Re: [RFC PATCH] audit: Add generic compat syscall support

lib/audit.c provides a generic definition for auditing system calls. lib/compat_audit.c similarly adds compat syscall support for bi-architectures (32/64-bit). Each architecture must define audit_is_compat() in asm/audit.h. Signed-off-by: AKASHI Takahiro <takahiro.akashi(a)linaro.org&gt; --- include/linux/audit.h | 3 +++ lib/Makefile | 3 +++ lib/audit.c | 10 ++++++++ lib/compat_audit.c | 64 +++++++++++++++++++++++++++++++++++++++++++++++++ 4 files changed, 80 insertions(+) create mode 100644 lib/compat_audit.c diff --git a/include/linux/audit.h b/include/linux/audit.h index 729a4d1..f6c8d18 100644 --- a/include/linux/audit.h +++ b/include/linux/audit.h @@ -75,6 +75,9 @@ struct audit_field { extern int __init audit_register_class(int class, unsigned *list); extern int audit_classify_syscall(int abi, unsigned syscall); +#ifdef CONFIG_COMPAT +extern int audit_classify_compat_syscall(int abi, unsigned syscall); +#endif extern int audit_classify_arch(int arch); /* audit_names->type values */ diff --git a/lib/Makefile b/lib/Makefile index f3bb2cb..5bb185a 100644 --- a/lib/Makefile +++ b/lib/Makefile @@ -96,6 +96,9 @@ 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 obj-$(CONFIG_SWIOTLB) += swiotlb.o obj-$(CONFIG_IOMMU_HELPER) += iommu-helper.o diff --git a/lib/audit.c b/lib/audit.c index 76bbed4..fa373bd 100644 --- 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; } int audit_classify_syscall(int abi, unsigned syscall) { +#ifdef CONFIG_COMPAT + if (audit_is_compat(abi)) + return audit_classify_compat_syscall(abi, syscall); +#endif + switch(syscall) { #ifdef __NR_open case __NR_open: diff --git a/lib/compat_audit.c b/lib/compat_audit.c new file mode 100644 index 0000000..837a6e6 --- /dev/null +++ b/lib/compat_audit.c @@ -0,0 +1,64 @@ +#include <linux/init.h> +#include <linux/types.h> +#include <linux/audit.h> +/* FIXME: this might be architecture dependent */ +#include <asm/unistd_32.h> + +static unsigned compat_dir_class[] = { +#include <asm-generic/audit_dir_write.h> +~0U +}; + +static unsigned compat_read_class[] = { +#include <asm-generic/audit_read.h> +~0U +}; + +static unsigned compat_write_class[] = { +#include <asm-generic/audit_write.h> +~0U +}; + +static unsigned compat_chattr_class[] = { +#include <asm-generic/audit_change_attr.h> +~0U +}; + +static unsigned compat_signal_class[] = { +#include <asm-generic/audit_signal.h> +~0U +}; + +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; + } +} + +static int __init audit_compat_classes_init(void) +{ + audit_register_class(AUDIT_CLASS_WRITE, compat_write_class); + audit_register_class(AUDIT_CLASS_READ, compat_read_class); + audit_register_class(AUDIT_CLASS_DIR_WRITE, compat_dir_class); + audit_register_class(AUDIT_CLASS_CHATTR, compat_chattr_class); + audit_register_class(AUDIT_CLASS_SIGNAL, compat_signal_class); + return 0; +} + +__initcall(audit_compat_classes_init);