From 6ade20327dbb808882888ed8ccded71e93067cf9 Mon Sep 17 00:00:00 2001 From: Liviu Dudau Date: Tue, 5 Mar 2019 15:42:54 -0800 Subject: mm/vmalloc.c: don't dereference possible NULL pointer in __vunmap() find_vmap_area() can return a NULL pointer and we're going to dereference it without checking it first. Use the existing find_vm_area() function which does exactly what we want and checks for the NULL pointer. Link: http://lkml.kernel.org/r/20181228171009.22269-1-liviu@dudau.co.uk Fixes: f3c01d2f3ade ("mm: vmalloc: avoid racy handling of debugobjects in vunmap") Signed-off-by: Liviu Dudau Reviewed-by: Andrew Morton Cc: Chintan Pandya Cc: Andrey Ryabinin Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- mm/vmalloc.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'mm/vmalloc.c') diff --git a/mm/vmalloc.c b/mm/vmalloc.c index 871e41c55e23..806047d7fda3 100644 --- a/mm/vmalloc.c +++ b/mm/vmalloc.c @@ -1505,7 +1505,7 @@ static void __vunmap(const void *addr, int deallocate_pages) addr)) return; - area = find_vmap_area((unsigned long)addr)->vm; + area = find_vm_area(addr); if (unlikely(!area)) { WARN(1, KERN_ERR "Trying to vfree() nonexistent vm area (%p)\n", addr); -- cgit v1.2.2 From 5a82ac715d1fd4f117d7b7e76664c0ea3d09e5e7 Mon Sep 17 00:00:00 2001 From: Roman Penyaev Date: Tue, 5 Mar 2019 15:43:17 -0800 Subject: mm/vmalloc.c: make vmalloc_32_user() align base kernel virtual address to SHMLBA This patch repeats the original one from David S Miller: 2dca6999eed5 ("mm, perf_event: Make vmalloc_user() align base kernel virtual address to SHMLBA") but for missed vmalloc_32_user() case, which also requires correct alignment of virtual address on kernel side to avoid D-caches aliases. A bit of copy-paste from original patch to recover in memory of what is all about: When a vmalloc'd area is mmap'd into userspace, some kind of co-ordination is necessary for this to work on platforms with cpu D-caches which can have aliases. Otherwise kernel side writes won't be seen properly in userspace and vice versa. If the kernel side mapping and the user side one have the same alignment, modulo SHMLBA, this can work as long as VM_SHARED is shared of VMA and for all current users this is true. VM_SHARED will force SHMLBA alignment of the user side mmap on platforms with D-cache aliasing matters. David S. Miller > What are the user-visible runtime effects of this change? In simple words: proper alignment avoids possible difference in data, seen by different virtual mapings: userspace and kernel in our case. I.e. userspace reads cache line A, kernel writes to cache line B. Both cache lines correspond to the same physical memory (thus aliases). So this should fix data corruption for archs with vivt and vipt caches, e.g. armv6. Personally I've never worked with this archs, I just spotted the strange difference in code: for one case we do alignment, for another - not. I have a strong feeling that David simply missed vmalloc_32_user() case. > > Is a -stable backport needed? No, I do not think so. The only one user of vmalloc_32_user() is virtual frame buffer device drivers/video/fbdev/vfb.c, which has in the description "The main use of this frame buffer device is testing and debugging the frame buffer subsystem. Do NOT enable it for normal systems!". And it seems to me that this vfb.c does not need 32bit addressable pages (vmalloc_32_user() case), because it is virtual device and should not care about things like dma32 zones, etc. Probably is better to clean the code and switch vfb.c from vmalloc_32_user() to vmalloc_user() case and wipe out vmalloc_32_user() from vmalloc.c completely. But I'm not very much sure that this is worth to do, that's so minor, so we can leave it as is. Link: http://lkml.kernel.org/r/20190108110944.23591-1-rpenyaev@suse.de Signed-off-by: Roman Penyaev Reviewed-by: Andrew Morton Cc: Stephen Rothwell Cc: Michal Hocko Cc: David S. Miller Cc: Peter Zijlstra Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- mm/vmalloc.c | 5 +++-- 1 file changed, 3 insertions(+), 2 deletions(-) (limited to 'mm/vmalloc.c') diff --git a/mm/vmalloc.c b/mm/vmalloc.c index 806047d7fda3..cb827624c006 100644 --- a/mm/vmalloc.c +++ b/mm/vmalloc.c @@ -1967,8 +1967,9 @@ void *vmalloc_32_user(unsigned long size) struct vm_struct *area; void *ret; - ret = __vmalloc_node(size, 1, GFP_VMALLOC32 | __GFP_ZERO, PAGE_KERNEL, - NUMA_NO_NODE, __builtin_return_address(0)); + ret = __vmalloc_node(size, SHMLBA, GFP_VMALLOC32 | __GFP_ZERO, + PAGE_KERNEL, NUMA_NO_NODE, + __builtin_return_address(0)); if (ret) { area = find_vm_area(ret); area->flags |= VM_USERMAP; -- cgit v1.2.2 From 401592d2e095947344e10ec0623adbcd58934dd4 Mon Sep 17 00:00:00 2001 From: Roman Penyaev Date: Tue, 5 Mar 2019 15:43:20 -0800 Subject: mm/vmalloc: fix size check for remap_vmalloc_range_partial() When VM_NO_GUARD is not set area->size includes adjacent guard page, thus for correct size checking get_vm_area_size() should be used, but not area->size. This fixes possible kernel oops when userspace tries to mmap an area on 1 page bigger than was allocated by vmalloc_user() call: the size check inside remap_vmalloc_range_partial() accounts non-existing guard page also, so check successfully passes but vmalloc_to_page() returns NULL (guard page does not physically exist). The following code pattern example should trigger an oops: static int oops_mmap(struct file *file, struct vm_area_struct *vma) { void *mem; mem = vmalloc_user(4096); BUG_ON(!mem); /* Do not care about