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[Linux-stable-mirror] Patch "kaiser: drop is_atomic arg to kaiser_pagetable_walk()" has been added to the 4.4-stable tree

by gregkh＠linuxfoundation.org

This is a note to let you know that I've just added the patch titled kaiser: drop is_atomic arg to kaiser_pagetable_walk() to the 4.4-stable tree which can be found at: http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=sum… The filename of the patch is: kaiser-drop-is_atomic-arg-to-kaiser_pagetable_walk.patch and it can be found in the queue-4.4 subdirectory. If you, or anyone else, feels it should not be added to the stable tree, please let <stable(a)vger.kernel.org> know about it. >From foo@baz Wed Jan 3 18:58:12 CET 2018 From: Hugh Dickins <hughd(a)google.com> Date: Sun, 29 Oct 2017 11:36:19 -0700 Subject: kaiser: drop is_atomic arg to kaiser_pagetable_walk() From: Hugh Dickins <hughd(a)google.com> I have not observed a might_sleep() warning from setup_fixmap_gdt()'s use of kaiser_add_mapping() in our tree (why not?), but like upstream we have not provided a way for that to pass is_atomic true down to kaiser_pagetable_walk(), and at startup it's far from a likely source of trouble: so just delete the walk's is_atomic arg and might_sleep(). Signed-off-by: Hugh Dickins <hughd(a)google.com> Acked-by: Jiri Kosina <jkosina(a)suse.cz> Signed-off-by: Greg Kroah-Hartman <gregkh(a)linuxfoundation.org> --- arch/x86/mm/kaiser.c | 10 ++-------- 1 file changed, 2 insertions(+), 8 deletions(-) --- a/arch/x86/mm/kaiser.c +++ b/arch/x86/mm/kaiser.c @@ -108,19 +108,13 @@ static inline unsigned long get_pa_from_ * * Returns a pointer to a PTE on success, or NULL on failure. */ -static pte_t *kaiser_pagetable_walk(unsigned long address, bool is_atomic) +static pte_t *kaiser_pagetable_walk(unsigned long address) { pmd_t *pmd; pud_t *pud; pgd_t *pgd = native_get_shadow_pgd(pgd_offset_k(address)); gfp_t gfp = (GFP_KERNEL | __GFP_NOTRACK | __GFP_ZERO); - if (is_atomic) { - gfp &= ~GFP_KERNEL; - gfp |= __GFP_HIGH | __GFP_ATOMIC; - } else - might_sleep(); - if (pgd_none(*pgd)) { WARN_ONCE(1, "All shadow pgds should have been populated"); return NULL; @@ -195,7 +189,7 @@ static int kaiser_add_user_map(const voi ret = -EIO; break; } - pte = kaiser_pagetable_walk(address, false); + pte = kaiser_pagetable_walk(address); if (!pte) { ret = -ENOMEM; break; Patches currently in stable-queue which might be from hughd(a)google.com are queue-4.4/kaiser-vmstat-show-nr_kaisertable-as-nr_overhead.patch queue-4.4/kaiser-add-nokaiser-boot-option-using-alternative.patch queue-4.4/kaiser-fix-unlikely-error-in-alloc_ldt_struct.patch queue-4.4/kaiser-_pgd_alloc-without-__gfp_repeat-to-avoid-stalls.patch queue-4.4/kaiser-kaiser_flush_tlb_on_return_to_user-check-pcid.patch queue-4.4/x86-paravirt-dont-patch-flush_tlb_single.patch queue-4.4/kaiser-merged-update.patch queue-4.4/kaiser-delete-kaiser_real_switch-option.patch queue-4.4/kaiser-kaiser_remove_mapping-move-along-the-pgd.patch queue-4.4/kaiser-fix-perf-crashes.patch queue-4.4/kaiser-drop-is_atomic-arg-to-kaiser_pagetable_walk.patch queue-4.4/kaiser-load_new_mm_cr3-let-switch_user_cr3-flush-user.patch queue-4.4/kaiser-enhanced-by-kernel-and-user-pcids.patch queue-4.4/kaiser-x86_cr3_pcid_noflush-and-x86_cr3_pcid_user.patch queue-4.4/kaiser-use-alternative-instead-of-x86_cr3_pcid_noflush.patch queue-4.4/kaiser-stack-map-page_size-at-thread_size-page_size.patch queue-4.4/kaiser-name-that-0x1000-kaiser_shadow_pgd_offset.patch queue-4.4/kaiser-fix-regs-to-do_nmi-ifndef-config_kaiser.patch queue-4.4/kaiser-do-not-set-_page_nx-on-pgd_none.patch queue-4.4/kaiser-tidied-up-asm-kaiser.h-somewhat.patch queue-4.4/kaiser-cleanups-while-trying-for-gold-link.patch queue-4.4/kaiser-tidied-up-kaiser_add-remove_mapping-slightly.patch queue-4.4/kaiser-fix-build-and-fixme-in-alloc_ldt_struct.patch queue-4.4/kaiser-kernel-address-isolation.patch queue-4.4/kaiser-enomem-if-kaiser_pagetable_walk-null.patch queue-4.4/kaiser-asm-tlbflush.h-handle-nopge-at-lower-level.patch queue-4.4/kaiser-paranoid_entry-pass-cr3-need-to-paranoid_exit.patch queue-4.4/kaiser-kaiser-depends-on-smp.patch queue-4.4/kaiser-pcid-0-for-kernel-and-128-for-user.patch

7 years, 4 months

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[Linux-stable-mirror] Patch "kaiser: do not set _PAGE_NX on pgd_none" has been added to the 4.4-stable tree

