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* ARC: uaccess: get_user to zero out dest in cause of faultVineet Gupta2016-09-131-2/+9
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Al reported potential issue with ARC get_user() as it wasn't clearing out destination pointer in case of fault due to bad address etc. Verified using following | { | u32 bogus1 = 0xdeadbeef; | u64 bogus2 = 0xdead; | int rc1, rc2; | | pr_info("Orig values %x %llx\n", bogus1, bogus2); | rc1 = get_user(bogus1, (u32 __user *)0x40000000); | rc2 = get_user(bogus2, (u64 __user *)0x50000000); | pr_info("access %d %d, new values %x %llx\n", | rc1, rc2, bogus1, bogus2); | } | [ARCLinux]# insmod /mnt/kernel-module/qtn.ko | Orig values deadbeef dead | access -14 -14, new values 0 0 Reported-by: Al Viro <viro@ZenIV.linux.org.uk> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: linux-snps-arc@lists.infradead.org Cc: linux-kernel@vger.kernel.org Cc: stable@vger.kernel.org Signed-off-by: Vineet Gupta <vgupta@synopsys.com> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
* Fix typosAndrea Gelmini2016-05-301-1/+1
| | | | | Signed-off-by: Andrea Gelmini <andrea.gelmini@gelma.net> Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
* ARCv2: Adhere to Zero Delay loop restrictionVineet Gupta2015-06-221-9/+8
| | | | | | Branch insn can't be scheduled as last insn of Zero Overhead loop Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
* ARC: Fix 32-bit wrap around in access_ok()Vineet Gupta2013-09-271-2/+2
| | | | | | | | | | | | | | | | | | 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>
* ARC: [optim] uaccess __{get,put}_user() optimisedVineet Gupta2013-02-111-0/+105
| | | | | | | | | | | | | | | | | | | | | | | | 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>
* ARC: uaccess friendsVineet Gupta2013-02-111-0/+646
Signed-off-by: Vineet Gupta <vgupta@synopsys.com>