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Commit 2798af1a authored by Kyle McMartin's avatar Kyle McMartin Committed by Kyle McMartin
Browse files

parisc: split syscall_trace into two halves 



Instead of fiddling with gr[20], restructure code to return whether
or not to -ENOSYS. (Also do a bit of fiddling to let them take
pt_regs directly instead of re-computing it.)

Signed-off-by: default avatarKyle McMartin <kyle@mcmartin.ca>
parent 5837d42f

arch/parisc/kernel/ptrace.c

+12 −13
Original line number Diff line number Diff line
@@ -264,20 +264,19 @@ long compat_arch_ptrace(struct task_struct *child, compat_long_t request, 
}

#endif



long do_syscall_trace_enter(struct pt_regs *regs)

{

	if (test_thread_flag(TIF_SYSCALL_TRACE) &&

	    tracehook_report_syscall_entry(regs))

		return -1L;



	return regs->gr[20];

}



void syscall_trace(int why)

void do_syscall_trace_exit(struct pt_regs *regs)

{

	struct pt_regs *regs = &current->thread.regs;

	int stepping = !!(current->ptrace & (PT_SINGLESTEP|PT_BLOCKSTEP));



	if (!test_thread_flag(TIF_SYSCALL_TRACE))

		return;

	/*

	 * Report the system call for tracing.  Entry tracing can

	 * decide to abort the call.  We handle that by setting an

	 * invalid syscall number (-1) to force an ENOSYS error.

	 */

	if (why)

		tracehook_report_syscall_exit(regs, 0);

	else if (tracehook_report_syscall_entry(regs))

		regs->gr[20] = -1;	/* force ENOSYS */

	if (stepping || test_thread_flag(TIF_SYSCALL_TRACE))

		tracehook_report_syscall_exit(regs, stepping);

}

arch/parisc/kernel/syscall.S

+13 −9
Original line number Diff line number Diff line
@@ -288,19 +288,23 @@ tracesys: 
	STREG	%r18,PT_GR18(%r2)

	/* Finished saving things for the debugger */



	ldi	0,%r26				/* syscall entry */

	ldil	L%syscall_trace,%r1

	copy	%r2,%r26

	ldil	L%do_syscall_trace_enter,%r1

	ldil	L%tracesys_next,%r2

	be	R%syscall_trace(%sr7,%r1)

	be	R%do_syscall_trace_enter(%sr7,%r1)

	ldo	R%tracesys_next(%r2),%r2

	

tracesys_next:

	/* do_syscall_trace_enter either returned the syscallno, or -1L,

	 *  so we skip restoring the PT_GR20 below, since we pulled it from

	 *  task->thread.regs.gr[20] above.

	 */

	copy	%ret0,%r20

	ldil	L%sys_call_table,%r1

	ldo     R%sys_call_table(%r1), %r19



	ldo     -THREAD_SZ_ALGN-FRAME_SIZE(%r30),%r1      /* get task ptr */

	LDREG	TI_TASK(%r1), %r1

	LDREG   TASK_PT_GR20(%r1), %r20

	LDREG   TASK_PT_GR26(%r1), %r26		/* Restore the users args */

	LDREG   TASK_PT_GR25(%r1), %r25

	LDREG   TASK_PT_GR24(%r1), %r24
@@ -337,8 +341,8 @@ tracesys_exit: 
#ifdef CONFIG_64BIT

	ldo	-16(%r30),%r29			/* Reference param save area */

#endif

	ldi	1,%r26				/* syscall exit */

	bl	syscall_trace, %r2

	ldo	TASK_REGS(%r1),%r26

	bl	do_syscall_trace_exit,%r2

	STREG   %r28,TASK_PT_GR28(%r1)          /* save return value now */

	ldo     -THREAD_SZ_ALGN-FRAME_SIZE(%r30),%r1      /* get task ptr */

	LDREG	TI_TASK(%r1), %r1
@@ -359,8 +363,8 @@ tracesys_sigexit: 
#ifdef CONFIG_64BIT

	ldo	-16(%r30),%r29			/* Reference param save area */

#endif

	bl	syscall_trace, %r2

	ldi	1,%r26				/* syscall exit */

	bl	do_syscall_trace_exit,%r2

	ldo	TASK_REGS(%r1),%r26



	ldil	L%syscall_exit_rfi,%r1

	be,n	R%syscall_exit_rfi(%sr7,%r1)