s390/ptrace: pass invalid syscall numbers to tracing

tracing expects to see invalid syscalls, so pass it through.
The syscall path in entry.S checks the syscall number before
looking up the handler, so it is still safe.

Signed-off-by: Sven Schnelle <svens@linux.ibm.com>
Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>

diff --git a/arch/s390/kernel/entry.S b/arch/s390/kernel/entry.S
index 50ff6dd0f995784298fb584d2a4eee7905b0051f..496f74d984732990a0da1e8a10e916c5c88773e9 100644 (file)
--- a/arch/s390/kernel/entry.S
+++ b/arch/s390/kernel/entry.S
@@ -401,9 +401,9 @@ ENTRY(system_call)
        jnz     .Lsysc_nr_ok
        # svc 0: system call number in %r1
        llgfr   %r1,%r1                         # clear high word in r1
+       sth     %r1,__PT_INT_CODE+2(%r11)
        cghi    %r1,NR_syscalls
        jnl     .Lsysc_nr_ok
-       sth     %r1,__PT_INT_CODE+2(%r11)
        slag    %r8,%r1,3
 .Lsysc_nr_ok:
        xc      __SF_BACKCHAIN(8,%r15),__SF_BACKCHAIN(%r15)

diff --git a/arch/s390/kernel/ptrace.c b/arch/s390/kernel/ptrace.c
index ceb8105a8086f8585c951ee274c09ee4e748b893..1fdbb2d19477b2bb23a55ee9767a37cf845128a1 100644 (file)
--- a/arch/s390/kernel/ptrace.c
+++ b/arch/s390/kernel/ptrace.c
@@ -847,11 +847,9 @@ asmlinkage long do_syscall_trace_enter(struct pt_regs *regs)
         * call number to gprs[2].
         */
        if (test_thread_flag(TIF_SYSCALL_TRACE) &&
-           (tracehook_report_syscall_entry(regs) ||
-            regs->gprs[2] >= NR_syscalls)) {
+           tracehook_report_syscall_entry(regs)) {
                /*
-                * Tracing decided this syscall should not happen or the
-                * debugger stored an invalid system call number. Skip
+                * Tracing decided this syscall should not happen. Skip
                 * the system call and the system call restart handling.
                 */
                goto skip;