Commit 669c4092 authored Jun 13, 2017 by David Daney Committed by Ralf Baechle Jun 28, 2017

MIPS: Give __secure_computing() access to syscall arguments.



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.daney@cavium.com>
Cc: Alexei Starovoitov <ast@kernel.org>
Cc: Daniel Borkmann <daniel@iogearbox.net>
Cc: Matt Redfearn <matt.redfearn@imgtec.com>
Cc: netdev@vger.kernel.org
Cc: linux-kernel@vger.kernel.org
Cc: linux-mips@linux-mips.org
Patchwork: https://patchwork.linux-mips.org/patch/16368/


Signed-off-by: Ralf Baechle <ralf@linux-mips.org>

parent f381bf6d

arch/mips/kernel/ptrace.c

+20 −2

Original line number	Diff line number	Diff line
		@@ -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]);

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