diff options
| -rw-r--r-- | arch/x86/kernel/uprobes.c | 5 | ||||
| -rw-r--r-- | include/linux/uprobes.h | 1 | ||||
| -rw-r--r-- | kernel/events/uprobes.c | 14 |
3 files changed, 12 insertions, 8 deletions
diff --git a/arch/x86/kernel/uprobes.c b/arch/x86/kernel/uprobes.c index acf8b90..bf4db6e 100644 --- a/arch/x86/kernel/uprobes.c +++ b/arch/x86/kernel/uprobes.c @@ -989,5 +989,8 @@ arch_uretprobe_hijack_return_addr(unsigned long trampoline_vaddr, struct pt_regs bool arch_uretprobe_is_alive(struct return_instance *ret, enum rp_check ctx, struct pt_regs *regs) { - return regs->sp <= ret->stack; + if (ctx == RP_CHECK_CALL) /* sp was just decremented by "call" insn */ + return regs->sp < ret->stack; + else + return regs->sp <= ret->stack; } diff --git a/include/linux/uprobes.h b/include/linux/uprobes.h index c0a5402..0bdc72f 100644 --- a/include/linux/uprobes.h +++ b/include/linux/uprobes.h @@ -104,6 +104,7 @@ struct return_instance { enum rp_check { RP_CHECK_CALL, + RP_CHECK_CHAIN_CALL, RP_CHECK_RET, }; diff --git a/kernel/events/uprobes.c b/kernel/events/uprobes.c index df5661a..0f370ef 100644 --- a/kernel/events/uprobes.c +++ b/kernel/events/uprobes.c @@ -1511,10 +1511,11 @@ static unsigned long get_trampoline_vaddr(void) return trampoline_vaddr; } -static void cleanup_return_instances(struct uprobe_task *utask, struct pt_regs *regs) +static void cleanup_return_instances(struct uprobe_task *utask, bool chained, + struct pt_regs *regs) { struct return_instance *ri = utask->return_instances; - enum rp_check ctx = RP_CHECK_CALL; + enum rp_check ctx = chained ? RP_CHECK_CHAIN_CALL : RP_CHECK_CALL; while (ri && !arch_uretprobe_is_alive(ri, ctx, regs)) { ri = free_ret_instance(ri); @@ -1528,7 +1529,7 @@ static void prepare_uretprobe(struct uprobe *uprobe, struct pt_regs *regs) struct return_instance *ri; struct uprobe_task *utask; unsigned long orig_ret_vaddr, trampoline_vaddr; - bool chained = false; + bool chained; if (!get_xol_area()) return; @@ -1554,14 +1555,15 @@ static void prepare_uretprobe(struct uprobe *uprobe, struct pt_regs *regs) goto fail; /* drop the entries invalidated by longjmp() */ - cleanup_return_instances(utask, regs); + chained = (orig_ret_vaddr == trampoline_vaddr); + cleanup_return_instances(utask, chained, regs); /* * We don't want to keep trampoline address in stack, rather keep the * original return address of first caller thru all the consequent * instances. This also makes breakpoint unwrapping easier. */ - if (orig_ret_vaddr == trampoline_vaddr) { + if (chained) { if (!utask->return_instances) { /* * This situation is not possible. Likely we have an @@ -1570,8 +1572,6 @@ static void prepare_uretprobe(struct uprobe *uprobe, struct pt_regs *regs) uprobe_warn(current, "handle tail call"); goto fail; } - - chained = true; orig_ret_vaddr = utask->return_instances->orig_ret_vaddr; } |