mem leak */ return remap_vmalloc_range(vma, mem, 0); } And userspace simply mmaps size + PAGE_SIZE: mmap(NULL, 8192, PROT_WRITE|PROT_READ, MAP_PRIVATE, fd, 0); Possible candidates for oops which do not have any explicit size checks: *** drivers/media/usb/stkwebcam/stk-webcam.c: v4l_stk_mmap[789] ret = remap_vmalloc_range(vma, sbuf->buffer, 0); Or the following one: *** drivers/video/fbdev/core/fbmem.c static int fb_mmap(struct file *file, struct vm_area_struct * vma) ... res = fb->fb_mmap(info, vma); Where fb_mmap callback calls remap_vmalloc_range() directly without any explicit checks: *** drivers/video/fbdev/vfb.c static int vfb_mmap(struct fb_info *info, struct vm_area_struct *vma) { return remap_vmalloc_range(vma, (void *)info->fix.smem_start, vma->vm_pgoff); } Link: http://lkml.kernel.org/r/20190103145954.16942-2-rpenyaev@suse.de Signed-off-by: Roman Penyaev Acked-by: Michal Hocko Cc: Andrey Ryabinin Cc: Joe Perches Cc: "Luis R. Rodriguez" Cc: Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- mm/vmalloc.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'mm/vmalloc.c') diff --git a/mm/vmalloc.c b/mm/vmalloc.c index cb827624c006..421ae07ffb37 100644 --- a/mm/vmalloc.c +++ b/mm/vmalloc.c @@ -2249,7 +2249,7 @@ int remap_vmalloc_range_partial(struct vm_area_struct *vma, unsigned long uaddr, if (!(area->flags & VM_USERMAP)) return -EINVAL; - if (kaddr + size > area->addr + area->size) + if (kaddr + size > area->addr + get_vm_area_size(area)) return -EINVAL; do { -- cgit v1.2.2 From c67dc6247576250a9c9f09adcabad0385a1e7d73 Mon Sep 17 00:00:00 2001 From: Roman Penyaev Date: Tue, 5 Mar 2019 15:43:24 -0800 Subject: mm/vmalloc: do not call kmemleak_free() on not yet accounted memory __vmalloc_area_node() calls vfree() on error path, which in turn calls kmemleak_free(), but area is not yet accounted by kmemleak_vmalloc(). Link: http://lkml.kernel.org/r/20190103145954.16942-3-rpenyaev@suse.de Signed-off-by: Roman Penyaev Reviewed-by: Andrew Morton Cc: Michal Hocko Cc: Andrey Ryabinin Cc: Joe Perches Cc: "Luis R. Rodriguez" Cc: Catalin Marinas Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- mm/vmalloc.c | 16 +++++++++++----- 1 file changed, 11 insertions(+), 5 deletions(-) (limited to 'mm/vmalloc.c') diff --git a/mm/vmalloc.c b/mm/vmalloc.c index 421ae07ffb37..351ec73b3288 100644 --- a/mm/vmalloc.c +++ b/mm/vmalloc.c @@ -1565,6 +1565,14 @@ void vfree_atomic(const void *addr) __vfree_deferred(addr); } +static void __vfree(const void *addr) +{ + if (unlikely(in_interrupt())) + __vfree_deferred(addr); + else + __vunmap(addr, 1); +} + /** * vfree - release memory allocated by vmalloc() * @addr: memory base address @@ -1591,10 +1599,8 @@ void vfree(const void *addr) if (!addr) return; - if (unlikely(in_interrupt())) - __vfree_deferred(addr); - else - __vunmap(addr, 1); + + __vfree(addr); } EXPORT_SYMBOL(vfree); @@ -1709,7 +1715,7 @@ fail: warn_alloc(gfp_mask, NULL, "vmalloc: allocation failure, allocated %ld of %ld bytes", (area->nr_pages*PAGE_SIZE), area->size); - vfree(area->addr); + __vfree(area->addr); return NULL; } -- cgit v1.2.2 From bc84c53525b4199317df1dab414263a68ba4b6f6 Mon Sep 17 00:00:00 2001 From: Roman Penyaev Date: Tue, 5 Mar 2019 15:43:27 -0800 Subject: mm/vmalloc: pass VM_USERMAP flags directly to __vmalloc_node_range() vmalloc_user*() calls differ from normal vmalloc() only in that they set VM_USERMAP flags for the area. During the whole history of vmalloc.c changes now it is possible simply to pass VM_USERMAP flags directly to __vmalloc_node_range() call instead of finding the area (which obviously takes time) after the allocation. Link: http://lkml.kernel.org/r/20190103145954.16942-4-rpenyaev@suse.de Signed-off-by: Roman Penyaev Acked-by: Michal Hocko Cc: Andrey Ryabinin Cc: Joe Perches Cc: "Luis R. Rodriguez" Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- mm/vmalloc.c | 31 ++++++++----------------------- 1 file changed, 8 insertions(+), 23 deletions(-) (limited to 'mm/vmalloc.c') diff --git a/mm/vmalloc.c b/mm/vmalloc.c index 351ec73b3288..895b2c522d86 100644 --- a/mm/vmalloc.c +++ b/mm/vmalloc.c @@ -1865,18 +1865,10 @@ EXPORT_SYMBOL(vzalloc); */ void *vmalloc_user(unsigned long size) { - struct vm_struct *area; - void *ret; - - ret = __vmalloc_node(size, SHMLBA, - GFP_KERNEL | __GFP_ZERO, - PAGE_KERNEL, NUMA_NO_NODE, - __builtin_return_address(0)); - if (ret) { - area = find_vm_area(ret); - area->flags |= VM_USERMAP; - } - return ret; + return __vmalloc_node_range(size, SHMLBA, VMALLOC_START, VMALLOC_END, + GFP_KERNEL | __GFP_ZERO, PAGE_KERNEL, + VM_USERMAP, NUMA_NO_NODE, + __builtin_return_address(0)); } EXPORT_SYMBOL(vmalloc_user); @@ -1970,17 +1962,10 @@ EXPORT_SYMBOL(vmalloc_32); */ void *vmalloc_32_user(unsigned long size) { - struct vm_struct *area; - void *ret; - - ret = __vmalloc_node(size, SHMLBA, GFP_VMALLOC32 | __GFP_ZERO, - PAGE_KERNEL, NUMA_NO_NODE, - __builtin_return_address(0)); - if (ret) { - area = find_vm_area(ret); - area->flags |= VM_USERMAP; - } - return ret; + return __vmalloc_node_range(size, SHMLBA, VMALLOC_START, VMALLOC_END, + GFP_VMALLOC32 | __GFP_ZERO, PAGE_KERNEL, + VM_USERMAP, NUMA_NO_NODE, + __builtin_return_address(0)); } EXPORT_SYMBOL(vmalloc_32_user); -- cgit v1.2.2 From 153178edc7819b5c550e5d498d50697ff9d5f223 Mon Sep 17 00:00:00 2001 From: "Uladzislau Rezki (Sony)" Date: Tue, 5 Mar 2019 15:43:30 -0800 Subject: vmalloc: export __vmalloc_node_range for CONFIG_TEST_VMALLOC_MODULE Export __vmaloc_node_range() function if CONFIG_TEST_VMALLOC_MODULE