Commit 2b740303 authored by Souptick Joarder's avatar Souptick Joarder Committed by Linus Torvalds
Browse files

mm: Change return type int to vm_fault_t for fault handlers 

Use new return type vm_fault_t for fault handler.  For now, this is just
documenting that the function returns a VM_FAULT value rather than an
errno.  Once all instances are converted, vm_fault_t will become a
distinct type.

Ref-> commit 1c8f4220 ("mm: change return type to vm_fault_t")

The aim is to change the return type of finish_fault() and
handle_mm_fault() to vm_fault_t type.  As part of that clean up return
type of all other recursively called functions have been changed to
vm_fault_t type.

The places from where handle_mm_fault() is getting invoked will be
change to vm_fault_t type but in a separate patch.

vmf_error() is the newly introduce inline function in 4.17-rc6.

[akpm@linux-foundation.org: don't shadow outer local `ret' in __do_huge_pmd_anonymous_page()]
Link: http://lkml.kernel.org/r/20180604171727.GA20279@jordon-HP-15-Notebook-PC


Signed-off-by: default avatarSouptick Joarder <jrdr.linux@gmail.com>
Reviewed-by: default avatarMatthew Wilcox <mawilcox@microsoft.com>
Reviewed-by: default avatarAndrew Morton <akpm@linux-foundation.org>
Cc: Matthew Wilcox <willy@infradead.org>
Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
parent a99237af

fs/userfaultfd.c

+2 −4
Original line number Diff line number Diff line
@@ -340,17 +340,15 @@ out: 
 * fatal_signal_pending()s, and the mmap_sem must be released before

 * returning it.

 */

int handle_userfault(struct vm_fault *vmf, unsigned long reason)

vm_fault_t handle_userfault(struct vm_fault *vmf, unsigned long reason)

{

	struct mm_struct *mm = vmf->vma->vm_mm;

	struct userfaultfd_ctx *ctx;

	struct userfaultfd_wait_queue uwq;

	int ret;

	vm_fault_t ret = VM_FAULT_SIGBUS;

	bool must_wait, return_to_userland;

	long blocking_state;



	ret = VM_FAULT_SIGBUS;



	/*

	 * We don't do userfault handling for the final child pid update.

	 *

include/linux/huge_mm.h

+5 −4
Original line number Diff line number Diff line
@@ -6,7 +6,7 @@ 


#include <linux/fs.h> /* only for vma_is_dax() */



extern int do_huge_pmd_anonymous_page(struct vm_fault *vmf);

extern vm_fault_t do_huge_pmd_anonymous_page(struct vm_fault *vmf);

extern int copy_huge_pmd(struct mm_struct *dst_mm, struct mm_struct *src_mm,

			 pmd_t *dst_pmd, pmd_t *src_pmd, unsigned long addr,

			 struct vm_area_struct *vma);
@@ -23,7 +23,7 @@ static inline void huge_pud_set_accessed(struct vm_fault *vmf, pud_t orig_pud) 
}

#endif



extern int do_huge_pmd_wp_page(struct vm_fault *vmf, pmd_t orig_pmd);

extern vm_fault_t do_huge_pmd_wp_page(struct vm_fault *vmf, pmd_t orig_pmd);

extern struct page *follow_trans_huge_pmd(struct vm_area_struct *vma,

					  unsigned long addr,

					  pmd_t *pmd,
@@ -216,7 +216,7 @@ struct page *follow_devmap_pmd(struct vm_area_struct *vma, unsigned long addr, 
struct page *follow_devmap_pud(struct vm_area_struct *vma, unsigned long addr,

		pud_t *pud, int flags);



extern int do_huge_pmd_numa_page(struct vm_fault *vmf, pmd_t orig_pmd);

extern vm_fault_t do_huge_pmd_numa_page(struct vm_fault *vmf, pmd_t orig_pmd);



extern struct page *huge_zero_page;
@@ -321,7 +321,8 @@ static inline spinlock_t *pud_trans_huge_lock(pud_t *pud, 
	return NULL;

