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| author | Ingo Molnar <mingo@kernel.org> | 2013-04-16 13:04:10 +0400 |
|---|---|---|
| committer | Ingo Molnar <mingo@kernel.org> | 2013-04-16 13:04:10 +0400 |
| commit | b5210b2a34bae35fc00675462333af45676d727c (patch) | |
| tree | 43f67fb370571aedb0ec8a1ad7e8da61834d19b2 /arch/x86 | |
| parent | f8378f5259647710f0b4ecb814b0a1b0d9040de0 (diff) | |
| parent | 515619f209114697fabd21eed1623bfa69746815 (diff) | |
| download | linux-b5210b2a34bae35fc00675462333af45676d727c.tar.xz | |
Merge branch 'uprobes/core' of git://git.kernel.org/pub/scm/linux/kernel/git/oleg/misc into perf/core
Pull uprobes updates from Oleg Nesterov:
- "uretprobes" - an optimization to uprobes, like kretprobes are an optimization
to kprobes. "perf probe -x file sym%return" now works like kretprobes.
- PowerPC fixes plus a couple of cleanups/optimizations in uprobes and trace_uprobes.
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Diffstat (limited to 'arch/x86')
| -rw-r--r-- | arch/x86/include/asm/uprobes.h | 1 | ||||
| -rw-r--r-- | arch/x86/kernel/uprobes.c | 29 |
2 files changed, 30 insertions, 0 deletions
diff --git a/arch/x86/include/asm/uprobes.h b/arch/x86/include/asm/uprobes.h index 8ff8be7835ab..6e5197910fd8 100644 --- a/arch/x86/include/asm/uprobes.h +++ b/arch/x86/include/asm/uprobes.h @@ -55,4 +55,5 @@ extern int arch_uprobe_post_xol(struct arch_uprobe *aup, struct pt_regs *regs); extern bool arch_uprobe_xol_was_trapped(struct task_struct *tsk); extern int arch_uprobe_exception_notify(struct notifier_block *self, unsigned long val, void *data); extern void arch_uprobe_abort_xol(struct arch_uprobe *aup, struct pt_regs *regs); +extern unsigned long arch_uretprobe_hijack_return_addr(unsigned long trampoline_vaddr, struct pt_regs *regs); #endif /* _ASM_UPROBES_H */ diff --git a/arch/x86/kernel/uprobes.c b/arch/x86/kernel/uprobes.c index 0ba4cfb4f412..2ed845928b5f 100644 --- a/arch/x86/kernel/uprobes.c +++ b/arch/x86/kernel/uprobes.c @@ -697,3 +697,32 @@ bool arch_uprobe_skip_sstep(struct arch_uprobe *auprobe, struct pt_regs *regs) send_sig(SIGTRAP, current, 0); return ret; } + +unsigned long +arch_uretprobe_hijack_return_addr(unsigned long trampoline_vaddr, struct pt_regs *regs) +{ + int rasize, ncopied; + unsigned long orig_ret_vaddr = 0; /* clear high bits for 32-bit apps */ + + rasize = is_ia32_task() ? 4 : 8; + ncopied = copy_from_user(&orig_ret_vaddr, (void __user *)regs->sp, rasize); + if (unlikely(ncopied)) + return -1; + + /* check whether address has been already hijacked */ + if (orig_ret_vaddr == trampoline_vaddr) + return orig_ret_vaddr; + + ncopied = copy_to_user((void __user *)regs->sp, &trampoline_vaddr, rasize); + if (likely(!ncopied)) + return orig_ret_vaddr; + + if (ncopied != rasize) { + pr_err("uprobe: return address clobbered: pid=%d, %%sp=%#lx, " + "%%ip=%#lx\n", current->pid, regs->sp, regs->ip); + + force_sig_info(SIGSEGV, SEND_SIG_FORCED, current); + } + + return -1; +} |