kernel/linux.git/lib/iov_iter.c, branch v4.18.11

lib/iov_iter: Fix pipe handling in _copy_to_iter_mcsafe()

2018-07-15T22:05:05+00:00

By mistake the ITER_PIPE early-exit / warning from copy_from_iter() was cargo-culted in _copy_to_iter_mcsafe() rather than a machine-check-safe version of copy_to_iter_pipe(). Implement copy_pipe_to_iter_mcsafe() being careful to return the indication of short copies due to a CPU exception. Without this regression-fix all splice reads to dax-mode files fail. Reported-by: Ross Zwisler Tested-by: Ross Zwisler Signed-off-by: Dan Williams Acked-by: Al Viro Cc: Andrew Morton Cc: Andy Lutomirski Cc: Borislav Petkov Cc: Linus Torvalds Cc: Peter Zijlstra Cc: Thomas Gleixner Cc: Tony Luck Fixes: 8780356ef630 ("x86/asm/memcpy_mcsafe: Define copy_to_iter_mcsafe()") Link: http://lkml.kernel.org/r/153108277278.37979.3327916996902264102.stgit@dwillia2-desk3.amr.corp.intel.com Signed-off-by: Ingo Molnar

lib/iov_iter: Document _copy_to_iter_flushcache()

2018-07-15T22:05:05+00:00

Add some theory of operation documentation to _copy_to_iter_flushcache(). Reported-by: Al Viro Signed-off-by: Dan Williams Cc: Andrew Morton Cc: Andy Lutomirski Cc: Borislav Petkov Cc: Linus Torvalds Cc: Peter Zijlstra Cc: Thomas Gleixner Cc: Tony Luck Link: http://lkml.kernel.org/r/153108276767.37979.9462477994086841699.stgit@dwillia2-desk3.amr.corp.intel.com Signed-off-by: Ingo Molnar

lib/iov_iter: Document _copy_to_iter_mcsafe()

2018-07-15T22:05:05+00:00

Add some theory of operation documentation to _copy_to_iter_mcsafe(). Reported-by: Al Viro Signed-off-by: Dan Williams Cc: Andrew Morton Cc: Andy Lutomirski Cc: Borislav Petkov Cc: Linus Torvalds Cc: Peter Zijlstra Cc: Thomas Gleixner Cc: Tony Luck Link: http://lkml.kernel.org/r/153108276256.37979.1689794213845539316.stgit@dwillia2-desk3.amr.corp.intel.com Signed-off-by: Ingo Molnar

Merge branch 'x86-dax-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

2018-06-05T02:23:13+00:00

Pull x86 dax updates from Ingo Molnar: "This contains x86 memcpy_mcsafe() fault handling improvements the nvdimm tree would like to make more use of" * 'x86-dax-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: x86/asm/memcpy_mcsafe: Define copy_to_iter_mcsafe() x86/asm/memcpy_mcsafe: Add write-protection-fault handling x86/asm/memcpy_mcsafe: Return bytes remaining x86/asm/memcpy_mcsafe: Add labels for __memcpy_mcsafe() write fault handling x86/asm/memcpy_mcsafe: Remove loop unrolling

x86/asm/memcpy_mcsafe: Define copy_to_iter_mcsafe()

2018-05-15T06:32:42+00:00

Use the updated memcpy_mcsafe() implementation to define copy_user_mcsafe() and copy_to_iter_mcsafe(). The most significant difference from typical copy_to_iter() is that the ITER_KVEC and ITER_BVEC iterator types can fail to complete a full transfer. Signed-off-by: Dan Williams Cc: Al Viro Cc: Andrew Morton Cc: Andy Lutomirski Cc: Borislav Petkov Cc: Linus Torvalds Cc: Peter Zijlstra Cc: Thomas Gleixner Cc: Tony Luck Cc: hch@lst.de Cc: linux-fsdevel@vger.kernel.org Cc: linux-nvdimm@lists.01.org Link: http://lkml.kernel.org/r/152539239150.31796.9189779163576449784.stgit@dwillia2-desk3.amr.corp.intel.com Signed-off-by: Ingo Molnar

iov_iter: fix memory leak in pipe_get_pages_alloc()

