From 922e3013046b79b444c87eda5baf43afae1326a8 Mon Sep 17 00:00:00 2001 From: "Eric W. Biederman" Date: Mon, 3 May 2021 12:52:43 -0500 Subject: signalfd: Remove SIL_PERF_EVENT fields from signalfd_siginfo With the addition of ssi_perf_data and ssi_perf_type struct signalfd_siginfo is dangerously close to running out of space. All that remains is just enough space for two additional 64bit fields. A practice of adding all possible siginfo_t fields into struct singalfd_siginfo can not be supported as adding the missing fields ssi_lower, ssi_upper, and ssi_pkey would require two 64bit fields and one 32bit fields. In practice the fields ssi_perf_data and ssi_perf_type can never be used by signalfd as the signal that generates them always delivers them synchronously to the thread that triggers them. Therefore until someone actually needs the fields ssi_perf_data and ssi_perf_type in signalfd_siginfo remove them. This leaves a bit more room for future expansion. v1: https://lkml.kernel.org/r/20210503203814.25487-12-ebiederm@xmission.com v2: https://lkml.kernel.org/r/20210505141101.11519-12-ebiederm@xmission.com Link: https://lkml.kernel.org/r/20210517195748.8880-5-ebiederm@xmission.com Reviewed-by: Marco Elver Signed-off-by: "Eric W. Biederman" --- fs/signalfd.c | 16 ++++++---------- 1 file changed, 6 insertions(+), 10 deletions(-) (limited to 'fs/signalfd.c') diff --git a/fs/signalfd.c b/fs/signalfd.c index 373df2f12415..167b5889db4b 100644 --- a/fs/signalfd.c +++ b/fs/signalfd.c @@ -114,12 +114,13 @@ static int signalfd_copyinfo(struct signalfd_siginfo __user *uinfo, break; case SIL_FAULT_BNDERR: case SIL_FAULT_PKUERR: + case SIL_PERF_EVENT: /* - * Fall through to the SIL_FAULT case. Both SIL_FAULT_BNDERR - * and SIL_FAULT_PKUERR are only generated by faults that - * deliver them synchronously to userspace. In case someone - * injects one of these signals and signalfd catches it treat - * it as SIL_FAULT. + * Fall through to the SIL_FAULT case. SIL_FAULT_BNDERR, + * SIL_FAULT_PKUERR, and SIL_PERF_EVENT are only + * generated by faults that deliver them synchronously to + * userspace. In case someone injects one of these signals + * and signalfd catches it treat it as SIL_FAULT. */ case SIL_FAULT: new.ssi_addr = (long) kinfo->si_addr; @@ -132,11 +133,6 @@ static int signalfd_copyinfo(struct signalfd_siginfo __user *uinfo, new.ssi_addr = (long) kinfo->si_addr; new.ssi_addr_lsb = (short) kinfo->si_addr_lsb; break; - case SIL_PERF_EVENT: - new.ssi_addr = (long) kinfo->si_addr; - new.ssi_perf_type = kinfo->si_perf_type; - new.ssi_perf_data = kinfo->si_perf_data; - break; case SIL_CHLD: new.ssi_pid = kinfo->si_pid; new.ssi_uid = kinfo->si_uid; -- cgit v1.2.3-58-ga151