by gregkh＠linuxfoundation.org

This is a note to let you know that I've just added the patch titled kaiser: do not set _PAGE_NX on pgd_none to the 4.4-stable tree which can be found at: http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=sum… The filename of the patch is: kaiser-do-not-set-_page_nx-on-pgd_none.patch and it can be found in the queue-4.4 subdirectory. If you, or anyone else, feels it should not be added to the stable tree, please let <stable(a)vger.kernel.org> know about it. >From foo@baz Wed Jan 3 18:58:12 CET 2018 From: Hugh Dickins <hughd(a)google.com> Date: Tue, 5 Sep 2017 12:05:01 -0700 Subject: kaiser: do not set _PAGE_NX on pgd_none From: Hugh Dickins <hughd(a)google.com> native_pgd_clear() uses native_set_pgd(), so native_set_pgd() must avoid setting the _PAGE_NX bit on an otherwise pgd_none() entry: usually that just generated a warning on exit, but sometimes more mysterious and damaging failures (our production machines could not complete booting). The original fix to this just avoided adding _PAGE_NX to an empty entry; but eventually more problems surfaced with kexec, and EFI mapping expected to be a problem too. So now instead change native_set_pgd() to update shadow only if _PAGE_USER: A few places (kernel/machine_kexec_64.c, platform/efi/efi_64.c for sure) use set_pgd() to set up a temporary internal virtual address space, with physical pages remapped at what Kaiser regards as userspace addresses: Kaiser then assumes a shadow pgd follows, which it will try to corrupt. This appears to be responsible for the recent kexec and kdump failures; though it's unclear how those did not manifest as a problem before. Ah, the shadow pgd will only be assumed to "follow" if the requested pgd is on an even-numbered page: so I suppose it was going wrong 50% of the time all along. What we need is a flag to set_pgd(), to tell it we're dealing with userspace. Er, isn't that what the pgd's _PAGE_USER bit is saying? Add a test for that. But we cannot do the same for pgd_clear() (which may be called to clear corrupted entries - set aside the question of "corrupt in which pgd?" until later), so there just rely on pgd_clear() not being called in the problematic cases - with a WARN_ON_ONCE() which should fire half the time if it is. But this is getting too big for an inline function: move it into arch/x86/mm/kaiser.c (which then demands a boot/compressed mod); and de-void and de-space native_get_shadow/normal_pgd() while here. Signed-off-by: Hugh Dickins <hughd(a)google.com> Acked-by: Jiri Kosina <jkosina(a)suse.cz> Signed-off-by: Greg Kroah-Hartman <gregkh(a)linuxfoundation.org> --- arch/x86/boot/compressed/misc.h | 1 arch/x86/include/asm/pgtable_64.h | 51 +++++++++----------------------------- arch/x86/mm/kaiser.c | 42 +++++++++++++++++++++++++++++++ 3 files changed, 56 insertions(+), 38 deletions(-) --- a/arch/x86/boot/compressed/misc.h +++ b/arch/x86/boot/compressed/misc.h @@ -9,6 +9,7 @@ */ #undef CONFIG_PARAVIRT #undef CONFIG_PARAVIRT_SPINLOCKS +#undef CONFIG_KAISER #undef CONFIG_KASAN #include <linux/linkage.h> --- a/arch/x86/include/asm/pgtable_64.h +++ b/arch/x86/include/asm/pgtable_64.h @@ -107,61 +107,36 @@ static inline void native_pud_clear(pud_ } #ifdef CONFIG_KAISER -static inline pgd_t * native_get_shadow_pgd(pgd_t *pgdp) +extern pgd_t kaiser_set_shadow_pgd(pgd_t *pgdp, pgd_t pgd); + +static inline pgd_t *native_get_shadow_pgd(pgd_t *pgdp) { - return (pgd_t *)(void*)((unsigned long)(void*)pgdp | (unsigned long)PAGE_SIZE); + return (pgd_t *)((unsigned long)pgdp | (unsigned long)PAGE_SIZE); } -static inline pgd_t * native_get_normal_pgd(pgd_t *pgdp) +static inline pgd_t *native_get_normal_pgd(pgd_t *pgdp) { - return (pgd_t *)(void*)((unsigned long)(void*)pgdp & ~(unsigned long)PAGE_SIZE); + return (pgd_t *)((unsigned long)pgdp & ~(unsigned long)PAGE_SIZE); } #else -static inline pgd_t * native_get_shadow_pgd(pgd_t *pgdp) +static inline pgd_t kaiser_set_shadow_pgd(pgd_t *pgdp, pgd_t pgd) +{ + return pgd; +} +static inline pgd_t *native_get_shadow_pgd(pgd_t *pgdp) { BUILD_BUG_ON(1); return NULL; } -static inline pgd_t * native_get_normal_pgd(pgd_t *pgdp) +static inline pgd_t *native_get_normal_pgd(pgd_t *pgdp) { return pgdp; } #endif /* CONFIG_KAISER */ -/* - * Page table pages are page-aligned. The lower half of the top - * level is used for userspace and the top half for the kernel. - * This returns true for user pages that need to get copied into - * both the user and kernel copies of the page tables, and false - * for kernel pages that should only be in the kernel copy. - */ -static inline bool is_userspace_pgd(void *__ptr) -{ - unsigned long ptr = (unsigned long)__ptr; - - return ((ptr % PAGE_SIZE) < (PAGE_SIZE / 2)); -} - static inline void native_set_pgd(pgd_t *pgdp, pgd_t pgd) { -#ifdef CONFIG_KAISER - pteval_t extra_kern_pgd_flags = 0; - /* Do we need to also populate the shadow pgd? */ - if (is_userspace_pgd(pgdp)) { - native_get_shadow_pgd(pgdp)->pgd = pgd.pgd; - /* - * Even if the entry is *mapping* userspace, ensure - * that userspace can not use it. This way, if we - * get out to userspace running on the kernel CR3, - * userspace will crash instead of running. - */ - extra_kern_pgd_flags = _PAGE_NX; - } - pgdp->pgd = pgd.pgd; - pgdp->pgd |= extra_kern_pgd_flags; -#else /* CONFIG_KAISER */ - *pgdp = pgd; -#endif + *pgdp = kaiser_set_shadow_pgd(pgdp, pgd); } static inline void native_pgd_clear(pgd_t *pgd) --- a/arch/x86/mm/kaiser.c +++ b/arch/x86/mm/kaiser.c @@ -303,4 +303,46 @@ void kaiser_remove_mapping(unsigned long unmap_pud_range_nofree(pgd, addr, end); } } + +/* + * Page table pages are page-aligned. The lower half of the top + * level is used for userspace and the top half for the kernel. + * This returns true for user pages that need to get copied into + * both the user and kernel copies of the page tables, and false + * for kernel pages that should only be in the kernel copy. + */ +static inline bool is_userspace_pgd(pgd_t *pgdp) +{ + return ((unsigned long)pgdp % PAGE_SIZE) < (PAGE_SIZE / 2); +} + +pgd_t kaiser_set_shadow_pgd(pgd_t *pgdp, pgd_t pgd) +{ + /* + * Do we need to also populate the shadow pgd? Check _PAGE_USER to + * skip cases like kexec and EFI which make temporary low mappings. + */ + if (pgd.pgd & _PAGE_USER) { + if (is_userspace_pgd(pgdp)) { + native_get_shadow_pgd(pgdp)->pgd = pgd.pgd; + /* + * Even if the entry is *mapping* userspace, ensure + * that userspace can not use it. This way, if we + * get out to userspace running on the kernel CR3, + * userspace will crash instead of running. + */ + pgd.pgd |= _PAGE_NX; + } + } else if (!pgd.pgd) { + /* + * pgd_clear() cannot check _PAGE_USER, and is even used to + * clear corrupted pgd entries: so just rely on cases like + * kexec and EFI never to be using pgd_clear(). + */ + if (!WARN_ON_ONCE((unsigned long)pgdp & PAGE_SIZE) && + is_userspace_pgd(pgdp)) + native_get_shadow_pgd(pgdp)->pgd = pgd.pgd; + } + return pgd; +} #endif /* CONFIG_KAISER */ Patches currently in stable-queue which might be from hughd(a)google.com are queue-4.4/kaiser-vmstat-show-nr_kaisertable-as-nr_overhead.patch queue-4.4/kaiser-add-nokaiser-boot-option-using-alternative.patch queue-4.4/kaiser-fix-unlikely-error-in-alloc_ldt_struct.patch queue-4.4/kaiser-_pgd_alloc-without-__gfp_repeat-to-avoid-stalls.patch queue-4.4/kaiser-kaiser_flush_tlb_on_return_to_user-check-pcid.patch queue-4.4/x86-paravirt-dont-patch-flush_tlb_single.patch queue-4.4/kaiser-merged-update.patch queue-4.4/kaiser-delete-kaiser_real_switch-option.patch queue-4.4/kaiser-kaiser_remove_mapping-move-along-the-pgd.patch queue-4.4/kaiser-fix-perf-crashes.patch queue-4.4/kaiser-drop-is_atomic-arg-to-kaiser_pagetable_walk.patch queue-4.4/kaiser-load_new_mm_cr3-let-switch_user_cr3-flush-user.patch queue-4.4/kaiser-enhanced-by-kernel-and-user-pcids.patch queue-4.4/kaiser-x86_cr3_pcid_noflush-and-x86_cr3_pcid_user.patch queue-4.4/kaiser-use-alternative-instead-of-x86_cr3_pcid_noflush.patch queue-4.4/kaiser-stack-map-page_size-at-thread_size-page_size.patch queue-4.4/kaiser-name-that-0x1000-kaiser_shadow_pgd_offset.patch queue-4.4/kaiser-fix-regs-to-do_nmi-ifndef-config_kaiser.patch queue-4.4/kaiser-do-not-set-_page_nx-on-pgd_none.patch queue-4.4/kaiser-tidied-up-asm-kaiser.h-somewhat.patch queue-4.4/kaiser-cleanups-while-trying-for-gold-link.patch queue-4.4/kaiser-tidied-up-kaiser_add-remove_mapping-slightly.patch queue-4.4/kaiser-fix-build-and-fixme-in-alloc_ldt_struct.patch queue-4.4/kaiser-kernel-address-isolation.patch queue-4.4/kaiser-enomem-if-kaiser_pagetable_walk-null.patch queue-4.4/kaiser-asm-tlbflush.h-handle-nopge-at-lower-level.patch queue-4.4/kaiser-paranoid_entry-pass-cr3-need-to-paranoid_exit.patch queue-4.4/kaiser-kaiser-depends-on-smp.patch queue-4.4/kaiser-pcid-0-for-kernel-and-128-for-user.patch

7 years, 4 months

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[Linux-stable-mirror] Patch "kaiser: delete KAISER_REAL_SWITCH option" has been added to the 4.4-stable tree

by gregkh＠linuxfoundation.org

This is a note to let you know that I've just added the patch titled kaiser: delete KAISER_REAL_SWITCH option to the 4.4-stable tree which can be found at: http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=sum… The filename of the patch is: kaiser-delete-kaiser_real_switch-option.patch and it can be found in the queue-4.4 subdirectory. If you, or anyone else, feels it should not be added to the stable tree, please let <stable(a)vger.kernel.org> know about it. >From foo@baz Wed Jan 3 18:58:12 CET 2018 From: Hugh Dickins <hughd(a)google.com> Date: Sun, 3 Sep 2017 18:30:43 -0700 Subject: kaiser: delete KAISER_REAL_SWITCH option From: Hugh Dickins <hughd(a)google.com> We fail to see what CONFIG_KAISER_REAL_SWITCH is for: it seems to be left over from early development, and now just obscures tricky parts of the code. Delete it before adding PCIDs, or nokaiser boot option. (Or if there is some good reason to keep the option, then it needs a help text - and a "depends on KAISER", so that all those without KAISER are not asked the question.) Signed-off-by: Hugh Dickins <hughd(a)google.com> Acked-by: Jiri Kosina <jkosina(a)suse.cz> Signed-off-by: Greg Kroah-Hartman <gregkh(a)linuxfoundation.org> --- arch/x86/entry/entry_64.S | 4 ---- arch/x86/include/asm/kaiser.h | 4 ---- security/Kconfig | 4 ---- 3 files changed, 12 deletions(-) --- a/arch/x86/entry/entry_64.S +++ b/arch/x86/entry/entry_64.S @@ -1291,9 +1291,7 @@ ENTRY(nmi) /* %rax is saved above, so OK to clobber here */ movq %cr3, %rax pushq %rax -#ifdef CONFIG_KAISER_REAL_SWITCH andq $(~KAISER_SHADOW_PGD_OFFSET), %rax -#endif movq %rax, %cr3 #endif call do_nmi @@ -1534,9 +1532,7 @@ end_repeat_nmi: /* %rax is saved above, so OK to clobber here */ movq %cr3, %rax pushq %rax -#ifdef CONFIG_KAISER_REAL_SWITCH andq $(~KAISER_SHADOW_PGD_OFFSET), %rax -#endif movq %rax, %cr3 #endif --- a/arch/x86/include/asm/kaiser.h +++ b/arch/x86/include/asm/kaiser.h @@ -21,17 +21,13 @@ .macro _SWITCH_TO_KERNEL_CR3 reg movq %cr3, \reg -#ifdef CONFIG_KAISER_REAL_SWITCH andq $(~KAISER_SHADOW_PGD_OFFSET), \reg -#endif movq \reg, %cr3 .endm .macro _SWITCH_TO_USER_CR3 reg movq %cr3, \reg -#ifdef CONFIG_KAISER_REAL_SWITCH orq $(KAISER_SHADOW_PGD_OFFSET), \reg -#endif movq \reg, %cr3 .endm --- a/security/Kconfig +++ b/security/Kconfig @@ -41,10 +41,6 @@ config KAISER If you are unsure how to answer this question, answer Y. -config KAISER_REAL_SWITCH - bool "KAISER: actually switch page tables" - default y - config SECURITYFS bool "Enable the securityfs filesystem" help Patches currently in stable-queue which might be from hughd(a)google.com are queue-4.4/kaiser-vmstat-show-nr_kaisertable-as-nr_overhead.patch queue-4.4/kaiser-add-nokaiser-boot-option-using-alternative.patch queue-4.4/kaiser-fix-unlikely-error-in-alloc_ldt_struct.patch queue-4.4/kaiser-_pgd_alloc-without-__gfp_repeat-to-avoid-stalls.patch queue-4.4/kaiser-kaiser_flush_tlb_on_return_to_user-check-pcid.patch queue-4.4/x86-paravirt-dont-patch-flush_tlb_single.patch queue-4.4/kaiser-merged-update.patch queue-4.4/kaiser-delete-kaiser_real_switch-option.patch queue-4.4/kaiser-kaiser_remove_mapping-move-along-the-pgd.patch queue-4.4/kaiser-fix-perf-crashes.patch queue-4.4/kaiser-drop-is_atomic-arg-to-kaiser_pagetable_walk.patch queue-4.4/kaiser-load_new_mm_cr3-let-switch_user_cr3-flush-user.patch queue-4.4/kaiser-enhanced-by-kernel-and-user-pcids.patch queue-4.4/kaiser-x86_cr3_pcid_noflush-and-x86_cr3_pcid_user.patch queue-4.4/kaiser-use-alternative-instead-of-x86_cr3_pcid_noflush.patch queue-4.4/kaiser-stack-map-page_size-at-thread_size-page_size.patch queue-4.4/kaiser-name-that-0x1000-kaiser_shadow_pgd_offset.patch queue-4.4/kaiser-fix-regs-to-do_nmi-ifndef-config_kaiser.patch queue-4.4/kaiser-do-not-set-_page_nx-on-pgd_none.patch queue-4.4/kaiser-tidied-up-asm-kaiser.h-somewhat.patch queue-4.4/kaiser-cleanups-while-trying-for-gold-link.patch queue-4.4/kaiser-tidied-up-kaiser_add-remove_mapping-slightly.patch queue-4.4/kaiser-fix-build-and-fixme-in-alloc_ldt_struct.patch queue-4.4/kaiser-kernel-address-isolation.patch queue-4.4/kaiser-enomem-if-kaiser_pagetable_walk-null.patch queue-4.4/kaiser-asm-tlbflush.h-handle-nopge-at-lower-level.patch queue-4.4/kaiser-paranoid_entry-pass-cr3-need-to-paranoid_exit.patch queue-4.4/kaiser-kaiser-depends-on-smp.patch queue-4.4/kaiser-pcid-0-for-kernel-and-128-for-user.patch

