* [PATCH v11 0/3] Add kernel seccomp support for m68k
@ 2023-01-10 0:45 Michael Schmitz
2023-01-10 0:45 ` [PATCH v11 1/3] m68k/kernel - check syscall_trace_enter() return code on m68k Michael Schmitz
` (2 more replies)
0 siblings, 3 replies; 6+ messages in thread
From: Michael Schmitz @ 2023-01-10 0:45 UTC (permalink / raw)
To: linux-m68k, geert; +Cc: glaubitz
Patch 1 from v10 of this series is now merged, so patch
numbering shifts by one.
Fixed a merge conflict in patch 2 (caused by change from
tracehook to ptrace API.
Added m68k seccomp self test support as patch 3.
Tested on ARAnyM, 63 out of 89 seccomp_bpf tests now pass
(33 with the old version).
Cheers,
Michael
^ permalink raw reply [flat|nested] 6+ messages in thread
* [PATCH v11 1/3] m68k/kernel - check syscall_trace_enter() return code on m68k
2023-01-10 0:45 [PATCH v11 0/3] Add kernel seccomp support for m68k Michael Schmitz
@ 2023-01-10 0:45 ` Michael Schmitz
2023-01-10 0:45 ` [PATCH v11 2/3] m68k: add kernel seccomp support Michael Schmitz
2023-01-10 0:45 ` [PATCH v11 3/3] tools/testing - seccomp test fixes for m68k Michael Schmitz
2 siblings, 0 replies; 6+ messages in thread
From: Michael Schmitz @ 2023-01-10 0:45 UTC (permalink / raw)
To: linux-m68k, geert; +Cc: glaubitz, Michael Schmitz
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 v7:
Al Viro:
- split return code checks from switch to syscall_trace_enter()
Changes from v6:
Geert Uytterhoeven:
- add syscall_trace_enter() return code check for 68000
and coldfire
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/68000/entry.S | 2 ++
arch/m68k/coldfire/entry.S | 2 ++
arch/m68k/kernel/entry.S | 2 ++
3 files changed, 6 insertions(+)
diff --git a/arch/m68k/68000/entry.S b/arch/m68k/68000/entry.S
index 997b54933015..7d63e2f1555a 100644
--- a/arch/m68k/68000/entry.S
+++ b/arch/m68k/68000/entry.S
@@ -45,6 +45,8 @@ do_trace:
jbsr syscall_trace_enter
RESTORE_SWITCH_STACK
addql #4,%sp
+ addql #1,%d0
+ jeq ret_from_exception
movel %sp@(PT_OFF_ORIG_D0),%d1
movel #-ENOSYS,%d0
cmpl #NR_syscalls,%d1
diff --git a/arch/m68k/coldfire/entry.S b/arch/m68k/coldfire/entry.S
index 9f337c70243a..35104c5417ff 100644
--- a/arch/m68k/coldfire/entry.S
+++ b/arch/m68k/coldfire/entry.S
@@ -90,6 +90,8 @@ ENTRY(system_call)
jbsr syscall_trace_enter
RESTORE_SWITCH_STACK
addql #4,%sp
+ addql #1,%d0
+ jeq ret_from_exception
movel %d3,%a0
jbsr %a0@
movel %d0,%sp@(PT_OFF_D0) /* save the return value */
diff --git a/arch/m68k/kernel/entry.S b/arch/m68k/kernel/entry.S
index 18f278bdbd21..0d5b7085d76f 100644
--- a/arch/m68k/kernel/entry.S
+++ b/arch/m68k/kernel/entry.S
@@ -184,6 +184,8 @@ do_trace_entry:
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
--
2.17.1
^ permalink raw reply related [flat|nested] 6+ messages in thread
* [PATCH v11 2/3] m68k: add kernel seccomp support
2023-01-10 0:45 [PATCH v11 0/3] Add kernel seccomp support for m68k Michael Schmitz
2023-01-10 0:45 ` [PATCH v11 1/3] m68k/kernel - check syscall_trace_enter() return code on m68k Michael Schmitz
@ 2023-01-10 0:45 ` Michael Schmitz
2023-01-10 17:00 ` Josh Juran
2023-01-10 0:45 ` [PATCH v11 3/3] tools/testing - seccomp test fixes for m68k Michael Schmitz
2 siblings, 1 reply; 6+ messages in thread
From: Michael Schmitz @ 2023-01-10 0:45 UTC (permalink / raw)
To: linux-m68k, geert; +Cc: glaubitz, 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.
seccomp_bpf self test on ARAnyM passes 63 out of 89 tests.
