m68k (other than Coldfire) uses syscall_trace for both trace entry
and trace exit. Seccomp support requires separate entry points for
trace entry and exit which are already provided for Coldfire.
Replace syscall_trace by syscall_trace_enter and syscall_trace_leave
in preparation for seccomp support. Check return code of
syscall_trace_enter(), and skip syscall if nonzero. Return code
will be left at what had been set by by ptrace or seccomp.
No regression seen in testing with strace on ARAnyM.
Signed-off-by: Michael Schmitz <schmitzmic@xxxxxxxxx>
---
Changes from RFC v1:
- add return code check in do_trace_entry branch to enable syscall
filtering (will return -EPERM)
- change to use testl for return code check (suggested by Andreas Schwab)
Changes from RFC v2:
- don't set return code of filtered syscall - seccomp may want to set
that for use by calling process.
---
arch/m68k/kernel/entry.S | 8 +++++---
arch/m68k/kernel/ptrace.c | 17 -----------------
2 files changed, 5 insertions(+), 20 deletions(-)
diff --git a/arch/m68k/kernel/entry.S b/arch/m68k/kernel/entry.S
index 9dd76fb..de3d54a 100644
--- a/arch/m68k/kernel/entry.S
+++ b/arch/m68k/kernel/entry.S
@@ -164,9 +164,11 @@ do_trace_entry:
movel #-ENOSYS,%sp@(PT_OFF_D0)| needed for strace
subql #4,%sp
SAVE_SWITCH_STACK
- jbsr syscall_trace
+ jbsr syscall_trace_enter
RESTORE_SWITCH_STACK
addql #4,%sp
+ tstl %d0
+ jne ret_from_syscall
movel %sp@(PT_OFF_ORIG_D0),%d0
cmpl #NR_syscalls,%d0
jcs syscall
@@ -177,7 +179,7 @@ badsys:
do_trace_exit:
subql #4,%sp
SAVE_SWITCH_STACK
- jbsr syscall_trace
+ jbsr syscall_trace_leave
RESTORE_SWITCH_STACK
addql #4,%sp
jra .Lret_from_exception
@@ -186,7 +188,7 @@ ENTRY(ret_from_signal)
movel %curptr@(TASK_STACK),%a1
tstb %a1@(TINFO_FLAGS+2)
jge 1f
- jbsr syscall_trace
+ jbsr syscall_trace_leave
1: RESTORE_SWITCH_STACK
addql #4,%sp
/* on 68040 complete pending writebacks if any */
diff --git a/arch/m68k/kernel/ptrace.c b/arch/m68k/kernel/ptrace.c
index 748c63b..b747a86 100644
--- a/arch/m68k/kernel/ptrace.c
+++ b/arch/m68k/kernel/ptrace.c
@@ -272,22 +272,6 @@ long arch_ptrace(struct task_struct *child, long request,
return -EIO;
}
-asmlinkage void syscall_trace(void)
-{
- ptrace_notify(SIGTRAP | ((current->ptrace & PT_TRACESYSGOOD)
- ? 0x80 : 0));
- /*
- * this isn't the same as continuing with a signal, but it will do
- * for normal use. strace only continues with a signal if the
- * stopping signal is not SIGTRAP. -brl
- */
- if (current->exit_code) {
- send_sig(current->exit_code, current, 1);
- current->exit_code = 0;
- }
-}
-
-#if defined(CONFIG_COLDFIRE) || !defined(CONFIG_MMU)
asmlinkage int syscall_trace_enter(void)
{
int ret = 0;
@@ -302,4 +286,3 @@ asmlinkage void syscall_trace_leave(void)
if (test_thread_flag(TIF_SYSCALL_TRACE))
tracehook_report_syscall_exit(task_pt_regs(current), 0);
}
-#endif /* CONFIG_COLDFIRE */
--
1.7.0.4
