[PATCH v6 0/2] Add kernel seccomp support for m68k

[PATCH v6 0/2] Add kernel seccomp support for m68k

[Michael Schmitz]

Respin of m68k kernel seccomp support. The number of syscall
arguments copied off the stack in syscall_get_arguments() is 
limited to 5. Need to figure out where to pull the last from,
for the few six-argument syscalls.

Cheers,

	Michael

[PATCH v6 1/2] m68k/kernel - wire up syscall_trace_enter/leave for m68k

[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 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 v5:

- add comment to explain optimization

Changes from v4:

Andreas Schwab:
- optimize return code test (addql #1,%d0 for cmpil #-1,%d0)
- spelling fix in commit message

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..d6f941d 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
+	addql	#1,%d0			| optimization for 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

[PATCH v6 2/2] m68k: add kernel seccomp support

[Michael Schmitz]

Add secure_computing() call to syscall_trace_enter to actually
filter system calls.

Add necessary arch Kconfig options, define TIF_SECCOMP trace
flag and provide basic seccomp filter support in asm/syscall.h

syscall_get_nr currently uses the syscall nr stored in orig_d0
because we change d0 to a default return code before starting a
syscall trace. This may be inconsistent with syscall_rollback
copying orig_d0 to d0 (which we never check upon return from
trace). We use d0 for the return code from syscall_trace_enter
in entry.S currently, and could perhaps expand that to store
a new syscall number returned by the seccomp filter before
executing the syscall. This clearly needs some discussion.

Compiles (for Atari) and boots on ARAnyM, otherwise untested.

Signed-off-by: Michael Schmitz <schmitzmic@gmail.com>

--
Changes from v5:

Geert Uytterhoeven:
- correct wrong offset for d1-d5 register copy
- update Documentation/features/seccomp/seccomp-filter/arch-support.txt
---
 .../seccomp/seccomp-filter/arch-support.txt        |  2 +-
 arch/m68k/Kconfig                                  |  2 ++
 arch/m68k/include/asm/seccomp.h                    | 11 ++++++++
 arch/m68k/include/asm/syscall.h                    | 33 ++++++++++++++++++++++
 arch/m68k/include/asm/thread_info.h                |  2 ++
 arch/m68k/kernel/ptrace.c                          |  5 ++++
 6 files changed, 54 insertions(+), 1 deletion(-)
 create mode 100644 arch/m68k/include/asm/seccomp.h

diff --git a/Documentation/features/seccomp/seccomp-filter/arch-support.txt b/Documentation/features/seccomp/seccomp-filter/arch-support.txt
index 26eec58..be71f20 100644
--- a/Documentation/features/seccomp/seccomp-filter/arch-support.txt
+++ b/Documentation/features/seccomp/seccomp-filter/arch-support.txt
@@ -14,7 +14,7 @@
     |       h8300: | TODO |
     |     hexagon: | TODO |
     |        ia64: | TODO |
-    |        m68k: | TODO |
+    |        m68k: |  ok  |
     |  microblaze: | TODO |
     |        mips: |  ok  |
     |       nds32: | TODO |
diff --git a/arch/m68k/Kconfig b/arch/m68k/Kconfig
index 372e4e6..deaea88 100644
--- a/arch/m68k/Kconfig
+++ b/arch/m68k/Kconfig
@@ -19,6 +19,8 @@ config M68K
 	select GENERIC_STRNCPY_FROM_USER if MMU
 	select GENERIC_STRNLEN_USER if MMU
 	select HAVE_AOUT if MMU
+	select HAVE_ARCH_SECCOMP
+	select HAVE_ARCH_SECCOMP_FILTER
 	select HAVE_ASM_MODVERSIONS
 	select HAVE_DEBUG_BUGVERBOSE
 	select HAVE_FUTEX_CMPXCHG if MMU && FUTEX
diff --git a/arch/m68k/include/asm/seccomp.h b/arch/m68k/include/asm/seccomp.h
new file mode 100644
index 0000000..de8a94e
--- /dev/null
+++ b/arch/m68k/include/asm/seccomp.h
@@ -0,0 +1,11 @@
+/* SPDX-License-Identifier: GPL-2.0-only */
+#ifndef _ASM_SECCOMP_H
+#define _ASM_SECCOMP_H
+
+#include <asm-generic/seccomp.h>
+
+#define SECCOMP_ARCH_NATIVE		AUDIT_ARCH_M68K
+#define SECCOMP_ARCH_NATIVE_NR		NR_syscalls
+#define SECCOMP_ARCH_NATIVE_NAME	"m68k"
+
+#endif /* _ASM_SECCOMP_H */
diff --git a/arch/m68k/include/asm/syscall.h b/arch/m68k/include/asm/syscall.h
index 465ac03..ab8ab94e 100644
--- a/arch/m68k/include/asm/syscall.h
+++ b/arch/m68k/include/asm/syscall.h
@@ -4,6 +4,39 @@
 
