0530 @@ -117,11 +117,12 @@ /* * We singlestepped with interrupts disabled. So, the result on * the stack would be incorrect for "pushfl" instruction. + * Note that regs->esp is actually the top of the stack when the + * trap occurs in kernel space. */ if (current_kprobe->opcode == 0x9c) { /* pushfl */ - unsigned long *stacktop = (unsigned long *)regs->esp; - *stacktop &= ~(TF_MASK | IF_MASK); - *stacktop |= kprobe_old_eflags; + regs->esp &= ~(TF_MASK | IF_MASK); + regs->esp |= kprobe_old_eflags; } rearm_kprobe(current_kprobe, regs); diff -u 31-dp/include/linux/kprobes.h 31-dp/include/linux/kprobes.h --- 31-dp/include/linux/kprobes.h 2002-08-21 11:20:18.000000000 +0530 +++ 31-dp/include/linux/kprobes.h 2002-08-21 12:30:24.000000000 +0530 @@ -2,6 +2,8 @@ #define _LINUX_KPROBES_H #include <linux/config.h> #include <linux/list.h> +#include <linux/notifier.h> +#include <linux/smp.h> #include <asm/kprobes.h> struct kprobe; - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/