From patchwork Tue Feb 26 16:12:47 2013 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Subject: [3.5.y.z, extended, stable] Patch "Purge existing TLB entries in set_pte_at and" has been added to staging queue Date: Tue, 26 Feb 2013 06:12:47 -0000 From: Luis Henriques X-Patchwork-Id: 223272 Message-Id: <1361895167-26791-1-git-send-email-luis.henriques@canonical.com> To: John David Anglin Cc: kernel-team@lists.ubuntu.com, James Bottomley This is a note to let you know that I have just added a patch titled Purge existing TLB entries in set_pte_at and to the linux-3.5.y-queue branch of the 3.5.y.z extended stable tree which can be found at: http://kernel.ubuntu.com/git?p=ubuntu/linux.git;a=shortlog;h=refs/heads/linux-3.5.y-queue If you, or anyone else, feels it should not be added to this tree, please reply to this email. For more information about the 3.5.y.z tree, see https://wiki.ubuntu.com/Kernel/Dev/ExtendedStable Thanks. -Luis ------ >From 2d65a71d04475edf0fac5fca580496639ded46e1 Mon Sep 17 00:00:00 2001 From: John David Anglin Date: Mon, 14 Jan 2013 19:45:00 -0500 Subject: [PATCH] Purge existing TLB entries in set_pte_at and ptep_set_wrprotect MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit commit 7139bc1579901b53db7e898789e916ee2fb52d78 upstream. This patch goes a long way toward fixing the minifail bug, and it  significantly improves the stability of SMP machines such as the rp3440.  When write  protecting a page for COW, we need to purge the existing translation.  Otherwise, the COW break doesn't occur as expected because the TLB may still have a stale entry which allows writes. [jejb: fix up checkpatch errors] Signed-off-by: John David Anglin Signed-off-by: James Bottomley Signed-off-by: Luis Henriques --- arch/parisc/include/asm/pgtable.h | 13 ++++++++++--- arch/parisc/kernel/cache.c | 18 ++++++++++++++++++ 2 files changed, 28 insertions(+), 3 deletions(-) -- 1.8.1.2 diff --git a/arch/parisc/include/asm/pgtable.h b/arch/parisc/include/asm/pgtable.h index ee99f23..7df49fa 100644 --- a/arch/parisc/include/asm/pgtable.h +++ b/arch/parisc/include/asm/pgtable.h @@ -12,11 +12,10 @@ #include #include +#include #include #include -struct vm_area_struct; - /* * kern_addr_valid(ADDR) tests if ADDR is pointing to valid kernel * memory. For the return value to be meaningful, ADDR must be >= @@ -40,7 +39,14 @@ struct vm_area_struct; do{ \ *(pteptr) = (pteval); \ } while(0) -#define set_pte_at(mm,addr,ptep,pteval) set_pte(ptep,pteval) + +extern void purge_tlb_entries(struct mm_struct *, unsigned long); + +#define set_pte_at(mm, addr, ptep, pteval) \ + do { \ + set_pte(ptep, pteval); \ + purge_tlb_entries(mm, addr); \ + } while (0) #endif /* !__ASSEMBLY__ */ @@ -466,6 +472,7 @@ static inline void ptep_set_wrprotect(struct mm_struct *mm, unsigned long addr, old = pte_val(*ptep); new = pte_val(pte_wrprotect(__pte (old))); } while (cmpxchg((unsigned long *) ptep, old, new) != old); + purge_tlb_entries(mm, addr); #else pte_t old_pte = *ptep; set_pte_at(mm, addr, ptep, pte_wrprotect(old_pte)); diff --git a/arch/parisc/kernel/cache.c b/arch/parisc/kernel/cache.c index 9d18189..fa21463 100644 --- a/arch/parisc/kernel/cache.c +++ b/arch/parisc/kernel/cache.c @@ -420,6 +420,24 @@ void kunmap_parisc(void *addr) EXPORT_SYMBOL(kunmap_parisc); #endif +void purge_tlb_entries(struct mm_struct *mm, unsigned long addr) +{ + unsigned long flags; + + /* Note: purge_tlb_entries can be called at startup with + no context. */ + + /* Disable preemption while we play with %sr1. */ + preempt_disable(); + mtsp(mm->context, 1); + purge_tlb_start(flags); + pdtlb(addr); + pitlb(addr); + purge_tlb_end(flags); + preempt_enable(); +} +EXPORT_SYMBOL(purge_tlb_entries); + void __flush_tlb_range(unsigned long sid, unsigned long start, unsigned long end) {