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author | Barry Song <song.bao.hua@hisilicon.com> | 2020-08-12 03:31:57 +0200 |
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committer | Linus Torvalds <torvalds@linux-foundation.org> | 2020-08-12 19:57:57 +0200 |
commit | 18e98e56f4407b8c766b6f6d9f2850fd2a081e4d (patch) | |
tree | 9ddb1fef5f305dcca449ed76a8c2389d00353f9f /mm/cma.c | |
parent | mm/cma.c: fix NULL pointer dereference when cma could not be activated (diff) | |
download | linux-18e98e56f4407b8c766b6f6d9f2850fd2a081e4d.tar.xz linux-18e98e56f4407b8c766b6f6d9f2850fd2a081e4d.zip |
mm: cma: fix the name of CMA areas
Patch series "mm: fix the names of general cma and hugetlb cma", v2.
The current code of CMA can only work when users pass a const string as
name parameter. we need to fix the way to handle names in CMA. On the
other hand, to avoid name conflicts after enabling CMA_DEBUGFS, each
hugetlb should get a different CMA name.
This patch (of 2):
If users give a name saved in stack, the current code will generate magic
pointer. if users don't give a name(NULL), kasprintf() will always return
NULL as we are at the early stage. that means cma_init_reserved_mem()
will return -ENOMEM if users set name parameter as NULL.
[natechancellor@gmail.com: return cma->name directly in cma_get_name]
Link: https://github.com/ClangBuiltLinux/linux/issues/1063
Link: http://lkml.kernel.org/r/20200623015840.621964-1-natechancellor@gmail.com
Signed-off-by: Barry Song <song.bao.hua@hisilicon.com>
Signed-off-by: Nathan Chancellor <natechancellor@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Reviewed-by: Mike Kravetz <mike.kravetz@oracle.com>
Acked-by: Roman Gushchin <guro@fb.com>
Link: http://lkml.kernel.org/r/20200616223131.33828-2-song.bao.hua@hisilicon.com
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'mm/cma.c')
-rw-r--r-- | mm/cma.c | 15 |
1 files changed, 7 insertions, 8 deletions
@@ -52,7 +52,7 @@ unsigned long cma_get_size(const struct cma *cma) const char *cma_get_name(const struct cma *cma) { - return cma->name ? cma->name : "(undefined)"; + return cma->name; } static unsigned long cma_bitmap_aligned_mask(const struct cma *cma, @@ -202,13 +202,12 @@ int __init cma_init_reserved_mem(phys_addr_t base, phys_addr_t size, * subsystems (like slab allocator) are available. */ cma = &cma_areas[cma_area_count]; - if (name) { - cma->name = name; - } else { - cma->name = kasprintf(GFP_KERNEL, "cma%d\n", cma_area_count); - if (!cma->name) - return -ENOMEM; - } + + if (name) + snprintf(cma->name, CMA_MAX_NAME, name); + else + snprintf(cma->name, CMA_MAX_NAME, "cma%d\n", cma_area_count); + cma->base_pfn = PFN_DOWN(base); cma->count = size >> PAGE_SHIFT; cma->order_per_bit = order_per_bit; |