* [PATCH 0/2] x86/mm: vmalloc_fault fix for CONFIG_HUGETLBFS off @ 2018-03-13 17:03 Toshi Kani 2018-03-13 17:03 ` [PATCH 1/2] x86/mm: fix vmalloc_fault to use pXd_large Toshi Kani 2018-03-13 17:03 ` [PATCH 2/2] x86/mm: remove pointless checks in vmalloc_fault Toshi Kani 0 siblings, 2 replies; 8+ messages in thread From: Toshi Kani @ 2018-03-13 17:03 UTC (permalink / raw) To: tglx, mingo, hpa; +Cc: bp, luto, gratian.crisan, x86, linux-mm, linux-kernel Gratian Crisan reported that vmalloc_fault() crashes when CONFIG_HUGETLBFS is not set since the function inadvertently uses pXn_huge(), which always return 0 in this case. [1] ioremap() does not depend on CONFIG_HUGETLBFS. Patch 01 fixes the issue in vmalloc_fault(). Patch 02 is a clean-up for vmalloc_fault(). [1] https://lkml.org/lkml/2018/3/8/1281 --- Toshi Kani (2): 1/2 x86/mm: fix vmalloc_fault to use pXd_large 2/2 x86/mm: remove pointless checks in vmalloc_fault --- arch/x86/mm/fault.c | 62 +++++++++++++++++------------------------------------ 1 file changed, 20 insertions(+), 42 deletions(-) ^ permalink raw reply [flat|nested] 8+ messages in thread
* [PATCH 1/2] x86/mm: fix vmalloc_fault to use pXd_large 2018-03-13 17:03 [PATCH 0/2] x86/mm: vmalloc_fault fix for CONFIG_HUGETLBFS off Toshi Kani @ 2018-03-13 17:03 ` Toshi Kani 2018-03-14 19:27 ` [tip:x86/urgent] x86/mm: Fix " tip-bot for Toshi Kani 2018-03-13 17:03 ` [PATCH 2/2] x86/mm: remove pointless checks in vmalloc_fault Toshi Kani 1 sibling, 1 reply; 8+ messages in thread From: Toshi Kani @ 2018-03-13 17:03 UTC (permalink / raw) To: tglx, mingo, hpa Cc: bp, luto, gratian.crisan, x86, linux-mm, linux-kernel, Toshi Kani, stable Gratian Crisan reported that vmalloc_fault() crashes when CONFIG_HUGETLBFS is not set since the function inadvertently uses pXn_huge(), which always return 0 in this case. ioremap() does not depend on CONFIG_HUGETLBFS. Fix vmalloc_fault() to call pXd_large() instead. fixes: f4eafd8bcd52 ("x86/mm: Fix vmalloc_fault() to handle large pages properly") Reported-by: Gratian Crisan <gratian.crisan@ni.com> Signed-off-by: Toshi Kani <toshi.kani@hpe.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Ingo Molnar <mingo@redhat.com> Cc: "H. Peter Anvin" <hpa@zytor.com> Cc: Borislav Petkov <bp@alien8.de> Cc: Andy Lutomirski <luto@kernel.org> Cc: Gratian Crisan <gratian.crisan@ni.com> Cc: stable@vger.kernel.org --- arch/x86/mm/fault.c | 6 +++--- 1 file changed, 3 insertions(+), 3 deletions(-) diff --git a/arch/x86/mm/fault.c b/arch/x86/mm/fault.c index c88573d90f3e..25a30b5d6582 100644 --- a/arch/x86/mm/fault.c +++ b/arch/x86/mm/fault.c @@ -330,7 +330,7 @@ static noinline int vmalloc_fault(unsigned long address) if (!pmd_k) return -1; - if (pmd_huge(*pmd_k)) + if (pmd_large(*pmd_k)) return 0; pte_k = pte_offset_kernel(pmd_k, address); @@ -475,7 +475,7 @@ static noinline int vmalloc_fault(unsigned long address) if (pud_none(*pud) || pud_pfn(*pud) != pud_pfn(*pud_ref)) BUG(); - if (pud_huge(*pud)) + if (pud_large(*pud)) return 0; pmd = pmd_offset(pud, address); @@ -486,7 +486,7 @@ static noinline int vmalloc_fault(unsigned long address) if (pmd_none(*pmd) || pmd_pfn(*pmd) != pmd_pfn(*pmd_ref)) BUG(); - if (pmd_huge(*pmd)) + if (pmd_large(*pmd)) return 0; pte_ref = pte_offset_kernel(pmd_ref, address); ^ permalink raw reply related [flat|nested] 8+ messages in thread
