From: Hugh Dickins Date: Thu, 8 Jun 2023 19:15:16 +0000 (-0700) Subject: m68k: allow pte_offset_map[_lock]() to fail X-Git-Tag: v6.6.7~2549^2~165 X-Git-Url: http://review.tizen.org/git/?a=commitdiff_plain;h=e67b37c368b7cc24b8c0fe5ab6c44422312eab37;p=platform%2Fkernel%2Flinux-starfive.git m68k: allow pte_offset_map[_lock]() to fail In rare transient cases, not yet made possible, pte_offset_map() and pte_offset_map_lock() may not find a page table: handle appropriately. Restructure cf_tlb_miss() with a pte_unmap() (previously omitted) at label out, followed by one local_irq_restore() for all. Link: https://lkml.kernel.org/r/795f6a7-bcca-cdf-ad2a-fbdaa232998c@google.com Signed-off-by: Hugh Dickins Cc: Alexander Gordeev Cc: Alexandre Ghiti Cc: Aneesh Kumar K.V Cc: Catalin Marinas Cc: Christian Borntraeger Cc: Chris Zankel Cc: Claudio Imbrenda Cc: David Hildenbrand Cc: "David S. Miller" Cc: Geert Uytterhoeven Cc: Greg Ungerer Cc: Heiko Carstens Cc: Helge Deller Cc: "H. Peter Anvin" Cc: Ingo Molnar Cc: John David Anglin Cc: John Paul Adrian Glaubitz Cc: Kirill A. Shutemov Cc: Matthew Wilcox (Oracle) Cc: Max Filippov Cc: Michael Ellerman Cc: Michal Simek Cc: Mike Kravetz Cc: Mike Rapoport (IBM) Cc: Palmer Dabbelt Cc: Peter Zijlstra Cc: Qi Zheng Cc: Russell King Cc: Suren Baghdasaryan Cc: Thomas Bogendoerfer Cc: Thomas Gleixner Cc: Will Deacon Signed-off-by: Andrew Morton --- diff --git a/arch/m68k/include/asm/mmu_context.h b/arch/m68k/include/asm/mmu_context.h index 8ed6ac1..141bbdf 100644 --- a/arch/m68k/include/asm/mmu_context.h +++ b/arch/m68k/include/asm/mmu_context.h @@ -99,7 +99,7 @@ static inline void load_ksp_mmu(struct task_struct *task) p4d_t *p4d; pud_t *pud; pmd_t *pmd; - pte_t *pte; + pte_t *pte = NULL; unsigned long mmuar; local_irq_save(flags); @@ -139,7 +139,7 @@ static inline void load_ksp_mmu(struct task_struct *task) pte = (mmuar >= PAGE_OFFSET) ? pte_offset_kernel(pmd, mmuar) : pte_offset_map(pmd, mmuar); - if (pte_none(*pte) || !pte_present(*pte)) + if (!pte || pte_none(*pte) || !pte_present(*pte)) goto bug; set_pte(pte, pte_mkyoung(*pte)); @@ -161,6 +161,8 @@ static inline void load_ksp_mmu(struct task_struct *task) bug: pr_info("ksp load failed: mm=0x%p ksp=0x08%lx\n", mm, mmuar); end: + if (pte && mmuar < PAGE_OFFSET) + pte_unmap(pte); local_irq_restore(flags); } diff --git a/arch/m68k/kernel/sys_m68k.c b/arch/m68k/kernel/sys_m68k.c index bd0274c..c586034 100644 --- a/arch/m68k/kernel/sys_m68k.c +++ b/arch/m68k/kernel/sys_m68k.c @@ -488,6 +488,8 @@ sys_atomic_cmpxchg_32(unsigned long newval, int oldval, int d3, int d4, int d5, if (!pmd_present(*pmd)) goto bad_access; pte = pte_offset_map_lock(mm, pmd, (unsigned long)mem, &ptl); + if (!pte) + goto bad_access; if (!pte_present(*pte) || !pte_dirty(*pte) || !pte_write(*pte)) { pte_unmap_unlock(pte, ptl); diff --git a/arch/m68k/mm/mcfmmu.c b/arch/m68k/mm/mcfmmu.c index 70aa097..42f45ab 100644 --- a/arch/m68k/mm/mcfmmu.c +++ b/arch/m68k/mm/mcfmmu.c @@ -91,7 +91,8 @@ int cf_tlb_miss(struct pt_regs *regs, int write, int dtlb, int extension_word) p4d_t *p4d; pud_t *pud; pmd_t *pmd; - pte_t *pte; + pte_t *pte = NULL; + int ret = -1; int asid; local_irq_save(flags); @@ -100,47 +101,33 @@ int cf_tlb_miss(struct pt_regs *regs, int write, int dtlb, int extension_word) regs->pc + (extension_word * sizeof(long)); mm = (!user_mode(regs) && KMAPAREA(mmuar)) ? &init_mm : current->mm; - if (!mm) { - local_irq_restore(flags); - return -1; - } + if (!mm) + goto out; pgd = pgd_offset(mm, mmuar); - if (pgd_none(*pgd)) { - local_irq_restore(flags); - return -1; - } + if (pgd_none(*pgd)) + goto out; p4d = p4d_offset(pgd, mmuar); - if (p4d_none(*p4d)) { - local_irq_restore(flags); - return -1; - } + if (p4d_none(*p4d)) + goto out; pud = pud_offset(p4d, mmuar); - if (pud_none(*pud)) { - local_irq_restore(flags); - return -1; - } + if (pud_none(*pud)) + goto out; pmd = pmd_offset(pud, mmuar); - if (pmd_none(*pmd)) { - local_irq_restore(flags); - return -1; - } + if (pmd_none(*pmd)) + goto out; pte = (KMAPAREA(mmuar)) ? pte_offset_kernel(pmd, mmuar) : pte_offset_map(pmd, mmuar); - if (pte_none(*pte) || !pte_present(*pte)) { - local_irq_restore(flags); - return -1; - } + if (!pte || pte_none(*pte) || !pte_present(*pte)) + goto out; if (write) { - if (!pte_write(*pte)) { - local_irq_restore(flags); - return -1; - } + if (!pte_write(*pte)) + goto out; set_pte(pte, pte_mkdirty(*pte)); } @@ -161,9 +148,12 @@ int cf_tlb_miss(struct pt_regs *regs, int write, int dtlb, int extension_word) mmu_write(MMUOR, MMUOR_ACC | MMUOR_UAA); else mmu_write(MMUOR, MMUOR_ITLB | MMUOR_ACC | MMUOR_UAA); - + ret = 0; +out: + if (pte && !KMAPAREA(mmuar)) + pte_unmap(pte); local_irq_restore(flags); - return 0; + return ret; } void __init cf_bootmem_alloc(void)