is enabled. Some test cases in vmalloc test suite module require and make use of that function. Please note, that it is not supposed to be used for other purposes. We need it only for performance analysis, stressing and stability check of vmalloc allocator. Link: http://lkml.kernel.org/r/20190103142108.20744-2-urezki@gmail.com Signed-off-by: Uladzislau Rezki (Sony) Reviewed-by: Andrew Morton Cc: Michal Hocko Cc: Kees Cook Cc: Matthew Wilcox Cc: Shuah Khan Cc: Oleksiy Avramchenko Cc: Thomas Gleixner Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- mm/vmalloc.c | 9 +++++++++ 1 file changed, 9 insertions(+) (limited to 'mm/vmalloc.c') diff --git a/mm/vmalloc.c b/mm/vmalloc.c index 895b2c522d86..e83961767dc1 100644 --- a/mm/vmalloc.c +++ b/mm/vmalloc.c @@ -1774,6 +1774,15 @@ fail: return NULL; } +/* + * This is only for performance analysis of vmalloc and stress purpose. + * It is required by vmalloc test module, therefore do not use it other + * than that. + */ +#ifdef CONFIG_TEST_VMALLOC_MODULE +EXPORT_SYMBOL_GPL(__vmalloc_node_range); +#endif + /** * __vmalloc_node - allocate virtually contiguous memory * @size: allocation size -- cgit v1.2.2 From afd07389d3f4933c7f7817a92fb5e053d59a3182 Mon Sep 17 00:00:00 2001 From: "Uladzislau Rezki (Sony)" Date: Tue, 5 Mar 2019 15:45:59 -0800 Subject: mm/vmalloc.c: fix kernel BUG at mm/vmalloc.c:512! One of the vmalloc stress test case triggers the kernel BUG(): [60.562151] ------------[ cut here ]------------ [60.562154] kernel BUG at mm/vmalloc.c:512! [60.562206] invalid opcode: 0000 [#1] PREEMPT SMP PTI [60.562247] CPU: 0 PID: 430 Comm: vmalloc_test/0 Not tainted 4.20.0+ #161 [60.562293] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.10.2-1 04/01/2014 [60.562351] RIP: 0010:alloc_vmap_area+0x36f/0x390 it can happen due to big align request resulting in overflowing of calculated address, i.e. it becomes 0 after ALIGN()'s fixup. Fix it by checking if calculated address is within vstart/vend range. Link: http://lkml.kernel.org/r/20190124115648.9433-2-urezki@gmail.com Signed-off-by: Uladzislau Rezki (Sony) Reviewed-by: Andrew Morton Cc: Ingo Molnar Cc: Joel Fernandes Cc: Matthew Wilcox Cc: Michal Hocko Cc: Oleksiy Avramchenko Cc: Steven Rostedt Cc: Tejun Heo Cc: Thomas Garnier Cc: Thomas Gleixner Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- mm/vmalloc.c | 6 +++++- 1 file changed, 5 insertions(+), 1 deletion(-) (limited to 'mm/vmalloc.c') diff --git a/mm/vmalloc.c b/mm/vmalloc.c index e83961767dc1..77006fa1a90b 100644 --- a/mm/vmalloc.c +++ b/mm/vmalloc.c @@ -498,7 +498,11 @@ nocache: } found: - if (addr + size > vend) + /* + * Check also calculated address against the vstart, + * because it can be 0 because of big align request. + */ + if (addr + size > vend || addr < vstart) goto overflow; va->va_start = addr; -- cgit v1.2.2 From 92eac16819e47ab919bd8f28ed49f8fadad0954e Mon Sep 17 00:00:00 2001 From: Mike Rapoport Date: Tue, 5 Mar 2019 15:48:36 -0800 Subject: docs/mm: vmalloc: re-indent kernel-doc comemnts Some kernel-doc comments in mm/vmalloc.c have leading tab in indentation. This leads to excessive indentation in the generated HTML and to the inconsistency of its layout ([1] vs [2]). Besides, multi-line Note: sections are not handled properly with extra indentation. [1] https://www.kernel.org/doc/html/v4.20/core-api/mm-api.html?#c.vm_map_ram [2] https://www.kernel.org/doc/html/v4.20/core-api/mm-api.html?#c.vfree Link: http://lkml.kernel.org/r/1549549644-4903-2-git-send-email-rppt@linux.ibm.com Signed-off-by: Mike Rapoport Reviewed-by: Andrew Morton Cc: Jonathan Corbet Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- mm/vmalloc.c | 367 +++++++++++++++++++++++++++++------------------------------ 1 file changed, 182 insertions(+), 185 deletions(-) (limited to 'mm/vmalloc.c') diff --git a/mm/vmalloc.c b/mm/vmalloc.c index 77006fa1a90b..03cbba890301 100644 --- a/mm/vmalloc.c +++ b/mm/vmalloc.c @@ -1191,6 +1191,7 @@ void *vm_map_ram(struct page **pages, unsigned int count, int node, pgprot_t pro EXPORT_SYMBOL(vm_map_ram); static struct vm_struct *vmlist __initdata; + /** * vm_area_add_early - add vmap area early during boot * @vm: vm_struct to add @@ -1425,13 +1426,13 @@ struct vm_struct *__get_vm_area_caller(unsigned long size, unsigned long flags, } /** - * get_vm_area - reserve a contiguous kernel virtual area - * @size: size of the area - * @flags: %VM_IOREMAP for I/O mappings or VM_ALLOC + * get_vm_area - reserve a contiguous kernel virtual area + * @size: size of the area + * @flags: %VM_IOREMAP for I/O mappings or VM_ALLOC * - * Search an area of @size in the kernel virtual mapping area, - * and reserved it for out purposes. Returns the area descriptor - * on success or %NULL on failure. + * Search an area of @size in the kernel virtual mapping area, + * and reserved it for out purposes. Returns the area descriptor + * on success or %NULL on failure. */ struct vm_struct *get_vm_area(unsigned long size, unsigned long flags) { @@ -1448,12 +1449,12 @@ struct vm_struct *get_vm_area_caller(unsigned long size, unsigned long flags, } /** - * find_vm_area - find a continuous kernel virtual area - * @addr: base address + * find_vm_area - find a continuous kernel virtual area + * @addr: base address * - * Search for the kernel VM area starting at @addr, and return it. - * It is up to the caller to do all required locking to keep the returned - * pointer valid. + * Search for the kernel VM area starting at @addr, and return it. + * It is