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authorAnton Arapov <anton@redhat.com>2013-04-03 18:00:34 +0200
committerOleg Nesterov <oleg@redhat.com>2013-04-13 15:31:56 +0200
commitf15706b79d6f71e016cd06afa21ee31500029067 (patch)
tree412045d4bd7922482a25eaaab76e741b8b457ea4
parent791eca10107f2886c1915d91c99a3b022a75909c (diff)
uretprobes/powerpc: Hijack return address
Hijack the return address and replace it with a trampoline address. PowerPC implementation. Signed-off-by: Anton Arapov <anton@redhat.com> Acked-by: Ananth N Mavinakayanahalli <ananth@in.ibm.com> Acked-by: Srikar Dronamraju <srikar@linux.vnet.ibm.com> Signed-off-by: Oleg Nesterov <oleg@redhat.com>
-rw-r--r--arch/powerpc/include/asm/uprobes.h1
-rw-r--r--arch/powerpc/kernel/uprobes.c13
2 files changed, 14 insertions, 0 deletions
diff --git a/arch/powerpc/include/asm/uprobes.h b/arch/powerpc/include/asm/uprobes.h
index b532060..2301602 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 2ecdbe3..59f419b 100644
--- a/arch/powerpc/kernel/uprobes.c
+++ b/arch/powerpc/kernel/uprobes.c
@@ -192,3 +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;
+}