KProbes of __seccomp_filter() are not very useful without access to
the syscall arguments.
Do what x86 does, and populate a struct seccomp_data to be passed to
__secure_computing(). This allows samples/bpf/tracex5 to extract a
sensible trace.
Signed-off-by: David Daney <david.da...@cavium.com>
---
arch/mips/kernel/ptrace.c | 22 ++++++++++++++++++++--
1 file changed, 20 insertions(+), 2 deletions(-)
diff --git a/arch/mips/kernel/ptrace.c b/arch/mips/kernel/ptrace.c
index 6931fe7..ba3b1f7 100644
--- a/arch/mips/kernel/ptrace.c
+++ b/arch/mips/kernel/ptrace.c
@@ -868,8 +868,26 @@ asmlinkage long syscall_trace_enter(struct pt_regs *regs,
long syscall)
tracehook_report_syscall_entry(regs))
return -1;
- if (secure_computing(NULL) == -1)
- return -1;
+#ifdef CONFIG_SECCOMP
+ if (unlikely(test_thread_flag(TIF_SECCOMP))) {
+ int ret, i;
+ struct seccomp_data sd;
+
+ sd.nr = syscall;
+ sd.arch = syscall_get_arch();
+ for (i = 0; i < 6; i++) {
+ unsigned long v, r;
+
+ r = mips_get_syscall_arg(&v, current, regs, i);
+ sd.args[i] = r ? 0 : v;
+ }
+ sd.instruction_pointer = KSTK_EIP(current);
+
+ ret = __secure_computing(&sd);
+ if (ret == -1)
+ return ret;
+ }
+#endif
if (unlikely(test_thread_flag(TIF_SYSCALL_TRACEPOINT)))
trace_sys_enter(regs, regs->regs[2]);
--
2.9.4
