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path: root/arch/arc/include/asm/uaccess.h
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2013-10-18ARC: Fix 32-bit wrap around in access_ok()Vineet Gupta
commit 0752adfda15f0eca9859a76da3db1800e129ad43 upstream. Anton reported | LTP tests syscalls/process_vm_readv01 and process_vm_writev01 fail | similarly in one testcase test_iov_invalid -> lvec->iov_base. | Testcase expects errno EFAULT and return code -1, | but it gets return code 1 and ERRNO is 0 what means success. Essentially test case was passing a pointer of -1 which access_ok() was not catching. It was doing [@addr + @sz <= TASK_SIZE] which would pass for @addr == -1 Fixed that by rewriting as [@addr <= TASK_SIZE - @sz] Reported-by: Anton Kolesov <Anton.Kolesov@synopsys.com> Signed-off-by: Vineet Gupta <vgupta@synopsys.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2013-02-11ARC: [optim] uaccess __{get,put}_user() optimisedVineet Gupta
Override asm-generic implementations. We basically gain on 2 fronts * checks for alignment no longer needed as we are only doing "unit" sized copies. (Careful observer could argue that While the kernel buffers are aligned, the user buffer in theory might not be - however in that case the user space is already broken when it tries to deref a hword/word straddling word boundary - so we are not making it any worse). * __copy_{to,from}_user( ) returns bytes that couldn't be copied, whereas get_user() returns 0 for success or -EFAULT (not size). Thus the code to do leftover bytes calculation can be avoided as well. The savings were significant: ~17k of code. bloat-o-meter vmlinux_uaccess_pre vmlinux_uaccess_post add/remove: 0/4 grow/shrink: 8/118 up/down: 1262/-18758 (-17496) ^^^^^^^^^ Signed-off-by: Vineet Gupta <vgupta@synopsys.com> Acked-by: Arnd Bergmann <arnd@arndb.de>
2013-02-11ARC: uaccess friendsVineet Gupta
Signed-off-by: Vineet Gupta <vgupta@synopsys.com>