[PATCH 3/4] arm64: audit: Add AArch32 support

[Will Deacon]

On Wed, Nov 06, 2013 at 10:25:45AM +0000, AKASHI Takahiro wrote:
> ---
>  arch/arm64/include/asm/audit32.h  |   12 ++
>  arch/arm64/include/asm/unistd32.h |  387 +++++++++++++++++++++++++++++++++++++
>  arch/arm64/kernel/Makefile        |    3 +
>  arch/arm64/kernel/audit.c         |   18 ++
>  arch/arm64/kernel/audit32.c       |   46 +++++
>  5 files changed, 466 insertions(+)
>  create mode 100644 arch/arm64/include/asm/audit32.h
>  create mode 100644 arch/arm64/kernel/audit32.c
> 
> diff --git a/arch/arm64/include/asm/audit32.h b/arch/arm64/include/asm/audit32.h
> new file mode 100644
> index 0000000..debfe57
> --- /dev/null
> +++ b/arch/arm64/include/asm/audit32.h
> @@ -0,0 +1,12 @@
> +#ifndef __ASM_AUDIT32_H
> +#define __ASM_AUDIT32_H
> +
> +extern unsigned aarch32_dir_class[];
> +extern unsigned aarch32_read_class[];
> +extern unsigned aarch32_write_class[];
> +extern unsigned aarch32_chattr_class[];
> +extern unsigned aarch32_signal_class[];
> +
> +extern int aarch32_classify_syscall(unsigned);
> +
> +#endif /* __ASM_AUDIT32_H */
> diff --git a/arch/arm64/include/asm/unistd32.h b/arch/arm64/include/asm/unistd32.h
> index 58125bf..fdf5e56 100644
> --- a/arch/arm64/include/asm/unistd32.h
> +++ b/arch/arm64/include/asm/unistd32.h
> @@ -21,6 +21,393 @@
>  #define __SYSCALL(x, y)
>  #endif
> 
> +#ifdef __AARCH32_AUDITSYSCALL
> +/*
> + * FIXME: Currenty only audit uses (part of) these definitions.
> + * See audit32.c
> + */
> +#define __NR_restart_syscall 0
> +#define __NR_exit 1
> +#define __NR_fork 2
> +#define __NR_read 3

Don't bother with this file. It's a needless replication of data already in
the file and you don't even need it all.

> diff --git a/arch/arm64/kernel/audit32.c b/arch/arm64/kernel/audit32.c
> new file mode 100644
> index 0000000..2aa4d7d
> --- /dev/null
> +++ b/arch/arm64/kernel/audit32.c
> @@ -0,0 +1,46 @@
> +#define __AARCH32_AUDITSYSCALL
> +#include <asm/unistd32.h>
> +
> +unsigned aarch32_dir_class[] = {
> +#include <asm-generic/audit_dir_write.h>
> +~0U
> +};
> +
> +unsigned aarch32_read_class[] = {
> +#include <asm-generic/audit_read.h>
> +~0U
> +};
> +
> +unsigned aarch32_write_class[] = {
> +#include <asm-generic/audit_write.h>
> +~0U
> +};
> +
> +unsigned aarch32_chattr_class[] = {
> +#include <asm-generic/audit_change_attr.h>
> +~0U
> +};
> +
> +unsigned aarch32_signal_class[] = {
> +#include <asm-generic/audit_signal.h>
> +~0U
> +};
> +
> +int aarch32_classify_syscall(unsigned syscall)
> +{
> +       switch(syscall) {
> +       case __NR_open:
> +               return 2;
> +       case __NR_openat:
> +               return 3;
> +       /*
> +        * obsolute in EABI
> +        * case __NR_socketcall:
> +        *      return 4;
> +        */
> +       case __NR_execve:
> +               return 5;
> +       default:
> +               return 1; /* 32-bit on biarch */
> +       }

Instead, just add __NR_compat_{open,openat,execve}, like we have done for
the signal-related syscalls.

Also, can't the generic lib/audit.c be reworked to work with compat too?

Will