From: "Eric W. Biederman" <ebiederm@xxxxxxxxxxxx> 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@xxxxxxxxxxxx Signed-off-by: "Eric W. Biederman" <ebiederm@xxxxxxxxxxxx> --- fs/signalfd.c | 16 ++++++---------- include/uapi/linux/signalfd.h | 4 +--- 2 files changed, 7 insertions(+), 13 deletions(-) diff --git a/fs/signalfd.c b/fs/signalfd.c index 335ad39f3900..040e1cf90528 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_FAULT_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_FAULT_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_FAULT_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; diff --git a/include/uapi/linux/signalfd.h b/include/uapi/linux/signalfd.h index e78dddf433fc..83429a05b698 100644 --- a/include/uapi/linux/signalfd.h +++ b/include/uapi/linux/signalfd.h @@ -39,8 +39,6 @@ struct signalfd_siginfo { __s32 ssi_syscall; __u64 ssi_call_addr; __u32 ssi_arch; - __u32 ssi_perf_type; - __u64 ssi_perf_data; /* * Pad strcture to 128 bytes. Remember to update the @@ -51,7 +49,7 @@ struct signalfd_siginfo { * comes out of a read(2) and we really don't want to have * a compat on read(2). */ - __u8 __pad[16]; + __u8 __pad[28]; }; -- 2.30.1
