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authorStephen Boyd <sboyd@codeaurora.org>2013-04-30 22:28:42 (GMT)
committerLinus Torvalds <torvalds@linux-foundation.org>2013-05-01 00:04:09 (GMT)
commit446f24d1199e8a546ba7c97da3fbb9a505a94795 (patch)
tree42c44a565fbdd6f923e0c2403b1c62154acab1b2 /arch/x86
parenta05342cbd62b7f6dacb8d71683d799f5e5e694b8 (diff)
downloadlinux-446f24d1199e8a546ba7c97da3fbb9a505a94795.tar.xz
Kconfig: consolidate CONFIG_DEBUG_STRICT_USER_COPY_CHECKS
The help text for this config is duplicated across the x86, parisc, and s390 Kconfig.debug files. Arnd Bergman noted that the help text was slightly misleading and should be fixed to state that enabling this option isn't a problem when using pre 4.4 gcc. To simplify the rewording, consolidate the text into lib/Kconfig.debug and modify it there to be more explicit about when you should say N to this config. Also, make the text a bit more generic by stating that this option enables compile time checks so we can cover architectures which emit warnings vs. ones which emit errors. The details of how an architecture decided to implement the checks isn't as important as the concept of compile time checking of copy_from_user() calls. While we're doing this, remove all the copy_from_user_overflow() code that's duplicated many times and place it into lib/ so that any architecture supporting this option can get the function for free. Signed-off-by: Stephen Boyd <sboyd@codeaurora.org> Acked-by: Arnd Bergmann <arnd@arndb.de> Acked-by: Ingo Molnar <mingo@kernel.org> Acked-by: H. Peter Anvin <hpa@zytor.com> Cc: Arjan van de Ven <arjan@linux.intel.com> Acked-by: Helge Deller <deller@gmx.de> Cc: Heiko Carstens <heiko.carstens@de.ibm.com> Cc: Stephen Rothwell <sfr@canb.auug.org.au> Cc: Chris Metcalf <cmetcalf@tilera.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'arch/x86')
-rw-r--r--arch/x86/Kconfig1
-rw-r--r--arch/x86/Kconfig.debug14
-rw-r--r--arch/x86/lib/usercopy_32.c6
3 files changed, 1 insertions, 20 deletions
diff --git a/arch/x86/Kconfig b/arch/x86/Kconfig
index 05b057d..5db2117 100644
--- a/arch/x86/Kconfig
+++ b/arch/x86/Kconfig
@@ -20,6 +20,7 @@ config X86_64
### Arch settings
config X86
def_bool y
+ select ARCH_HAS_DEBUG_STRICT_USER_COPY_CHECKS
select HAVE_AOUT if X86_32
select HAVE_UNSTABLE_SCHED_CLOCK
select ARCH_SUPPORTS_NUMA_BALANCING
diff --git a/arch/x86/Kconfig.debug b/arch/x86/Kconfig.debug
index 16f7383..c198b7e 100644
--- a/arch/x86/Kconfig.debug
+++ b/arch/x86/Kconfig.debug
@@ -292,20 +292,6 @@ config OPTIMIZE_INLINING
If unsure, say N.
-config DEBUG_STRICT_USER_COPY_CHECKS
- bool "Strict copy size checks"
- depends on DEBUG_KERNEL && !TRACE_BRANCH_PROFILING
- ---help---
- Enabling this option turns a certain set of sanity checks for user
- copy operations into compile time failures.
-
- The copy_from_user() etc checks are there to help test if there
- are sufficient security checks on the length argument of
- the copy operation, by having gcc prove that the argument is
- within bounds.
-
- If unsure, or if you run an older (pre 4.4) gcc, say N.
-
config DEBUG_NMI_SELFTEST
bool "NMI Selftest"
depends on DEBUG_KERNEL && X86_LOCAL_APIC
diff --git a/arch/x86/lib/usercopy_32.c b/arch/x86/lib/usercopy_32.c
index f0312d7..3eb18ac 100644
--- a/arch/x86/lib/usercopy_32.c
+++ b/arch/x86/lib/usercopy_32.c
@@ -689,9 +689,3 @@ _copy_from_user(void *to, const void __user *from, unsigned long n)
return n;
}
EXPORT_SYMBOL(_copy_from_user);
-
-void copy_from_user_overflow(void)
-{
- WARN(1, "Buffer overflow detected!\n");
-}
-EXPORT_SYMBOL(copy_from_user_overflow);