 #include <uapi/linux/audit.h>
 
+#include <asm/unistd.h>
+
+extern const unsigned long sys_call_table[];
+
+static inline int syscall_get_nr(struct task_struct *task,
+				 struct pt_regs *regs)
+{
+	return regs->orig_d0;
+}
+
+static inline void syscall_rollback(struct task_struct *task,
+				    struct pt_regs *regs)
+{
+	regs->d0 = regs->orig_d0;
+}
+
+static inline void syscall_set_return_value(struct task_struct *task,
+					    struct pt_regs *regs,
+					    int error, long val)
+{
+	regs->d0 = (long) error ? error : val;
+}
+
+static inline void syscall_get_arguments(struct task_struct *task,
+					 struct pt_regs *regs,
+					 unsigned long *args)
+{
+	args[0] = regs->orig_d0;
+	args++;
+
+	memcpy(args, &regs->d1, 5 * sizeof(args[0]));
+}
+
 static inline int syscall_get_arch(struct task_struct *task)
 {
 	return AUDIT_ARCH_M68K;
diff --git a/arch/m68k/include/asm/thread_info.h b/arch/m68k/include/asm/thread_info.h
index 15a7570..d813fed 100644
--- a/arch/m68k/include/asm/thread_info.h
+++ b/arch/m68k/include/asm/thread_info.h
@@ -64,6 +64,7 @@ static inline struct thread_info *current_thread_info(void)
 #define TIF_NOTIFY_RESUME	5	/* callback before returning to user */
 #define TIF_SIGPENDING		6	/* signal pending */
 #define TIF_NEED_RESCHED	7	/* rescheduling necessary */
+#define TIF_SECCOMP		13	/* seccomp syscall filtering active */
 #define TIF_DELAYED_TRACE	14	/* single step a syscall */
 #define TIF_SYSCALL_TRACE	15	/* syscall trace active */
 #define TIF_MEMDIE		16	/* is terminating due to OOM killer */
@@ -72,6 +73,7 @@ static inline struct thread_info *current_thread_info(void)
 #define _TIF_NOTIFY_RESUME	(1 << TIF_NOTIFY_RESUME)
 #define _TIF_SIGPENDING		(1 << TIF_SIGPENDING)
 #define _TIF_NEED_RESCHED	(1 << TIF_NEED_RESCHED)
+#define _TIF_SECCOMP		(1 << TIF_SECCOMP)
 #define _TIF_DELAYED_TRACE	(1 << TIF_DELAYED_TRACE)
 #define _TIF_SYSCALL_TRACE	(1 << TIF_SYSCALL_TRACE)
 #define _TIF_MEMDIE		(1 << TIF_MEMDIE)
diff --git a/arch/m68k/kernel/ptrace.c b/arch/m68k/kernel/ptrace.c
index 74d58a8..bc2490c 100644
--- a/arch/m68k/kernel/ptrace.c
+++ b/arch/m68k/kernel/ptrace.c
@@ -19,6 +19,7 @@
 #include <linux/ptrace.h>
 #include <linux/user.h>
 #include <linux/signal.h>
+#include <linux/seccomp.h>
 #include <linux/tracehook.h>
 
 #include <linux/uaccess.h>
@@ -277,6 +278,10 @@ asmlinkage int syscall_trace_enter(void)
 
 	if (test_thread_flag(TIF_SYSCALL_TRACE))
 		ret = tracehook_report_syscall_entry(task_pt_regs(current));
+
+	if (secure_computing() == -1)
+		return -1;
+
 	return ret;
 }
 
-- 
2.7.4

Re: [PATCH v6 2/2] m68k: add kernel seccomp support

[Geert Uytterhoeven]