* [tip:x86/urgent] x86/mm: Fix vmalloc_fault to use pXd_large 2018-03-13 17:03 ` [PATCH 1/2] x86/mm: fix vmalloc_fault to use pXd_large Toshi Kani @ 2018-03-14 19:27 ` tip-bot for Toshi Kani 0 siblings, 0 replies; 8+ messages in thread From: tip-bot for Toshi Kani @ 2018-03-14 19:27 UTC (permalink / raw) To: linux-tip-commits Cc: tglx, luto, linux-kernel, mingo, toshi.kani, bp, hpa, gratian.crisan Commit-ID: 18a955219bf7d9008ce480d4451b6b8bf4483a22 Gitweb: https://git.kernel.org/tip/18a955219bf7d9008ce480d4451b6b8bf4483a22 Author: Toshi Kani <toshi.kani@hpe.com> AuthorDate: Tue, 13 Mar 2018 11:03:46 -0600 Committer: Thomas Gleixner <tglx@linutronix.de> CommitDate: Wed, 14 Mar 2018 20:22:42 +0100 x86/mm: Fix vmalloc_fault to use pXd_large Gratian Crisan reported that vmalloc_fault() crashes when CONFIG_HUGETLBFS is not set since the function inadvertently uses pXn_huge(), which always return 0 in this case. ioremap() does not depend on CONFIG_HUGETLBFS. Fix vmalloc_fault() to call pXd_large() instead. Fixes: f4eafd8bcd52 ("x86/mm: Fix vmalloc_fault() to handle large pages properly") Reported-by: Gratian Crisan <gratian.crisan@ni.com> Signed-off-by: Toshi Kani <toshi.kani@hpe.com> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Cc: stable@vger.kernel.org Cc: linux-mm@kvack.org Cc: Borislav Petkov <bp@alien8.de> Cc: Andy Lutomirski <luto@kernel.org> Link: https://lkml.kernel.org/r/20180313170347.3829-2-toshi.kani@hpe.com --- arch/x86/mm/fault.c | 6 +++--- 1 file changed, 3 insertions(+), 3 deletions(-) diff --git a/arch/x86/mm/fault.c b/arch/x86/mm/fault.c index c88573d90f3e..25a30b5d6582 100644 --- a/arch/x86/mm/fault.c +++ b/arch/x86/mm/fault.c @@ -330,7 +330,7 @@ static noinline int vmalloc_fault(unsigned long address) if (!pmd_k) return -1; - if (pmd_huge(*pmd_k)) + if (pmd_large(*pmd_k)) return 0; pte_k = pte_offset_kernel(pmd_k, address); @@ -475,7 +475,7 @@ static noinline int vmalloc_fault(unsigned long address) if (pud_none(*pud) || pud_pfn(*pud) != pud_pfn(*pud_ref)) BUG(); - if (pud_huge(*pud)) + if (pud_large(*pud)) return 0; pmd = pmd_offset(pud, address); @@ -486,7 +486,7 @@ static noinline int vmalloc_fault(unsigned long address) if (pmd_none(*pmd) || pmd_pfn(*pmd) != pmd_pfn(*pmd_ref)) BUG(); - if (pmd_huge(*pmd)) + if (pmd_large(*pmd)) return 0; pte_ref = pte_offset_kernel(pmd_ref, address); ^ permalink raw reply related [flat|nested] 8+ messages in thread
* [PATCH 2/2] x86/mm: remove pointless checks in vmalloc_fault 2018-03-13 17:03 [PATCH 0/2] x86/mm: vmalloc_fault fix for CONFIG_HUGETLBFS off Toshi Kani 2018-03-13 17:03 ` [PATCH 1/2] x86/mm: fix vmalloc_fault to use pXd_large Toshi Kani @ 2018-03-13 17:03 ` Toshi Kani 2018-03-14 19:27 ` Thomas Gleixner 1 sibling, 1 reply; 8+ messages in thread From: Toshi Kani @ 2018-03-13 17:03 UTC (permalink / raw) To: tglx, mingo, hpa Cc: bp, luto, gratian.crisan, x86, linux-mm, linux-kernel, Toshi Kani vmalloc_fault() sets user's pgd or p4d from the kernel page table. Once it's set, all tables underneath are identical. There is no point of following the same page table with two separate pointers and makes sure they see the same with BUG(). Remove the pointless checks in vmalloc_fault(). Also rename the kernel pgd/p4d pointers to pgd_k/p4d_k so that their names are consistent in the file. Suggested-by: Andy Lutomirski <luto@kernel.org> Signed-off-by: Toshi Kani <toshi.kani@hpe.