1. It doesn't make sense to continue if handle_trampoline() fails,
change handle_swbp() to always return after this call.
2. Turn pr_warn() into uprobe_warn(), and change handle_trampoline()
to send SIGILL on failure. It is pointless to return to user mode
with the corrupted instruction_pointer() which we can't restore.
Signed-off-by: Oleg Nesterov <o...@redhat.com>
Acked-by: Srikar Dronamraju <sri...@linux.vnet.ibm.com>
Acked-by: Anton Arapov <ara...@gmail.com>
Tested-by: Pratyush Anand <pan...@redhat.com>
---
kernel/events/uprobes.c | 21 ++++++++++-----------
1 files changed, 10 insertions(+), 11 deletions(-)
diff --git a/kernel/events/uprobes.c b/kernel/events/uprobes.c
index d8c702f..eabdc21 100644
--- a/kernel/events/uprobes.c
+++ b/kernel/events/uprobes.c
@@ -1770,7 +1770,7 @@ handle_uretprobe_chain(struct return_instance *ri, struct
pt_regs *regs)
up_read(&uprobe->register_rwsem);
}
-static bool handle_trampoline(struct pt_regs *regs)
+static void handle_trampoline(struct pt_regs *regs)
{
struct uprobe_task *utask;
struct return_instance *ri;
@@ -1778,11 +1778,11 @@ static bool handle_trampoline(struct pt_regs *regs)
utask = current->utask;
if (!utask)
- return false;
+ goto sigill;
ri = utask->return_instances;
if (!ri)
- return false;
+ goto sigill;
/*
* TODO: we should throw out return_instance's invalidated by
@@ -1804,8 +1804,12 @@ static bool handle_trampoline(struct pt_regs *regs)
}
utask->return_instances = ri;
+ return;
+
+ sigill:
+ uprobe_warn(current, "handle uretprobe, sending SIGILL.");
+ force_sig_info(SIGILL, SEND_SIG_FORCED, current);
- return true;
}
bool __weak arch_uprobe_ignore(struct arch_uprobe *aup, struct pt_regs *regs)
@@ -1824,13 +1828,8 @@ static void handle_swbp(struct pt_regs *regs)
int uninitialized_var(is_swbp);
bp_vaddr = uprobe_get_swbp_addr(regs);
- if (bp_vaddr == get_trampoline_vaddr()) {
- if (handle_trampoline(regs))
- return;
-
- pr_warn("uprobe: unable to handle uretprobe pid/tgid=%d/%d\n",
- current->pid, current->tgid);
- }
+ if (bp_vaddr == get_trampoline_vaddr())
+ return handle_trampoline(regs);
uprobe = find_active_uprobe(bp_vaddr, &is_swbp);
if (!uprobe) {
--
1.5.5.1
--
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