7 years, 4 months

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[Linux-stable-mirror] Patch "kaiser: disabled on Xen PV" has been added to the 4.4-stable tree

by gregkh＠linuxfoundation.org

This is a note to let you know that I've just added the patch titled kaiser: disabled on Xen PV to the 4.4-stable tree which can be found at: http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=sum… The filename of the patch is: kaiser-disabled-on-xen-pv.patch and it can be found in the queue-4.4 subdirectory. If you, or anyone else, feels it should not be added to the stable tree, please let <stable(a)vger.kernel.org> know about it. >From foo@baz Wed Jan 3 18:58:12 CET 2018 From: Jiri Kosina <jkosina(a)suse.cz> Date: Tue, 2 Jan 2018 14:19:49 +0100 Subject: kaiser: disabled on Xen PV From: Jiri Kosina <jkosina(a)suse.cz> Kaiser cannot be used on paravirtualized MMUs (namely reading and writing CR3). This does not work with KAISER as the CR3 switch from and to user space PGD would require to map the whole XEN_PV machinery into both. More importantly, enabling KAISER on Xen PV doesn't make too much sense, as PV guests use distinct %cr3 values for kernel and user already. Signed-off-by: Jiri Kosina <jkosina(a)suse.cz> Signed-off-by: Greg Kroah-Hartman <gregkh(a)linuxfoundation.org> --- arch/x86/mm/kaiser.c | 5 +++++ 1 file changed, 5 insertions(+) --- a/arch/x86/mm/kaiser.c +++ b/arch/x86/mm/kaiser.c @@ -264,6 +264,9 @@ void __init kaiser_check_boottime_disabl char arg[5]; int ret; + if (boot_cpu_has(X86_FEATURE_XENPV)) + goto silent_disable; + ret = cmdline_find_option(boot_command_line, "pti", arg, sizeof(arg)); if (ret > 0) { if (!strncmp(arg, "on", 2)) @@ -291,6 +294,8 @@ enable: disable: pr_info("Kernel/User page tables isolation: disabled\n"); + +silent_disable: kaiser_enabled = 0; setup_clear_cpu_cap(X86_FEATURE_KAISER); } Patches currently in stable-queue which might be from jkosina(a)suse.cz are queue-4.4/kaiser-vmstat-show-nr_kaisertable-as-nr_overhead.patch queue-4.4/kaiser-add-nokaiser-boot-option-using-alternative.patch queue-4.4/kaiser-fix-unlikely-error-in-alloc_ldt_struct.patch queue-4.4/kaiser-_pgd_alloc-without-__gfp_repeat-to-avoid-stalls.patch queue-4.4/kaiser-kaiser_flush_tlb_on_return_to_user-check-pcid.patch queue-4.4/kaiser-merged-update.patch queue-4.4/kaiser-delete-kaiser_real_switch-option.patch queue-4.4/kaiser-kaiser_remove_mapping-move-along-the-pgd.patch queue-4.4/kaiser-fix-perf-crashes.patch queue-4.4/kaiser-drop-is_atomic-arg-to-kaiser_pagetable_walk.patch queue-4.4/kaiser-load_new_mm_cr3-let-switch_user_cr3-flush-user.patch queue-4.4/kaiser-enhanced-by-kernel-and-user-pcids.patch queue-4.4/kaiser-x86_cr3_pcid_noflush-and-x86_cr3_pcid_user.patch queue-4.4/kaiser-use-alternative-instead-of-x86_cr3_pcid_noflush.patch queue-4.4/kaiser-stack-map-page_size-at-thread_size-page_size.patch queue-4.4/kaiser-name-that-0x1000-kaiser_shadow_pgd_offset.patch queue-4.4/kaiser-fix-regs-to-do_nmi-ifndef-config_kaiser.patch queue-4.4/kaiser-do-not-set-_page_nx-on-pgd_none.patch queue-4.4/kaiser-tidied-up-asm-kaiser.h-somewhat.patch queue-4.4/kaiser-cleanups-while-trying-for-gold-link.patch queue-4.4/kaiser-disabled-on-xen-pv.patch queue-4.4/kaiser-tidied-up-kaiser_add-remove_mapping-slightly.patch queue-4.4/kaiser-fix-build-and-fixme-in-alloc_ldt_struct.patch queue-4.4/kaiser-kernel-address-isolation.patch queue-4.4/kaiser-enomem-if-kaiser_pagetable_walk-null.patch queue-4.4/kaiser-asm-tlbflush.h-handle-nopge-at-lower-level.patch queue-4.4/kaiser-paranoid_entry-pass-cr3-need-to-paranoid_exit.patch queue-4.4/kaiser-kaiser-depends-on-smp.patch queue-4.4/kaiser-pcid-0-for-kernel-and-128-for-user.patch

7 years, 4 months

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[Linux-stable-mirror] Patch "kaiser: cleanups while trying for gold link" has been added to the 4.4-stable tree

by gregkh＠linuxfoundation.org

This is a note to let you know that I've just added the patch titled kaiser: cleanups while trying for gold link to the 4.4-stable tree which can be found at: http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=sum… The filename of the patch is: kaiser-cleanups-while-trying-for-gold-link.patch and it can be found in the queue-4.4 subdirectory. If you, or anyone else, feels it should not be added to the stable tree, please let <stable(a)vger.kernel.org> know about it. >From foo@baz Wed Jan 3 18:58:12 CET 2018 From: Hugh Dickins <hughd(a)google.com> Date: Mon, 21 Aug 2017 20:11:43 -0700 Subject: kaiser: cleanups while trying for gold link From: Hugh Dickins <hughd(a)google.com> While trying to get our gold link to work, four cleanups: matched the gdt_page declaration to its definition; in fiddling unsuccessfully with PERCPU_INPUT(), lined up backslashes; lined up the backslashes according to convention in percpu-defs.h; deleted the unused irq_stack_pointer addition to irq_stack_union. Sad to report that aligning backslashes does not appear to help gold align to 8192: but while these did not help, they are worth keeping. Signed-off-by: Hugh Dickins <hughd(a)google.com> Acked-by: Jiri Kosina <jkosina(a)suse.cz> Signed-off-by: Greg Kroah-Hartman <gregkh(a)linuxfoundation.org> --- arch/x86/include/asm/desc.h | 2 +- arch/x86/include/asm/processor.h | 5 ----- include/asm-generic/vmlinux.lds.h | 18 ++++++++---------- include/linux/percpu-defs.h | 24 ++++++++++++------------ 4 files changed, 21 insertions(+), 28 deletions(-) --- a/arch/x86/include/asm/desc.h +++ b/arch/x86/include/asm/desc.h @@ -43,7 +43,7 @@ struct gdt_page { struct desc_struct gdt[GDT_ENTRIES]; } __attribute__((aligned(PAGE_SIZE))); -DECLARE_PER_CPU_PAGE_ALIGNED(struct gdt_page, gdt_page); +DECLARE_PER_CPU_PAGE_ALIGNED_USER_MAPPED(struct gdt_page, gdt_page); static inline struct desc_struct *get_cpu_gdt_table(unsigned int cpu) { --- a/arch/x86/include/asm/processor.h +++ b/arch/x86/include/asm/processor.h @@ -332,11 +332,6 @@ union irq_stack_union { char gs_base[40]; unsigned long stack_canary; }; - - struct { - char irq_stack_pointer[64]; - char unused[IRQ_STACK_SIZE - 64]; - }; }; DECLARE_PER_CPU_FIRST(union irq_stack_union, irq_stack_union) __visible; --- a/include/asm-generic/vmlinux.lds.h +++ b/include/asm-generic/vmlinux.lds.h @@ -725,16 +725,14 @@ */ #define PERCPU_INPUT(cacheline) \ VMLINUX_SYMBOL(__per_cpu_start) = .; \ - \ - VMLINUX_SYMBOL(__per_cpu_user_mapped_start) = .; \ - *(.data..percpu..first) \ - . = ALIGN(cacheline); \ - *(.data..percpu..user_mapped) \ - *(.data..percpu..user_mapped..shared_aligned) \ - . = ALIGN(PAGE_SIZE); \ - *(.data..percpu..user_mapped..page_aligned) \ - VMLINUX_SYMBOL(__per_cpu_user_mapped_end) = .; \ - \ + VMLINUX_SYMBOL(__per_cpu_user_mapped_start) = .; \ + *(.data..percpu..first) \ + . = ALIGN(cacheline); \ + *(.data..percpu..user_mapped) \ + *(.data..percpu..user_mapped..shared_aligned) \ + . = ALIGN(PAGE_SIZE); \ + *(.data..percpu..user_mapped..page_aligned) \ + VMLINUX_SYMBOL(__per_cpu_user_mapped_end) = .; \ . = ALIGN(PAGE_SIZE); \ *(.data..percpu..page_aligned) \ . = ALIGN(cacheline); \ --- a/include/linux/percpu-defs.h +++ b/include/linux/percpu-defs.h @@ -121,10 +121,10 @@ #define DEFINE_PER_CPU(type, name) \ DEFINE_PER_CPU_SECTION(type, name, "") -#define DECLARE_PER_CPU_USER_MAPPED(type, name) \ +#define DECLARE_PER_CPU_USER_MAPPED(type, name) \ DECLARE_PER_CPU_SECTION(type, name, USER_MAPPED_SECTION) -#define DEFINE_PER_CPU_USER_MAPPED(type, name) \ +#define DEFINE_PER_CPU_USER_MAPPED(type, name) \ DEFINE_PER_CPU_SECTION(type, name, USER_MAPPED_SECTION) /* @@ -156,11 +156,11 @@ DEFINE_PER_CPU_SECTION(type, name, PER_CPU_SHARED_ALIGNED_SECTION) \ ____cacheline_aligned_in_smp -#define DECLARE_PER_CPU_SHARED_ALIGNED_USER_MAPPED(type, name) \ +#define DECLARE_PER_CPU_SHARED_ALIGNED_USER_MAPPED(type, name) \ DECLARE_PER_CPU_SECTION(type, name, USER_MAPPED_SECTION PER_CPU_SHARED_ALIGNED_SECTION) \ ____cacheline_aligned_in_smp -#define DEFINE_PER_CPU_SHARED_ALIGNED_USER_MAPPED(type, name) \ +#define DEFINE_PER_CPU_SHARED_ALIGNED_USER_MAPPED(type, name) \ DEFINE_PER_CPU_SECTION(type, name, USER_MAPPED_SECTION PER_CPU_SHARED_ALIGNED_SECTION) \ ____cacheline_aligned_in_smp @@ -185,18 +185,18 @@ /* * Declaration/definition used for per-CPU variables that must be page aligned and need to be mapped in user mode. */ -#define DECLARE_PER_CPU_PAGE_ALIGNED_USER_MAPPED(type, name) \ - DECLARE_PER_CPU_SECTION(type, name, USER_MAPPED_SECTION"..page_aligned") \ - __aligned(PAGE_SIZE) - -#define DEFINE_PER_CPU_PAGE_ALIGNED_USER_MAPPED(type, name) \ - DEFINE_PER_CPU_SECTION(type, name, USER_MAPPED_SECTION"..page_aligned") \ - __aligned(PAGE_SIZE) +#define DECLARE_PER_CPU_PAGE_ALIGNED_USER_MAPPED(type, name) \ + DECLARE_PER_CPU_SECTION(type, name, USER_MAPPED_SECTION"..page_aligned") \ + __aligned(PAGE_SIZE) + +#define DEFINE_PER_CPU_PAGE_ALIGNED_USER_MAPPED(type, name) \ + DEFINE_PER_CPU_SECTION(type, name, USER_MAPPED_SECTION"..page_aligned") \ + __aligned(PAGE_SIZE) /* * Declaration/definition used for per-CPU variables that must be read mostly. */ -#define DECLARE_PER_CPU_READ_MOSTLY(type, name) \ +#define DECLARE_PER_CPU_READ_MOSTLY(type, name) \ DECLARE_PER_CPU_SECTION(type, name, "..read_mostly") #define DEFINE_PER_CPU_READ_MOSTLY(type, name) \ Patches currently in stable-queue which might be from hughd(a)google.com are queue-4.4/kaiser-vmstat-show-nr_kaisertable-as-nr_overhead.patch queue-4.4/kaiser-add-nokaiser-boot-option-using-alternative.patch queue-4.4/kaiser-fix-unlikely-error-in-alloc_ldt_struct.patch queue-4.4/kaiser-_pgd_alloc-without-__gfp_repeat-to-avoid-stalls.patch queue-4.4/kaiser-kaiser_flush_tlb_on_return_to_user-check-pcid.patch queue-4.4/x86-paravirt-dont-patch-flush_tlb_single.patch queue-4.4/kaiser-merged-update.patch queue-4.4/kaiser-delete-kaiser_real_switch-option.patch queue-4.4/kaiser-kaiser_remove_mapping-move-along-the-pgd.patch queue-4.4/kaiser-fix-perf-crashes.patch queue-4.4/kaiser-drop-is_atomic-arg-to-kaiser_pagetable_walk.patch queue-4.4/kaiser-load_new_mm_cr3-let-switch_user_cr3-flush-user.patch queue-4.4/kaiser-enhanced-by-kernel-and-user-pcids.patch queue-4.4/kaiser-x86_cr3_pcid_noflush-and-x86_cr3_pcid_user.patch queue-4.4/kaiser-use-alternative-instead-of-x86_cr3_pcid_noflush.patch queue-4.4/kaiser-stack-map-page_size-at-thread_size-page_size.patch queue-4.4/kaiser-name-that-0x1000-kaiser_shadow_pgd_offset.patch queue-4.4/kaiser-fix-regs-to-do_nmi-ifndef-config_kaiser.patch queue-4.4/kaiser-do-not-set-_page_nx-on-pgd_none.patch queue-4.4/kaiser-tidied-up-asm-kaiser.h-somewhat.patch queue-4.4/kaiser-cleanups-while-trying-for-gold-link.patch queue-4.4/kaiser-tidied-up-kaiser_add-remove_mapping-slightly.patch queue-4.4/kaiser-fix-build-and-fixme-in-alloc_ldt_struct.patch queue-4.4/kaiser-kernel-address-isolation.patch queue-4.4/kaiser-enomem-if-kaiser_pagetable_walk-null.patch queue-4.4/kaiser-asm-tlbflush.h-handle-nopge-at-lower-level.patch queue-4.4/kaiser-paranoid_entry-pass-cr3-need-to-paranoid_exit.patch queue-4.4/kaiser-kaiser-depends-on-smp.patch queue-4.4/kaiser-pcid-0-for-kernel-and-128-for-user.patch

