Re: [PATCH v17 09/15] seccomp: remove duplicated failure logging

[Will Drewry]

On Fri, Apr 6, 2012 at 4:14 PM, Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx> wrote:
> On Thu, 29 Mar 2012 15:01:54 -0500
> Will Drewry <wad@xxxxxxxxxxxx> wrote:
>
>> From: Kees Cook <keescook@xxxxxxxxxxxx>
>>
>> This consolidates the seccomp filter error logging path and adds more
>> details to the audit log.
>>
>> ...
>>
>> --- a/include/linux/audit.h
>> +++ b/include/linux/audit.h
>>
>> ...
>>
>>  #define audit_inode(n,d) do { (void)(d); } while (0)
>>  #define audit_inode_child(i,p) do { ; } while (0)
>>  #define audit_core_dumps(i) do { ; } while (0)
>> -#define audit_seccomp(i) do { ; } while (0)
>> +#define audit_seccomp(i,s,c) do { ; } while (0)
>
> Sigh.  Someone please convert all these to C.  That way we get
> typechecking and don't need dopey party tricks like that "(void)(d)" to
> squish compilation warnings.
>
>> ...
>> --- a/kernel/auditsc.c
>> +++ b/kernel/auditsc.c
>> @@ -67,6 +67,7 @@
>>  #include <linux/syscalls.h>
>>  #include <linux/capability.h>
>>  #include <linux/fs_struct.h>
>> +#include <linux/compat.h>
>>
>>  #include "audit.h"
>>
>> @@ -2710,13 +2711,18 @@ void audit_core_dumps(long signr)
>>       audit_log_end(ab);
>>  }
>>
>> -void __audit_seccomp(unsigned long syscall)
>> +void __audit_seccomp(unsigned long syscall, long signr, int code)
>>  {
>>       struct audit_buffer *ab;
>>
>>       ab = audit_log_start(NULL, GFP_KERNEL, AUDIT_ANOM_ABEND);
>> -     audit_log_abend(ab, "seccomp", SIGKILL);
>> +     audit_log_abend(ab, "seccomp", signr);
>>       audit_log_format(ab, " syscall=%ld", syscall);
>> +#ifdef CONFIG_COMPAT
>> +     audit_log_format(ab, " compat=%d", is_compat_task());
>> +#endif
>
> We don't need the ifdef for compilation reasons now.
>
> The question is: should we emit the compat= record on
> non-compat-capable architectures?  Doing so would be safer - making it
> conditional invites people to write x86-only usersapce.

I'd certainly prefer it always being there for exactly that reason.

Kees, Eric, any preferences?  Unless I hear one, I'll just drop the
ifdefs in the next revision.

thanks!
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