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authorIngo Molnar <mingo@elte.hu>2011-05-12 23:00:28 +0200
committerLinus Torvalds <torvalds@linux-foundation.org>2011-05-12 15:18:16 -0700
commit411f05f123cbd7f8aa1edcae86970755a6e2a9d9 (patch)
tree63fa10cd8d895c36bbbacd8c5b38b25e3e1f3448
parentca1376d10810bc2c20c8d0821a9ee04ca2507c01 (diff)
downloadlwn-411f05f123cbd7f8aa1edcae86970755a6e2a9d9.tar.gz
lwn-411f05f123cbd7f8aa1edcae86970755a6e2a9d9.zip
vsprintf: Turn kptr_restrict off by default
kptr_restrict has been triggering bugs in apps such as perf, and it also makes the system less useful by default, so turn it off by default. This is how we generally handle security features that remove functionality, such as firewall code or SELinux - they have to be configured and activated from user-space. Distributions can turn kptr_restrict on again via this line in /etc/sysctrl.conf: kernel.kptr_restrict = 1 ( Also mark the variable __read_mostly while at it, as it's typically modified only once per bootup, or not at all. ) Signed-off-by: Ingo Molnar <mingo@elte.hu> Acked-by: David S. Miller <davem@davemloft.net> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
-rw-r--r--lib/vsprintf.c2
1 files changed, 1 insertions, 1 deletions
diff --git a/lib/vsprintf.c b/lib/vsprintf.c
index bc0ac6b333dc..dfd60192bc2e 100644
--- a/lib/vsprintf.c
+++ b/lib/vsprintf.c
@@ -797,7 +797,7 @@ char *uuid_string(char *buf, char *end, const u8 *addr,
return string(buf, end, uuid, spec);
}
-int kptr_restrict = 1;
+int kptr_restrict __read_mostly;
/*
* Show a '%p' thing. A kernel extension is that the '%p' is followed