7 years, 4 months

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[Linux-stable-mirror] Patch "kaiser: asm/tlbflush.h handle noPGE at lower level" has been added to the 4.4-stable tree

by gregkh＠linuxfoundation.org

This is a note to let you know that I've just added the patch titled kaiser: asm/tlbflush.h handle noPGE at lower level to the 4.4-stable tree which can be found at: http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=sum… The filename of the patch is: kaiser-asm-tlbflush.h-handle-nopge-at-lower-level.patch and it can be found in the queue-4.4 subdirectory. If you, or anyone else, feels it should not be added to the stable tree, please let <stable(a)vger.kernel.org> know about it. >From foo@baz Wed Jan 3 18:58:12 CET 2018 From: Hugh Dickins <hughd(a)google.com> Date: Sat, 4 Nov 2017 18:23:24 -0700 Subject: kaiser: asm/tlbflush.h handle noPGE at lower level From: Hugh Dickins <hughd(a)google.com> I found asm/tlbflush.h too twisty, and think it safer not to avoid __native_flush_tlb_global_irq_disabled() in the kaiser_enabled case, but instead let it handle kaiser_enabled along with cr3: it can just use __native_flush_tlb() for that, no harm in re-disabling preemption. (This is not the same change as Kirill and Dave have suggested for upstream, flipping PGE in cr4: that's neat, but needs a cpu_has_pge check; cr3 is enough for kaiser, and thought to be cheaper than cr4.) Also delete the X86_FEATURE_INVPCID invpcid_flush_all_nonglobals() preference from __native_flush_tlb(): unlike the invpcid_flush_all() preference in __native_flush_tlb_global(), it's not seen in upstream 4.14, and was recently reported to be surprisingly slow. Signed-off-by: Hugh Dickins <hughd(a)google.com> Acked-by: Jiri Kosina <jkosina(a)suse.cz> Signed-off-by: Greg Kroah-Hartman <gregkh(a)linuxfoundation.org> --- arch/x86/include/asm/tlbflush.h | 27 +++------------------------ 1 file changed, 3 insertions(+), 24 deletions(-) --- a/arch/x86/include/asm/tlbflush.h +++ b/arch/x86/include/asm/tlbflush.h @@ -151,14 +151,6 @@ static inline void kaiser_flush_tlb_on_r static inline void __native_flush_tlb(void) { - if (this_cpu_has(X86_FEATURE_INVPCID)) { - /* - * Note, this works with CR4.PCIDE=0 or 1. - */ - invpcid_flush_all_nonglobals(); - return; - } - /* * If current->mm == NULL then we borrow a mm which may change during a * task switch and therefore we must not be preempted while we write CR3 @@ -182,11 +174,8 @@ static inline void __native_flush_tlb_gl /* restore PGE as it was before */ native_write_cr4(cr4); } else { - /* - * x86_64 microcode update comes this way when CR4.PGE is not - * enabled, and it's safer for all callers to allow this case. - */ - native_write_cr3(native_read_cr3()); + /* do it with cr3, letting kaiser flush user PCID */ + __native_flush_tlb(); } } @@ -194,12 +183,6 @@ static inline void __native_flush_tlb_gl { unsigned long flags; - if (kaiser_enabled) { - /* Globals are not used at all */ - __native_flush_tlb(); - return; - } - if (this_cpu_has(X86_FEATURE_INVPCID)) { /* * Using INVPCID is considerably faster than a pair of writes @@ -255,11 +238,7 @@ static inline void __native_flush_tlb_si static inline void __flush_tlb_all(void) { - if (cpu_has_pge) - __flush_tlb_global(); - else - __flush_tlb(); - + __flush_tlb_global(); /* * Note: if we somehow had PCID but not PGE, then this wouldn't work -- * we'd end up flushing kernel translations for the current ASID but Patches currently in stable-queue which might be from hughd(a)google.com are queue-4.4/kaiser-vmstat-show-nr_kaisertable-as-nr_overhead.patch queue-4.4/kaiser-add-nokaiser-boot-option-using-alternative.patch queue-4.4/kaiser-fix-unlikely-error-in-alloc_ldt_struct.patch queue-4.4/kaiser-_pgd_alloc-without-__gfp_repeat-to-avoid-stalls.patch queue-4.4/kaiser-kaiser_flush_tlb_on_return_to_user-check-pcid.patch queue-4.4/x86-paravirt-dont-patch-flush_tlb_single.patch queue-4.4/kaiser-merged-update.patch queue-4.4/kaiser-delete-kaiser_real_switch-option.patch queue-4.4/kaiser-kaiser_remove_mapping-move-along-the-pgd.patch queue-4.4/kaiser-fix-perf-crashes.patch queue-4.4/kaiser-drop-is_atomic-arg-to-kaiser_pagetable_walk.patch queue-4.4/kaiser-load_new_mm_cr3-let-switch_user_cr3-flush-user.patch queue-4.4/kaiser-enhanced-by-kernel-and-user-pcids.patch queue-4.4/kaiser-x86_cr3_pcid_noflush-and-x86_cr3_pcid_user.patch queue-4.4/kaiser-use-alternative-instead-of-x86_cr3_pcid_noflush.patch queue-4.4/kaiser-stack-map-page_size-at-thread_size-page_size.patch queue-4.4/kaiser-name-that-0x1000-kaiser_shadow_pgd_offset.patch queue-4.4/kaiser-fix-regs-to-do_nmi-ifndef-config_kaiser.patch queue-4.4/kaiser-do-not-set-_page_nx-on-pgd_none.patch queue-4.4/kaiser-tidied-up-asm-kaiser.h-somewhat.patch queue-4.4/kaiser-cleanups-while-trying-for-gold-link.patch queue-4.4/kaiser-tidied-up-kaiser_add-remove_mapping-slightly.patch queue-4.4/kaiser-fix-build-and-fixme-in-alloc_ldt_struct.patch queue-4.4/kaiser-kernel-address-isolation.patch queue-4.4/kaiser-enomem-if-kaiser_pagetable_walk-null.patch queue-4.4/kaiser-asm-tlbflush.h-handle-nopge-at-lower-level.patch queue-4.4/kaiser-paranoid_entry-pass-cr3-need-to-paranoid_exit.patch queue-4.4/kaiser-kaiser-depends-on-smp.patch queue-4.4/kaiser-pcid-0-for-kernel-and-128-for-user.patch