2018-05-02T19:43:19+00:00

Make n signed to avoid leaking the pages array if __pipe_get_pages() fails to allocate any pages. Signed-off-by: Ilya Dryomov Signed-off-by: Al Viro

iov_iter: fix return type of __pipe_get_pages()

2018-05-02T19:43:15+00:00

It returns -EFAULT and happens to be a helper for pipe_get_pages() whose return type is ssize_t. Signed-off-by: Ilya Dryomov Signed-off-by: Al Viro

new primitive: iov_iter_for_each_range()

2017-10-12T02:36:54+00:00

For kvec and bvec: feeds segments to given callback as long as it returns 0. For iovec and pipe: fails. Signed-off-by: Al Viro

iov_iter: fix page_copy_sane for compound pages

2017-09-21T03:27:48+00:00

Issue is that if the data crosses a page boundary inside a compound page, this check will incorrectly trigger a WARN_ON. To fix this, compute the order using the head of the compound page and adjust the offset to be relative to that head. Fixes: 72e809ed81ed ("iov_iter: sanity checks for copy to/from page primitives") Signed-off-by: Petar Penkov CC: Al Viro CC: Eric Dumazet Signed-off-by: Al Viro

Merge branch 'uaccess-work.iov_iter' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs

2017-07-08T03:39:20+00:00

Pull iov_iter hardening from Al Viro: "This is the iov_iter/uaccess/hardening pile. For one thing, it trims the inline part of copy_to_user/copy_from_user to the minimum that *does* need to be inlined - object size checks, basically. For another, it sanitizes the checks for iov_iter primitives. There are 4 groups of checks: access_ok(), might_fault(), object size and KASAN. - access_ok() had been verified by whoever had set the iov_iter up. However, that has happened in a function far away, so proving that there's no path to actual copying bypassing those checks is hard and proving that iov_iter has not been buggered in the meanwhile is also not pleasant. So we want those redone in actual copyin/copyout. - might_fault() is better off consolidated - we know whether it needs to be checked as soon as we enter iov_iter primitive and observe the iov_iter flavour. No need to wait until the copyin/copyout. The call chains are short enough to make sure we won't miss anything - in fact, it's more robust that way, since there are cases where we do e.g. forced fault-in before getting to copyin/copyout. It's not quite what we need to check (in particular, combination of iovec-backed and set_fs(KERNEL_DS) is almost certainly a bug, not a cause to skip checks), but that's for later series. For now let's keep might_fault(). - KASAN checks belong in copyin/copyout - at the same level where other iov_iter flavours would've hit them in memcpy(). - object size checks should apply to *all* iov_iter flavours, not just iovec-backed ones. There are two groups of primitives - one gets the kernel object described as pointer + size (copy_to_iter(), etc.) while another gets it as page + offset + size (copy_page_to_iter(), etc.) For the first group the checks are best done where we actually have a chance to find the object size. In other words, those belong in inline wrappers in uio.h, before calling into iov_iter.c. Same kind as we have for inlined part of copy_to_user(). For the second group there is no object to look at - offset in page is just a number, it bears no type information. So we do them in the common helper called by iov_iter.c primitives of that kind. All it currently does is checking that we are not trying to access outside of the compound page; eventually we might want to add some sanity checks on the page involved. So the things we need in copyin/copyout part of iov_iter.c do not quite match anything in uaccess.h (we want no zeroing, we *do* want access_ok() and KASAN and we want no might_fault() or object size checks done on that level). OTOH, these needs are simple enough to provide a couple of helpers (static in iov_iter.c) doing just what we need..." * 'uaccess-work.iov_iter' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs: iov_iter: saner checks on copyin/copyout iov_iter: sanity checks for copy to/from page primitives iov_iter/hardening: move object size checks to inlined part copy_{to,from}_user(): consolidate object size checks copy_{from,to}_user(): move kasan checks and might_fault() out-of-line