arch/x86 doesn't care (so far), but as Pratyush Anand pointed out other architectures might want why arch_uretprobe_is_alive() was called and use different checks depending on the context. Add the new argument to distinguish 2 callers.
Signed-off-by: Oleg Nesterov <[email protected]> --- arch/x86/kernel/uprobes.c | 3 ++- include/linux/uprobes.h | 7 ++++++- kernel/events/uprobes.c | 9 ++++++--- 3 files changed, 14 insertions(+), 5 deletions(-) diff --git a/arch/x86/kernel/uprobes.c b/arch/x86/kernel/uprobes.c index 9d5f570..67eb168 100644 --- a/arch/x86/kernel/uprobes.c +++ b/arch/x86/kernel/uprobes.c @@ -994,7 +994,8 @@ arch_uretprobe_hijack_return_addr(unsigned long trampoline_vaddr, struct pt_regs return -1; } -bool arch_uretprobe_is_alive(struct return_instance *ret, struct pt_regs *regs) +bool arch_uretprobe_is_alive(struct return_instance *ret, enum rp_check ctx, + struct pt_regs *regs) { return regs->sp <= ret->stack; } diff --git a/include/linux/uprobes.h b/include/linux/uprobes.h index 7ab6d2c..c0a5402 100644 --- a/include/linux/uprobes.h +++ b/include/linux/uprobes.h @@ -102,6 +102,11 @@ struct return_instance { struct return_instance *next; /* keep as stack */ }; +enum rp_check { + RP_CHECK_CALL, + RP_CHECK_RET, +}; + struct xol_area; struct uprobes_state { @@ -138,7 +143,7 @@ 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); -extern bool arch_uretprobe_is_alive(struct return_instance *ret, struct pt_regs *regs); +extern bool arch_uretprobe_is_alive(struct return_instance *ret, enum rp_check ctx, struct pt_regs *regs); extern bool arch_uprobe_ignore(struct arch_uprobe *aup, struct pt_regs *regs); extern void arch_uprobe_copy_ixol(struct page *page, unsigned long vaddr, void *src, unsigned long len); diff --git a/kernel/events/uprobes.c b/kernel/events/uprobes.c index 7e61c8c..df5661a 100644 --- a/kernel/events/uprobes.c +++ b/kernel/events/uprobes.c @@ -1514,7 +1514,9 @@ static unsigned long get_trampoline_vaddr(void) static void cleanup_return_instances(struct uprobe_task *utask, struct pt_regs *regs) { struct return_instance *ri = utask->return_instances; - while (ri && !arch_uretprobe_is_alive(ri, regs)) { + enum rp_check ctx = RP_CHECK_CALL; + + while (ri && !arch_uretprobe_is_alive(ri, ctx, regs)) { ri = free_ret_instance(ri); utask->depth--; } @@ -1805,7 +1807,7 @@ static void handle_trampoline(struct pt_regs *regs) * could hit this trampoline on return. TODO: sigaltstack(). */ next = find_next_ret_chain(ri); - valid = !next || arch_uretprobe_is_alive(next, regs); + valid = !next || arch_uretprobe_is_alive(next, RP_CHECK_RET, regs); instruction_pointer_set(regs, ri->orig_ret_vaddr); do { @@ -1830,7 +1832,8 @@ bool __weak arch_uprobe_ignore(struct arch_uprobe *aup, struct pt_regs *regs) return false; } -bool __weak arch_uretprobe_is_alive(struct return_instance *ret, struct pt_regs *regs) +bool __weak arch_uretprobe_is_alive(struct return_instance *ret, enum rp_check ctx, + struct pt_regs *regs) { return true; } -- 1.5.5.1 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
