Commit 00332c16 authored by Sven Schnelle's avatar Sven Schnelle Committed by Vasily Gorbik
Browse files

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: default avatarSven Schnelle <svens@linux.ibm.com>
Signed-off-by: default avatarVasily Gorbik <gor@linux.ibm.com>
parent cd29fa79

arch/s390/kernel/entry.S

+1 −1
Original line number Diff line number Diff line
@@ -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)

arch/s390/kernel/ptrace.c

+2 −4
Original line number Diff line number Diff line
@@ -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;

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