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| author | Oleg Nesterov <oleg@redhat.com> | 2014-04-24 19:21:38 +0200 |
|---|---|---|
| committer | Oleg Nesterov <oleg@redhat.com> | 2014-04-30 19:10:38 +0200 |
| commit | 2b82cadffc4154a25c25d88a63c7fb3397cda9d6 (patch) | |
| tree | 05f8ea13caaf1fdd84adf154d0bd33b63cb27220 | |
| parent | uprobes/x86: Cleanup the usage of arch_uprobe->def.fixups, make it u8 (diff) | |
| download | linux-2b82cadffc4154a25c25d88a63c7fb3397cda9d6.tar.xz linux-2b82cadffc4154a25c25d88a63c7fb3397cda9d6.zip | |
uprobes/x86: Introduce push_ret_address()
Extract the "push return address" code from branch_emulate_op() into
the new simple helper, push_ret_address(). It will have more users.
Signed-off-by: Oleg Nesterov <oleg@redhat.com>
| -rw-r--r-- | arch/x86/kernel/uprobes.c | 15 |
1 files changed, 12 insertions, 3 deletions
diff --git a/arch/x86/kernel/uprobes.c b/arch/x86/kernel/uprobes.c index a8e1d7e47001..df75913acfc0 100644 --- a/arch/x86/kernel/uprobes.c +++ b/arch/x86/kernel/uprobes.c @@ -407,6 +407,17 @@ static int default_pre_xol_op(struct arch_uprobe *auprobe, struct pt_regs *regs) return 0; } +static int push_ret_address(struct pt_regs *regs, unsigned long ip) +{ + unsigned long new_sp = regs->sp - sizeof_long(); + + if (copy_to_user((void __user *)new_sp, &ip, sizeof_long())) + return -EFAULT; + + regs->sp = new_sp; + return 0; +} + /* * Adjust the return address pushed by a call insn executed out of line. */ @@ -517,7 +528,6 @@ static bool branch_emulate_op(struct arch_uprobe *auprobe, struct pt_regs *regs) unsigned long offs = (long)auprobe->branch.offs; if (branch_is_call(auprobe)) { - unsigned long new_sp = regs->sp - sizeof_long(); /* * If it fails we execute this (mangled, see the comment in * branch_clear_offset) insn out-of-line. In the likely case @@ -527,9 +537,8 @@ static bool branch_emulate_op(struct arch_uprobe *auprobe, struct pt_regs *regs) * * But there is corner case, see the comment in ->post_xol(). */ - if (copy_to_user((void __user *)new_sp, &new_ip, sizeof_long())) + if (push_ret_address(regs, new_ip)) return false; - regs->sp = new_sp; } else if (!check_jmp_cond(auprobe, regs)) { offs = 0; } |