7 years, 4 months

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[Linux-stable-mirror] Patch "kaiser: add "nokaiser" boot option, using ALTERNATIVE" has been added to the 4.4-stable tree

by gregkh＠linuxfoundation.org

This is a note to let you know that I've just added the patch titled kaiser: add "nokaiser" boot option, using ALTERNATIVE to the 4.4-stable tree which can be found at: http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=sum… The filename of the patch is: kaiser-add-nokaiser-boot-option-using-alternative.patch and it can be found in the queue-4.4 subdirectory. If you, or anyone else, feels it should not be added to the stable tree, please let <stable(a)vger.kernel.org> know about it. >From foo@baz Wed Jan 3 18:58:12 CET 2018 From: Hugh Dickins <hughd(a)google.com> Date: Sun, 24 Sep 2017 16:59:49 -0700 Subject: kaiser: add "nokaiser" boot option, using ALTERNATIVE From: Hugh Dickins <hughd(a)google.com> Added "nokaiser" boot option: an early param like "noinvpcid". Most places now check int kaiser_enabled (#defined 0 when not CONFIG_KAISER) instead of #ifdef CONFIG_KAISER; but entry_64.S and entry_64_compat.S are using the ALTERNATIVE technique, which patches in the preferred instructions at runtime. That technique is tied to x86 cpu features, so X86_FEATURE_KAISER is fabricated. Prior to "nokaiser", Kaiser #defined _PAGE_GLOBAL 0: revert that, but be careful with both _PAGE_GLOBAL and CR4.PGE: setting them when nokaiser like when !CONFIG_KAISER, but not setting either when kaiser - neither matters on its own, but it's hard to be sure that _PAGE_GLOBAL won't get set in some obscure corner, or something add PGE into CR4. By omitting _PAGE_GLOBAL from __supported_pte_mask when kaiser_enabled, all page table setup which uses pte_pfn() masks it out of the ptes. It's slightly shameful that the same declaration versus definition of kaiser_enabled appears in not one, not two, but in three header files (asm/kaiser.h, asm/pgtable.h, asm/tlbflush.h). I felt safer that way, than with #including any of those in any of the others; and did not feel it worth an asm/kaiser_enabled.h - kernel/cpu/common.c includes them all, so we shall hear about it if they get out of synch. Cleanups while in the area: removed the silly #ifdef CONFIG_KAISER from kaiser.c; removed the unused native_get_normal_pgd(); removed the spurious reg clutter from SWITCH_*_CR3 macro stubs; corrected some comments. But more interestingly, set CR4.PSE in secondary_startup_64: the manual is clear that it does not matter whether it's 0 or 1 when 4-level-pts are enabled, but I was distracted to find cr4 different on BSP and auxiliaries - BSP alone was adding PSE, in probe_page_size_mask(). Signed-off-by: Hugh Dickins <hughd(a)google.com> Acked-by: Jiri Kosina <jkosina(a)suse.cz> Signed-off-by: Greg Kroah-Hartman <gregkh(a)linuxfoundation.org> --- Documentation/kernel-parameters.txt | 2 + arch/x86/entry/entry_64.S | 15 +++++++------ arch/x86/include/asm/cpufeature.h | 3 ++ arch/x86/include/asm/kaiser.h | 27 +++++++++++++++++------- arch/x86/include/asm/pgtable.h | 20 ++++++++++++----- arch/x86/include/asm/pgtable_64.h | 13 +++-------- arch/x86/include/asm/pgtable_types.h | 4 --- arch/x86/include/asm/tlbflush.h | 39 ++++++++++++++++++++++------------- arch/x86/kernel/cpu/common.c | 28 ++++++++++++++++++++++++- arch/x86/kernel/espfix_64.c | 3 +- arch/x86/kernel/head_64.S | 4 +-- arch/x86/mm/init.c | 2 - arch/x86/mm/init_64.c | 10 ++++++++ arch/x86/mm/kaiser.c | 26 +++++++++++++++++++---- arch/x86/mm/pgtable.c | 8 +------ arch/x86/mm/tlb.c | 4 --- 16 files changed, 143 insertions(+), 65 deletions(-) --- a/Documentation/kernel-parameters.txt +++ b/Documentation/kernel-parameters.txt @@ -2523,6 +2523,8 @@ bytes respectively. Such letter suffixes nojitter [IA-64] Disables jitter checking for ITC timers. + nokaiser [X86-64] Disable KAISER isolation of kernel from user. + no-kvmclock [X86,KVM] Disable paravirtualized KVM clock driver no-kvmapf [X86,KVM] Disable paravirtualized asynchronous page --- a/arch/x86/entry/entry_64.S +++ b/arch/x86/entry/entry_64.S @@ -1051,7 +1051,7 @@ ENTRY(paranoid_entry) * unconditionally, but we need to find out whether the reverse * should be done on return (conveyed to paranoid_exit in %ebx). */ - movq %cr3, %rax + ALTERNATIVE "jmp 2f", "movq %cr3, %rax", X86_FEATURE_KAISER testl $KAISER_SHADOW_PGD_OFFSET, %eax jz 2f orl $2, %ebx @@ -1083,6 +1083,7 @@ ENTRY(paranoid_exit) TRACE_IRQS_OFF_DEBUG TRACE_IRQS_IRETQ_DEBUG #ifdef CONFIG_KAISER + /* No ALTERNATIVE for X86_FEATURE_KAISER: paranoid_entry sets %ebx */ testl $2, %ebx /* SWITCH_USER_CR3 needed? */ jz paranoid_exit_no_switch SWITCH_USER_CR3 @@ -1315,13 +1316,14 @@ ENTRY(nmi) #ifdef CONFIG_KAISER /* Unconditionally use kernel CR3 for do_nmi() */ /* %rax is saved above, so OK to clobber here */ - movq %cr3, %rax + ALTERNATIVE "jmp 2f", "movq %cr3, %rax", X86_FEATURE_KAISER /* If PCID enabled, NOFLUSH now and NOFLUSH on return */ orq x86_cr3_pcid_noflush, %rax pushq %rax /* mask off "user" bit of pgd address and 12 PCID bits: */ andq $(~(X86_CR3_PCID_ASID_MASK | KAISER_SHADOW_PGD_OFFSET)), %rax movq %rax, %cr3 +2: #endif call do_nmi @@ -1331,8 +1333,7 @@ ENTRY(nmi) * kernel code that needs user CR3, but do we ever return * to "user mode" where we need the kernel CR3? */ - popq %rax - mov %rax, %cr3 + ALTERNATIVE "", "popq %rax; movq %rax, %cr3", X86_FEATURE_KAISER #endif /* @@ -1559,13 +1560,14 @@ end_repeat_nmi: #ifdef CONFIG_KAISER /* Unconditionally use kernel CR3 for do_nmi() */ /* %rax is saved above, so OK to clobber here */ - movq %cr3, %rax + ALTERNATIVE "jmp 2f", "movq %cr3, %rax", X86_FEATURE_KAISER /* If PCID enabled, NOFLUSH now and NOFLUSH on return */ orq x86_cr3_pcid_noflush, %rax pushq %rax /* mask off "user" bit of pgd address and 12 PCID bits: */ andq $(~(X86_CR3_PCID_ASID_MASK | KAISER_SHADOW_PGD_OFFSET)), %rax movq %rax, %cr3 +2: #endif /* paranoidentry do_nmi, 0; without TRACE_IRQS_OFF */ @@ -1577,8 +1579,7 @@ end_repeat_nmi: * kernel code that needs user CR3, like just just before * a sysret. */ - popq %rax - mov %rax, %cr3 + ALTERNATIVE "", "popq %rax; movq %rax, %cr3", X86_FEATURE_KAISER #endif testl %ebx, %ebx /* swapgs needed? */ --- a/arch/x86/include/asm/cpufeature.h +++ b/arch/x86/include/asm/cpufeature.h @@ -200,6 +200,9 @@ #define X86_FEATURE_HWP_PKG_REQ ( 7*32+14) /* Intel HWP_PKG_REQ */ #define X86_FEATURE_INTEL_PT ( 7*32+15) /* Intel Processor Trace */ +/* Because the ALTERNATIVE scheme is for members of the X86_FEATURE club... */ +#define X86_FEATURE_KAISER ( 7*32+31) /* CONFIG_KAISER w/o nokaiser */ + /* Virtualization flags: Linux defined, word 8 */ #define X86_FEATURE_TPR_SHADOW ( 8*32+ 0) /* Intel TPR Shadow */ #define X86_FEATURE_VNMI ( 8*32+ 1) /* Intel Virtual NMI */ --- a/arch/x86/include/asm/kaiser.h +++ b/arch/x86/include/asm/kaiser.h @@ -46,28 +46,33 @@ movq \reg, %cr3 .endm .macro SWITCH_KERNEL_CR3 -pushq %rax +ALTERNATIVE "jmp 8f", "pushq %rax", X86_FEATURE_KAISER _SWITCH_TO_KERNEL_CR3 %rax popq %rax +8: .endm .macro SWITCH_USER_CR3 -pushq %rax +ALTERNATIVE "jmp 8f", "pushq %rax", X86_FEATURE_KAISER _SWITCH_TO_USER_CR3 %rax %al popq %rax +8: .endm .macro SWITCH_KERNEL_CR3_NO_STACK -movq %rax, PER_CPU_VAR(unsafe_stack_register_backup) +ALTERNATIVE "jmp 8f", \ + __stringify(movq %rax, PER_CPU_VAR(unsafe_stack_register_backup)), \ + X86_FEATURE_KAISER _SWITCH_TO_KERNEL_CR3 %rax movq PER_CPU_VAR(unsafe_stack_register_backup), %rax +8: .endm #else /* CONFIG_KAISER */ -.macro SWITCH_KERNEL_CR3 reg +.macro SWITCH_KERNEL_CR3 .endm -.macro SWITCH_USER_CR3 reg regb +.macro SWITCH_USER_CR3 .endm .macro SWITCH_KERNEL_CR3_NO_STACK .endm @@ -90,6 +95,16 @@ DECLARE_PER_CPU(unsigned long, x86_cr3_p extern char __per_cpu_user_mapped_start[], __per_cpu_user_mapped_end[]; +extern int kaiser_enabled; +#else +#define kaiser_enabled 0 +#endif /* CONFIG_KAISER */ + +/* + * Kaiser function prototypes are needed even when CONFIG_KAISER is not set, + * so as to build with tests on kaiser_enabled instead of #ifdefs. + */ + /** * kaiser_add_mapping - map a virtual memory part to the shadow (user) mapping * @addr: the start address of the range @@ -119,8 +134,6 @@ extern void kaiser_remove_mapping(unsign */ extern void kaiser_init(void); -#endif /* CONFIG_KAISER */ - #endif /* __ASSEMBLY */ #endif /* _ASM_X86_KAISER_H */ --- a/arch/x86/include/asm/pgtable.h +++ b/arch/x86/include/asm/pgtable.h @@ -18,6 +18,12 @@ #ifndef __ASSEMBLY__ #include <asm/x86_init.h> +#ifdef CONFIG_KAISER +extern int kaiser_enabled; +#else +#define kaiser_enabled 0 +#endif + void ptdump_walk_pgd_level(struct seq_file *m, pgd_t *pgd); void ptdump_walk_pgd_level_checkwx(void); @@ -660,7 +666,7 @@ static inline int pgd_bad(pgd_t pgd) * page table by accident; it will fault on the first * instruction it tries to run. See native_set_pgd(). */ - if (IS_ENABLED(CONFIG_KAISER)) + if (kaiser_enabled) ignore_flags |= _PAGE_NX; return (pgd_flags(pgd) & ~ignore_flags) != _KERNPG_TABLE; @@ -865,12 +871,14 @@ static inline void pmdp_set_wrprotect(st */ static inline void clone_pgd_range(pgd_t *dst, pgd_t *src, int count) { - memcpy(dst, src, count * sizeof(pgd_t)); + memcpy(dst, src, count * sizeof(pgd_t)); #ifdef CONFIG_KAISER - /* Clone the shadow pgd part as well */ - memcpy(native_get_shadow_pgd(dst), - native_get_shadow_pgd(src), - count * sizeof(pgd_t)); + if (kaiser_enabled) { + /* Clone the shadow pgd part as well */ + memcpy(native_get_shadow_pgd(dst), + native_get_shadow_pgd(src), + count * sizeof(pgd_t)); + } #endif } --- a/arch/x86/include/asm/pgtable_64.h +++ b/arch/x86/include/asm/pgtable_64.h @@ -111,13 +111,12 @@ extern pgd_t kaiser_set_shadow_pgd(pgd_t static inline pgd_t *native_get_shadow_pgd(pgd_t *pgdp) { +#ifdef CONFIG_DEBUG_VM + /* linux/mmdebug.h may not have been included at this point */ + BUG_ON(!kaiser_enabled); +#endif return (pgd_t *)((unsigned long)pgdp | (unsigned long)PAGE_SIZE); } - -static inline pgd_t *native_get_normal_pgd(pgd_t *pgdp) -{ - return (pgd_t *)((unsigned long)pgdp & ~(unsigned long)PAGE_SIZE); -} #else static inline pgd_t kaiser_set_shadow_pgd(pgd_t *pgdp, pgd_t pgd) { @@ -128,10 +127,6 @@ static inline pgd_t *native_get_shadow_p BUILD_BUG_ON(1); return NULL; } -static inline pgd_t *native_get_normal_pgd(pgd_t *pgdp) -{ - return pgdp; -} #endif /* CONFIG_KAISER */ static inline void native_set_pgd(pgd_t *pgdp, pgd_t pgd) --- a/arch/x86/include/asm/pgtable_types.h +++ b/arch/x86/include/asm/pgtable_types.h @@ -39,11 +39,7 @@ #define _PAGE_ACCESSED (_AT(pteval_t, 1) << _PAGE_BIT_ACCESSED) #define _PAGE_DIRTY (_AT(pteval_t, 1) << _PAGE_BIT_DIRTY) #define _PAGE_PSE (_AT(pteval_t, 1) << _PAGE_BIT_PSE) -#ifdef CONFIG_KAISER -#define _PAGE_GLOBAL (_AT(pteval_t, 0)) -#else #define _PAGE_GLOBAL (_AT(pteval_t, 1) << _PAGE_BIT_GLOBAL) -#endif #define _PAGE_SOFTW1 (_AT(pteval_t, 1) << _PAGE_BIT_SOFTW1) #define _PAGE_SOFTW2 (_AT(pteval_t, 1) << _PAGE_BIT_SOFTW2) #define _PAGE_PAT (_AT(pteval_t, 1) << _PAGE_BIT_PAT) --- a/arch/x86/include/asm/tlbflush.h +++ b/arch/x86/include/asm/tlbflush.h @@ -136,9 +136,11 @@ static inline void cr4_set_bits_and_upda * to avoid the need for asm/kaiser.h in unexpected places. */ #ifdef CONFIG_KAISER +extern int kaiser_enabled; extern void kaiser_setup_pcid(void); extern void kaiser_flush_tlb_on_return_to_user(void); #else +#define kaiser_enabled 0 static inline void kaiser_setup_pcid(void) { } @@ -163,7 +165,7 @@ static inline void __native_flush_tlb(vo * back: */ preempt_disable(); - if (this_cpu_has(X86_FEATURE_PCID)) + if (kaiser_enabled && this_cpu_has(X86_FEATURE_PCID)) kaiser_flush_tlb_on_return_to_user(); native_write_cr3(native_read_cr3()); preempt_enable(); @@ -174,20 +176,30 @@ static inline void __native_flush_tlb_gl unsigned long cr4; cr4 = this_cpu_read(cpu_tlbstate.cr4); - /* clear PGE */ - native_write_cr4(cr4 & ~X86_CR4_PGE); - /* write old PGE again and flush TLBs */ - native_write_cr4(cr4); + if (cr4 & X86_CR4_PGE) { + /* clear PGE and flush TLB of all entries */ + native_write_cr4(cr4 & ~X86_CR4_PGE); + /* restore PGE as it was before */ + native_write_cr4(cr4); + } else { + /* + * x86_64 microcode update comes this way when CR4.PGE is not + * enabled, and it's safer for all callers to allow this case. + */ + native_write_cr3(native_read_cr3()); + } } static inline void __native_flush_tlb_global(void) { -#ifdef CONFIG_KAISER - /* Globals are not used at all */ - __native_flush_tlb(); -#else unsigned long flags; + if (kaiser_enabled) { + /* Globals are not used at all */ + __native_flush_tlb(); + return; + } + if (this_cpu_has(X86_FEATURE_INVPCID)) { /* * Using INVPCID is considerably faster than a pair of writes @@ -207,7 +219,6 @@ static inline void __native_flush_tlb_gl raw_local_irq_save(flags); __native_flush_tlb_global_irq_disabled(); raw_local_irq_restore(flags); -#endif } static inline void __native_flush_tlb_single(unsigned long addr) @@ -222,7 +233,7 @@ static inline void __native_flush_tlb_si */ if (!this_cpu_has(X86_FEATURE_INVPCID_SINGLE)) { - if (this_cpu_has(X86_FEATURE_PCID)) + if (kaiser_enabled && this_cpu_has(X86_FEATURE_PCID)) kaiser_flush_tlb_on_return_to_user(); asm volatile("invlpg (%0)" ::"r" (addr) : "memory"); return; @@ -237,9 +248,9 @@ static inline void __native_flush_tlb_si * Make sure to do only a single invpcid when KAISER is * disabled and we have only a single ASID. */ - if (X86_CR3_PCID_ASID_KERN != X86_CR3_PCID_ASID_USER) - invpcid_flush_one(X86_CR3_PCID_ASID_KERN, addr); - invpcid_flush_one(X86_CR3_PCID_ASID_USER, addr); + if (kaiser_enabled) + invpcid_flush_one(X86_CR3_PCID_ASID_USER, addr); + invpcid_flush_one(X86_CR3_PCID_ASID_KERN, addr); } static inline void __flush_tlb_all(void) --- a/arch/x86/kernel/cpu/common.c +++ b/arch/x86/kernel/cpu/common.c @@ -178,6 +178,20 @@ static int __init x86_pcid_setup(char *s return 1; } __setup("nopcid", x86_pcid_setup); + +static int __init x86_nokaiser_setup(char *s) +{ + /* nokaiser doesn't accept parameters */ + if (s) + return -EINVAL; +#ifdef CONFIG_KAISER + kaiser_enabled = 0; + setup_clear_cpu_cap(X86_FEATURE_KAISER); + pr_info("nokaiser: KAISER feature disabled\n"); +#endif + return 0; +} +early_param("nokaiser", x86_nokaiser_setup); #endif static int __init x86_noinvpcid_setup(char *s) @@ -324,7 +338,7 @@ static __always_inline void setup_smap(s static void setup_pcid(struct cpuinfo_x86 *c) { if (cpu_has(c, X86_FEATURE_PCID)) { - if (cpu_has(c, X86_FEATURE_PGE)) { + if (cpu_has(c, X86_FEATURE_PGE) || kaiser_enabled) { cr4_set_bits(X86_CR4_PCIDE); /* * INVPCID has two "groups" of types: @@ -747,6 +761,10 @@ void get_cpu_cap(struct cpuinfo_x86 *c) c->x86_power = cpuid_edx(0x80000007); init_scattered_cpuid_features(c); +#ifdef CONFIG_KAISER + if (kaiser_enabled) + set_cpu_cap(c, X86_FEATURE_KAISER); +#endif } static void identify_cpu_without_cpuid(struct cpuinfo_x86 *c) @@ -1406,6 +1424,14 @@ void cpu_init(void) * try to read it. */ cr4_init_shadow(); + if (!kaiser_enabled) { + /* + * secondary_startup_64() deferred