diff options
author | kib <kib@FreeBSD.org> | 2013-08-10 17:36:42 +0000 |
---|---|---|
committer | kib <kib@FreeBSD.org> | 2013-08-10 17:36:42 +0000 |
commit | 4675fcfce0ca7178b334ea67fe2d3ab745477a95 (patch) | |
tree | 2ae4177fdf8f77bdbf75571d149fb9e54db96bda /sys/i386 | |
parent | 29e6d17ad1d88a5156b4c44ff927a4ae7be2c279 (diff) | |
download | FreeBSD-src-4675fcfce0ca7178b334ea67fe2d3ab745477a95.zip FreeBSD-src-4675fcfce0ca7178b334ea67fe2d3ab745477a95.tar.gz |
Different consumers of the struct vm_page abuse pageq member to keep
additional information, when the page is guaranteed to not belong to a
paging queue. Usually, this results in a lot of type casts which make
reasoning about the code correctness harder.
Sometimes m->object is used instead of pageq, which could cause real
and confusing bugs if non-NULL m->object is leaked. See r141955 and
r253140 for examples.
Change the pageq member into a union containing explicitly-typed
members. Use them instead of type-punning or abusing m->object in x86
pmaps, uma and vm_page_alloc_contig().
Requested and reviewed by: alc
Sponsored by: The FreeBSD Foundation
Diffstat (limited to 'sys/i386')
-rw-r--r-- | sys/i386/i386/pmap.c | 89 |
1 files changed, 46 insertions, 43 deletions
diff --git a/sys/i386/i386/pmap.c b/sys/i386/i386/pmap.c index 49f3ee7..6a987b6 100644 --- a/sys/i386/i386/pmap.c +++ b/sys/i386/i386/pmap.c @@ -317,12 +317,12 @@ static boolean_t pmap_protect_pde(pmap_t pmap, pd_entry_t *pde, vm_offset_t sva, vm_prot_t prot); static void pmap_pte_attr(pt_entry_t *pte, int cache_bits); static void pmap_remove_pde(pmap_t pmap, pd_entry_t *pdq, vm_offset_t sva, - vm_page_t *free); + struct spglist *free); static int pmap_remove_pte(pmap_t pmap, pt_entry_t *ptq, vm_offset_t sva, - vm_page_t *free); + struct spglist *free); static void pmap_remove_pt_page(pmap_t pmap, vm_page_t mpte); static void pmap_remove_page(struct pmap *pmap, vm_offset_t va, - vm_page_t *free); + struct spglist *free); static void pmap_remove_entry(struct pmap *pmap, vm_page_t m, vm_offset_t va); static void pmap_insert_entry(pmap_t pmap, vm_offset_t va, vm_page_t m); @@ -335,10 +335,10 @@ static void pmap_update_pde_invalidate(vm_offset_t va, pd_entry_t newpde); static vm_page_t pmap_allocpte(pmap_t pmap, vm_offset_t va, int flags); static vm_page_t _pmap_allocpte(pmap_t pmap, u_int ptepindex, int flags); -static void _pmap_unwire_ptp(pmap_t pmap, vm_page_t m, vm_page_t *free); +static void _pmap_unwire_ptp(pmap_t pmap, vm_page_t m, struct spglist *free); static pt_entry_t *pmap_pte_quick(pmap_t pmap, vm_offset_t va); static void pmap_pte_release(pt_entry_t *pte); -static int pmap_unuse_pt(pmap_t, vm_offset_t, vm_page_t *); +static int pmap_unuse_pt(pmap_t, vm_offset_t, struct spglist *); #ifdef PAE static void *pmap_pdpt_allocf(uma_zone_t zone, int bytes, u_int8_t *flags, int wait); #endif @@ -1568,14 +1568,12 @@ pmap_qremove(vm_offset_t sva, int count) * Page table page management routines..... ***************************************************/ static __inline void -pmap_free_zero_pages(vm_page_t free) +pmap_free_zero_pages(struct spglist *free) { vm_page_t m; - while (free != NULL) { - m = free; - free = (void *)m->object; - m->object = NULL; + while ((m = SLIST_FIRST(free)) != NULL) { + SLIST_REMOVE_HEAD(free, plinks.s.ss); /* Preserve the page's PG_ZERO setting. */ vm_page_free_toq(m); } @@ -1587,15 +1585,15 @@ pmap_free_zero_pages(vm_page_t free) * physical memory manager after the TLB has been updated. */ static __inline void -pmap_add_delayed_free_list(vm_page_t m, vm_page_t *free, boolean_t set_PG_ZERO) +pmap_add_delayed_free_list(vm_page_t m, struct spglist *free, + boolean_t set_PG_ZERO) { if (set_PG_ZERO) m->flags |= PG_ZERO; else m->flags &= ~PG_ZERO; - m->object = (void *)*free; - *free = m; + SLIST_INSERT_HEAD(free, m, plinks.s.ss); } /* @@ -1645,7 +1643,7 @@ pmap_remove_pt_page(pmap_t pmap, vm_page_t mpte) * page table page was unmapped and FALSE otherwise. */ static inline boolean_t -pmap_unwire_ptp(pmap_t pmap, vm_page_t m, vm_page_t *free) +pmap_unwire_ptp(pmap_t pmap, vm_page_t m, struct spglist *free) { --m->wire_count; @@ -1657,7 +1655,7 @@ pmap_unwire_ptp(pmap_t pmap, vm_page_t m, vm_page_t *free) } static void -_pmap_unwire_ptp(pmap_t pmap, vm_page_t m, vm_page_t *free) +_pmap_unwire_ptp(pmap_t pmap, vm_page_t m, struct spglist *free) { vm_offset_t pteva; @@ -1693,7 +1691,7 @@ _pmap_unwire_ptp(pmap_t pmap, vm_page_t m, vm_page_t *free) * conditionally free the page, and manage the hold/wire counts. */ static int -pmap_unuse_pt(pmap_t pmap, vm_offset_t va, vm_page_t *free) +pmap_unuse_pt(pmap_t pmap, vm_offset_t va, struct spglist *free) { pd_entry_t ptepde; vm_page_t mpte; @@ -2193,16 +2191,18 @@ pmap_pv_reclaim(pmap_t locked_pmap) pt_entry_t *pte, tpte; pv_entry_t pv; vm_offset_t va; - vm_page_t free, m, m_pc; + vm_page_t m, m_pc; + struct spglist free; uint32_t inuse; int bit, field, freed; PMAP_LOCK_ASSERT(locked_pmap, MA_OWNED); pmap = NULL; - free = m_pc = NULL; + m_pc = NULL; + SLIST_INIT(&free); TAILQ_INIT(&newtail); while ((pc = TAILQ_FIRST(&pv_chunks)) != NULL && (pv_vafree == 0 || - free == NULL)) { + SLIST_EMPTY(&free))) { TAILQ_REMOVE(&pv_chunks, pc, pc_lru); if (pmap != pc->pc_pmap) { if (pmap != NULL) { @@ -2307,15 +2307,14 @@ out: if (pmap != locked_pmap) PMAP_UNLOCK(pmap); } - if (m_pc == NULL && pv_vafree != 0 && free != NULL) { - m_pc = free; - free = (void *)m_pc->object; - m_pc->object = NULL; + if (m_pc == NULL && pv_vafree != 0 && SLIST_EMPTY(&free)) { + m_pc = SLIST_FIRST(&free); + SLIST_REMOVE_HEAD(&free, plinks.s.ss); /* Recycle a freed page table page. */ m_pc->wire_count = 1; atomic_add_int(&cnt.v_wire_count, 1); } - pmap_free_zero_pages(free); + pmap_free_zero_pages(&free); return (m_pc); } @@ -2636,7 +2635,8 @@ pmap_demote_pde(pmap_t pmap, pd_entry_t *pde, vm_offset_t va) pd_entry_t newpde, oldpde; pt_entry_t *firstpte, newpte; vm_paddr_t mptepa; - vm_page_t free, mpte; + vm_page_t mpte; + struct spglist free; PMAP_LOCK_ASSERT(pmap, MA_OWNED); oldpde = *pde; @@ -2658,10 +2658,10 @@ pmap_demote_pde(pmap_t pmap, pd_entry_t *pde, vm_offset_t va) if ((oldpde & PG_A) == 0 || (mpte = vm_page_alloc(NULL, va >> PDRSHIFT, VM_ALLOC_NOOBJ | VM_ALLOC_NORMAL | VM_ALLOC_WIRED)) == NULL) { - free = NULL; + SLIST_INIT(&free); pmap_remove_pde(pmap, pde, trunc_4mpage(va), &free); pmap_invalidate_page(pmap, trunc_4mpage(va)); - pmap_free_zero_pages(free); + pmap_free_zero_pages(&free); CTR2(KTR_PMAP, "pmap_demote_pde: failure for va %#x" " in pmap %p", va, pmap); return (FALSE); @@ -2814,7 +2814,7 @@ pmap_remove_kernel_pde(pmap_t pmap, pd_entry_t *pde, vm_offset_t va) */ static void pmap_remove_pde(pmap_t pmap, pd_entry_t *pdq, vm_offset_t sva, - vm_page_t *free) + struct spglist *free) { struct md_page *pvh; pd_entry_t oldpde; @@ -2870,7 +2870,8 @@ pmap_remove_pde(pmap_t pmap, pd_entry_t *pdq, vm_offset_t sva, * pmap_remove_pte: do the things to unmap a page in a process */ static int -pmap_remove_pte(pmap_t