Frederik Deweerdt wrote: > Same problems here with 2.6.20-rc1-mm1 (ie with the %gs->%fs patch). > It seems to me that the problem comes from the EFL_OFFSET no longer > beeing accurate. > The following patch fixes the problem for me. >
Thanks Frederik; that's exactly the kind of thing I thought it might be. I wonder if there's some way we can make this more robust though... Does this work for you? I did a slightly larger cleanup which should make it less fragile and more comprehensible. J diff -r e775f6e42258 arch/i386/kernel/ptrace.c --- a/arch/i386/kernel/ptrace.c Tue Dec 19 10:32:40 2006 -0800 +++ b/arch/i386/kernel/ptrace.c Wed Dec 20 11:18:56 2006 -0800 @@ -45,7 +45,7 @@ /* * Offset of eflags on child stack.. */ -#define EFL_OFFSET ((EFL-2)*4-sizeof(struct pt_regs)) +#define EFL_OFFSET offsetof(struct pt_regs, eflags) static inline struct pt_regs *get_child_regs(struct task_struct *task) { @@ -54,24 +54,24 @@ static inline struct pt_regs *get_child_ } /* - * this routine will get a word off of the processes privileged stack. - * the offset is how far from the base addr as stored in the TSS. - * this routine assumes that all the privileged stacks are in our + * This routine will get a word off of the processes privileged stack. + * the offset is bytes into the pt_regs structure on the stack. + * This routine assumes that all the privileged stacks are in our * data space. */ static inline int get_stack_long(struct task_struct *task, int offset) { unsigned char *stack; - stack = (unsigned char *)task->thread.esp0; + stack = (unsigned char *)task->thread.esp0 - sizeof(struct pt_regs); stack += offset; return (*((int *)stack)); } /* - * this routine will put a word on the processes privileged stack. - * the offset is how far from the base addr as stored in the TSS. - * this routine assumes that all the privileged stacks are in our + * This routine will put a word on the processes privileged stack. + * the offset is bytes into the pt_regs structure on the stack. + * This routine assumes that all the privileged stacks are in our * data space. */ static inline int put_stack_long(struct task_struct *task, int offset, @@ -79,7 +79,7 @@ static inline int put_stack_long(struct { unsigned char * stack; - stack = (unsigned char *) task->thread.esp0; + stack = (unsigned char *)task->thread.esp0 - sizeof(struct pt_regs); stack += offset; *(unsigned long *) stack = data; return 0; @@ -114,7 +114,7 @@ static int putreg(struct task_struct *ch } if (regno > ES*4) regno -= 1*4; - put_stack_long(child, regno - sizeof(struct pt_regs), value); + put_stack_long(child, regno, value); return 0; } @@ -137,7 +137,6 @@ static unsigned long getreg(struct task_ default: if (regno > ES*4) regno -= 1*4; - regno = regno - sizeof(struct pt_regs); retval &= get_stack_long(child, regno); } return retval; - 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/