Signed-off-by: Michael Schmitz <schmitzmic@gmail.com>
--
Changes from v10:
- fix merge conflicts
Changes from v9:
- add test for TIF_SECCOMP bit to call syscall_trace_enter()
if seccomp syscall filtering is active
Changes from v6:
Geert Uytterhoeven:
- add syscall_get_error(), syscall_get_return_value(), and
syscall_set_arguments() (not needed to compile!)
Changes from v5:
Geert Uytterhoeven:
- correct wrong offset for d1-d5 register copy
- update Documentation/features/seccomp/seccomp-filter/arch-support.txt
add syscall_get_error(), syscall_get_return_value(), syscall_set_arguments()
---
.../seccomp/seccomp-filter/arch-support.txt | 4 ++
arch/m68k/Kconfig | 2 +
arch/m68k/include/asm/seccomp.h | 11 ++++
arch/m68k/include/asm/syscall.h | 56 +++++++++++++++++++
arch/m68k/include/asm/thread_info.h | 2 +
arch/m68k/kernel/entry.S | 3 +
arch/m68k/kernel/ptrace.c | 6 +-
7 files changed, 83 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 dc71bf7b1a7e..0c2ac424094d 100644
--- a/Documentation/features/seccomp/seccomp-filter/arch-support.txt
+++ b/Documentation/features/seccomp/seccomp-filter/arch-support.txt
@@ -13,8 +13,12 @@
| csky: | ok |
| hexagon: | TODO |
| ia64: | TODO |
+<<<<<<< HEAD
| loongarch: | ok |
| m68k: | TODO |
+=======
+ | m68k: | ok |
+>>>>>>> 596095b777b9... m68k: add kernel seccomp support
| microblaze: | TODO |
| mips: | ok |
| nios2: | TODO |
diff --git a/arch/m68k/Kconfig b/arch/m68k/Kconfig
index 7bff88118507..82154952e574 100644
--- a/arch/m68k/Kconfig
+++ b/arch/m68k/Kconfig
@@ -18,6 +18,8 @@ config M68K
select GENERIC_CPU_DEVICES
select GENERIC_IOMAP
select GENERIC_IRQ_SHOW
+ select HAVE_ARCH_SECCOMP
+ select HAVE_ARCH_SECCOMP_FILTER
select HAVE_ASM_MODVERSIONS
select HAVE_DEBUG_BUGVERBOSE
select HAVE_EFFICIENT_UNALIGNED_ACCESS if !CPU_HAS_NO_UNALIGNED
diff --git a/arch/m68k/include/asm/seccomp.h b/arch/m68k/include/asm/seccomp.h
new file mode 100644
index 000000000000..de8a94e1fb3f
--- /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 465ac039be09..2b49ad725655 100644
--- a/arch/m68k/include/asm/syscall.h
+++ b/arch/m68k/include/asm/syscall.h
@@ -4,6 +4,62 @@
#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 long syscall_get_error(struct task_struct *task,
+ struct pt_regs *regs)
+{
+ unsigned long error = regs->d0;
+ return IS_ERR_VALUE(error) ? error : 0;
+}
+
+static inline long syscall_get_return_value(struct task_struct *task,
+ struct pt_regs *regs)
+{
+ return regs->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, ®s->d1, 5 * sizeof(args[0]));
+}
+
+static inline void syscall_set_arguments(struct task_struct *task,
+ struct pt_regs *regs,
+ unsigned long *args)
+{
+ regs->orig_d0 = args[0];
+ args++;
+
+ memcpy(®s->d1, args, 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 c952658ba792..31be2ad999ca 100644
--- a/arch/m68k/include/asm/thread_info.h
+++ b/arch/m68k/include/asm/thread_info.h
@@ -61,6 +61,7 @@ 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 */
@@ -69,6 +70,7 @@ 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/entry.S b/arch/m68k/kernel/entry.S
index 0d5b7085d76f..ee0a905b5f74 100644
--- a/arch/m68k/kernel/entry.S
+++ b/arch/m68k/kernel/entry.S
@@ -213,6 +213,9 @@ ENTRY(system_call)
| syscall trace?
tstb %a1@(TINFO_FLAGS+2)
jmi do_trace_entry
+ | seccomp filter active?