up to the caller to do all required locking to keep the returned + * pointer valid. */ struct vm_struct *find_vm_area(const void *addr) { @@ -1467,12 +1468,12 @@ struct vm_struct *find_vm_area(const void *addr) } /** - * remove_vm_area - find and remove a continuous kernel virtual area - * @addr: base address + * remove_vm_area - find and remove a continuous kernel virtual area + * @addr: base address * - * Search for the kernel VM area starting at @addr, and remove it. - * This function returns the found VM area, but using it is NOT safe - * on SMP machines, except for its size or flags. + * Search for the kernel VM area starting at @addr, and remove it. + * This function returns the found VM area, but using it is NOT safe + * on SMP machines, except for its size or flags. */ struct vm_struct *remove_vm_area(const void *addr) { @@ -1552,11 +1553,11 @@ static inline void __vfree_deferred(const void *addr) } /** - * vfree_atomic - release memory allocated by vmalloc() - * @addr: memory base address + * vfree_atomic - release memory allocated by vmalloc() + * @addr: memory base address * - * This one is just like vfree() but can be called in any atomic context - * except NMIs. + * This one is just like vfree() but can be called in any atomic context + * except NMIs. */ void vfree_atomic(const void *addr) { @@ -1578,20 +1579,20 @@ static void __vfree(const void *addr) } /** - * vfree - release memory allocated by vmalloc() - * @addr: memory base address + * vfree - release memory allocated by vmalloc() + * @addr: memory base address * - * Free the virtually continuous memory area starting at @addr, as - * obtained from vmalloc(), vmalloc_32() or __vmalloc(). If @addr is - * NULL, no operation is performed. + * Free the virtually continuous memory area starting at @addr, as + * obtained from vmalloc(), vmalloc_32() or __vmalloc(). If @addr is + * NULL, no operation is performed. * - * Must not be called in NMI context (strictly speaking, only if we don't - * have CONFIG_ARCH_HAVE_NMI_SAFE_CMPXCHG, but making the calling - * conventions for vfree() arch-depenedent would be a really bad idea) + * Must not be called in NMI context (strictly speaking, only if we don't + * have CONFIG_ARCH_HAVE_NMI_SAFE_CMPXCHG, but making the calling + * conventions for vfree() arch-depenedent would be a really bad idea) * - * May sleep if called *not* from interrupt context. + * May sleep if called *not* from interrupt context. * - * NOTE: assumes that the object at @addr has a size >= sizeof(llist_node) + * NOTE: assumes that the object at @addr has a size >= sizeof(llist_node) */ void vfree(const void *addr) { @@ -1609,13 +1610,13 @@ void vfree(const void *addr) EXPORT_SYMBOL(vfree); /** - * vunmap - release virtual mapping obtained by vmap() - * @addr: memory base address + * vunmap - release virtual mapping obtained by vmap() + * @addr: memory base address * - * Free the virtually contiguous memory area starting at @addr, - * which was created from the page array passed to vmap(). + * Free the virtually contiguous memory area starting at @addr, + * which was created from the page array passed to vmap(). * - * Must not be called in interrupt context. + * Must not be called in interrupt context. */ void vunmap(const void *addr) { @@ -1627,17 +1628,17 @@ void vunmap(const void *addr) EXPORT_SYMBOL(vunmap); /** - * vmap - map an array of pages into virtually contiguous space - * @pages: array of page pointers - * @count: number of pages to map - * @flags: vm_area->flags - * @prot: page protection for the mapping - * - * Maps @count pages from @pages into contiguous kernel virtual - * space. + * vmap - map an array of pages into virtually contiguous space + * @pages: array of page pointers + * @count: number of pages to map + * @flags: vm_area->flags + * @prot: page protection for the mapping + * + * Maps @count pages from @pages into contiguous kernel virtual + * space. */ void *vmap(struct page **pages, unsigned int count, - unsigned long flags, pgprot_t prot) + unsigned long flags, pgprot_t prot) { struct vm_struct *area; unsigned long size; /* In bytes */ @@ -1724,20 +1725,20 @@ fail: } /** - * __vmalloc_node_range - allocate virtually contiguous memory - * @size: allocation size - * @align: desired alignment - * @start: vm area range start - * @end: vm area range end - * @gfp_mask: flags for the page level allocator - * @prot: protection mask for the allocated pages - * @vm_flags: additional vm area flags (e.g. %VM_NO_GUARD) - * @node: node to use for allocation or NUMA_NO_NODE - * @caller: caller's return address - * - * Allocate enough pages to cover @size from the page level - * allocator with @gfp_mask flags. Map them into contiguous - * kernel virtual space, using a pagetable protection of @prot. + * __vmalloc_node_range - allocate virtually contiguous memory + * @size: allocation size + * @align: desired alignment + * @start: vm area range start + * @end: vm area range end + * @gfp_mask: flags for the page level allocator + * @prot: protection mask for the allocated pages + * @vm_flags: additional vm area flags (e.g. %VM_NO_GUARD) + * @node: node to use for allocation or NUMA_NO_NODE + * @caller: caller's return address + * + * Allocate enough pages to cover @size from the page level + * allocator with @gfp_mask flags. Map them into contiguous + * kernel virtual space, using a pagetable protection of @prot. */ void *__vmalloc_node_range(unsigned long size, unsigned long align, unsigned long start, unsigned long