On Fri, Jan 17, 2014 at 08:03:15AM +0000, AKASHI Takahiro wrote:
lib/audit.c provides a generic definition for auditing system calls. This patch extends it for compat syscall support on bi-architectures (32/64-bit) by adding lib/compat_audit.c when CONFIG_COMPAT enabled.
Each architecture that wants to use this must define audit_is_compat() in asm/audit.h.
Signed-off-by: AKASHI Takahiro takahiro.akashi@linaro.org
I'm not familiar with the audit subsystem but I have some (cosmetic) comments below.
diff --git a/include/linux/audit.h b/include/linux/audit.h index bf1ef22..3d71949 100644 --- a/include/linux/audit.h +++ b/include/linux/audit.h @@ -78,6 +78,15 @@ extern int is_audit_feature_set(int which); extern int __init audit_register_class(int class, unsigned *list); extern int audit_classify_syscall(int abi, unsigned syscall); extern int audit_classify_arch(int arch); +#if defined(CONFIG_AUDIT_GENERIC) && defined(CONFIG_COMPAT) +extern unsigned compat_write_class[]; +extern unsigned compat_read_class[]; +extern unsigned compat_dir_class[]; +extern unsigned compat_chattr_class[]; +extern unsigned compat_signal_class[];
+extern int audit_classify_compat_syscall(int abi, unsigned syscall); +#endif /* audit_names->type values */ #define AUDIT_TYPE_UNKNOWN 0 /* we don't know yet */ diff --git a/lib/Makefile b/lib/Makefile index a459c31..73ea908 100644 --- a/lib/Makefile +++ b/lib/Makefile @@ -93,6 +93,9 @@ obj-$(CONFIG_TEXTSEARCH_BM) += ts_bm.o obj-$(CONFIG_TEXTSEARCH_FSM) += ts_fsm.o obj-$(CONFIG_SMP) += percpu_counter.o obj-$(CONFIG_AUDIT_GENERIC) += audit.o +ifeq ($(CONFIG_COMPAT),y) +obj-$(CONFIG_AUDIT_GENERIC) += compat_audit.o +endif
You could use a CONFIG_AUDIT_COMPAT_GENERIC and simplify other #ifdefs as well.
--- a/lib/audit.c +++ b/lib/audit.c @@ -1,6 +1,7 @@ #include <linux/init.h> #include <linux/types.h> #include <linux/audit.h> +#include <asm/audit.h> #include <asm/unistd.h> static unsigned dir_class[] = { @@ -30,11 +31,20 @@ static unsigned signal_class[] = { int audit_classify_arch(int arch) { +#ifdef CONFIG_COMPAT
- if (audit_is_compat(arch))
return 1;+#endif return 0; }
Here and in other places, just define a default audit_is_compat() functions which returns false when !CONFIG_COMPAT to avoid the #ifdefs.
diff --git a/lib/compat_audit.c b/lib/compat_audit.c new file mode 100644 index 0000000..94f6480 --- /dev/null +++ b/lib/compat_audit.c @@ -0,0 +1,51 @@ +#include <linux/init.h> +#include <linux/types.h> +/* FIXME: this might be architecture dependent */ +#include <asm/unistd_32.h>
It most likely is architecture dependent.
+int audit_classify_compat_syscall(int abi, unsigned syscall) +{
- switch (syscall) {
+#ifdef __NR_open
- case __NR_open:
return 2;+#endif +#ifdef __NR_openat
- case __NR_openat:
return 3;+#endif +#ifdef __NR_socketcall
- case __NR_socketcall:
return 4;+#endif
- case __NR_execve:
return 5;- default:
return 1;- }
+}
BTW, since they aren't many, you could get the arch code to define __NR_compat_open etc. explicitly and use these. On arm64 we have a few of these defined to avoid name collision in signal handling code.