Commit Graph

13 Commits

Author SHA1 Message Date
Vineet Gupta 79435ac78d ARC: uaccess: dont use "l" gcc inline asm constraint modifier
This used to setup the LP_COUNT register automatically, but now has been
removed.

There was an earlier fix 3c7c7a2fc8 which fixed instance in delay.h but
somehow missed this one as gcc change had not made its way into
production toolchains and was not pedantic as it is now !

Cc: stable@vger.kernel.org
Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
2017-12-20 12:41:46 -08:00
Vineet Gupta e13909a4ac ARC: uaccess: enable INLINE_COPY_{TO,FROM}_USER ...
... and switch to generic out of line version in lib/usercopy.c

Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2017-03-30 00:07:48 -04:00
Al Viro 839cc2954c arc: switch to RAW_COPY_USER
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2017-03-28 23:41:31 -04:00
Al Viro 3a1e37ae00 arc: get rid of unused declaration
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2017-03-28 18:23:20 -04:00
Al Viro db68ce10c4 new helper: uaccess_kernel()
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2017-03-28 16:43:25 -04:00
Al Viro aaa2e7ac80 add asm-generic/extable.h
... and make the users of generic uaccess.h use that.

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2017-03-27 20:27:28 -04:00
Al Viro af1d5b37d6 uaccess: drop duplicate includes from asm/uaccess.h
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2017-03-05 21:57:49 -05:00
Vineet Gupta 05d9d0b96e ARC: uaccess: get_user to zero out dest in cause of fault
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>
2016-09-13 17:49:41 -04:00
Andrea Gelmini 2547476a5e Fix typos
Signed-off-by: Andrea Gelmini <andrea.gelmini@gelma.net>
Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
2016-05-30 10:07:32 +05:30
Vineet Gupta 8922bc3058 ARCv2: Adhere to Zero Delay loop restriction
Branch insn can't be scheduled as last insn of Zero Overhead loop

Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
2015-06-22 14:06:56 +05:30
Vineet Gupta 0752adfda1 ARC: Fix 32-bit wrap around in access_ok()
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>
2013-09-27 16:28:47 +05:30
Vineet Gupta 0a5eae458e ARC: [optim] uaccess __{get,put}_user() optimised
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>
2013-02-11 20:00:32 +05:30
Vineet Gupta 43697cb097 ARC: uaccess friends
Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
2013-02-11 20:00:31 +05:30