Hi Michael,

On Thu, Jun 24, 2021 at 2:46 AM Michael Schmitz <schmitzmic@gmail.com> wrote:
> Add secure_computing() call to syscall_trace_enter to actually
> filter system calls.
>
> Add necessary arch Kconfig options, define TIF_SECCOMP trace
> flag and provide basic seccomp filter support in asm/syscall.h
>
> syscall_get_nr currently uses the syscall nr stored in orig_d0
> because we change d0 to a default return code before starting a
> syscall trace. This may be inconsistent with syscall_rollback
> copying orig_d0 to d0 (which we never check upon return from
> trace). We use d0 for the return code from syscall_trace_enter
> in entry.S currently, and could perhaps expand that to store
> a new syscall number returned by the seccomp filter before
> executing the syscall. This clearly needs some discussion.
>
> Compiles (for Atari) and boots on ARAnyM, otherwise untested.
>
> Signed-off-by: Michael Schmitz <schmitzmic@gmail.com>

> --- a/arch/m68k/include/asm/syscall.h
> +++ b/arch/m68k/include/asm/syscall.h
> @@ -4,6 +4,39 @@
>
>  #include <uapi/linux/audit.h>
>
> +#include <asm/unistd.h>
> +
> +extern const unsigned long sys_call_table[];
> +
> +static inline int syscall_get_nr(struct task_struct *task,
> +                                struct pt_regs *regs)
> +{
> +       return regs->orig_d0;
> +}
> +
> +static inline void syscall_rollback(struct task_struct *task,
> +                                   struct pt_regs *regs)
> +{
> +       regs->d0 = regs->orig_d0;
> +}
> +
> +static inline void syscall_set_return_value(struct task_struct *task,
> +                                           struct pt_regs *regs,
> +                                           int error, long val)
> +{
> +       regs->d0 = (long) error ? error : val;
> +}
> +
> +static inline void syscall_get_arguments(struct task_struct *task,
> +                                        struct pt_regs *regs,
> +                                        unsigned long *args)
> +{
> +       args[0] = regs->orig_d0;
> +       args++;
> +
> +       memcpy(args, &regs->d1, 5 * sizeof(args[0]));
> +}
> +
>  static inline int syscall_get_arch(struct task_struct *task)
>  {
>         return AUDIT_ARCH_M68K;

Comparing this to what I had before, I noticed syscall_get_return_value()
is missing.

Upon closer look, we don't need it (yet), as we don't select any
of GENERIC_ENTRY, HAVE_ARCH_TRACEHOOK, or HAVE_SYSCALL_TRACEPOINTS,
but why not add it while we're at it?

Gr{oetje,eeting}s,

                        Geert

-- 
Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- geert@linux-m68k.org

In personal conversations with technical people, I call myself a hacker. But
when I'm talking to journalists I just say "programmer" or something like that.
                                -- Linus Torvalds

Re: [PATCH v6 1/2] m68k/kernel - wire up syscall_trace_enter/leave for m68k

[Geert Uytterhoeven]

On Thu, Jun 24, 2021 at 2:46 AM Michael Schmitz <schmitzmic@gmail.com> 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 ptrace or seccomp (in regs->d0).
>
> No regression seen in testing with strace on ARAnyM.
>
> Signed-off-by: Michael Schmitz <schmitzmic@gmail.com>

Thanks for your patch!

>  arch/m68k/kernel/entry.S  |  8 +++++---

We need similar changes to arch/m68k/68000/entry.S and
arch/m68k/coldfire/entry.S

>  arch/m68k/kernel/ptrace.c | 17 -----------------
>  2 files changed, 5 insertions(+), 20 deletions(-)

Gr{oetje,eeting}s,

                        Geert

-- 
Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- geert@linux-m68k.org

In personal conversations with technical people, I call myself a hacker. But
when I'm talking to journalists I just say "programmer" or something like that.
                                -- Linus Torvalds

Re: [PATCH v6 2/2] m68k: add kernel seccomp support

[Michael Schmitz]

Hi Geert,

On 28/06/21 7:23 pm, Geert Uytterhoeven wrote:
>
>> --- a/arch/m68k/include/asm/syscall.h
>> +++ b/arch/m68k/include/asm/syscall.h
>> @@ -4,6 +4,39 @@
>>
>>   #include <uapi/linux/audit.h>
>>
>> +#include <asm/unistd.h>
>> +
>> +extern const unsigned long sys_call_table[];
>> +
>> +static inline int syscall_get_nr(struct task_struct *task,
>> +                                struct pt_regs *regs)
>> +{
>> +       return regs->orig_d0;
>> +}
>> +
>> +static inline void syscall_rollback(struct task_struct *task,
>> +                                   struct pt_regs *regs)
>> +{
>> +       regs->d0 = regs->orig_d0;
>> +}
>> +
>> +static inline void syscall_set_return_value(struct task_struct *task,
>> +                                           struct pt_regs *regs,
>> +                                           int error, long val)
>> +{
>> +       regs->d0 = (long) error ? error : val;
>> +}
>> +
>> +static inline void syscall_get_arguments(struct task_struct *task,
>> +                                        struct pt_regs *regs,
>> +                                        unsigned long *args)
>> +{
>> +       args[0] = regs->orig_d0;
>> +       args++;
>> +
>> +       memcpy(args, &regs->d1, 5 * sizeof(args[0]));
>> +}
>> +
>>   static inline int syscall_get_arch(struct task_struct *task)
>>   {
>>          return AUDIT_ARCH_M68K;
> Comparing this to what I had before, I noticed syscall_get_return_value()
> is missing.
Yes - I only added the bare minimum I needed to compile.
> Upon closer look, we don't need it (yet), as we don't select any
> of GENERIC_ENTRY, HAVE_ARCH_TRACEHOOK, or HAVE_SYSCALL_TRACEPOINTS,
> but why not add it while we're at it?

I can do that - the trouble with this entire series is that I can't 
meaningfully test anything. But syscall_get_return_value() isn't that 
difficult.

Cheers,

     Michael

>
> Gr{oetje,eeting}s,
>
>                          Geert
>

Re: [PATCH v6 1/2] m68k/kernel - wire up syscall_trace_enter/leave for m68k

[Michael Schmitz]

Hi Geert,

On 28/06/21 7:25 pm, Geert Uytterhoeven wrote:
> On Thu, Jun 24, 2021 at 2:46 AM Michael Schmitz <schmitzmic@gmail.com> 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 ptrace or seccomp (in regs->d0).
>>
>> No regression seen in testing with strace on ARAnyM.
>>
>> Signed-off-by: Michael Schmitz <schmitzmic@gmail.com>
> Thanks for your patch!
>
>>   arch/m68k/kernel/entry.S  |  8 +++++---
> We need similar changes to arch/m68k/68000/entry.S and
> arch/m68k/coldfire/entry.S
>
Ouch - I misparsed the #endif right above ENTRY(syscall) and thought the 
syscall trace entry code was common for all.

Will fix ... but that will have to be tested by someone else!

Cheers,

     Michael

>>   arch/m68k/kernel/ptrace.c | 17 -----------------
>>   2 files changed, 5 insertions(+), 20 deletions(-)
> Gr{oetje,eeting}s,
>
>                          Geert
>

Re: [PATCH v6 1/2] m68k/kernel - wire up syscall_trace_enter/leave for m68k

[Michael Schmitz]

Hi Geert,

On 28/06/21 7:25 pm, Geert Uytterhoeven wrote:
> On Thu, Jun 24, 2021 at 2:46 AM Michael Schmitz <schmitzmic@gmail.com> 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 ptrace or seccomp (in regs->d0).
>>
>> No regression seen in testing with strace on ARAnyM.
>>
>> Signed-off-by: Michael Schmitz <schmitzmic@gmail.com>
> b
> Thanks for your patch!
>
>>   arch/m68k/kernel/entry.S  |  8 +++++---
> We need similar changes to arch/m68k/68000/entry.S and
> arch/m68k/coldfire/entry.S

Do you have a current defconfig for 68000? I've test compiled my patch 
with two coldfire defconfigs, but could not find one for m68kclassic ...

