kernel/linux.git/lib/scatterlist.c, branch v4.14.306

sgl_alloc_order: fix memory leak

2020-11-05T10:06:58+00:00

[ Upstream commit b2a182a40278bc5849730e66bca01a762188ed86 ] sgl_alloc_order() can fail when 'length' is large on a memory constrained system. When order > 0 it will potentially be making several multi-page allocations with the later ones more likely to fail than the earlier one. So it is important that sgl_alloc_order() frees up any pages it has obtained before returning NULL. In the case when order > 0 it calls the wrong free page function and leaks. In testing the leak was sufficient to bring down my 8 GiB laptop with OOM. Reviewed-by: Bart Van Assche Signed-off-by: Douglas Gilbert Signed-off-by: Jens Axboe Signed-off-by: Sasha Levin

lib/scatterlist.c: adjust indentation in __sg_alloc_table

2020-02-28T15:36:08+00:00

[ Upstream commit 4e456fee215677584cafa7f67298a76917e89c64 ] Clang warns: ../lib/scatterlist.c:314:5: warning: misleading indentation; statement is not part of the previous 'if' [-Wmisleading-indentation] return -ENOMEM; ^ ../lib/scatterlist.c:311:4: note: previous statement is here if (prv) ^ 1 warning generated. This warning occurs because there is a space before the tab on this line. Remove it so that the indentation is consistent with the Linux kernel coding style and clang no longer warns. Link: http://lkml.kernel.org/r/20191218033606.11942-1-natechancellor@gmail.com Link: https://github.com/ClangBuiltLinux/linux/issues/830 Fixes: edce6820a9fd ("scatterlist: prevent invalid free when alloc fails") Signed-off-by: Nathan Chancellor Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds Signed-off-by: Sasha Levin

lib/scatterlist: Introduce sgl_alloc() and sgl_free()

2019-11-12T18:18:30+00:00

commit e80a0af4759a164214f02da157a3800753ce135f upstream. Many kernel drivers contain code that allocates and frees both a scatterlist and the pages that populate that scatterlist. Introduce functions in lib/scatterlist.c that perform these tasks instead of duplicating this functionality in multiple drivers. Only include these functions in the build if CONFIG_SGL_ALLOC=y to avoid that the kernel size increases if this functionality is not used. Signed-off-by: Bart Van Assche Reviewed-by: Hannes Reinecke Reviewed-by: Johannes Thumshirn Signed-off-by: Jens Axboe Signed-off-by: Greg Kroah-Hartman

lib/scatterlist: Fix mapping iterator when sg->offset is greater than PAGE_SIZE

2019-07-31T05:28:37+00:00

commit aeb87246537a83c2aff482f3f34a2e0991e02cbc upstream. All mapping iterator logic is based on the assumption that sg->offset is always lower than PAGE_SIZE. But there are situations where sg->offset is such that the SG item is on the second page. In that case sg_copy_to_buffer() fails properly copying the data into the buffer. One of the reason is that the data will be outside the kmapped area used to access that data. This patch fixes the issue by adjusting the mapping iterator offset and pgoffset fields such that offset is always lower than PAGE_SIZE. Signed-off-by: Christophe Leroy Fixes: 4225fc8555a9 ("lib/scatterlist: use page iterator in the mapping iterator") Cc: stable@vger.kernel.org Signed-off-by: Herbert Xu Signed-off-by: Greg Kroah-Hartman

scatterlist: add sg_zero_buffer() helper

2017-06-15T12:30:14+00:00

The sg_zero_buffer() helper is used to zero fill an area in a SG list. Signed-off-by: Johannes Thumshirn Reviewed-by: Sagi Grimberg [hch: renamed to sg_zero_buffer] Signed-off-by: Christoph Hellwig

scatterlist: do not disable IRQs in sg_copy_buffer

2017-02-28T02:43:46+00:00

Commit 50bed2e2862a ("sg: disable interrupts inside sg_copy_buffer") introduced disabling interrupts in sg_copy_buffer() since atomic uses of miter required it due to use of kmap_atomic(). However, as commit 8290e2d2dcbf ("scatterlist: atomic sg_mapping_iter() no longer needs disabled IRQs") acknowledges disabling interrupts is no longer needed for calls to kmap_atomic() and therefore unneeded for miter ops either, so remove it from sg_copy_buffer(). Link: http://lkml.kernel.org/r/1486040150-14109-3-git-send-email-gilad@benyossef.com Signed-off-by: Gilad Ben-Yossef Cc: Jens Axboe Cc: Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

scatterlist: reorder compound boolean expression

2017-02-28T02:43:46+00:00

Test the cheaper boolean expression with no side effects first. Link: http://lkml.kernel.org/r/1486040150-14109-2-git-send-email-gilad@benyossef.com Signed-off-by: Gilad Ben-Yossef Cc: Jens Axboe Cc: Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

scatterlist: fix a typo in comment block of sg_miter_stop()

2016-02-08T18:15:17+00:00

Fix the doubled "started" and tidy up the following sentences. Signed-off-by: Masahiro Yamada Signed-off-by: Linus Torvalds

scatterlist: allow limited chaining without ARCH_HAS_SG_CHAIN

2015-08-17T14:12:51+00:00

There are a couple of uses of struct scatterlist that never go to the dma_map_sg() helper and thus don't care about ARCH_HAS_SG_CHAIN which indicates that we can map chained S/G list. The most important one is the crypto code, which currently has to open code a few helpers to always allow chaining. This patch removes a few #ifdef ARCH_HAS_SG_CHAIN statements so that we can switch the crypto code to these common helpers. Signed-off-by: Christoph Hellwig Signed-off-by: Jens Axboe

drivers/scsi/scsi_debug.c: resolve sg buffer const-ness issue

2015-07-01T02:44:59+00:00

do_device_access() takes a separate parameter to indicate the direction of data transfer, which it used to use to select the appropriate function out of sg_pcopy_{to,from}_buffer(). However these two functions now have So this patch makes it bypass these wrappers and call the underlying function sg_copy_buffer() directly; this has the same calling style as do_device_access() i.e. a separate direction-of-transfer parameter and no pointers-to-const, so skipping the wrappers not only eliminates the warning, it also make the code simpler :) [akpm@linux-foundation.org: fix very broken build] Signed-off-by: Dave Gordon Acked-by: Arnd Bergmann Cc: James Bottomley Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds