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2020-04-18rslib.h: Replace zero-length array with flexible-array memberGustavo A. R. Silva1-1/+1
The current codebase makes use of the zero-length array language extension to the C90 standard, but the preferred mechanism to declare variable-length types such as these ones is a flexible array member[1][2], introduced in C99: struct foo { int stuff; struct boo array[]; }; By making use of the mechanism above, we will get a compiler warning in case the flexible array does not occur last in the structure, which will help us prevent some kind of undefined behavior bugs from being inadvertently introduced[3] to the codebase from now on. Also, notice that, dynamic memory allocations won't be affected by this change: "Flexible array members have incomplete type, and so the sizeof operator may not be applied. As a quirk of the original implementation of zero-length arrays, sizeof evaluates to zero."[1] This issue was found with the help of Coccinelle. [1] https://gcc.gnu.org/onlinedocs/gcc/Zero-Length.html [2] https://github.com/KSPP/linux/issues/21 [3] commit 76497732932f ("cxgb3/l2t: Fix undefined behaviour") Signed-off-by: Gustavo A. R. Silva <gustavo@embeddedor.com>
2018-04-24rslib: Allocate decoder buffers to avoid VLAsThomas Gleixner1-0/+2
To get rid of the variable length arrays on stack in the RS decoder it's necessary to allocate the decoder buffers per control structure instance. All usage sites have been checked for potential parallel decoder usage and fixed where necessary. Kees confirmed that the pstore decoding is strictly single threaded so there should be no surprises. Allocate them in the rs control structure sized depending on the number of roots for the chosen codec and adapt the decoder code to make use of them. Document the fact that decode operations based on a particular rs control instance cannot run in parallel and the caller has to ensure that as it's not possible to provide a proper locking construct which fits all use cases. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Acked-by: Kees Cook <keescook@chromium.org> Cc: Boris Brezillon <boris.brezillon@free-electrons.com> Cc: Tony Luck <tony.luck@intel.com> Cc: Segher Boessenkool <segher@kernel.crashing.org> Cc: Kernel Hardening <kernel-hardening@lists.openwall.com> Cc: Richard Weinberger <richard@nod.at> Cc: Mike Snitzer <snitzer@redhat.com> Cc: Anton Vorontsov <anton@enomsg.org> Cc: Colin Cross <ccross@android.com> Cc: Andrew Morton <akpm@linuxfoundation.org> Cc: David Woodhouse <dwmw2@infradead.org> Cc: Alasdair Kergon <agk@redhat.com> Signed-off-by: Kees Cook <keescook@chromium.org>
2018-04-24rslib: Split rs control structThomas Gleixner1-6/+13
The decoder library uses variable length arrays on stack. To get rid of them it would be simple to allocate fixed length arrays on stack, but those might become rather large. The other solution is to allocate the buffers in the rs control structure, but this cannot be done as long as the structure can be shared by several users. Sharing is desired because the RS polynom tables are large and initialization is time consuming. To solve this split the codec information out of the control structure and have a pointer to a shared codec in it. Instantiate the control structure for each user, create a new codec if no shareable is avaiable yet. Adjust all affected usage sites to the new scheme. This allows to add per instance decoder buffers to the control structure later on. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Acked-by: Boris Brezillon <boris.brezillon@bootlin.com> Cc: Tony Luck <tony.luck@intel.com> Cc: Kees Cook <keescook@chromium.org> Cc: Segher Boessenkool <segher@kernel.crashing.org> Cc: Kernel Hardening <kernel-hardening@lists.openwall.com> Cc: Richard Weinberger <richard@nod.at> Cc: Mike Snitzer <snitzer@redhat.com> Cc: Anton Vorontsov <anton@enomsg.org> Cc: Colin Cross <ccross@android.com> Cc: Andrew Morton <akpm@linuxfoundation.org> Cc: David Woodhouse <dwmw2@infradead.org> Cc: Alasdair Kergon <agk@redhat.com> Signed-off-by: Kees Cook <keescook@chromium.org>
2018-04-24rslib: Remove GPL boilerplateThomas Gleixner1-5/+0
