git: a7f81b488df2 - main - libvmm: explicitly save and restore errno in vm_open()

[Robert Wing]

The branch main has been updated by rew:

URL: https://cgit.FreeBSD.org/src/commit/?id=a7f81b488df2d4a5dcd785b4112e04ffb6ca0442

commit a7f81b488df2d4a5dcd785b4112e04ffb6ca0442
Author:     Robert Wing <rew at FreeBSD.org>
AuthorDate: 2021-03-11 19:27:43 +0000
Commit:     Robert Wing <rew at FreeBSD.org>
CommitDate: 2021-05-11 23:11:52 +0000

    libvmm: explicitly save and restore errno in vm_open()
    
    In commit 6bb140e3ca895a14, vm_destroy() was replaced with free() to
    preserve errno. However, it's possible that free() may change the errno
    as well. Keep the free() call, but explicitly save and restore errno.
    
    Noted by: jhb
    Fixes: 6bb140e3ca895a14
---
 lib/libvmmapi/vmmapi.c | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/lib/libvmmapi/vmmapi.c b/lib/libvmmapi/vmmapi.c
index 7faa2fc545ea..5810274c9a73 100644
--- a/lib/libvmmapi/vmmapi.c
+++ b/lib/libvmmapi/vmmapi.c
@@ -118,6 +118,7 @@ struct vmctx *
 vm_open(const char *name)
 {
 	struct vmctx *vm;
+	int saved_errno;
 
 	vm = malloc(sizeof(struct vmctx) + strlen(name) + 1);
 	assert(vm != NULL);
@@ -133,7 +134,9 @@ vm_open(const char *name)
 
 	return (vm);
 err:
+	saved_errno = errno;
 	free(vm);
+	errno = saved_errno;
 	return (NULL);
 }