Re: [PATCH 1/2] riscv: add audit support

From: Paul Moore
Date: Tue Nov 13 2018 - 18:34:36 EST

On Tue, Nov 13, 2018 at 5:07 AM Palmer Dabbelt <palmer@xxxxxxxxxx> wrote:
> On Mon, 29 Oct 2018 03:48:53 PDT (-0700), david.abdurachmanov@xxxxxxxxx wrote:
> > On RISC-V (riscv) audit is supported through generic lib/audit.c.
> > The patch adds required arch specific definitions.
> >
> > Signed-off-by: David Abdurachmanov <david.abdurachmanov@xxxxxxxxx>
> > ---
> > arch/riscv/Kconfig | 1 +
> > arch/riscv/include/asm/ptrace.h | 5 +++++
> > arch/riscv/include/asm/syscall.h | 10 ++++++++++
> > arch/riscv/include/asm/thread_info.h | 6 ++++++
> > arch/riscv/kernel/entry.S | 4 ++--
> > include/uapi/linux/audit.h | 2 ++
> > 6 files changed, 26 insertions(+), 2 deletions(-)
> >
> > diff --git a/arch/riscv/Kconfig b/arch/riscv/Kconfig
> > index a344980287a5..8e6d404a4ed0 100644
> > --- a/arch/riscv/Kconfig
> > +++ b/arch/riscv/Kconfig
> > @@ -28,6 +28,7 @@ config RISCV
> > select GENERIC_STRNLEN_USER
> > select GENERIC_SMP_IDLE_THREAD
> > select GENERIC_ATOMIC64 if !64BIT || !RISCV_ISA_A
> > + select HAVE_ARCH_AUDITSYSCALL
> > select HAVE_MEMBLOCK
> > select HAVE_MEMBLOCK_NODE_MAP
> > select HAVE_DMA_CONTIGUOUS
> > diff --git a/arch/riscv/include/asm/ptrace.h b/arch/riscv/include/asm/ptrace.h
> > index 2c5df945d43c..62c5e9d35596 100644
> > --- a/arch/riscv/include/asm/ptrace.h
> > +++ b/arch/riscv/include/asm/ptrace.h
> > @@ -113,6 +113,11 @@ static inline void frame_pointer_set(struct pt_regs *regs,
> > SET_FP(regs, val);
> > }
> >
> > +static inline unsigned long regs_return_value(struct pt_regs *regs)
> > +{
> > + return regs->a0;
> > +}
> > +
> > #endif /* __ASSEMBLY__ */
> >
> > #endif /* _ASM_RISCV_PTRACE_H */
> > diff --git a/arch/riscv/include/asm/syscall.h b/arch/riscv/include/asm/syscall.h
> > index 8d25f8904c00..bba3da6ef157 100644
> > --- a/arch/riscv/include/asm/syscall.h
> > +++ b/arch/riscv/include/asm/syscall.h
> > @@ -18,6 +18,7 @@
> > #ifndef _ASM_RISCV_SYSCALL_H
> > #define _ASM_RISCV_SYSCALL_H
> >
> > +#include <uapi/linux/audit.h>
> > #include <linux/sched.h>
> > #include <linux/err.h>
> >
> > @@ -99,4 +100,13 @@ static inline void syscall_set_arguments(struct task_struct *task,
> > memcpy(&regs->a1 + i * sizeof(regs->a1), args, n * sizeof(regs->a0));
> > }
> >
> > +static inline int syscall_get_arch(void)
> > +{
> > +#ifdef CONFIG_64BIT
> > + return AUDIT_ARCH_RISCV64;
> > +#else
> > + return AUDIT_ARCH_RISCV32;
> > +#endif
> > +}
> > +
> > #endif /* _ASM_RISCV_SYSCALL_H */
> > diff --git a/arch/riscv/include/asm/thread_info.h b/arch/riscv/include/asm/thread_info.h
> > index f8fa1cd2dad9..1c9cc8389928 100644
> > --- a/arch/riscv/include/asm/thread_info.h
> > +++ b/arch/riscv/include/asm/thread_info.h
> > @@ -80,13 +80,19 @@ struct thread_info {
> > #define TIF_RESTORE_SIGMASK 4 /* restore signal mask in do_signal() */