Now that SPDX identifiers are in place, remove the GPL boiler plate text. Leave the notices which document that Phil Karn granted permission in place (encode/decode source code). The modified files are code written for the kernel by me. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Kate Stewart <kstewart@linuxfoundation.org> Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: Boris Brezillon <boris.brezillon@free-electrons.com> Cc: Tony Luck <tony.luck@intel.com> Cc: Kees Cook <keescook@chromium.org> Cc: Segher Boessenkool <segher@kernel.crashing.org> Cc: Kernel Hardening <kernel-hardening@lists.openwall.com> Cc: Richard Weinberger <richard@nod.at> Cc: Mike Snitzer <snitzer@redhat.com> Cc: Anton Vorontsov <anton@enomsg.org> Cc: Colin Cross <ccross@android.com> Cc: Andrew Morton <akpm@linuxfoundation.org> Cc: David Woodhouse <dwmw2@infradead.org> Cc: Alasdair Kergon <agk@redhat.com> Signed-off-by: Kees Cook <keescook@chromium.org>
2018-04-24rslib: Add SPDX identifiersThomas Gleixner1-0/+1
The Reed-Solomon library is based on code from Phil Karn who granted permission to import it into the kernel under the GPL V2. See commit 15b5423757a7 ("Shared Reed-Solomon ECC library") in the history git tree at: git://git.kernel.org/pub/scm/linux/kernel/git/tglx/history.git ... The encoder/decoder code is lifted from the GPL'd userspace RS-library written by Phil Karn. I modified/wrapped it to provide the different functions which we need in the MTD/NAND code. ... Signed-Off-By: Thomas Gleixner <tglx@linutronix.de> Signed-Off-By: David Woodhouse <dwmw2@infradead.org> "No objections at all. Just keep the authorship notices." -- Phil Karn Add the proper SPDX identifiers according to Documentation/process/license-rules.rst. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Kate Stewart <kstewart@linuxfoundation.org> Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: Boris Brezillon <boris.brezillon@free-electrons.com> Cc: Tony Luck <tony.luck@intel.com> Cc: Kees Cook <keescook@chromium.org> Cc: Segher Boessenkool <segher@kernel.crashing.org> Cc: Kernel Hardening <kernel-hardening@lists.openwall.com> Cc: Richard Weinberger <richard@nod.at> Cc: Mike Snitzer <snitzer@redhat.com> Cc: Anton Vorontsov <anton@enomsg.org> Cc: Colin Cross <ccross@android.com> Cc: Andrew Morton <akpm@linuxfoundation.org> Cc: David Woodhouse <dwmw2@infradead.org> Cc: Alasdair Kergon <agk@redhat.com> Signed-off-by: Kees Cook <keescook@chromium.org>
2018-04-24rslib: Cleanup top level commentsThomas Gleixner1-6/+1
File references and stale CVS ids are really not useful. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Cc: Boris Brezillon <boris.brezillon@free-electrons.com> Cc: Tony Luck <tony.luck@intel.com> Cc: Kees Cook <keescook@chromium.org> Cc: Segher Boessenkool <segher@kernel.crashing.org> Cc: Kernel Hardening <kernel-hardening@lists.openwall.com> Cc: Richard Weinberger <richard@nod.at> Cc: Mike Snitzer <snitzer@redhat.com> Cc: Anton Vorontsov <anton@enomsg.org> Cc: Colin Cross <ccross@android.com> Cc: Andrew Morton <akpm@linuxfoundation.org> Cc: David Woodhouse <dwmw2@infradead.org> Cc: Alasdair Kergon <agk@redhat.com> Signed-off-by: Kees Cook <keescook@chromium.org>
2018-04-24rslib: Cleanup whitespace damageThomas Gleixner1-6/+6
Instead of mixing the whitespace cleanup into functional changes, mop it up first. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Cc: Boris Brezillon <boris.brezillon@free-electrons.com> Cc: Tony Luck <tony.luck@intel.com> Cc: Kees Cook <keescook@chromium.org> Cc: Segher Boessenkool <segher@kernel.crashing.org> Cc: Kernel Hardening <kernel-hardening@lists.openwall.com> Cc: Richard Weinberger <richard@nod.at> Cc: Mike Snitzer <snitzer@redhat.com> Cc: Anton Vorontsov <anton@enomsg.org> Cc: Colin Cross <ccross@android.com> Cc: Andrew Morton <akpm@linuxfoundation.org> Cc: David Woodhouse <dwmw2@infradead.org> Cc: Alasdair Kergon <agk@redhat.com> Signed-off-by: Kees Cook <keescook@chromium.org>
2018-04-24rslib: Add GFP aware init functionThomas Gleixner1-3/+25
The rslib usage in dm/verity_fec is broken because init_rs() can nest in GFP_NOIO mempool allocations as init_rs() is invoked from the mempool alloc callback. Provide a variant which takes gfp_t flags as argument. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Cc: Mike Snitzer <snitzer@redhat.com> Cc: Alasdair Kergon <agk@redhat.com> Cc: Neil Brown <neilb@suse.com> Signed-off-by: Kees Cook <keescook@chromium.org>
2007-05-02[RSLIB] Support non-canonical GF representationsSegher Boessenkool1-0/+4
For the CAFÉ NAND controller, we need to support non-canonical representations of the Galois field. Allow the caller to provide its own function for generating the field, and CAFÉ can use rslib instead of its own implementation. Signed-off-by: Segher Boessenkool <segher@kernel.crashing.org> Signed-off-by: David Woodhouse <dwmw2@infradead.org>
2005-11-07[LIB] reed_solomon: Clean up trailing white spacesThomas Gleixner1-14/+14
2005-04-16Linux-2.6.12-rc2Linus Torvalds1-0/+105
Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!