Tycho Andersen af33d2433b riscv: fix seccomp reject syscall code path ... If secure_computing() rejected a system call, we were previously setting the system call number to -1, to indicate to later code that the syscall failed. However, if something (e.g. a user notification) was sleeping, and received a signal, we may set a0 to -ERESTARTSYS and re-try the system call again. In this case, seccomp "denies" the syscall (because of the signal), and we would set a7 to -1, thus losing the value of the system call we want to restart. Instead, let's return -1 from do_syscall_trace_enter() to indicate that the syscall was rejected, so we don't clobber the value in case of -ERESTARTSYS or whatever. This commit fixes the user_notification_signal seccomp selftest on riscv to no longer hang. That test expects the system call to be re-issued after the signal, and it wasn't due to the above bug. Now that it is, everything works normally. Note that in the ptrace (tracer) case, the tracer can set the register values to whatever they want, so we still need to keep the code that handles out-of-bounds syscalls. However, we can drop the comment. We can also drop syscall_set_nr(), since it is no longer used anywhere, and the code that re-loads the value in a7 because of it. Reported in: https://lore.kernel.org/bpf/CAEn-LTp=ss0Dfv6J00=rCAy+N78U2AmhqJNjfqjr2FDpPYjxEQ@mail.gmail.com/ Reported-by: David Abdurachmanov <david.abdurachmanov@gmail.com> Signed-off-by: Tycho Andersen <tycho@tycho.ws> Reviewed-by: Kees Cook <keescook@chromium.org> Signed-off-by: Palmer Dabbelt <palmerdabbelt@google.com>		2020-03-05 13:58:15 -08:00
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asm	riscv: fix seccomp reject syscall code path	2020-03-05 13:58:15 -08:00
uapi/asm	riscv, bpf: Add missing uapi header for BPF_PROG_TYPE_PERF_EVENT programs	2019-12-19 16:03:31 +01:00