end, gfp_t gfp_mask, @@ -1788,24 +1789,23 @@ EXPORT_SYMBOL_GPL(__vmalloc_node_range); #endif /** - * __vmalloc_node - allocate virtually contiguous memory - * @size: allocation size - * @align: desired alignment - * @gfp_mask: flags for the page level allocator - * @prot: protection mask for the allocated pages - * @node: node to use for allocation or NUMA_NO_NODE - * @caller: caller's return address - * - * Allocate enough pages to cover @size from the page level - * allocator with @gfp_mask flags. Map them into contiguous - * kernel virtual space, using a pagetable protection of @prot. + * __vmalloc_node - allocate virtually contiguous memory + * @size: allocation size + * @align: desired alignment + * @gfp_mask: flags for the page level allocator + * @prot: protection mask for the allocated pages + * @node: node to use for allocation or NUMA_NO_NODE + * @caller: caller's return address * - * Reclaim modifiers in @gfp_mask - __GFP_NORETRY, __GFP_RETRY_MAYFAIL - * and __GFP_NOFAIL are not supported + * Allocate enough pages to cover @size from the page level + * allocator with @gfp_mask flags. Map them into contiguous + * kernel virtual space, using a pagetable protection of @prot. * - * Any use of gfp flags outside of GFP_KERNEL should be consulted - * with mm people. + * Reclaim modifiers in @gfp_mask - __GFP_NORETRY, __GFP_RETRY_MAYFAIL + * and __GFP_NOFAIL are not supported * + * Any use of gfp flags outside of GFP_KERNEL should be consulted + * with mm people. */ static void *__vmalloc_node(unsigned long size, unsigned long align, gfp_t gfp_mask, pgprot_t prot, @@ -1837,13 +1837,14 @@ void *__vmalloc_node_flags_caller(unsigned long size, int node, gfp_t flags, } /** - * vmalloc - allocate virtually contiguous memory - * @size: allocation size - * Allocate enough pages to cover @size from the page level - * allocator and map them into contiguous kernel virtual space. + * vmalloc - allocate virtually contiguous memory + * @size: allocation size + * + * Allocate enough pages to cover @size from the page level + * allocator and map them into contiguous kernel virtual space. * - * For tight control over page level allocator and protection flags - * use __vmalloc() instead. + * For tight control over page level allocator and protection flags + * use __vmalloc() instead. */ void *vmalloc(unsigned long size) { @@ -1853,14 +1854,15 @@ void *vmalloc(unsigned long size) EXPORT_SYMBOL(vmalloc); /** - * vzalloc - allocate virtually contiguous memory with zero fill - * @size: allocation size - * Allocate enough pages to cover @size from the page level - * allocator and map them into contiguous kernel virtual space. - * The memory allocated is set to zero. - * - * For tight control over page level allocator and protection flags - * use __vmalloc() instead. + * vzalloc - allocate virtually contiguous memory with zero fill + * @size: allocation size + * + * Allocate enough pages to cover @size from the page level + * allocator and map them into contiguous kernel virtual space. + * The memory allocated is set to zero. + * + * For tight control over page level allocator and protection flags + * use __vmalloc() instead. */ void *vzalloc(unsigned long size) { @@ -1886,15 +1888,15 @@ void *vmalloc_user(unsigned long size) EXPORT_SYMBOL(vmalloc_user); /** - * vmalloc_node - allocate memory on a specific node - * @size: allocation size - * @node: numa node + * vmalloc_node - allocate memory on a specific node + * @size: allocation size + * @node: numa node * - * Allocate enough pages to cover @size from the page level - * allocator and map them into contiguous kernel virtual space. + * Allocate enough pages to cover @size from the page level + * allocator and map them into contiguous kernel virtual space. * - * For tight control over page level allocator and protection flags - * use __vmalloc() instead. + * For tight control over page level allocator and protection flags + * use __vmalloc() instead. */ void *vmalloc_node(unsigned long size, int node) { @@ -1923,17 +1925,16 @@ void *vzalloc_node(unsigned long size, int node) EXPORT_SYMBOL(vzalloc_node); /** - * vmalloc_exec - allocate virtually contiguous, executable memory - * @size: allocation size + * vmalloc_exec - allocate virtually contiguous, executable memory + * @size: allocation size * - * Kernel-internal function to allocate enough pages to cover @size - * the page level allocator and map them into contiguous and - * executable kernel virtual space. + * Kernel-internal function to allocate enough pages to cover @size + * the page level allocator and map them into contiguous and + * executable kernel virtual space. * - * For tight control over page level allocator and protection flags - * use __vmalloc() instead. + * For tight control over page level allocator and protection flags + * use __vmalloc() instead. */ - void *vmalloc_exec(unsigned long size) { return __vmalloc_node(size, 1, GFP_KERNEL, PAGE_KERNEL_EXEC, @@ -1953,11 +1954,11 @@ void *vmalloc_exec(unsigned long size) #endif /** - * vmalloc_32 - allocate virtually contiguous memory (32bit addressable) - * @size: allocation size + * vmalloc_32 - allocate virtually contiguous memory (32bit addressable) + * @size: allocation size * - * Allocate enough 32bit PA addressable pages to cover @size from the - * page level allocator and map them into contiguous kernel virtual space. + * Allocate enough 32bit PA addressable pages to cover @size from the + * page level allocator and map them into contiguous kernel