setting PGE in cr4: + * probe_page_size_mask() sets it on the boot cpu, + * but it needs to be set on each secondary cpu. + */ + cr4_set_bits(X86_CR4_PGE); + } /* * Load microcode on this cpu if a valid microcode is available. --- a/arch/x86/kernel/espfix_64.c +++ b/arch/x86/kernel/espfix_64.c @@ -132,9 +132,10 @@ void __init init_espfix_bsp(void) * area to ensure it is mapped into the shadow user page * tables. */ - if (IS_ENABLED(CONFIG_KAISER)) + if (kaiser_enabled) { set_pgd(native_get_shadow_pgd(pgd_p), __pgd(_KERNPG_TABLE | __pa((pud_t *)espfix_pud_page))); + } /* Randomize the locations */ init_espfix_random(); --- a/arch/x86/kernel/head_64.S +++ b/arch/x86/kernel/head_64.S @@ -183,8 +183,8 @@ ENTRY(secondary_startup_64) movq $(init_level4_pgt - __START_KERNEL_map), %rax 1: - /* Enable PAE mode and PGE */ - movl $(X86_CR4_PAE | X86_CR4_PGE), %ecx + /* Enable PAE and PSE, but defer PGE until kaiser_enabled is decided */ + movl $(X86_CR4_PAE | X86_CR4_PSE), %ecx movq %rcx, %cr4 /* Setup early boot stage 4 level pagetables. */ --- a/arch/x86/mm/init.c +++ b/arch/x86/mm/init.c @@ -165,7 +165,7 @@ static void __init probe_page_size_mask( cr4_set_bits_and_update_boot(X86_CR4_PSE); /* Enable PGE if available */ - if (cpu_has_pge) { + if (cpu_has_pge && !kaiser_enabled) { cr4_set_bits_and_update_boot(X86_CR4_PGE); __supported_pte_mask |= _PAGE_GLOBAL; } else --- a/arch/x86/mm/init_64.c +++ b/arch/x86/mm/init_64.c @@ -395,6 +395,16 @@ void __init cleanup_highmap(void) continue; if (vaddr < (unsigned long) _text || vaddr > end) set_pmd(pmd, __pmd(0)); + else if (kaiser_enabled) { + /* + * level2_kernel_pgt is initialized with _PAGE_GLOBAL: + * clear that now. This is not important, so long as + * CR4.PGE remains clear, but it removes an anomaly. + * Physical mapping setup below avoids _PAGE_GLOBAL + * by use of massage_pgprot() inside pfn_pte() etc. + */ + set_pmd(pmd, pmd_clear_flags(*pmd, _PAGE_GLOBAL)); + } } } --- a/arch/x86/mm/kaiser.c +++ b/arch/x86/mm/kaiser.c @@ -17,7 +17,9 @@ #include <asm/pgalloc.h> #include <asm/desc.h> -#ifdef CONFIG_KAISER +int kaiser_enabled __read_mostly = 1; +EXPORT_SYMBOL(kaiser_enabled); /* for inlined TLB flush functions */ + __visible DEFINE_PER_CPU_USER_MAPPED(unsigned long, unsafe_stack_register_backup); @@ -168,8 +170,8 @@ static pte_t *kaiser_pagetable_walk(unsi return pte_offset_kernel(pmd, address); } -int kaiser_add_user_map(const void *__start_addr, unsigned long size, - unsigned long flags) +static int kaiser_add_user_map(const void *__start_addr, unsigned long size, + unsigned long flags) { int ret = 0; pte_t *pte; @@ -178,6 +180,15 @@ int kaiser_add_user_map(const void *__st unsigned long end_addr = PAGE_ALIGN(start_addr + size); unsigned long target_address; + /* + * It is convenient for callers to pass in __PAGE_KERNEL etc, + * and there is no actual harm from setting _PAGE_GLOBAL, so + * long as CR4.PGE is not set. But it is nonetheless troubling + * to see Kaiser itself setting _PAGE_GLOBAL (now that "nokaiser" + * requires that not to be #defined to 0): so mask it off here. + */ + flags &= ~_PAGE_GLOBAL; + for (; address < end_addr; address += PAGE_SIZE) { target_address = get_pa_from_mapping(address); if (target_address == -1) { @@ -264,6 +275,8 @@ void __init kaiser_init(void) { int cpu; + if (!kaiser_enabled) + return; kaiser_init_all_pgds(); for_each_possible_cpu(cpu) { @@ -312,6 +325,8 @@ void __init kaiser_init(void) /* Add a mapping to the shadow mapping, and synchronize the mappings */ int kaiser_add_mapping(unsigned long addr, unsigned long size, unsigned long flags) { + if (!kaiser_enabled) + return 0; return kaiser_add_user_map((const void *)addr, size, flags); } @@ -323,6 +338,8 @@ void kaiser_remove_mapping(unsigned long unsigned long addr, next; pgd_t *pgd; + if (!kaiser_enabled) + return; pgd = native_get_shadow_pgd(pgd_offset_k(start)); for (addr = start; addr < end; pgd++, addr = next) { next = pgd_addr_end(addr, end); @@ -344,6 +361,8 @@ static inline bool is_userspace_pgd(pgd_ pgd_t kaiser_set_shadow_pgd(pgd_t *pgdp, pgd_t pgd) { + if (!kaiser_enabled) + return pgd; /* * Do we need to also populate the shadow pgd? Check _PAGE_USER to * skip cases like kexec and EFI which make temporary low mappings. @@ -400,4 +419,3 @@ void kaiser_flush_tlb_on_return_to_user( X86_CR3_PCID_USER_FLUSH | KAISER_SHADOW_PGD_OFFSET); } EXPORT_SYMBOL(kaiser_flush_tlb_on_return_to_user); -#endif /* CONFIG_KAISER */ --- a/arch/x86/mm/pgtable.c +++ b/arch/x86/mm/pgtable.c @@ -341,16 +341,12 @@ static inline void _pgd_free(pgd_t *pgd) } #else -#ifdef CONFIG_KAISER /* - * Instead of one pmd, we aquire two pmds. Being order-1, it is + * Instead of one pgd, Kaiser acquires two pgds. Being order-1, it is * both 8k in size and 8k-aligned. That lets us just flip bit 12 * in a pointer to swap between the two 4k halves. */ -#define PGD_ALLOCATION_ORDER 1 -#else -#define PGD_ALLOCATION_ORDER 0 -#endif +#define PGD_ALLOCATION_ORDER kaiser_enabled static inline pgd_t *_pgd_alloc(void) { --- a/arch/x86/mm/tlb.c +++ b/arch/x86/mm/tlb.c @@ -39,8 +39,7 @@ static void load_new_mm_cr3(pgd_t *pgdir { unsigned long new_mm_cr3 = __pa(pgdir); -#ifdef CONFIG_KAISER - if (this_cpu_has(X86_FEATURE_PCID)) { + if (kaiser_enabled && this_cpu_has(X86_FEATURE_PCID)) { /* * We reuse the same PCID for different tasks, so we must * flush all the entries for the PCID out when we change tasks. @@ -57,7 +56,6 @@ static void load_new_mm_cr3(pgd_t *pgdir new_mm_cr3 |= X86_CR3_PCID_KERN_FLUSH; kaiser_flush_tlb_on_return_to_user(); } -#endif /* CONFIG_KAISER */ /* * Caution: many callers of this function expect Patches currently in stable-queue which might be from hughd(a)google.com are queue-4.4/kaiser-vmstat-show-nr_kaisertable-as-nr_overhead.patch queue-4.4/kaiser-add-nokaiser-boot-option-using-alternative.patch queue-4.4/kaiser-fix-unlikely-error-in-alloc_ldt_struct.patch queue-4.4/kaiser-_pgd_alloc-without-__gfp_repeat-to-avoid-stalls.patch queue-4.4/kaiser-kaiser_flush_tlb_on_return_to_user-check-pcid.patch queue-4.4/x86-paravirt-dont-patch-flush_tlb_single.patch queue-4.4/kaiser-merged-update.patch queue-4.4/kaiser-delete-kaiser_real_switch-option.patch queue-4.4/kaiser-kaiser_remove_mapping-move-along-the-pgd.patch queue-4.4/kaiser-fix-perf-crashes.patch queue-4.4/kaiser-drop-is_atomic-arg-to-kaiser_pagetable_walk.patch queue-4.4/kaiser-load_new_mm_cr3-let-switch_user_cr3-flush-user.patch queue-4.4/kaiser-enhanced-by-kernel-and-user-pcids.patch queue-4.4/kaiser-x86_cr3_pcid_noflush-and-x86_cr3_pcid_user.patch queue-4.4/kaiser-use-alternative-instead-of-x86_cr3_pcid_noflush.patch queue-4.4/kaiser-stack-map-page_size-at-thread_size-page_size.patch queue-4.4/kaiser-name-that-0x1000-kaiser_shadow_pgd_offset.patch queue-4.4/kaiser-fix-regs-to-do_nmi-ifndef-config_kaiser.patch queue-4.4/kaiser-do-not-set-_page_nx-on-pgd_none.patch queue-4.4/kaiser-tidied-up-asm-kaiser.h-somewhat.patch queue-4.4/kaiser-cleanups-while-trying-for-gold-link.patch queue-4.4/kaiser-tidied-up-kaiser_add-remove_mapping-slightly.patch queue-4.4/kaiser-fix-build-and-fixme-in-alloc_ldt_struct.patch queue-4.4/kaiser-kernel-address-isolation.patch queue-4.4/kaiser-enomem-if-kaiser_pagetable_walk-null.patch queue-4.4/kaiser-asm-tlbflush.h-handle-nopge-at-lower-level.patch queue-4.4/kaiser-paranoid_entry-pass-cr3-need-to-paranoid_exit.patch queue-4.4/kaiser-kaiser-depends-on-smp.patch queue-4.4/kaiser-pcid-0-for-kernel-and-128-for-user.patch