+ btst #5,%a1@(TINFO_FLAGS+2)
+ bnes do_trace_entry
cmpl #NR_syscalls,%d0
jcc badsys
syscall:
diff --git a/arch/m68k/kernel/ptrace.c b/arch/m68k/kernel/ptrace.c
index 0a4184a37461..cd0172d29430 100644
--- a/arch/m68k/kernel/ptrace.c
+++ b/arch/m68k/kernel/ptrace.c
@@ -21,7 +21,7 @@
#include <linux/signal.h>
#include <linux/regset.h>
#include <linux/elf.h>
-
+#include <linux/seccomp.h>
#include <linux/uaccess.h>
#include <asm/page.h>
#include <asm/processor.h>
@@ -278,6 +278,10 @@ asmlinkage int syscall_trace_enter(void)
if (test_thread_flag(TIF_SYSCALL_TRACE))
ret = ptrace_report_syscall_entry(task_pt_regs(current));
+
+ if (secure_computing() == -1)
+ return -1;
+
return ret;
}
--
2.17.1
^ permalink raw reply related [flat|nested] 6+ messages in thread
* [PATCH v11 3/3] tools/testing - seccomp test fixes for m68k
2023-01-10 0:45 [PATCH v11 0/3] Add kernel seccomp support for m68k Michael Schmitz
2023-01-10 0:45 ` [PATCH v11 1/3] m68k/kernel - check syscall_trace_enter() return code on m68k Michael Schmitz
2023-01-10 0:45 ` [PATCH v11 2/3] m68k: add kernel seccomp support Michael Schmitz
@ 2023-01-10 0:45 ` Michael Schmitz
2 siblings, 0 replies; 6+ messages in thread
From: Michael Schmitz @ 2023-01-10 0:45 UTC (permalink / raw)
To: linux-m68k, geert; +Cc: glaubitz, Michael Schmitz
Add m68k seccomp definitions to seccomp_bpf self test code.
Tested on ARAnyM.
Signed-off-by: Michael Schmitz <schmitzmic@gmail.com>
---
tools/testing/selftests/seccomp/seccomp_bpf.c | 8 +++++++-
1 file changed, 7 insertions(+), 1 deletion(-)
diff --git a/tools/testing/selftests/seccomp/seccomp_bpf.c b/tools/testing/selftests/seccomp/seccomp_bpf.c
index 9c2f448bb3a9..9f854524eed3 100644
--- a/tools/testing/selftests/seccomp/seccomp_bpf.c
+++ b/tools/testing/selftests/seccomp/seccomp_bpf.c
@@ -138,6 +138,8 @@ struct seccomp_data {
# define __NR_seccomp 337
# elif defined(__sh__)
# define __NR_seccomp 372
+# elif defined(__mc68000__)
+# define __NR_seccomp 380
# else
# warning "seccomp syscall number unknown for this architecture"
# define __NR_seccomp 0xffff
@@ -1838,6 +1840,10 @@ TEST_F(TRACE_poke, getpid_runs_normally)
# define ARCH_REGS struct pt_regs
# define SYSCALL_NUM(_regs) (_regs).regs[3]
# define SYSCALL_RET(_regs) (_regs).regs[0]
+#elif defined(__mc68000__)
+# define ARCH_REGS struct pt_regs
+# define SYSCALL_NUM(_regs) (_regs).orig_d0
+# define SYSCALL_RET(_regs) (_regs).d0
#else
# error "Do not know how to find your architecture's registers and syscalls"
#endif
@@ -1902,7 +1908,7 @@ const bool ptrace_entry_set_syscall_ret =
* Use PTRACE_GETREGS and PTRACE_SETREGS when available. This is useful for
* architectures without HAVE_ARCH_TRACEHOOK (e.g. User-mode Linux).
