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| author | Linus Torvalds <torvalds@linux-foundation.org> | 2023-06-24 13:45:51 -0700 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2023-07-01 13:16:25 +0200 |
| commit | e6bbad75712a97b9b16433563c1358652a33003e (patch) | |
| tree | f6b5576d36aeb448ba285be34556ad9a3ef96465 /include | |
| parent | c4b31d1b694e101cae7469a20762647185e11721 (diff) | |
| download | linux-e6bbad75712a97b9b16433563c1358652a33003e.tar.gz | |
mm: always expand the stack with the mmap write lock held
commit 8d7071af890768438c14db6172cc8f9f4d04e184 upstream This finishes the job of always holding the mmap write lock when extending the user stack vma, and removes the 'write_locked' argument from the vm helper functions again. For some cases, we just avoid expanding the stack at all: drivers and page pinning really shouldn't be extending any stacks. Let's see if any strange users really wanted that. It's worth noting that architectures that weren't converted to the new lock_mm_and_find_vma() helper function are left using the legacy "expand_stack()" function, but it has been changed to drop the mmap_lock and take it for writing while expanding the vma. This makes it fairly straightforward to convert the remaining architectures. As a result of dropping and re-taking the lock, the calling conventions for this function have also changed, since the old vma may no longer be valid. So it will now return the new vma if successful, and NULL - and the lock dropped - if the area could not be extended. Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> [6.1: Patch drivers/iommu/io-pgfault.c instead] Signed-off-by: Samuel Mendoza-Jonas <samjonas@amazon.com> Signed-off-by: David Woodhouse <dwmw@amazon.co.uk> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'include')
| -rw-r--r-- | include/linux/mm.h | 16 |
1 files changed, 4 insertions, 12 deletions
diff --git a/include/linux/mm.h b/include/linux/mm.h index e1915eb18916..f1f0fc179a90 100644 --- a/include/linux/mm.h +++ b/include/linux/mm.h @@ -2810,18 +2810,11 @@ extern vm_fault_t filemap_page_mkwrite(struct vm_fault *vmf); extern unsigned long stack_guard_gap; /* Generic expand stack which grows the stack according to GROWS{UP,DOWN} */ -int expand_stack_locked(struct vm_area_struct *vma, unsigned long address, - bool write_locked); -#define expand_stack(vma,addr) expand_stack_locked(vma,addr,false) +int expand_stack_locked(struct vm_area_struct *vma, unsigned long address); +struct vm_area_struct *expand_stack(struct mm_struct * mm, unsigned long addr); /* CONFIG_STACK_GROWSUP still needs to grow downwards at some places */ -int expand_downwards(struct vm_area_struct *vma, unsigned long address, - bool write_locked); -#if VM_GROWSUP -extern int expand_upwards(struct vm_area_struct *vma, unsigned long address); -#else - #define expand_upwards(vma, address) (0) -#endif +int expand_downwards(struct vm_area_struct *vma, unsigned long address); /* Look up the first VMA which satisfies addr < vm_end, NULL if none. */ extern struct vm_area_struct * find_vma(struct mm_struct * mm, unsigned long addr); @@ -2916,9 +2909,8 @@ unsigned long change_prot_numa(struct vm_area_struct *vma, unsigned long start, unsigned long end); #endif -struct vm_area_struct *find_extend_vma(struct mm_struct *, unsigned long addr); struct vm_area_struct *find_extend_vma_locked(struct mm_struct *, - unsigned long addr, bool write_locked); + unsigned long addr); int remap_pfn_range(struct vm_area_struct *, unsigned long addr, unsigned long pfn, unsigned long size, pgprot_t); int remap_pfn_range_notrack(struct vm_area_struct *vma, unsigned long addr, |