s390/seccomp: pass syscall arguments via seccomp_data

[ Upstream commit 664f5f8de825648d1d31f6f5652e3cd117c77b50 ]

Use __secure_computing() and pass the register data via
seccomp_data so secure computing doesn't have to fetch it
again.

Signed-off-by: Sven Schnelle <svens@linux.ibm.com>
Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>

diff --git a/arch/s390/kernel/ptrace.c b/arch/s390/kernel/ptrace.c
index 58faa12542a1b86526953f7ce729a1ab44d4db53..9eee3455688900de72f4e2036cab3bdfc97e1993 100644 (file)
--- a/arch/s390/kernel/ptrace.c
+++ b/arch/s390/kernel/ptrace.c
@@ -839,6 +839,9 @@ asmlinkage long do_syscall_trace_enter(struct pt_regs *regs)
 {
        unsigned long mask = -1UL;
 
+       if (is_compat_task())
+               mask = 0xffffffff;
+
        /*
         * The sysc_tracesys code in entry.S stored the system
         * call number to gprs[2].
@@ -855,17 +858,35 @@ asmlinkage long do_syscall_trace_enter(struct pt_regs *regs)
                return -1;
        }
 
+#ifdef CONFIG_SECCOMP
        /* Do the secure computing check after ptrace. */
-       if (secure_computing()) {
-               /* seccomp failures shouldn't expose any additional code. */
-               return -1;
+       if (unlikely(test_thread_flag(TIF_SECCOMP))) {
+               struct seccomp_data sd;
+
+               if (is_compat_task()) {
+                       sd.instruction_pointer = regs->psw.addr & 0x7fffffff;
+                       sd.arch = AUDIT_ARCH_S390;
+               } else {
+                       sd.instruction_pointer = regs->psw.addr;
+                       sd.arch = AUDIT_ARCH_S390X;
+               }
+
+               sd.nr = regs->gprs[2] & 0xffff;
+               sd.args[0] = regs->orig_gpr2 & mask;
+               sd.args[1] = regs->gprs[3] & mask;
+               sd.args[2] = regs->gprs[4] & mask;
+               sd.args[3] = regs->gprs[5] & mask;
+               sd.args[4] = regs->gprs[6] & mask;
+               sd.args[5] = regs->gprs[7] & mask;
+
+               if (__secure_computing(&sd) == -1)
+                       return -1;
        }
+#endif /* CONFIG_SECCOMP */
 
        if (unlikely(test_thread_flag(TIF_SYSCALL_TRACEPOINT)))
                trace_sys_enter(regs, regs->gprs[2]);
 
-       if (is_compat_task())
-               mask = 0xffffffff;
 
        audit_syscall_entry(regs->gprs[2], regs->orig_gpr2 & mask,
                            regs->gprs[3] &mask, regs->gprs[4] &mask,