vsftpd/0002-Repeat-pututxline-if-it-fails-with-EINTR.patch

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From 896b3694ca062d747cd67e9e9ba246adb3fc706b Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Ond=C5=99ej=20Lyson=C4=9Bk?= <olysonek@redhat.com>
Date: Mon, 5 Aug 2019 13:55:37 +0200
Subject: [PATCH 2/3] Repeat pututxline() if it fails with EINTR
This is a partial fix for rhbz#1688848. We cannot resolve it
completely until glibc bug rhbz#1734791 is fixed. See
https://bugzilla.redhat.com/show_bug.cgi?id=1688848#c13.
The maximum number of attempts is currently 2, which might seem
low. However setting it to 2 was a decision based on data - see
https://bugzilla.redhat.com/show_bug.cgi?id=1688848#c16.
Resolves: rhbz#1688848
---
sysdeputil.c | 53 +++++++++++++++++++++++++++++++++++++++++++++-------
1 file changed, 46 insertions(+), 7 deletions(-)
diff --git a/sysdeputil.c b/sysdeputil.c
index bd1e8c9..4fbcca7 100644
--- a/sysdeputil.c
+++ b/sysdeputil.c
@@ -1203,6 +1203,8 @@ void
vsf_insert_uwtmp(const struct mystr* p_user_str,
const struct mystr* p_host_str)
{
+ int attempts;
+
if (sizeof(s_utent.ut_line) < 16)
{
return;
@@ -1231,16 +1233,35 @@ vsf_insert_uwtmp(const struct mystr* p_user_str,
vsf_sysutil_strcpy(s_utent.ut_host, str_getbuf(p_host_str),
sizeof(s_utent.ut_host));
s_utent.ut_tv.tv_sec = vsf_sysutil_get_time_sec();
- setutxent();
- (void) pututxline(&s_utent);
- endutxent();
- s_uwtmp_inserted = 1;
+ for (attempts = 2; attempts > 0; --attempts)
+ {
+ struct utmpx* p_res;
+ setutxent();
+ p_res = pututxline(&s_utent);
+ /* For now we'll ignore errors other than EINTR and EAGAIN */
+ if (p_res != NULL || (errno != EINTR && errno != EAGAIN))
+ {
+ break;
+ }
+ }
+ if (attempts == 0)
+ {
+ /* This makes us skip pututxline() in vsf_remove_uwtmp() */
+ s_uwtmp_inserted = -1;
+ }
+ else
+ {
+ s_uwtmp_inserted = 1;
+ endutxent();
+ }
updwtmpx(WTMPX_FILE, &s_utent);
}
void
vsf_remove_uwtmp(void)
{
+ int attempts;
+
if (!s_uwtmp_inserted)
{
return;
@@ -1249,9 +1270,27 @@ vsf_remove_uwtmp(void)
vsf_sysutil_memclr(s_utent.ut_user, sizeof(s_utent.ut_user));
vsf_sysutil_memclr(s_utent.ut_host, sizeof(s_utent.ut_host));
s_utent.ut_tv.tv_sec = 0;
- setutxent();
- (void) pututxline(&s_utent);
- endutxent();
+ if (s_uwtmp_inserted == 1)
+ {
+ for (attempts = 2; attempts > 0; --attempts)
+ {
+ struct utmpx* p_res;
+ setutxent();
+ p_res = pututxline(&s_utent);
+ /* For now we'll ignore errors other than EINTR and EAGAIN */
+ if (p_res != NULL || (errno != EINTR && errno != EAGAIN))
+ {
+ break;
+ }
+ }
+ if (attempts != 0)
+ {
+ endutxent();
+ }
+ }
+ /* Set s_uwtmp_inserted to 0 regardless of the result of
+ * pututxline() to make sure we won't run this function twice.
+ */
s_uwtmp_inserted = 0;
s_utent.ut_tv.tv_sec = vsf_sysutil_get_time_sec();
updwtmpx(WTMPX_FILE, &s_utent);
--
2.20.1