svn commit: r366456 - head/sys/arm64/arm64
Edward Tomasz Napierala
trasz at FreeBSD.org
Mon Oct 5 18:46:14 UTC 2020
Author: trasz
Date: Mon Oct 5 18:46:14 2020
New Revision: 366456
URL: https://svnweb.freebsd.org/changeset/base/366456
Log:
Tweak arm64's cpu_fetch_syscall_args(). This should make it possible
for the compiler to inline the memcpy().
Reviewed by: andrew
Sponsored by: DARPA
Differential Revision: https://reviews.freebsd.org/D26629
Modified:
head/sys/arm64/arm64/trap.c
Modified: head/sys/arm64/arm64/trap.c
==============================================================================
--- head/sys/arm64/arm64/trap.c Mon Oct 5 18:45:32 2020 (r366455)
+++ head/sys/arm64/arm64/trap.c Mon Oct 5 18:46:14 2020 (r366456)
@@ -123,30 +123,31 @@ int
cpu_fetch_syscall_args(struct thread *td)
{
struct proc *p;
- register_t *ap;
+ register_t *ap, *dst_ap;
struct syscall_args *sa;
- int nap;
- nap = MAXARGS;
p = td->td_proc;
- ap = td->td_frame->tf_x;
sa = &td->td_sa;
+ ap = td->td_frame->tf_x;
+ dst_ap = &sa->args[0];
sa->code = td->td_frame->tf_x[8];
- if (sa->code == SYS_syscall || sa->code == SYS___syscall) {
+ if (__predict_false(sa->code == SYS_syscall || sa->code == SYS___syscall)) {
sa->code = *ap++;
- nap--;
+ } else {
+ *dst_ap++ = *ap++;
}
- if (sa->code >= p->p_sysent->sv_size)
+ if (__predict_false(sa->code >= p->p_sysent->sv_size))
sa->callp = &p->p_sysent->sv_table[0];
else
sa->callp = &p->p_sysent->sv_table[sa->code];
- memcpy(sa->args, ap, nap * sizeof(register_t));
- if (sa->callp->sy_narg > nap)
- panic("ARM64TODO: Could we have more than %d args?", MAXARGS);
+ KASSERT(sa->callp->sy_narg <= nitems(sa->args),
+ ("Syscall %d takes too many arguments", sa->code));
+
+ memcpy(dst_ap, ap, (MAXARGS - 1) * sizeof(register_t));
td->td_retval[0] = 0;
td->td_retval[1] = 0;
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