Re: [PATCH v4 2/3] audit: add support for the openat2 syscall

On Wed, May 19, 2021 at 04:00:21PM -0400, Richard Guy Briggs wrote: > The openat2(2) syscall was added in kernel v5.6 with commit fddb5d430ad9 > ("open: introduce openat2(2) syscall") > > Add the openat2(2) syscall to the audit syscall classifier. > > Link: https://github.com/linux-audit/audit-kernel/issues/67 > Signed-off-by: Richard Guy Briggs <rgb(a)redhat.com&gt; > Link: https://lore.kernel.org/r/f5f1a4d8699613f8c02ce762807228c841c2e26f.162136... > --- > arch/alpha/kernel/audit.c | 2 ++ > arch/ia64/kernel/audit.c | 2 ++ > arch/parisc/kernel/audit.c | 2 ++ > arch/parisc/kernel/compat_audit.c | 2 ++ > arch/powerpc/kernel/audit.c | 2 ++ > arch/powerpc/kernel/compat_audit.c | 2 ++ > arch/s390/kernel/audit.c | 2 ++ > arch/s390/kernel/compat_audit.c | 2 ++ > arch/sparc/kernel/audit.c | 2 ++ > arch/sparc/kernel/compat_audit.c | 2 ++ > arch/x86/ia32/audit.c | 2 ++ > arch/x86/kernel/audit_64.c | 2 ++ > include/linux/auditsc_classmacros.h | 1 + > kernel/auditsc.c | 3 +++ > lib/audit.c | 4 ++++ > lib/compat_audit.c | 4 ++++ > 16 files changed, 36 insertions(+)

> diff --git a/kernel/auditsc.c b/kernel/auditsc.c > index d775ea16505b..3f59ab209dfd 100644 > --- a/kernel/auditsc.c > +++ b/kernel/auditsc.c > @@ -76,6 +76,7 @@ > #include <linux/fsnotify_backend.h> > #include <uapi/linux/limits.h> > #include <uapi/linux/netfilter/nf_tables.h> > +#include <uapi/linux/openat2.h> > > #include "audit.h" > > @@ -196,6 +197,8 @@ static int audit_match_perm(struct audit_context *ctx, int mask) > return ((mask & AUDIT_PERM_WRITE) && ctx->argv[0] == SYS_BIND); > case AUDITSC_EXECVE: > return mask & AUDIT_PERM_EXEC; > + case AUDITSC_OPENAT2: > + return mask & ACC_MODE((u32)((struct open_how *)ctx->argv[2])->flags); That's a lot of dereferncing, casting and masking all at once. Maybe a small static inline helper would be good for the sake of legibility? Sm like: static inline u32 audit_openat2_acc(struct open_how *how, int mask) { u32 flags = how->flags; return mask & ACC_MODE(flags); } but not sure. Just seems more legible to me. Otherwise.