* [PATCH v4] m68k/kernel - wire up syscall_trace_enter/leave for m68k
@ 2021-06-16 0:49 Michael Schmitz
2021-06-16 7:27 ` Andreas Schwab
0 siblings, 1 reply; 3+ messages in thread
From: Michael Schmitz @ 2021-06-16 0:49 UTC (permalink / raw)
To: linux-m68k, geert; +Cc: glaubitz, schwab, Michael Schmitz
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 -1. Return code will be
left at what had been set by by ptrace or seccomp (in regs->d0).
No regression seen in testing with strace on ARAnyM.
Signed-off-by: Michael Schmitz <schmitzmic@gmail.com>
--
Changes from v3:
- change syscall_trace_enter return code test from !=0 to ==-1
---
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..e949b66 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
+ cmpil #-1,%d0
+ jeq 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 94b3b27..74d58a8 100644
--- a/arch/m68k/kernel/ptrace.c
+++ b/arch/m68k/kernel/ptrace.c
@@ -271,22 +271,6 @@ 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;
@@ -301,4 +285,3 @@ 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 */
--
2.7.4
^ permalink raw reply related [flat|nested] 3+ messages in thread
* Re: [PATCH v4] m68k/kernel - wire up syscall_trace_enter/leave for m68k
2021-06-16 0:49 [PATCH v4] m68k/kernel - wire up syscall_trace_enter/leave for m68k Michael Schmitz
@ 2021-06-16 7:27 ` Andreas Schwab
2021-06-16 23:37 ` Michael Schmitz
0 siblings, 1 reply; 3+ messages in thread
From: Andreas Schwab @ 2021-06-16 7:27 UTC (permalink / raw)
To: Michael Schmitz; +Cc: linux-m68k, geert, glaubitz
On Jun 16 2021, Michael Schmitz wrote:
> 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 -1. Return code will be
> left at what had been set by by ptrace or seccomp (in regs->d0).
s/by by/by/
> diff --git a/arch/m68k/kernel/entry.S b/arch/m68k/kernel/entry.S
> index 9dd76fb..e949b66 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
> + cmpil #-1,%d0
That can be optimized as addql #1,%d0.
> + jeq ret_from_syscall
Andreas.
--
Andreas Schwab, schwab@linux-m68k.org
GPG Key fingerprint = 7578 EB47 D4E5 4D69 2510 2552 DF73 E780 A9DA AEC1
"And now for something completely different."
^ permalink raw reply [flat|nested] 3+ messages in thread
* Re: [PATCH v4] m68k/kernel - wire up syscall_trace_enter/leave for m68k
2021-06-16 7:27 ` Andreas Schwab
@ 2021-06-16 23:37 ` Michael Schmitz
0 siblings, 0 replies; 3+ messages in thread
From: Michael Schmitz @ 2021-06-16 23:37 UTC (permalink / raw)
To: Andreas Schwab; +Cc: linux-m68k, geert, glaubitz
Hi Andreas,
On 16/06/21 7:27 pm, Andreas Schwab wrote:
> On Jun 16 2021, Michael Schmitz wrote:
>
>> 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 -1. Return code will be
>> left at what had been set by by ptrace or seccomp (in regs->d0).
> s/by by/by/
Ouch ...
>
>> diff --git a/arch/m68k/kernel/entry.S b/arch/m68k/kernel/entry.S
>> index 9dd76fb..e949b66 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
>> + cmpil #-1,%d0
> That can be optimized as addql #1,%d0.
Thanks, that wasn't obvious at first glance!
Will fix in v5 ...
Cheers,
Michael
>
>> + jeq ret_from_syscall
> Andreas.
>
^ permalink raw reply [flat|nested] 3+ messages in thread
end of thread, other threads:[~2021-06-16 23:37 UTC | newest]
Thread overview: 3+ messages (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
2021-06-16 0:49 [PATCH v4] m68k/kernel - wire up syscall_trace_enter/leave for m68k Michael Schmitz
2021-06-16 7:27 ` Andreas Schwab
2021-06-16 23:37 ` Michael Schmitz
This is an external index of several public inboxes,
see mirroring instructions on how to clone and mirror
all data and code used by this external index.