From f939dccfd770df2f9070cd30aa52105b7afe1bde Mon Sep 17 00:00:00 2001
From: Edward Tomasz Napierala <trasz@FreeBSD.org>
Date: Fri, 29 Oct 2021 15:28:56 +0100
Subject: [PATCH] linux: Make PTRACE_GETREGSET return proper buffer size

This fixes Chrome warning:

[1022/152319.328632:ERROR:ptracer.cc(476)] Unexpected registers size 0 != 216, 68

Reviewed By:	emaste
Sponsored By:	EPSRC
Differential Revision: https://reviews.freebsd.org/D32616
---
 sys/amd64/linux/linux_ptrace.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/sys/amd64/linux/linux_ptrace.c b/sys/amd64/linux/linux_ptrace.c
index d16e875ba5c..275450d63b2 100644
--- a/sys/amd64/linux/linux_ptrace.c
+++ b/sys/amd64/linux/linux_ptrace.c
@@ -540,7 +540,7 @@ linux_ptrace_getregset_prstatus(struct thread *td, pid_t pid, l_ulong data)
 		return (error);
 	}
 
-	iov.iov_len -= len;
+	iov.iov_len = len;
 	error = copyout(&iov, (void *)data, sizeof(iov));
 	if (error != 0) {
 		linux_msg(td, "iov copyout error %d", error);