}



static inline int do_huge_pmd_numa_page(struct vm_fault *vmf, pmd_t orig_pmd)

static inline vm_fault_t do_huge_pmd_numa_page(struct vm_fault *vmf,

		pmd_t orig_pmd)

{

	return 0;

}

include/linux/hugetlb.h

+1 −1
Original line number Diff line number Diff line
@@ -105,7 +105,7 @@ void hugetlb_report_meminfo(struct seq_file *); 
int hugetlb_report_node_meminfo(int, char *);

void hugetlb_show_meminfo(void);

unsigned long hugetlb_total_pages(void);

int hugetlb_fault(struct mm_struct *mm, struct vm_area_struct *vma,

vm_fault_t hugetlb_fault(struct mm_struct *mm, struct vm_area_struct *vma,

			unsigned long address, unsigned int flags);

int hugetlb_mcopy_atomic_pte(struct mm_struct *dst_mm, pte_t *dst_pte,

				struct vm_area_struct *dst_vma,

include/linux/mm.h

+7 −7
Original line number Diff line number Diff line
@@ -728,10 +728,10 @@ static inline pte_t maybe_mkwrite(pte_t pte, struct vm_area_struct *vma) 
	return pte;

}



int alloc_set_pte(struct vm_fault *vmf, struct mem_cgroup *memcg,

vm_fault_t alloc_set_pte(struct vm_fault *vmf, struct mem_cgroup *memcg,

		struct page *page);

int finish_fault(struct vm_fault *vmf);

int finish_mkwrite_fault(struct vm_fault *vmf);

vm_fault_t finish_fault(struct vm_fault *vmf);

vm_fault_t finish_mkwrite_fault(struct vm_fault *vmf);

#endif



/*
@@ -1403,8 +1403,8 @@ int generic_error_remove_page(struct address_space *mapping, struct page *page); 
int invalidate_inode_page(struct page *page);



#ifdef CONFIG_MMU

extern int handle_mm_fault(struct vm_area_struct *vma, unsigned long address,

		unsigned int flags);

extern vm_fault_t handle_mm_fault(struct vm_area_struct *vma,

			unsigned long address, unsigned int flags);

extern int fixup_user_fault(struct task_struct *tsk, struct mm_struct *mm,

			    unsigned long address, unsigned int fault_flags,

			    bool *unlocked);
@@ -1413,7 +1413,7 @@ void unmap_mapping_pages(struct address_space *mapping, 
void unmap_mapping_range(struct address_space *mapping,

		loff_t const holebegin, loff_t const holelen, int even_cows);

#else

static inline int handle_mm_fault(struct vm_area_struct *vma,

static inline vm_fault_t handle_mm_fault(struct vm_area_struct *vma,

		unsigned long address, unsigned int flags)

{

	/* should never happen if there's no MMU */
@@ -2563,7 +2563,7 @@ static inline struct page *follow_page(struct vm_area_struct *vma, 
#define FOLL_COW	0x4000	/* internal GUP flag */

#define FOLL_ANON	0x8000	/* don't do file mappings */



static inline int vm_fault_to_errno(int vm_fault, int foll_flags)

static inline int vm_fault_to_errno(vm_fault_t vm_fault, int foll_flags)

{

	if (vm_fault & VM_FAULT_OOM)

		return -ENOMEM;

include/linux/oom.h

+1 −1
Original line number Diff line number Diff line
@@ -88,7 +88,7 @@ static inline bool mm_is_oom_victim(struct mm_struct *mm) 
 *

 * Return 0 when the PF is safe VM_FAULT_SIGBUS otherwise.

 */

static inline int check_stable_address_space(struct mm_struct *mm)

static inline vm_fault_t check_stable_address_space(struct mm_struct *mm)

{

	if (unlikely(test_bit(MMF_UNSTABLE, &mm->flags)))

		return VM_FAULT_SIGBUS;

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