diff options
Diffstat (limited to 'common/recipes-kernel/linux/linux-yocto-4.9.21/0033-kaiser-kaiser_flush_tlb_on_return_to_user-check-PCID.patch')
| -rw-r--r-- | common/recipes-kernel/linux/linux-yocto-4.9.21/0033-kaiser-kaiser_flush_tlb_on_return_to_user-check-PCID.patch | 93 |
1 files changed, 93 insertions, 0 deletions
diff --git a/common/recipes-kernel/linux/linux-yocto-4.9.21/0033-kaiser-kaiser_flush_tlb_on_return_to_user-check-PCID.patch b/common/recipes-kernel/linux/linux-yocto-4.9.21/0033-kaiser-kaiser_flush_tlb_on_return_to_user-check-PCID.patch new file mode 100644 index 00000000..85d10cc6 --- /dev/null +++ b/common/recipes-kernel/linux/linux-yocto-4.9.21/0033-kaiser-kaiser_flush_tlb_on_return_to_user-check-PCID.patch @@ -0,0 +1,93 @@ +From e57b7ded6155d14093d87783a34eb2d33384b059 Mon Sep 17 00:00:00 2001 +From: Hugh Dickins <hughd@google.com> +Date: Sat, 4 Nov 2017 18:43:06 -0700 +Subject: [PATCH 033/102] kaiser: kaiser_flush_tlb_on_return_to_user() check + PCID + +Let kaiser_flush_tlb_on_return_to_user() do the X86_FEATURE_PCID +check, instead of each caller doing it inline first: nobody needs +to optimize for the noPCID case, it's clearer this way, and better +suits later changes. Replace those no-op X86_CR3_PCID_KERN_FLUSH lines +by a BUILD_BUG_ON() in load_new_mm_cr3(), in case something changes. + +Signed-off-by: Hugh Dickins <hughd@google.com> +Acked-by: Jiri Kosina <jkosina@suse.cz> +Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> +--- + arch/x86/include/asm/tlbflush.h | 4 ++-- + arch/x86/mm/kaiser.c | 6 +++--- + arch/x86/mm/tlb.c | 8 ++++---- + 3 files changed, 9 insertions(+), 9 deletions(-) + +diff --git a/arch/x86/include/asm/tlbflush.h b/arch/x86/include/asm/tlbflush.h +index bc6f979..8db339a 100644 +--- a/arch/x86/include/asm/tlbflush.h ++++ b/arch/x86/include/asm/tlbflush.h +@@ -159,7 +159,7 @@ static inline void __native_flush_tlb(void) + * back: + */ + preempt_disable(); +- if (kaiser_enabled && this_cpu_has(X86_FEATURE_PCID)) ++ if (kaiser_enabled) + kaiser_flush_tlb_on_return_to_user(); + native_write_cr3(native_read_cr3()); + preempt_enable(); +@@ -218,7 +218,7 @@ static inline void __native_flush_tlb_single(unsigned long addr) + */ + + if (!this_cpu_has(X86_FEATURE_INVPCID_SINGLE)) { +- if (kaiser_enabled && this_cpu_has(X86_FEATURE_PCID)) ++ if (kaiser_enabled) + kaiser_flush_tlb_on_return_to_user(); + asm volatile("invlpg (%0)" ::"r" (addr) : "memory"); + return; +diff --git a/arch/x86/mm/kaiser.c b/arch/x86/mm/kaiser.c +index 65ac3fd..8600663 100644 +--- a/arch/x86/mm/kaiser.c ++++ b/arch/x86/mm/kaiser.c +@@ -435,12 +435,12 @@ void kaiser_setup_pcid(void) + + /* + * Make a note that this cpu will need to flush USER tlb on return to user. +- * Caller checks whether this_cpu_has(X86_FEATURE_PCID) before calling: +- * if cpu does not, then the NOFLUSH bit will never have been set. ++ * If cpu does not have PCID, then the NOFLUSH bit will never have been set. + */ + void kaiser_flush_tlb_on_return_to_user(void) + { +- this_cpu_write(x86_cr3_pcid_user, ++ if (this_cpu_has(X86_FEATURE_PCID)) ++ this_cpu_write(x86_cr3_pcid_user, + X86_CR3_PCID_USER_FLUSH | KAISER_SHADOW_PGD_OFFSET); + } + EXPORT_SYMBOL(kaiser_flush_tlb_on_return_to_user); +diff --git a/arch/x86/mm/tlb.c b/arch/x86/mm/tlb.c +index fde44bb..e81f8bb 100644 +--- a/arch/x86/mm/tlb.c ++++ b/arch/x86/mm/tlb.c +@@ -41,7 +41,7 @@ static void load_new_mm_cr3(pgd_t *pgdir) + { + unsigned long new_mm_cr3 = __pa(pgdir); + +- if (kaiser_enabled && this_cpu_has(X86_FEATURE_PCID)) { ++ if (kaiser_enabled) { + /* + * We reuse the same PCID for different tasks, so we must + * flush all the entries for the PCID out when we change tasks. +@@ -52,10 +52,10 @@ static void load_new_mm_cr3(pgd_t *pgdir) + * do it here, but can only be used if X86_FEATURE_INVPCID is + * available - and many machines support pcid without invpcid. + * +- * The line below is a no-op: X86_CR3_PCID_KERN_FLUSH is now 0; +- * but keep that line in there in case something changes. ++ * If X86_CR3_PCID_KERN_FLUSH actually added something, then it ++ * would be needed in the write_cr3() below - if PCIDs enabled. + */ +- new_mm_cr3 |= X86_CR3_PCID_KERN_FLUSH; ++ BUILD_BUG_ON(X86_CR3_PCID_KERN_FLUSH); + kaiser_flush_tlb_on_return_to_user(); + } + +-- +2.7.4 + |