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uprobes/x86: move the UPROBE_FIX_{RIP,IP,CALL} code at the end of pre/post hooks

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No functional changes. Preparation to simplify the review of the next
change. Just reorder the code in arch_uprobe_pre/post_xol() functions
so that UPROBE_FIX_{RIP_*,IP,CALL} logic goes to the end.

Also change arch_uprobe_pre_xol() to use utask instead of autask, to
make the code more symmetrical with arch_uprobe_post_xol().

Signed-off-by: Oleg Nesterov <oleg@redhat.com>
Reviewed-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Reviewed-by: Jim Keniston <jkenisto@us.ibm.com>
Acked-by: Srikar Dronamraju <srikar@linux.vnet.ibm.com>
This commit is contained in:
Oleg Nesterov 2014-03-31 19:38:09 +02:00
parent d20737c07a
commit 34e7317d6a
1 changed files with 14 additions and 16 deletions
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30
arch/x86/kernel/uprobes.c
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@ -474,19 +474,18 @@ int arch_uprobe_analyze_insn(struct arch_uprobe *auprobe, struct mm_struct *mm,
*/
int arch_uprobe_pre_xol(struct arch_uprobe *auprobe, struct pt_regs *regs)
{
struct arch_uprobe_task *autask;
struct uprobe_task *utask = current->utask;
autask = &current->utask->autask;
autask->saved_trap_nr = current->thread.trap_nr;
regs->ip = utask->xol_vaddr;
utask->autask.saved_trap_nr = current->thread.trap_nr;
current->thread.trap_nr = UPROBE_TRAP_NR;
regs->ip = current->utask->xol_vaddr;
pre_xol_rip_insn(auprobe, regs, autask);
autask->saved_tf = !!(regs->flags & X86_EFLAGS_TF);
utask->autask.saved_tf = !!(regs->flags & X86_EFLAGS_TF);
regs->flags |= X86_EFLAGS_TF;
if (test_tsk_thread_flag(current, TIF_BLOCKSTEP))
set_task_blockstep(current, false);
pre_xol_rip_insn(auprobe, regs, &utask->autask);
return 0;
}
@ -560,22 +559,13 @@ bool arch_uprobe_xol_was_trapped(struct task_struct *t)
*/
int arch_uprobe_post_xol(struct arch_uprobe *auprobe, struct pt_regs *regs)
{
struct uprobe_task *utask;
struct uprobe_task *utask = current->utask;
long correction;
int result = 0;
WARN_ON_ONCE(current->thread.trap_nr != UPROBE_TRAP_NR);
utask = current->utask;
current->thread.trap_nr = utask->autask.saved_trap_nr;
correction = (long)(utask->vaddr - utask->xol_vaddr);
handle_riprel_post_xol(auprobe, regs, &correction);
if (auprobe->fixups & UPROBE_FIX_IP)
regs->ip += correction;
if (auprobe->fixups & UPROBE_FIX_CALL)
result = adjust_ret_addr(regs->sp, correction);
/*
* arch_uprobe_pre_xol() doesn't save the state of TIF_BLOCKSTEP
* so we can get an extra SIGTRAP if we do not clear TF. We need
@ -586,6 +576,14 @@ int arch_uprobe_post_xol(struct arch_uprobe *auprobe, struct pt_regs *regs)
else if (!(auprobe->fixups & UPROBE_FIX_SETF))
regs->flags &= ~X86_EFLAGS_TF;
correction = (long)(utask->vaddr - utask->xol_vaddr);
handle_riprel_post_xol(auprobe, regs, &correction);
if (auprobe->fixups & UPROBE_FIX_IP)
regs->ip += correction;
if (auprobe->fixups & UPROBE_FIX_CALL)
result = adjust_ret_addr(regs->sp, correction);
return result;
}