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Ingo Molnar <mingo@redhat.com> Cc: "H. Peter Anvin" <hpa@zytor.com> Cc: Borislav Petkov <bp@alien8.de> Cc: Andy Lutomirski <luto@kernel.org> Cc: Gratian Crisan <gratian.crisan@ni.com> --- arch/x86/mm/fault.c | 56 +++++++++++++++------------------------------------ 1 file changed, 17 insertions(+), 39 deletions(-) diff --git a/arch/x86/mm/fault.c b/arch/x86/mm/fault.c index 25a30b5d6582..e7bc79853538 100644 --- a/arch/x86/mm/fault.c +++ b/arch/x86/mm/fault.c @@ -417,11 +417,11 @@ void vmalloc_sync_all(void) */ static noinline int vmalloc_fault(unsigned long address) { - pgd_t *pgd, *pgd_ref; - p4d_t *p4d, *p4d_ref; - pud_t *pud, *pud_ref; - pmd_t *pmd, *pmd_ref; - pte_t *pte, *pte_ref; + pgd_t *pgd, *pgd_k; + p4d_t *p4d, *p4d_k; + pud_t *pud; + pmd_t *pmd; + pte_t *pte; /* Make sure we are in vmalloc area: */ if (!(address >= VMALLOC_START && address < VMALLOC_END)) @@ -435,73 +435,51 @@ static noinline int vmalloc_fault(unsigned long address) * case just flush: */ pgd = (pgd_t *)__va(read_cr3_pa()) + pgd_index(address); - pgd_ref = pgd_offset_k(address); - if (pgd_none(*pgd_ref)) + pgd_k = pgd_offset_k(address); + if (pgd_none(*pgd_k)) return -1; if (CONFIG_PGTABLE_LEVELS > 4) { if (pgd_none(*pgd)) { - set_pgd(pgd, *pgd_ref); + set_pgd(pgd, *pgd_k); arch_flush_lazy_mmu_mode(); } else { - BUG_ON(pgd_page_vaddr(*pgd) != pgd_page_vaddr(*pgd_ref)); + BUG_ON(pgd_page_vaddr(*pgd) != pgd_page_vaddr(*pgd_k)); } } /* With 4-level paging, copying happens on the p4d level. */ p4d = p4d_offset(pgd, address); - p4d_ref = p4d_offset(pgd_ref, address); - if (p4d_none(*p4d_ref)) + p4d_k = p4d_offset(pgd_k, address); + if (p4d_none(*p4d_k)) return -1; if (p4d_none(*p4d) && CONFIG_PGTABLE_LEVELS == 4) { - set_p4d(p4d, *p4d_ref); + set_p4d(p4d, *p4d_k); arch_flush_lazy_mmu_mode(); } else { - BUG_ON(p4d_pfn(*p4d) != p4d_pfn(*p4d_ref)); + BUG_ON(p4d_pfn(*p4d) != p4d_pfn(*p4d_k)); } - /* - * Below here mismatches are bugs because these lower tables - * are shared: - */ BUILD_BUG_ON(CONFIG_PGTABLE_LEVELS < 4); pud = pud_offset(p4d, address); - pud_ref = pud_offset(p4d_ref, address); - if (pud_none(*pud_ref)) + if (pud_none(*pud)) return -1; - if (pud_none(*pud) || pud_pfn(*pud) != pud_pfn(*pud_ref)) - BUG(); - if (pud_large(*pud)) return 0; pmd = pmd_offset(pud, address); - pmd_ref = pmd_offset(pud_ref, address); - if (pmd_none(*pmd_ref)) + if (pmd_none(*pmd)) return -1; - if (pmd_none(*pmd) || pmd_pfn(*pmd) != pmd_pfn(*pmd_ref)) - BUG(); - if (pmd_large(*pmd)) return 0; - pte_ref = pte_offset_kernel(pmd_ref, address); - if (!pte_present(*pte_ref)) - return -1; - pte = pte_offset_kernel(pmd, address); - - /* - * Don't use pte_page here, because the mappings can point - * outside mem_map, and the NUMA hash lookup cannot handle - * that: - */ - if (!pte_present(*pte) || pte_pfn(*pte) != pte_pfn(*pte_ref)) - BUG(); + if (!pte_present(*pte)) + return -1; return 0; } ^ permalink raw reply related [flat|nested] 8+ messages in thread
