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authorIngo Molnar <mingo@kernel.org>2013-04-16 11:04:10 +0200
committerIngo Molnar <mingo@kernel.org>2013-04-16 11:04:10 +0200
commitb5210b2a34bae35fc00675462333af45676d727c (patch)
tree43f67fb370571aedb0ec8a1ad7e8da61834d19b2 /arch/powerpc
parentf8378f5259647710f0b4ecb814b0a1b0d9040de0 (diff)
parent515619f209114697fabd21eed1623bfa69746815 (diff)
downloadlinux-b5210b2a34bae35fc00675462333af45676d727c.tar.gz
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/powerpc')
-rw-r--r--arch/powerpc/include/asm/uprobes.h1
-rw-r--r--arch/powerpc/kernel/uprobes.c29
2 files changed, 24 insertions, 6 deletions
diff --git a/arch/powerpc/include/asm/uprobes.h b/arch/powerpc/include/asm/uprobes.h
index b532060d091..23016020915 100644
--- a/arch/powerpc/include/asm/uprobes.h
+++ b/arch/powerpc/include/asm/uprobes.h
@@ -51,4 +51,5 @@ 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/powerpc/kernel/uprobes.c b/arch/powerpc/kernel/uprobes.c
index bc77834dbf4..59f419b935f 100644
--- a/arch/powerpc/kernel/uprobes.c
+++ b/arch/powerpc/kernel/uprobes.c
@@ -31,6 +31,16 @@
#define UPROBE_TRAP_NR UINT_MAX
/**
+ * is_trap_insn - check if the instruction is a trap variant
+ * @insn: instruction to be checked.
+ * Returns true if @insn is a trap variant.
+ */
+bool is_trap_insn(uprobe_opcode_t *insn)
+{
+ return (is_trap(*insn));
+}
+
+/**
* arch_uprobe_analyze_insn
* @mm: the probed address space.
* @arch_uprobe: the probepoint information.
@@ -43,12 +53,6 @@ int arch_uprobe_analyze_insn(struct arch_uprobe *auprobe,
if (addr & 0x03)
return -EINVAL;
- /*
- * We currently don't support a uprobe on an already
- * existing breakpoint instruction underneath
- */
- if (is_trap(auprobe->ainsn))
- return -ENOTSUPP;
return 0;
}
@@ -188,3 +192,16 @@ bool arch_uprobe_skip_sstep(struct arch_uprobe *auprobe, struct pt_regs *regs)
return false;
}
+
+unsigned long
+arch_uretprobe_hijack_return_addr(unsigned long trampoline_vaddr, struct pt_regs *regs)
+{
+ unsigned long orig_ret_vaddr;
+
+ orig_ret_vaddr = regs->link;
+
+ /* Replace the return addr with trampoline addr */
+ regs->link = trampoline_vaddr;
+
+ return orig_ret_vaddr;
+}