signal: Properly deliver SIGILL from uprobes

For userspace to tell the difference between a random signal and an
exception, the exception must include siginfo information.

Using SEND_SIG_FORCED for SIGILL is thus wrong, and it will result
in userspace seeing si_code == SI_USER (like a random signal) instead
of si_code == SI_KERNEL or a more specific si_code as all exceptions
deliver.

Therefore replace force_sig_info(SIGILL, SEND_SIG_FORCE, current)
with force_sig(SIG_ILL, current) which gets this right and is
shorter and easier to type.

Fixes: 014940bad8 ("uprobes/x86: Send SIGILL if arch_uprobe_post_xol() fails")
Fixes: 0b5256c7f1 ("uprobes: Send SIGILL if handle_trampoline() fails")
Reviewed-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
This commit is contained in:
Eric W. Biederman 2018-07-19 20:33:53 -05:00
parent 86989c41b5
commit 55a3235fc7

View File

@ -1858,7 +1858,7 @@ static void handle_trampoline(struct pt_regs *regs)
sigill:
uprobe_warn(current, "handle uretprobe, sending SIGILL.");
force_sig_info(SIGILL, SEND_SIG_FORCED, current);
force_sig(SIGILL, current);
}
@ -1966,7 +1966,7 @@ static void handle_singlestep(struct uprobe_task *utask, struct pt_regs *regs)
if (unlikely(err)) {
uprobe_warn(current, "execute the probed insn, sending SIGILL.");
force_sig_info(SIGILL, SEND_SIG_FORCED, current);
force_sig(SIGILL, current);
}
}