> > #define TIF_MEMDIE 5 /* is terminating due to OOM killer */
> > #define TIF_SYSCALL_TRACEPOINT 6 /* syscall tracepoint instrumentation */
> > +#define TIF_SYSCALL_AUDIT 7 /* syscall auditing */
> >
> > #define _TIF_SYSCALL_TRACE (1 << TIF_SYSCALL_TRACE)
> > #define _TIF_NOTIFY_RESUME (1 << TIF_NOTIFY_RESUME)
> > #define _TIF_SIGPENDING (1 << TIF_SIGPENDING)
> > #define _TIF_NEED_RESCHED (1 << TIF_NEED_RESCHED)
> > +#define _TIF_SYSCALL_TRACEPOINT (1 << TIF_SYSCALL_TRACEPOINT)
> > +#define _TIF_SYSCALL_AUDIT (1 << TIF_SYSCALL_AUDIT)
> >
> > #define _TIF_WORK_MASK \
> > (_TIF_NOTIFY_RESUME | _TIF_SIGPENDING | _TIF_NEED_RESCHED)
> >
> > +#define _TIF_SYSCALL_WORK \
> > + (_TIF_SYSCALL_TRACE | _TIF_SYSCALL_TRACEPOINT | _TIF_SYSCALL_AUDIT)
> > +
> > #endif /* _ASM_RISCV_THREAD_INFO_H */
> > diff --git a/arch/riscv/kernel/entry.S b/arch/riscv/kernel/entry.S
> > index fa2c08e3c05e..2a6c2e7aaff3 100644
> > --- a/arch/riscv/kernel/entry.S
> > +++ b/arch/riscv/kernel/entry.S
> > @@ -202,7 +202,7 @@ handle_syscall:
> > REG_S s2, PT_SEPC(sp)
> > /* Trace syscalls, but only if requested by the user. */
> > REG_L t0, TASK_TI_FLAGS(tp)
> > - andi t0, t0, _TIF_SYSCALL_TRACE
> > + andi t0, t0, _TIF_SYSCALL_WORK
> > bnez t0, handle_syscall_trace_enter
> > check_syscall_nr:
> > /* Check to make sure we don't jump to a bogus syscall number. */
> > @@ -222,7 +222,7 @@ ret_from_syscall:
> > REG_S a0, PT_A0(sp)
> > /* Trace syscalls, but only if requested by the user. */
> > REG_L t0, TASK_TI_FLAGS(tp)
> > - andi t0, t0, _TIF_SYSCALL_TRACE
> > + andi t0, t0, _TIF_SYSCALL_WORK
> > bnez t0, handle_syscall_trace_exit
> >
> > ret_from_exception:
> > diff --git a/include/uapi/linux/audit.h b/include/uapi/linux/audit.h
> > index 818ae690ab79..d0e037a96a7b 100644
> > --- a/include/uapi/linux/audit.h
> > +++ b/include/uapi/linux/audit.h
> > @@ -399,6 +399,8 @@ enum {
> > /* do not define AUDIT_ARCH_PPCLE since it is not supported by audit */
> > #define AUDIT_ARCH_PPC64 (EM_PPC64|__AUDIT_ARCH_64BIT)
> > #define AUDIT_ARCH_PPC64LE (EM_PPC64|__AUDIT_ARCH_64BIT|__AUDIT_ARCH_LE)
> > +#define AUDIT_ARCH_RISCV32 (EM_RISCV|__AUDIT_ARCH_LE)
> > +#define AUDIT_ARCH_RISCV64 (EM_RISCV|__AUDIT_ARCH_64BIT|__AUDIT_ARCH_LE)
> > #define AUDIT_ARCH_S390 (EM_S390)
> > #define AUDIT_ARCH_S390X (EM_S390|__AUDIT_ARCH_64BIT)
> > #define AUDIT_ARCH_SH (EM_SH)
>
> I can't seem to figure out how to dig the rest of the thread out of my inbox
> (I'm in an airport), so I'm just replying here.
>
> I've added this to next-audit, which will soon filter into for-next. I'm not
> sure if this is 100% settled, but I can't find any issues with it so I think
> it's best to get this out for testing.

If you RISCV guys are happy, and it is passing the audit-testsuite
(which I believe it is based on some brief discussions with David on
Freenode), then I think it is okay from my point of view.

--
paul moore
www.paul-moore.com