virtual space. */ void *vmalloc_32(unsigned long size) { @@ -1968,7 +1969,7 @@ EXPORT_SYMBOL(vmalloc_32); /** * vmalloc_32_user - allocate zeroed virtually contiguous 32bit memory - * @size: allocation size + * @size: allocation size * * The resulting memory area is 32bit addressable and zeroed so it can be * mapped to userspace without leaking data. @@ -2064,31 +2065,29 @@ static int aligned_vwrite(char *buf, char *addr, unsigned long count) } /** - * vread() - read vmalloc area in a safe way. - * @buf: buffer for reading data - * @addr: vm address. - * @count: number of bytes to be read. - * - * Returns # of bytes which addr and buf should be increased. - * (same number to @count). Returns 0 if [addr...addr+count) doesn't - * includes any intersect with alive vmalloc area. - * - * This function checks that addr is a valid vmalloc'ed area, and - * copy data from that area to a given buffer. If the given memory range - * of [addr...addr+count) includes some valid address, data is copied to - * proper area of @buf. If there are memory holes, they'll be zero-filled. - * IOREMAP area is treated as memory hole and no copy is done. - * - * If [addr...addr+count) doesn't includes any intersects with alive - * vm_struct area, returns 0. @buf should be kernel's buffer. - * - * Note: In usual ops, vread() is never necessary because the caller - * should know vmalloc() area is valid and can use memcpy(). - * This is for routines which have to access vmalloc area without - * any informaion, as /dev/kmem. - * + * vread() - read vmalloc area in a safe way. + * @buf: buffer for reading data + * @addr: vm address. + * @count: number of bytes to be read. + * + * Returns # of bytes which addr and buf should be increased. + * (same number to @count). Returns 0 if [addr...addr+count) doesn't + * includes any intersect with alive vmalloc area. + * + * This function checks that addr is a valid vmalloc'ed area, and + * copy data from that area to a given buffer. If the given memory range + * of [addr...addr+count) includes some valid address, data is copied to + * proper area of @buf. If there are memory holes, they'll be zero-filled. + * IOREMAP area is treated as memory hole and no copy is done. + * + * If [addr...addr+count) doesn't includes any intersects with alive + * vm_struct area, returns 0. @buf should be kernel's buffer. + * + * Note: In usual ops, vread() is never necessary because the caller + * should know vmalloc() area is valid and can use memcpy(). + * This is for routines which have to access vmalloc area without + * any informaion, as /dev/kmem. */ - long vread(char *buf, char *addr, unsigned long count) { struct vmap_area *va; @@ -2145,31 +2144,30 @@ finished: } /** - * vwrite() - write vmalloc area in a safe way. - * @buf: buffer for source data - * @addr: vm address. - * @count: number of bytes to be read. - * - * Returns # of bytes which addr and buf should be incresed. - * (same number to @count). - * If [addr...addr+count) doesn't includes any intersect with valid - * vmalloc area, returns 0. - * - * This function checks that addr is a valid vmalloc'ed area, and - * copy data from a buffer to the given addr. If specified range of - * [addr...addr+count) includes some valid address, data is copied from - * proper area of @buf. If there are memory holes, no copy to hole. - * IOREMAP area is treated as memory hole and no copy is done. - * - * If [addr...addr+count) doesn't includes any intersects with alive - * vm_struct area, returns 0. @buf should be kernel's buffer. - * - * Note: In usual ops, vwrite() is never necessary because the caller - * should know vmalloc() area is valid and can use memcpy(). - * This is for routines which have to access vmalloc area without - * any informaion, as /dev/kmem. + * vwrite() - write vmalloc area in a safe way. + * @buf: buffer for source data + * @addr: vm address. + * @count: number of bytes to be read. + * + * Returns # of bytes which addr and buf should be incresed. + * (same number to @count). + * If [addr...addr+count) doesn't includes any intersect with valid + * vmalloc area, returns 0. + * + * This function checks that addr is a valid vmalloc'ed area, and + * copy data from a buffer to the given addr. If specified range of + * [addr...addr+count) includes some valid address, data is copied from + * proper area of @buf. If there are memory holes, no copy to hole. + * IOREMAP area is treated as memory hole and no copy is done. + * + * If [addr...addr+count) doesn't includes any intersects with alive + * vm_struct area, returns 0. @buf should be kernel's buffer. + * + * Note: In usual ops, vwrite() is never necessary because the caller + * should know vmalloc() area is valid and can use memcpy(). + * This is for routines which have to access vmalloc area without + * any informaion, as /dev/kmem. */ - long vwrite(char *buf, char *addr, unsigned long count) { struct vmap_area *va; @@ -2221,20 +2219,20 @@ finished: } /** - * remap_vmalloc_range_partial - map vmalloc pages to userspace - * @vma: vma to cover - * @uaddr: target user address to start at - * @kaddr: virtual address of vmalloc kernel memory - * @size: size of map area + * remap_vmalloc_range_partial - map vmalloc pages to userspace + * @vma: vma to cover + * @uaddr: target user address to start at + * @kaddr: virtual address of vmalloc kernel memory + * @size: size of map area * - * Returns: 0 for success, -Exxx on failure + * Returns: 0 for success, -Exxx on failure * - * This function checks