Commit 31c56299 authored by Petr Malat's avatar Petr Malat Committed by Andrew Morton
Browse files

mm: add RCU annotation to pte_offset_map(_lock) 

RCU lock is taken by ___pte_offset_map() unless it returns NULL.  Add this
information to its inline callers to avoid sparse warning about context
imbalance in pte_unmap().

Link: https://lkml.kernel.org/r/20241210000604.700710-1-oss@malat.biz


Signed-off-by: default avatarPetr Malat <oss@malat.biz>
Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
parent 42c4e4b2

include/linux/mm.h

+11 −2
Original line number Diff line number Diff line
@@ -3010,7 +3010,15 @@ static inline void pagetable_pte_dtor(struct ptdesc *ptdesc) 
	lruvec_stat_sub_folio(folio, NR_PAGETABLE);

}



pte_t *__pte_offset_map(pmd_t *pmd, unsigned long addr, pmd_t *pmdvalp);

pte_t *___pte_offset_map(pmd_t *pmd, unsigned long addr, pmd_t *pmdvalp);

static inline pte_t *__pte_offset_map(pmd_t *pmd, unsigned long addr,

			pmd_t *pmdvalp)

{

	pte_t *pte;



	__cond_lock(RCU, pte = ___pte_offset_map(pmd, addr, pmdvalp));

	return pte;

}

static inline pte_t *pte_offset_map(pmd_t *pmd, unsigned long addr)

{

	return __pte_offset_map(pmd, addr, NULL);
@@ -3023,7 +3031,8 @@ static inline pte_t *pte_offset_map_lock(struct mm_struct *mm, pmd_t *pmd, 
{

	pte_t *pte;



	__cond_lock(*ptlp, pte = __pte_offset_map_lock(mm, pmd, addr, ptlp));

	__cond_lock(RCU, __cond_lock(*ptlp,

			pte = __pte_offset_map_lock(mm, pmd, addr, ptlp)));

	return pte;

}

mm/pgtable-generic.c

+1 −1
Original line number Diff line number Diff line
@@ -279,7 +279,7 @@ static unsigned long pmdp_get_lockless_start(void) { return 0; } 
static void pmdp_get_lockless_end(unsigned long irqflags) { }

#endif



pte_t *__pte_offset_map(pmd_t *pmd, unsigned long addr, pmd_t *pmdvalp)

pte_t *___pte_offset_map(pmd_t *pmd, unsigned long addr, pmd_t *pmdvalp)

{

	unsigned long irqflags;

	pmd_t pmdval;