From 82c9df820112c6286a8e8fbe482e94b65b49062c Mon Sep 17 00:00:00 2001 From: Yi Yang Date: Fri, 30 Dec 2005 16:37:10 +0800 Subject: [PATCH] [PATCH] Fix false old value return of sysctl For the sysctl syscall, if the user wants to get the old value of a sysctl entry and set a new value for it in the same syscall, the old value is always overwritten by the new value if the sysctl entry is of string type and if the user sets its strategy to sysctl_string. This issue lies in the strategy being run twice if the strategy is set to sysctl_string, the general strategy sysctl_string always returns 0 if success. Such strategy routines as sysctl_jiffies and sysctl_jiffies_ms return 1 because they do read and write for the sysctl entry. The strategy routine sysctl_string return 0 although it actually read and write the sysctl entry. According to my analysis, if a strategy routine do read and write, it should return 1, if it just does some necessary check but not read and write, it should return 0, for example sysctl_intvec. Signed-off-by: Yi Yang Signed-off-by: Linus Torvalds --- kernel/sysctl.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/kernel/sysctl.c b/kernel/sysctl.c index ad0425a8f709..e5102ea6e104 100644 --- a/kernel/sysctl.c +++ b/kernel/sysctl.c @@ -2221,7 +2221,7 @@ int sysctl_string(ctl_table *table, int __user *name, int nlen, len--; ((char *) table->data)[len] = 0; } - return 0; + return 1; } /* -- 2.20.1