*/
-#if defined(__x86_64__) || defined(__i386__) || defined(__mips__)
+#if defined(__x86_64__) || defined(__i386__) || defined(__mips__) || defined(__mc68000__)
# define ARCH_GETREGS(_regs) ptrace(PTRACE_GETREGS, tracee, 0, &(_regs))
# define ARCH_SETREGS(_regs) ptrace(PTRACE_SETREGS, tracee, 0, &(_regs))
#else
--
2.17.1
^ permalink raw reply related [flat|nested] 6+ messages in thread
* Re: [PATCH v11 2/3] m68k: add kernel seccomp support
2023-01-10 0:45 ` [PATCH v11 2/3] m68k: add kernel seccomp support Michael Schmitz
@ 2023-01-10 17:00 ` Josh Juran
2023-01-10 19:12 ` Michael Schmitz
0 siblings, 1 reply; 6+ messages in thread
From: Josh Juran @ 2023-01-10 17:00 UTC (permalink / raw)
To: Michael Schmitz; +Cc: linux-m68k, geert, glaubitz
On Jan 9, 2023, at 7:45 PM, Michael Schmitz <schmitzmic@gmail.com> wrote:
> Add necessary arch Kconfig options, define TIF_SECCOMP trace
> flag and provide basic seccomp filter support in asm/syscall.h
...
> Signed-off-by: Michael Schmitz <schmitzmic@gmail.com>
>
> --
> Changes from v10:
>
> - fix merge conflicts
...
The patch below adds, rather than removes, merge conflict markers. Am I missing something?
> diff --git a/Documentation/features/seccomp/seccomp-filter/arch-support.txt b/Documentation/features/seccomp/seccomp-filter/arch-support.txt
> index dc71bf7b1a7e..0c2ac424094d 100644
> --- a/Documentation/features/seccomp/seccomp-filter/arch-support.txt
> +++ b/Documentation/features/seccomp/seccomp-filter/arch-support.txt
> @@ -13,8 +13,12 @@
> | csky: | ok |
> | hexagon: | TODO |
> | ia64: | TODO |
> +<<<<<<< HEAD
> | loongarch: | ok |
> | m68k: | TODO |
> +=======
> + | m68k: | ok |
> +>>>>>>> 596095b777b9... m68k: add kernel seccomp support
> | microblaze: | TODO |
> | mips: | ok |
> | nios2: | TODO |
Cheers,
Josh
^ permalink raw reply [flat|nested] 6+ messages in thread
* Re: [PATCH v11 2/3] m68k: add kernel seccomp support
2023-01-10 17:00 ` Josh Juran
@ 2023-01-10 19:12 ` Michael Schmitz
0 siblings, 0 replies; 6+ messages in thread
From: Michael Schmitz @ 2023-01-10 19:12 UTC (permalink / raw)
To: Josh Juran; +Cc: linux-m68k, geert, glaubitz
Hi Josh,
Thanks - that's a merge conflict I overlooked, fixed in the resent version.
But, as Geert points out this breaks patch management tools. I'll resend
as v12 later.
Cheers,
Michael
Am 11.01.2023 um 06:00 schrieb Josh Juran:
> On Jan 9, 2023, at 7:45 PM, Michael Schmitz <schmitzmic@gmail.com> wrote:
>
>> Add necessary arch Kconfig options, define TIF_SECCOMP trace
>> flag and provide basic seccomp filter support in asm/syscall.h
>
> ...
>
>> Signed-off-by: Michael Schmitz <schmitzmic@gmail.com>
>>
>> --
>> Changes from v10:
>>
>> - fix merge conflicts
>
> ...
>
> The patch below adds, rather than removes, merge conflict markers. Am I missing something?
>
>> diff --git a/Documentation/features/seccomp/seccomp-filter/arch-support.txt b/Documentation/features/seccomp/seccomp-filter/arch-support.txt
>> index dc71bf7b1a7e..0c2ac424094d 100644
>> --- a/Documentation/features/seccomp/seccomp-filter/arch-support.txt
>> +++ b/Documentation/features/seccomp/seccomp-filter/arch-support.txt
>> @@ -13,8 +13,12 @@
>> | csky: | ok |
>> | hexagon: | TODO |
>> | ia64: | TODO |
>> +<<<<<<< HEAD
>> | loongarch: | ok |
>> | m68k: | TODO |
>> +=======
>> + | m68k: | ok |
>> +>>>>>>> 596095b777b9... m68k: add kernel seccomp support
>> | microblaze: | TODO |
>> | mips: | ok |
>> | nios2: | TODO |
>
> Cheers,
> Josh
>
^ permalink raw reply [flat|nested] 6+ messages in thread
end of thread, other threads:[~2023-01-10 19:12 UTC | newest]
Thread overview: 6+ messages (download: mbox.gz / follow: Atom feed)
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2023-01-10 0:45 ` [PATCH v11 2/3] m68k: add kernel seccomp support Michael Schmitz
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