git: f948f5ed7cda - stable/13 - linux(4): Improve comment about SA_RESTORER

The branch stable/13 has been updated by trasz:

URL: https://cgit.FreeBSD.org/src/commit/?id=f948f5ed7cdaa0ab499dfa13bd6e8e6a4c7587e6

commit f948f5ed7cdaa0ab499dfa13bd6e8e6a4c7587e6
Author:     Edward Tomasz Napierala <trasz@FreeBSD.org>
AuthorDate: 2021-07-13 09:38:08 +0000
Commit:     Edward Tomasz Napierala <trasz@FreeBSD.org>
CommitDate: 2022-02-14 00:09:13 +0000

    linux(4): Improve comment about SA_RESTORER
    
    No functional changes.
    
    Sponsored By:   EPSRC
    
    (cherry picked from commit 3eaf271d3c0e4fa18b74971a71c950fd43fa4189)
---
 sys/compat/linux/linux_signal.c | 7 ++++++-
 1 file changed, 6 insertions(+), 1 deletion(-)

diff --git a/sys/compat/linux/linux_signal.c b/sys/compat/linux/linux_signal.c
index 71b00da569dc..0e2fbd31b398 100644
--- a/sys/compat/linux/linux_signal.c
+++ b/sys/compat/linux/linux_signal.c
@@ -91,7 +91,12 @@ linux_to_bsd_sigaction(l_sigaction_t *lsa, struct sigaction *bsa)
 	}
 	if (lsa->lsa_flags & LINUX_SA_RESTORER) {
 		flags &= ~LINUX_SA_RESTORER;
-		/* XXX: We might want to handle it; see Linux sigreturn(2). */
+		/*
+		 * We ignore the lsa_restorer and always use our own signal
+		 * trampoline instead.  It looks like SA_RESTORER is obsolete
+		 * in Linux too - it doesn't seem to be used at all on arm64.
+		 * In any case: see Linux sigreturn(2).
+		 */
 	}
 	if (lsa->lsa_flags & LINUX_SA_ONSTACK) {
 		flags &= ~LINUX_SA_ONSTACK;