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* x86: use the new generic strnlen_user() functionLinus Torvalds2012-05-261-17/+0
| | | | | | | This throws away the old x86-specific functions in favor of the generic optimized version. Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* x86: merge 32/64-bit versions of 'strncpy_from_user()' and speed it upLinus Torvalds2012-04-111-5/+0
| | | | | | | | | | | | | | | | | | | | | | | | | | | | This merges the 32- and 64-bit versions of the x86 strncpy_from_user() by just rewriting it in C rather than the ancient inline asm versions that used lodsb/stosb and had been duplicated for (trivial) differences between the 32-bit and 64-bit versions. While doing that, it also speeds them up by doing the accesses a word at a time. Finally, the new routines also properly handle the case of hitting the end of the address space, which we have never done correctly before (fs/namei.c has a hack around it for that reason). Despite all these improvements, it actually removes more lines than it adds, due to the de-duplication. Also, we no longer export (or define) the legacy __strncpy_from_user() function (that was defined to not do the user permission checks), since it's not actually used anywhere, and the user address space checks are built in to the new code. Other architecture maintainers have been notified that the old hack in fs/namei.c will be going away in the 3.5 merge window, in case they copied the x86 approach of being a bit cavalier about the end of the address space. Cc: linux-arch@vger.kernel.org Cc: Ingo Molnar <mingo@kernel.org> Cc: Peter Anvin" <hpa@zytor.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* sanitize <linux/prefetch.h> usageLinus Torvalds2011-05-201-1/+0
| | | | | | | | | | | | | | | | | | | | | Commit e66eed651fd1 ("list: remove prefetching from regular list iterators") removed the include of prefetch.h from list.h, which uncovered several cases that had apparently relied on that rather obscure header file dependency. So this fixes things up a bit, using grep -L linux/prefetch.h $(git grep -l '[^a-z_]prefetchw*(' -- '*.[ch]') grep -L 'prefetchw*(' $(git grep -l 'linux/prefetch.h' -- '*.[ch]') to guide us in finding files that either need <linux/prefetch.h> inclusion, or have it despite not needing it. There are more of them around (mostly network drivers), but this gets many core ones. Reported-by: Stephen Rothwell <sfr@canb.auug.org.au> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* x86: copy_from_user() should not return -EFAULTHeiko Carstens2010-01-051-3/+2
| | | | | | | | | | | | | | | | Callers of copy_from_user() expect it to return the number of bytes it could not copy. In no case it is supposed to return -EFAULT. In case of a detected buffer overflow just return the requested length. In addition one could think of a memset that would clear the size of the target object. [ hpa: code is not in .32 so not needed for -stable ] Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com> Acked-by: Arjan van de Ven <arjan@linux.intel.com> LKML-Reference: <20100105131911.GC5480@osiris.boeblingen.de.ibm.com> Signed-off-by: H. Peter Anvin <hpa@zytor.com>
* x86: Add a Kconfig option to turn the copy_from_user warnings into errorsArjan van de Ven2009-10-021-1/+3
| | | | | | | | | | | | | | | | | | For automated testing it is useful to have the option to turn the warnings on copy_from_user() etc checks into errors: In function ‘copy_from_user’, inlined from ‘fd_copyin’ at drivers/block/floppy.c:3080, inlined from ‘fd_ioctl’ at drivers/block/floppy.c:3503: linux/arch/x86/include/asm/uaccess_32.h:213: error: call to ‘copy_from_user_overflow’ declared with attribute error: copy_from_user buffer size is not provably correct Signed-off-by: Arjan van de Ven <arjan@linux.intel.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Andrew Morton <akpm@linux-foundation.org> LKML-Reference: <20091002075050.4e9f7641@infradead.org> Signed-off-by: Ingo Molnar <mingo@elte.hu>
* x86: Turn the copy_from_user check into an (optional) compile time warningArjan van de Ven2009-10-011-3/+9
| | | | | | | | | | | | | | | | | | | | | | | | | A previous patch added the buffer size check to copy_from_user(). One of the things learned from analyzing the result of the previous patch is that in general, gcc is really good at proving that the code contains sufficient security checks to not need to do a runtime check. But that for those cases where gcc could not prove this, there was a relatively high percentage of real security issues. This patch turns the case of "gcc cannot prove" into a compile time warning, as long as a sufficiently new gcc is in use that supports this. The objective is that these warnings will trigger developers checking new cases out before a security hole enters a linux kernel release. Signed-off-by: Arjan van de Ven <arjan@linux.intel.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: "David S. Miller" <davem@davemloft.net> Cc: James Morris <jmorris@namei.org> Cc: Jan Beulich <jbeulich@novell.com> LKML-Reference: <20090930130523.348ae6c4@infradead.org> Signed-off-by: Ingo Molnar <mingo@elte.hu>
* x86: Use __builtin_object_size() to validate the buffer size for ↵Arjan van de Ven2009-09-261-1/+18
| | | | | | | | | | | | | | | | | | | | | copy_from_user() gcc (4.x) supports the __builtin_object_size() builtin, which reports the size of an object that a pointer point to, when known at compile time. If the buffer size is not known at compile time, a constant -1 is returned. This patch uses this feature to add a sanity check to copy_from_user(); if the target buffer is known to be smaller than the copy size, the copy is aborted and a WARNing is emitted in memory debug mode. These extra checks compile away when the object size is not known, or if both the buffer size and the copy length are constants. Signed-off-by: Arjan van de Ven <arjan@linux.intel.com> LKML-Reference: <20090926143301.2c396b94@infradead.org> Signed-off-by: Ingo Molnar <mingo@elte.hu>
* x86: Fix uaccess_32.h typoSergey Senozhatsky2009-09-201-1/+1
| | | | | | | | Trivial: correct "that the we don't" typo. Signed-off-by: Sergey Senozhatsky <sergey.senozhatsky@gmail.com> LKML-Reference: <20090917125401.GU3717@localdomain.by> Signed-off-by: Ingo Molnar <mingo@elte.hu>
* Merge commit 'v2.6.28-rc2' into core/lockingIngo Molnar2008-10-281-4/+4
| | | | | Conflicts: arch/um/include/asm/system.h
* x86: Fix ASM_X86__ header guardsH. Peter Anvin2008-10-221-3/+3
| | | | | | | | | Change header guards named "ASM_X86__*" to "_ASM_X86_*" since: a. the double underscore is ugly and pointless. b. no leading underscore violates namespace constraints. Signed-off-by: H. Peter Anvin <hpa@zytor.com>
* x86, um: ... and asm-x86 moveAl Viro2008-10-221-0/+218
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk> Signed-off-by: H. Peter Anvin <hpa@zytor.com>
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