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[Linux-stable-mirror] Patch "kaiser: _pgd_alloc() without __GFP_REPEAT to avoid stalls" has been added to the 4.4-stable tree

by gregkh＠linuxfoundation.org

This is a note to let you know that I've just added the patch titled kaiser: _pgd_alloc() without __GFP_REPEAT to avoid stalls to the 4.4-stable tree which can be found at: http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=sum… The filename of the patch is: kaiser-_pgd_alloc-without-__gfp_repeat-to-avoid-stalls.patch and it can be found in the queue-4.4 subdirectory. If you, or anyone else, feels it should not be added to the stable tree, please let <stable(a)vger.kernel.org> know about it. >From foo@baz Wed Jan 3 18:58:12 CET 2018 From: Hugh Dickins <hughd(a)google.com> Date: Fri, 13 Oct 2017 12:10:00 -0700 Subject: kaiser: _pgd_alloc() without __GFP_REPEAT to avoid stalls From: Hugh Dickins <hughd(a)google.com> Synthetic filesystem mempressure testing has shown softlockups, with hour-long page allocation stalls, and pgd_alloc() trying for order:1 with __GFP_REPEAT in one of the backtraces each time. That's _pgd_alloc() going for a Kaiser double-pgd, using the __GFP_REPEAT common to all page table allocations, but actually having no effect on order:0 (see should_alloc_oom() and should_continue_reclaim() in this tree, but beware that ports to another tree might behave differently). Order:1 stack allocation has been working satisfactorily without __GFP_REPEAT forever, and page table allocation only asks __GFP_REPEAT for awkward occasions in a long-running process: it's not appropriate at fork or exec time, and seems to be doing much more harm than good: getting those contiguous pages under very heavy mempressure can be hard (though even without it, Kaiser does generate more mempressure). Mask out that __GFP_REPEAT inside _pgd_alloc(). Why not take it out of the PGALLOG_GFP altogether, as v4.7 commit a3a9a59d2067 ("x86: get rid of superfluous __GFP_REPEAT") did? Because I think that might make a difference to our page table memcg charging, which I'd prefer not to interfere with at this time. hughd adds: __alloc_pages_slowpath() in the 4.4.89-stable tree handles __GFP_REPEAT a little differently than in prod kernel or 3.18.72-stable, so it may not always be exactly a no-op on order:0 pages, as said above; but I think still appropriate to omit it from Kaiser or non-Kaiser pgd. Signed-off-by: Hugh Dickins <hughd(a)google.com> Acked-by: Jiri Kosina <jkosina(a)suse.cz> Signed-off-by: Greg Kroah-Hartman <gregkh(a)linuxfoundation.org> --- arch/x86/mm/pgtable.c | 6 ++++-- 1 file changed, 4 insertions(+), 2 deletions(-) --- a/arch/x86/mm/pgtable.c +++ b/arch/x86/mm/pgtable.c @@ -6,7 +6,7 @@ #include <asm/fixmap.h> #include <asm/mtrr.h> -#define PGALLOC_GFP GFP_KERNEL | __GFP_NOTRACK | __GFP_REPEAT | __GFP_ZERO +#define PGALLOC_GFP (GFP_KERNEL | __GFP_NOTRACK | __GFP_REPEAT | __GFP_ZERO) #ifdef CONFIG_HIGHPTE #define PGALLOC_USER_GFP __GFP_HIGHMEM @@ -354,7 +354,9 @@ static inline void _pgd_free(pgd_t *pgd) static inline pgd_t *_pgd_alloc(void) { - return (pgd_t *)__get_free_pages(PGALLOC_GFP, PGD_ALLOCATION_ORDER); + /* No __GFP_REPEAT: to avoid page allocation stalls in order-1 case */ + return (pgd_t *)__get_free_pages(PGALLOC_GFP & ~__GFP_REPEAT, + PGD_ALLOCATION_ORDER); } static inline void _pgd_free(pgd_t *pgd) Patches currently in stable-queue which might be from hughd(a)google.com are queue-4.4/kaiser-vmstat-show-nr_kaisertable-as-nr_overhead.patch queue-4.4/kaiser-add-nokaiser-boot-option-using-alternative.patch queue-4.4/kaiser-fix-unlikely-error-in-alloc_ldt_struct.patch queue-4.4/kaiser-_pgd_alloc-without-__gfp_repeat-to-avoid-stalls.patch queue-4.4/kaiser-kaiser_flush_tlb_on_return_to_user-check-pcid.patch queue-4.4/x86-paravirt-dont-patch-flush_tlb_single.patch queue-4.4/kaiser-merged-update.patch queue-4.4/kaiser-delete-kaiser_real_switch-option.patch queue-4.4/kaiser-kaiser_remove_mapping-move-along-the-pgd.patch queue-4.4/kaiser-fix-perf-crashes.patch queue-4.4/kaiser-drop-is_atomic-arg-to-kaiser_pagetable_walk.patch queue-4.4/kaiser-load_new_mm_cr3-let-switch_user_cr3-flush-user.patch queue-4.4/kaiser-enhanced-by-kernel-and-user-pcids.patch queue-4.4/kaiser-x86_cr3_pcid_noflush-and-x86_cr3_pcid_user.patch queue-4.4/kaiser-use-alternative-instead-of-x86_cr3_pcid_noflush.patch queue-4.4/kaiser-stack-map-page_size-at-thread_size-page_size.patch queue-4.4/kaiser-name-that-0x1000-kaiser_shadow_pgd_offset.patch queue-4.4/kaiser-fix-regs-to-do_nmi-ifndef-config_kaiser.patch queue-4.4/kaiser-do-not-set-_page_nx-on-pgd_none.patch queue-4.4/kaiser-tidied-up-asm-kaiser.h-somewhat.patch queue-4.4/kaiser-cleanups-while-trying-for-gold-link.patch queue-4.4/kaiser-tidied-up-kaiser_add-remove_mapping-slightly.patch queue-4.4/kaiser-fix-build-and-fixme-in-alloc_ldt_struct.patch queue-4.4/kaiser-kernel-address-isolation.patch queue-4.4/kaiser-enomem-if-kaiser_pagetable_walk-null.patch queue-4.4/kaiser-asm-tlbflush.h-handle-nopge-at-lower-level.patch queue-4.4/kaiser-paranoid_entry-pass-cr3-need-to-paranoid_exit.patch queue-4.4/kaiser-kaiser-depends-on-smp.patch queue-4.4/kaiser-pcid-0-for-kernel-and-128-for-user.patch

7 years, 4 months

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Re: [Linux-stable-mirror] v3.18.86 build: 0 failures 1 warnings (v3.18.86)

by Greg KH

On Wed, Jan 03, 2018 at 03:41:21PM +0000, Mark Brown wrote: > On Wed, Jan 03, 2018 at 04:32:35PM +0100, Arnd Bergmann wrote: > > > It might be a problem with different 'make' versions, or something else > > in the environment that leads to "-Wno-frame-address" not being set > > on the command line instead. > > I'm using "GNU Make 4.1" - this is all just the default Debian stuff, > I've not customized my x86 host environment. Make 4.2.1 here with gcc 7.2.1 and I get tons of build warnings on my 3.18.y tree on my laptop, but my build machine running Fedora (make 4.2.1 and gcc 7.2.1) I get no build warnings at all. I've given up trying to track it down for my laptop, something is preventing the compiler flag from being added to the gcc command line, and I don't care anymore... thanks, greg k-h

7 years, 4 months

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Re: [Linux-stable-mirror] [PATCH] IB/core: Fix two kernel warnings triggered by rxe registration

by Jason Gunthorpe

On Mon, Dec 25, 2017 at 12:28:39PM +0200, Leon Romanovsky wrote: > On Fri, Dec 22, 2017 at 01:38:52PM -0800, Bart Van Assche wrote: > > Avoid that the following two warnings are reported when registering an > > rxe device: > > > > WARNING: CPU: 2 PID: 1005 at drivers/infiniband/core/device.c:449 ib_register_device+0x591/0x640 [ib_core] > > CPU: 2 PID: 1005 Comm: run_tests Not tainted 4.15.0-rc4-dbg+ #2 > > Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.0.0-prebuilt.qemu-project.org 04/01/2014 > > RIP: 0010:ib_register_device+0x591/0x640 [ib_core] > > Call Trace: > > rxe_register_device+0x3c6/0x470 [rdma_rxe] > > rxe_add+0x543/0x5e0 [rdma_rxe] > > rxe_net_add+0x37/0xb0 [rdma_rxe] > > rxe_param_set_add+0x5a/0x120 [rdma_rxe] > > param_attr_store+0x5e/0xc0 > > module_attr_store+0x19/0x30 > > sysfs_kf_write+0x3d/0x50 > > kernfs_fop_write+0x116/0x1a0 > > __vfs_write+0x23/0x120 > > vfs_write+0xbe/0x1b0 > > SyS_write+0x44/0xa0 > > entry_SYSCALL_64_fastpath+0x23/0x9a > > > > WARNING: CPU: 2 PID: 1005 at drivers/infiniband/core/sysfs.c:1279 ib_device_register_sysfs+0x11d/0x160 [ib_core] > > CPU: 2 PID: 1005 Comm: run_tests Tainted: G W 4.15.0-rc4-dbg+ #2 > > Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.0.0-prebuilt.qemu-project.org 04/01/2014 > > RIP: 0010:ib_device_register_sysfs+0x11d/0x160 [ib_core] > > Call Trace: > > ib_register_device+0x3f7/0x640 [ib_core] > > rxe_register_device+0x3c6/0x470 [rdma_rxe] > > rxe_add+0x543/0x5e0 [rdma_rxe] > > rxe_net_add+0x37/0xb0 [rdma_rxe] > > rxe_param_set_add+0x5a/0x120 [rdma_rxe] > > param_attr_store+0x5e/0xc0 > > module_attr_store+0x19/0x30 > > sysfs_kf_write+0x3d/0x50 > > kernfs_fop_write+0x116/0x1a0 > > __vfs_write+0x23/0x120 > > vfs_write+0xbe/0x1b0 > > SyS_write+0x44/0xa0 > > entry_SYSCALL_64_fastpath+0x23/0x9a > > > > Fixes: commit 99db9494035f ("IB/core: Remove ib_device.dma_device") > > ^^^^^^ redundant > > > Signed-off-by: Bart Van Assche <bart.vanassche(a)wdc.com> > > Cc: Leon Romanovsky <leon(a)kernel.org> > > Cc: stable(a)vger.kernel.org # v4.11 > > drivers/infiniband/core/device.c | 2 +- > > drivers/infiniband/core/sysfs.c | 1 - > > 2 files changed, 1 insertion(+), 2 deletions(-) > > > > diff --git a/drivers/infiniband/core/device.c b/drivers/infiniband/core/device.c > > index 30914f3baa5f..b9d7570e9989 100644 > > +++ b/drivers/infiniband/core/device.c > > @@ -446,7 +446,6 @@ int ib_register_device(struct ib_device *device, > > struct ib_udata uhw = {.outlen = 0, .inlen = 0}; > > struct device *parent = device->dev.parent; > > > > - WARN_ON_ONCE(!parent); > > WARN_ON_ONCE(device->dma_device); > > if (device->dev.dma_ops) { > > I understand that it fixed warning for you, but why is it correct? > You are using "parent" in this "if (device->dev.dma_ops)" too. If no parent is specified then the caller must provide a full set of DMA data and none should be copied from the parent. Presumably rxe does this, and has no parent because it is a virtual device. I'm a little more worried about the ib_device_register_sysfs - why was the WARN_ON ever there? What do you think about this as a clarification Bart? diff --git a/drivers/infiniband/core/device.c b/drivers/infiniband/core/device.c index bb2686d56d3c65..c535c7803d80a7 100644 --- a/drivers/infiniband/core/device.c +++ b/drivers/infiniband/core/device.c @@ -446,7 +446,6 @@ int ib_register_device(struct ib_device *device, struct ib_udata uhw = {.outlen = 0, .inlen = 0}; struct device *parent = device->dev.parent; - WARN_ON_ONCE(!parent); WARN_ON_ONCE(device->dma_device); if (device->dev.dma_ops) { /* @@ -455,16 +454,20 @@ int ib_register_device(struct ib_device *device, * into device->dev. */ device->dma_device = &device->dev; - if (!device->dev.dma_mask) - device->dev.dma_mask = parent->dma_mask; - if (!device->dev.coherent_dma_mask) - device->dev.coherent_dma_mask = - parent->coherent_dma_mask; + + if (parent) { + if (!device->dev.dma_mask) + device->dev.dma_mask = parent->dma_mask; + if (!device->dev.coherent_dma_mask) + device->dev.coherent_dma_mask = + parent->coherent_dma_mask; + } } else { /* * The caller did not provide custom DMA operations. Use the * DMA mapping operations of the parent device. */ + WARN_ON_ONCE(!parent); device->dma_device = parent; }

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