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Subject[PATCH] check_syslog_permissions() cleanup
Patch fixes drawbacks in heck_syslog_permissions() noticed by AKPM:
"from_file handling makes me cry.

That's not a boolean - it's an enumerated value with two values
currently defined.

But the code in check_syslog_permissions() treats it as a boolean and
also hardwires the knowledge that SYSLOG_FROM_PROC == 1 (or == `true`).

And the name is wrong: it should be called from_proc to match
SYSLOG_FROM_PROC."

Signed-off-by: Vasily Averin <vvs@virtuozzo.com>
---
include/linux/syslog.h | 6 +++---
kernel/printk/printk.c | 10 +++++-----
2 files changed, 8 insertions(+), 8 deletions(-)

diff --git a/include/linux/syslog.h b/include/linux/syslog.h
index 4b7b875..c3a7f0c 100644
--- a/include/linux/syslog.h
+++ b/include/linux/syslog.h
@@ -47,12 +47,12 @@
#define SYSLOG_FROM_READER 0
#define SYSLOG_FROM_PROC 1

-int do_syslog(int type, char __user *buf, int count, bool from_file);
+int do_syslog(int type, char __user *buf, int count, int source);

#ifdef CONFIG_PRINTK
-int check_syslog_permissions(int type, bool from_file);
+int check_syslog_permissions(int type, int source);
#else
-static inline int check_syslog_permissions(int type, bool from_file)
+static inline int check_syslog_permissions(int type, int source)
{
return 0;
}
diff --git a/kernel/printk/printk.c b/kernel/printk/printk.c
index bff0169..5ed9d6d 100644
--- a/kernel/printk/printk.c
+++ b/kernel/printk/printk.c
@@ -477,13 +477,13 @@ static int syslog_action_restricted(int type)
type != SYSLOG_ACTION_SIZE_BUFFER;
}

-int check_syslog_permissions(int type, bool from_file)
+int check_syslog_permissions(int type, int source)
{
/*
* If this is from /proc/kmsg and we've already opened it, then we've
* already done the capabilities checks at open time.
*/
- if (from_file && type != SYSLOG_ACTION_OPEN)
+ if (source == SYSLOG_FROM_PROC && type != SYSLOG_ACTION_OPEN)
goto ok;

if (syslog_action_restricted(type)) {
@@ -1254,13 +1254,13 @@ static int syslog_print_all(char __user *buf, int size, bool clear)
return len;
}

-int do_syslog(int type, char __user *buf, int len, bool from_file)
+int do_syslog(int type, char __user *buf, int len, int source)
{
bool clear = false;
static int saved_console_loglevel = LOGLEVEL_DEFAULT;
int error;

- error = check_syslog_permissions(type, from_file);
+ error = check_syslog_permissions(type, source);
if (error)
goto out;

@@ -1343,7 +1343,7 @@ int do_syslog(int type, char __user *buf, int len, bool from_file)
syslog_prev = 0;
syslog_partial = 0;
}
- if (from_file) {
+ if (source == SYSLOG_FROM_PROC) {
/*
* Short-cut for poll(/"proc/kmsg") which simply checks
* for pending data, not the size; return the count of
--
1.9.1


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