pmap, pt_entry_t *ptq, vm_offset_t va, vm_page_t *free) +pmap_remove_pte(pmap_t pmap, pt_entry_t *ptq, vm_offset_t va, + struct spglist *free) { pt_entry_t oldpte; vm_page_t m; @@ -2904,7 +2905,7 @@ pmap_remove_pte(pmap_t pmap, pt_entry_t *ptq, vm_offset_t va, vm_page_t *free) * Remove a single page from a process address space */ static void -pmap_remove_page(pmap_t pmap, vm_offset_t va, vm_page_t *free) +pmap_remove_page(pmap_t pmap, vm_offset_t va, struct spglist *free) { pt_entry_t *pte; @@ -2929,7 +2930,7 @@ pmap_remove(pmap_t pmap, vm_offset_t sva, vm_offset_t eva) vm_offset_t pdnxt; pd_entry_t ptpaddr; pt_entry_t *pte; - vm_page_t free = NULL; + struct spglist free; int anyvalid; /* @@ -2939,6 +2940,7 @@ pmap_remove(pmap_t pmap, vm_offset_t sva, vm_offset_t eva) return; anyvalid = 0; + SLIST_INIT(&free); rw_wlock(&pvh_global_lock); sched_pin(); @@ -3031,7 +3033,7 @@ out: pmap_invalidate_all(pmap); rw_wunlock(&pvh_global_lock); PMAP_UNLOCK(pmap); - pmap_free_zero_pages(free); + pmap_free_zero_pages(&free); } /* @@ -3056,11 +3058,11 @@ pmap_remove_all(vm_page_t m) pt_entry_t *pte, tpte; pd_entry_t *pde; vm_offset_t va; - vm_page_t free; + struct spglist free; KASSERT((m->oflags & VPO_UNMANAGED) == 0, ("pmap_remove_all: page %p is not managed", m)); - free = NULL; + SLIST_INIT(&free); rw_wlock(&pvh_global_lock); sched_pin(); if ((m->flags & PG_FICTITIOUS) != 0) @@ -3105,7 +3107,7 @@ small_mappings: vm_page_aflag_clear(m, PGA_WRITEABLE); sched_unpin(); rw_wunlock(&pvh_global_lock); - pmap_free_zero_pages(free); + pmap_free_zero_pages(&free); } /* @@ -3769,7 +3771,7 @@ pmap_enter_quick_locked(pmap_t pmap, vm_offset_t va, vm_page_t m, { pt_entry_t *pte; vm_paddr_t pa; - vm_page_t free; + struct spglist free; KASSERT(va < kmi.clean_sva || va >= kmi.clean_eva || (m->oflags & VPO_UNMANAGED) != 0, @@ -3838,10 +3840,10 @@ pmap_enter_quick_locked(pmap_t pmap, vm_offset_t va, vm_page_t m, if ((m->oflags & VPO_UNMANAGED) == 0 && !pmap_try_insert_pv_entry(pmap, va, m)) { if (mpte != NULL) { - free = NULL; + SLIST_INIT(&free); if (pmap_unwire_ptp(pmap, mpte, &free)) { pmap_invalidate_page(pmap, va); - pmap_free_zero_pages(free); + pmap_free_zero_pages(&free); } mpte = NULL; @@ -4024,7 +4026,7 @@ void pmap_copy(pmap_t dst_pmap, pmap_t src_pmap, vm_offset_t dst_addr, vm_size_t len, vm_offset_t src_addr) { - vm_page_t free; + struct spglist free; vm_offset_t addr; vm_offset_t end_addr = src_addr + len; vm_offset_t pdnxt; @@ -4107,12 +4109,12 @@ pmap_copy(pmap_t dst_pmap, pmap_t src_pmap, vm_offset_t dst_addr, vm_size_t len, PG_A); dst_pmap->pm_stats.resident_count++; } else { - free = NULL; + SLIST_INIT(&free); if (pmap_unwire_ptp(dst_pmap, dstmpte, &free)) { pmap_invalidate_page(dst_pmap, addr); - pmap_free_zero_pages(free); + pmap_free_zero_pages(&free); } goto out; } @@ -4419,11 +4421,11 @@ void pmap_remove_pages(pmap_t pmap) { pt_entry_t *pte, tpte; - vm_page_t free = NULL; vm_page_t m, mpte, mt; pv_entry_t pv; struct md_page *pvh; struct pv_chunk *pc, *npc; + struct spglist free; int field, idx; int32_t bit; uint32_t inuse, bitmask; @@ -4433,6 +4435,7 @@ pmap_remove_pages(pmap_t pmap) printf("warning: pmap_remove_pages called with non-current pmap\n"); return; } + SLIST_INIT(&free); rw_wlock(&pvh_global_lock); PMAP_LOCK(pmap); sched_pin(); @@ -4541,7 +4544,7 @@ pmap_remove_pages(pmap_t pmap) pmap_invalidate_all(pmap); rw_wunlock(&pvh_global_lock); PMAP_UNLOCK(pmap); - pmap_free_zero_pages(free); + pmap_free_zero_pages(&free); } /* |