* Re: [PATCH 2/2] x86/mm: remove pointless checks in vmalloc_fault 2018-03-13 17:03 ` [PATCH 2/2] x86/mm: remove pointless checks in vmalloc_fault Toshi Kani @ 2018-03-14 19:27 ` Thomas Gleixner 2018-03-14 19:38 ` Kani, Toshi 0 siblings, 1 reply; 8+ messages in thread From: Thomas Gleixner @ 2018-03-14 19:27 UTC (permalink / raw) To: Toshi Kani Cc: mingo, hpa, bp, luto, gratian.crisan, x86, linux-mm, linux-kernel On Tue, 13 Mar 2018, Toshi Kani wrote: > vmalloc_fault() sets user's pgd or p4d from the kernel page table. > Once it's set, all tables underneath are identical. There is no point > of following the same page table with two separate pointers and makes > sure they see the same with BUG(). > > Remove the pointless checks in vmalloc_fault(). Also rename the kernel > pgd/p4d pointers to pgd_k/p4d_k so that their names are consistent in > the file. I have no idea to which branch this might apply. The first patch applies cleanly on linus head, but this one fails in hunk #2 on everything I tried. Can you please check? Thanks, tglx ^ permalink raw reply [flat|nested] 8+ messages in thread
* Re: [PATCH 2/2] x86/mm: remove pointless checks in vmalloc_fault 2018-03-14 19:27 ` Thomas Gleixner @ 2018-03-14 19:38 ` Kani, Toshi 2018-03-14 19:56 ` Thomas Gleixner 0 siblings, 1 reply; 8+ messages in thread From: Kani, Toshi @ 2018-03-14 19:38 UTC (permalink / raw) To: tglx; +Cc: linux-kernel, linux-mm, gratian.crisan, x86, hpa, mingo, luto, bp On Wed, 2018-03-14 at 20:27 +0100, Thomas Gleixner wrote: > On Tue, 13 Mar 2018, Toshi Kani wrote: > > > vmalloc_fault() sets user's pgd or p4d from the kernel page table. > > Once it's set, all tables underneath are identical. There is no point > > of following the same page table with two separate pointers and makes > > sure they see the same with BUG(). > > > > Remove the pointless checks in vmalloc_fault(). Also rename the kernel > > pgd/p4d pointers to pgd_k/p4d_k so that their names are consistent in > > the file. > > I have no idea to which branch this might apply. The first patch applies > cleanly on linus head, but this one fails in hunk #2 on everything I > tried. Can you please check? Sorry for the trouble. The patches are based on linus head. I just tried and they applied clean to me... Thanks, -Toshi ^ permalink raw reply [flat|nested] 8+ messages in thread
* Re: [PATCH 2/2] x86/mm: remove pointless checks in vmalloc_fault 2018-03-14 19:38 ` Kani, Toshi @ 2018-03-14 19:56 ` Thomas Gleixner 2018-03-14 20:07 ` Kani, Toshi 0 siblings, 1 reply; 8+ messages in thread From: Thomas Gleixner @ 2018-03-14 19:56 UTC (permalink / raw) To: Kani, Toshi Cc: linux-kernel, linux-mm, gratian.crisan, x86, hpa, mingo, luto, bp On Wed, 14 Mar 2018, Kani, Toshi wrote: > On Wed, 2018-03-14 at 20:27 +0100, Thomas Gleixner wrote: > > On Tue, 13 Mar 2018, Toshi Kani wrote: > > > > > vmalloc_fault() sets user's pgd or p4d from the kernel page table. > > > Once it's set, all tables underneath are identical. There is no point > > > of following the same page table with two separate pointers and makes > > > sure they see the same with BUG(). > > > > > > Remove the pointless checks in vmalloc_fault(). Also rename the kernel > > > pgd/p4d pointers to pgd_k/p4d_k so that their