Hijack the return address and replace it with a trampoline address.
PowerPC implementation.
Signed-off-by: Anton Arapov <an...@redhat.com>
---
arch/powerpc/include/asm/uprobes.h | 1 +
arch/powerpc/kernel/uprobes.c | 13 +++++++++++++
2 files changed, 14 insertions(+)
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 bc77834..567b975 100644
--- a/arch/powerpc/kernel/uprobes.c
+++ b/arch/powerpc/kernel/uprobes.c
@@ -188,3 +188,16 @@ 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;
+}
--
1.8.1.4
--
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