Cheers,

     Michael


>
>>   arch/m68k/kernel/ptrace.c | 17 -----------------
>>   2 files changed, 5 insertions(+), 20 deletions(-)
> Gr{oetje,eeting}s,
>
>                          Geert
>

Re: [PATCH v6 1/2] m68k/kernel - wire up syscall_trace_enter/leave for m68k

[Geert Uytterhoeven]

Hi Michael,

On Tue, Jun 29, 2021 at 12:16 AM Michael Schmitz <schmitzmic@gmail.com> wrote:
> On 28/06/21 7:25 pm, Geert Uytterhoeven wrote:
> > On Thu, Jun 24, 2021 at 2:46 AM Michael Schmitz <schmitzmic@gmail.com> 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 ptrace or seccomp (in regs->d0).
> >>
> >> No regression seen in testing with strace on ARAnyM.
> >>
> >> Signed-off-by: Michael Schmitz <schmitzmic@gmail.com>
> > b
> > Thanks for your patch!
> >
> >>   arch/m68k/kernel/entry.S  |  8 +++++---
> > We need similar changes to arch/m68k/68000/entry.S and
> > arch/m68k/coldfire/entry.S
>
> Do you have a current defconfig for 68000? I've test compiled my patch
> with two coldfire defconfigs, but could not find one for m68kclassic ...

Unfortunately not.
Greg?

Gr{oetje,eeting}s,

                        Geert

-- 
Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- geert@linux-m68k.org

In personal conversations with technical people, I call myself a hacker. But
when I'm talking to journalists I just say "programmer" or something like that.
                                -- Linus Torvalds

Re: [PATCH v6 1/2] m68k/kernel - wire up syscall_trace_enter/leave for m68k

[Greg Ungerer]

Hi Michael, Geert,

On 29/6/21 5:31 pm, Geert Uytterhoeven wrote:
> Hi Michael,
> 
> On Tue, Jun 29, 2021 at 12:16 AM Michael Schmitz <schmitzmic@gmail.com> wrote:
>> On 28/06/21 7:25 pm, Geert Uytterhoeven wrote:
>>> On Thu, Jun 24, 2021 at 2:46 AM Michael Schmitz <schmitzmic@gmail.com> 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 ptrace or seccomp (in regs->d0).
>>>>
>>>> No regression seen in testing with strace on ARAnyM.
>>>>
>>>> Signed-off-by: Michael Schmitz <schmitzmic@gmail.com>
>>> b
>>> Thanks for your patch!
>>>
>>>>    arch/m68k/kernel/entry.S  |  8 +++++---
>>> We need similar changes to arch/m68k/68000/entry.S and
>>> arch/m68k/coldfire/entry.S
>>
>> Do you have a current defconfig for 68000? I've test compiled my patch
>> with two coldfire defconfigs, but could not find one for m68kclassic ...
> 
> Unfortunately not.
> Greg?

Sorry, no, I don't have one.
Whenever I need to compile for a 68000 target I manually configure one
("make menuconfig" and friends).

Would be nice to have one in mainline ;-)

Regards
Greg

Re: [PATCH v6 1/2] m68k/kernel - wire up syscall_trace_enter/leave for m68k

[Michael Schmitz]

Hi Geert, Greg,

no matter - I managed to at least get entry.S to 'compile' for 68000, 
even though the final link failed.

I'm reasonably certain that 'ret_from_exception' is the correct branch 
target if a syscall is to be skipped, but I'd like to have that double 
checked?

Cheers,

	Michael

Am 29.06.2021 um 19:35 schrieb Greg Ungerer:
> Hi Michael, Geert,
>
> On 29/6/21 5:31 pm, Geert Uytterhoeven wrote:
>> Hi Michael,
>>
>> On Tue, Jun 29, 2021 at 12:16 AM Michael Schmitz
>> <schmitzmic@gmail.com> wrote:
>>> On 28/06/21 7:25 pm, Geert Uytterhoeven wrote:
>>>> On Thu, Jun 24, 2021 at 2:46 AM Michael Schmitz
>>>> <schmitzmic@gmail.com> 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 ptrace or seccomp (in regs->d0).
>>>>>
>>>>> No regression seen in testing with strace on ARAnyM.
>>>>>
>>>>> Signed-off-by: Michael Schmitz <schmitzmic@gmail.com>
>>>> b
>>>> Thanks for your patch!
>>>>
>>>>>    arch/m68k/kernel/entry.S  |  8 +++++---
>>>> We need similar changes to arch/m68k/68000/entry.S and
>>>> arch/m68k/coldfire/entry.S
>>>
>>> Do you have a current defconfig for 68000? I've test compiled my patch
>>> with two coldfire defconfigs, but could not find one for m68kclassic ...
>>
>> Unfortunately not.
>> Greg?
>
> Sorry, no, I don't have one.
> Whenever I need to compile for a 68000 target I manually configure one
> ("make menuconfig" and friends).
>
> Would be nice to have one in mainline ;-)
>
> Regards
> Greg
>