names are consistent in > > > the file. > > > > I have no idea to which branch this might apply. The first patch applies > > cleanly on linus head, but this one fails in hunk #2 on everything I > > tried. Can you please check? > > Sorry for the trouble. The patches are based on linus head. I just tried > and they applied clean to me... Hmm. Looks like I tried on the wrong branch. Nevertheless, 1/2 is queued in urgent, but 2/2 will go through tip/x86/mm which already has changes in that area causing the patch to fail. I just merged x86/urgent into x86/mm and pushed it out. Can you please rebase 2/2 on top of that bracnh and resend ? Thanks, tglx ^ permalink raw reply [flat|nested] 8+ messages in thread
* Re: [PATCH 2/2] x86/mm: remove pointless checks in vmalloc_fault 2018-03-14 19:56 ` Thomas Gleixner @ 2018-03-14 20:07 ` Kani, Toshi 0 siblings, 0 replies; 8+ messages in thread From: Kani, Toshi @ 2018-03-14 20:07 UTC (permalink / raw) To: tglx; +Cc: linux-kernel, linux-mm, gratian.crisan, x86, hpa, mingo, luto, bp On Wed, 2018-03-14 at 20:56 +0100, Thomas Gleixner wrote: > On Wed, 14 Mar 2018, Kani, Toshi wrote: > > On Wed, 2018-03-14 at 20:27 +0100, Thomas Gleixner wrote: > > > On Tue, 13 Mar 2018, Toshi Kani wrote: > > > > > > > vmalloc_fault() sets user's pgd or p4d from the kernel page table. > > > > Once it's set, all tables underneath are identical. There is no point > > > > of following the same page table with two separate pointers and makes > > > > sure they see the same with BUG(). > > > > > > > > Remove the pointless checks in vmalloc_fault(). Also rename the kernel > > > > pgd/p4d pointers to pgd_k/p4d_k so that their names are consistent in > > > > the file. > > > > > > I have no idea to which branch this might apply. The first patch applies > > > cleanly on linus head, but this one fails in hunk #2 on everything I > > > tried. Can you please check? > > > > Sorry for the trouble. The patches are based on linus head. I just tried > > and they applied clean to me... > > Hmm. Looks like I tried on the wrong branch. Nevertheless, 1/2 is queued in > urgent, but 2/2 will go through tip/x86/mm which already has changes in > that area causing the patch to fail. I just merged x86/urgent into x86/mm > and pushed it out. Can you please rebase 2/2 on top of that bracnh and > resend ? Yes, I will merge up 2/2 and resend. Thanks, -Toshi ^ permalink raw reply [flat|nested] 8+ messages in thread
end of thread, other threads:[~2018-03-14 20:07 UTC | newest] Thread overview: 8+ messages (download: mbox.gz / follow: Atom feed) -- links below jump to the message on this page -- 2018-03-13 17:03 [PATCH 0/2] x86/mm: vmalloc_fault fix for CONFIG_HUGETLBFS off Toshi Kani 2018-03-13 17:03 ` [PATCH 1/2] x86/mm: fix vmalloc_fault to use pXd_large Toshi Kani 2018-03-14 19:27 ` [tip:x86/urgent] x86/mm: Fix " tip-bot for Toshi Kani 2018-03-13 17:03 ` [PATCH 2/2] x86/mm: remove pointless checks in vmalloc_fault Toshi Kani 2018-03-14 19:27 ` Thomas Gleixner 2018-03-14 19:38 ` Kani, Toshi 2018-03-14 19:56 ` Thomas Gleixner 2018-03-14 20:07 ` Kani, Toshi
This is a public inbox, see mirroring instructions for how to clone and mirror all data and code used for this inbox; as well as URLs for NNTP newsgroup(s).