that @kaddr is a valid vmalloc'ed area, - * and that it is big enough to cover the range starting at - * @uaddr in @vma. Will return failure if that criteria isn't - * met. + * This function checks that @kaddr is a valid vmalloc'ed area, + * and that it is big enough to cover the range starting at + * @uaddr in @vma. Will return failure if that criteria isn't + * met. * - * Similar to remap_pfn_range() (see mm/memory.c) + * Similar to remap_pfn_range() (see mm/memory.c) */ int remap_vmalloc_range_partial(struct vm_area_struct *vma, unsigned long uaddr, void *kaddr, unsigned long size) @@ -2276,18 +2274,18 @@ int remap_vmalloc_range_partial(struct vm_area_struct *vma, unsigned long uaddr, EXPORT_SYMBOL(remap_vmalloc_range_partial); /** - * remap_vmalloc_range - map vmalloc pages to userspace - * @vma: vma to cover (map full range of vma) - * @addr: vmalloc memory - * @pgoff: number of pages into addr before first page to map + * remap_vmalloc_range - map vmalloc pages to userspace + * @vma: vma to cover (map full range of vma) + * @addr: vmalloc memory + * @pgoff: number of pages into addr before first page to map * - * Returns: 0 for success, -Exxx on failure + * Returns: 0 for success, -Exxx on failure * - * This function checks that addr is a valid vmalloc'ed area, and - * that it is big enough to cover the vma. Will return failure if - * that criteria isn't met. + * This function checks that addr is a valid vmalloc'ed area, and + * that it is big enough to cover the vma. Will return failure if + * that criteria isn't met. * - * Similar to remap_pfn_range() (see mm/memory.c) + * Similar to remap_pfn_range() (see mm/memory.c) */ int remap_vmalloc_range(struct vm_area_struct *vma, void *addr, unsigned long pgoff) @@ -2319,18 +2317,18 @@ static int f(pte_t *pte, pgtable_t table, unsigned long addr, void *data) } /** - * alloc_vm_area - allocate a range of kernel address space - * @size: size of the area - * @ptes: returns the PTEs for the address space + * alloc_vm_area - allocate a range of kernel address space + * @size: size of the area + * @ptes: returns the PTEs for the address space * - * Returns: NULL on failure, vm_struct on success + * Returns: NULL on failure, vm_struct on success * - * This function reserves a range of kernel address space, and - * allocates pagetables to map that range. No actual mappings - * are created. + * This function reserves a range of kernel address space, and + * allocates pagetables to map that range. No actual mappings + * are created. * - * If @ptes is non-NULL, pointers to the PTEs (in init_mm) - * allocated for the VM area are returned. + * If @ptes is non-NULL, pointers to the PTEs (in init_mm) + * allocated for the VM area are returned. */ struct vm_struct *alloc_vm_area(size_t size, pte_t **ptes) { @@ -2756,4 +2754,3 @@ static int __init proc_vmalloc_init(void) module_init(proc_vmalloc_init); #endif - -- cgit v1.2.2 From a862f68a8b360086f248cbc3606029441b5f5197 Mon Sep 17 00:00:00 2001 From: Mike Rapoport Date: Tue, 5 Mar 2019 15:48:42 -0800 Subject: docs/core-api/mm: fix return value descriptions in mm/ Many kernel-doc comments in mm/ have the return value descriptions either misformatted or omitted at all which makes kernel-doc script unhappy: $ make V=1 htmldocs ... ./mm/util.c:36: info: Scanning doc for kstrdup ./mm/util.c:41: warning: No description found for return value of 'kstrdup' ./mm/util.c:57: info: Scanning doc for kstrdup_const ./mm/util.c:66: warning: No description found for return value of 'kstrdup_const' ./mm/util.c:75: info: Scanning doc for kstrndup ./mm/util.c:83: warning: No description found for return value of 'kstrndup' ... Fixing the formatting and adding the missing return value descriptions eliminates ~100 such warnings. Link: http://lkml.kernel.org/r/1549549644-4903-4-git-send-email-rppt@linux.ibm.com Signed-off-by: Mike Rapoport Reviewed-by: Andrew Morton Cc: Jonathan Corbet Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- mm/vmalloc.c | 47 +++++++++++++++++++++++++++++++++++++---------- 1 file changed, 37 insertions(+), 10 deletions(-) (limited to 'mm/vmalloc.c') diff --git a/mm/vmalloc.c b/mm/vmalloc.c index 03cbba890301..e86ba6e74b50 100644 --- a/mm/vmalloc.c +++ b/mm/vmalloc.c @@ -844,7 +844,7 @@ static void *vmap_block_vaddr(unsigned long va_start, unsigned long pages_off) * @order: how many 2^order pages should be occupied in newly allocated block * @gfp_mask: flags for the page level allocator * - * Returns: virtual address in a newly allocated block or ERR_PTR(-errno) + * Return: virtual address in a newly allocated block or ERR_PTR(-errno) */ static void *new_vmap_block(unsigned int order, gfp_t gfp_mask) { @@ -1433,6 +1433,8 @@ struct vm_struct *__get_vm_area_caller(unsigned long size, unsigned long flags, * Search an area of @size in the kernel virtual mapping area, * and reserved it for out purposes. Returns the area descriptor * on success or %NULL on failure. + * + * Return: the area descriptor on success or %NULL on failure. */ struct vm_struct *get_vm_area(unsigned long size, unsigned long flags) { @@ -1455,6 +1457,8 @@ struct vm_struct *get_vm_area_caller(unsigned long size, unsigned long flags, * Search for the kernel VM area starting at @addr, and return it. * It is up to the caller to do all required locking to keep the returned * pointer valid. + * + * Return: pointer to the found area or %NULL on faulure */ struct vm_struct *find_vm_area(const void *addr) { @@ -1474,6 +1478,8 @@ struct vm_struct *find_vm_area(const void *addr) * Search for the kernel VM area starting at @addr, and remove it. * This function returns the found VM area, but using it is NOT safe * on SMP machines, except for its size or flags. + * + * Return: pointer to the found area or %NULL on faulure */ struct vm_struct *remove_vm_area(const void *addr) { @@ -1636,6 +1642,8 @@ EXPORT_SYMBOL(vunmap); * * Maps @count pages from @pages into contiguous kernel virtual * space. + * + * Return: the address of the area or %NULL on failure */ void *vmap(struct page **pages, unsigned int count, unsigned long flags, pgprot_t prot) @@ -1739,6 +1747,8 @@ fail: * Allocate enough pages to cover @size from the page level * allocator with @gfp_mask flags. Map them into contiguous * kernel virtual space, using a pagetable protection of @prot. + * + * Return: the address of the area or %NULL on failure */ void *__vmalloc_node_range(unsigned long size, unsigned long align, unsigned long start, unsigned long end, gfp_t gfp_mask, @@ -1806,6 +1816,8 @@ EXPORT_SYMBOL_GPL(__vmalloc_node_range); * * Any use of gfp flags outside of GFP_KERNEL should be consulted * with mm people. + * + * Return: pointer to the allocated memory or %NULL on error */ static void *__vmalloc_node(unsigned long size, unsigned long align, gfp_t gfp_mask, pgprot_t prot, @@ -1845,6 +1857,8 @@ void *__vmalloc_node_flags_caller(unsigned long size, int node, gfp_t flags, * * For tight control over page level allocator and protection flags * use __vmalloc() instead. + * + * Return: pointer to the allocated memory or %NULL on error */ void *vmalloc(unsigned long size) { @@ -1863,6 +1877,8 @@ EXPORT_SYMBOL(vmalloc); * * For tight control over page level allocator and protection flags * use __vmalloc() instead. + * + * Return: pointer to the allocated memory or %NULL on error */ void *vzalloc(unsigned long size) { @@ -1877,6 +1893,8 @@ EXPORT_SYMBOL(vzalloc); * * The resulting memory area is zeroed so it can be mapped to userspace * without leaking data. + * + * Return: pointer to the allocated memory or %NULL on error */ void *vmalloc_user(unsigned long size) { @@ -1897,6 +1915,8 @@ EXPORT_SYMBOL(vmalloc_user); * * For tight control over page level allocator and protection flags * use __vmalloc() instead. + * + * Return: pointer to the allocated memory or %NULL on error */ void *vmalloc_node(unsigned long size, int node) { @@ -1916,6 +1936,8 @@ EXPORT_SYMBOL(vmalloc_node); * * For tight control over page level allocator and protection flags * use __vmalloc_node() instead. + * + * Return: pointer to the allocated memory or %NULL on error */ void *vzalloc_node(unsigned long size, int node) { @@ -1934,6 +1956,8 @@ EXPORT_SYMBOL(vzalloc_node); * * For tight control over page level allocator and protection flags * use __vmalloc() instead. + * + * Return: pointer to the allocated memory or %NULL on error */ void *vmalloc_exec(unsigned long size) { @@ -1959,6 +1983,8 @@ void *vmalloc_exec(unsigned long size) * * Allocate enough 32bit PA addressable pages to cover @size from the * page level allocator and map them into contiguous kernel virtual space. + * + * Return: pointer to the allocated memory or %NULL on error */ void *vmalloc_32(unsigned long size) { @@ -1973,6 +1999,8 @@ EXPORT_SYMBOL(vmalloc_32); * * The resulting memory area is 32bit addressable and zeroed so it can be * mapped to userspace without leaking data. + * + * Return: pointer to the allocated memory or %NULL on error */ void *vmalloc_32_user(unsigned long size) { @@ -2070,10 +2098,6 @@ static int aligned_vwrite(char *buf, char *addr, unsigned long count) * @addr: vm address. * @count: number of bytes to be read. * - * Returns # of bytes which addr and buf should be increased. - * (same number to @count). Returns 0 if [addr...addr+count) doesn't - * includes any intersect with alive vmalloc area. - * * This function checks that addr is a valid vmalloc'ed area, and * copy data from that area to a given buffer. If the given memory range * of [addr...addr+count) includes some valid address, data is copied to @@ -2087,6 +2111,10 @@ static int aligned_vwrite(char *buf, char *addr, unsigned long count) * should know vmalloc() area is valid and can use memcpy(). * This is for routines which have to access vmalloc area without * any informaion, as /dev/kmem. + * + * Return: number of bytes for which addr and buf should be increased + * (same number as @count) or %0 if [addr...addr+count) doesn't + * include any intersection with valid vmalloc area */ long vread(char *buf, char *addr, unsigned long count) { @@ -2149,11 +2177,6 @@ finished: * @addr: vm address. * @count: number of bytes to be read. * - * Returns # of bytes which addr and buf should be incresed. - * (same number to @count). - * If [addr...addr+count) doesn't includes any intersect with valid - * vmalloc area, returns 0. - * * This function checks that addr is a valid vmalloc'ed area, and * copy data from a buffer to the given addr. If specified range of * [addr...addr+count) includes some valid address, data is copied from @@ -2167,6 +2190,10 @@ finished: * should know vmalloc() area is valid and can use memcpy(). * This is for routines which have to access vmalloc area without * any informaion, as /dev/kmem. + * + * Return: number of bytes for which addr and buf should be + * increased (same number as @count) or %0 if [addr...addr+count) + * doesn't include any intersection with valid vmalloc area */ long vwrite(char *buf, char *addr, unsigned long count) { -- cgit v1.2.2