- Linux-stable-mirror - lists.linaro.org

[Linux-stable-mirror] Patch "kaiser: kaiser_remove_mapping() move along the pgd" 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: kaiser_remove_mapping() move along the pgd 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-kaiser_remove_mapping-move-along-the-pgd.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, 2 Oct 2017 10:57:24 -0700 Subject: kaiser: kaiser_remove_mapping() move along the pgd From: Hugh Dickins <hughd(a)google.com> When removing the bogus comment from kaiser_remove_mapping(), I really ought to have checked the extent of its bogosity: as Neel points out, there is nothing to stop unmap_pud_range_nofree() from continuing beyond the end of a pud (and starting in the wrong position on the next). Fix kaiser_remove_mapping() to constrain the extent and advance pgd pointer correctly: use pgd_addr_end() macro as used throughout base mm (but don't assume page-rounded start and size in this case). But this bug was very unlikely to trigger in this backport: since any buddy allocation is contained within a single pud extent, and we are not using vmapped stacks (and are only mapping one page of stack anyway): the only way to hit this bug here would be when freeing a large modified ldt. 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, 6 insertions(+), 4 deletions(-) --- a/arch/x86/mm/kaiser.c +++ b/arch/x86/mm/kaiser.c @@ -297,11 +297,13 @@ void kaiser_remove_mapping(unsigned long extern void unmap_pud_range_nofree(pgd_t *pgd, unsigned long start, unsigned long end); unsigned long end = start + size; - unsigned long addr; + unsigned long addr, next; + pgd_t *pgd; - for (addr = start; addr < end; addr += PGDIR_SIZE) { - pgd_t *pgd = native_get_shadow_pgd(pgd_offset_k(addr)); - unmap_pud_range_nofree(pgd, addr, end); + pgd = native_get_shadow_pgd(pgd_offset_k(start)); + for (addr = start; addr < end; pgd++, addr = next) { + next = pgd_addr_end(addr, end); + unmap_pud_range_nofree(pgd, addr, next); } } 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

1
0
0 0

[Linux-stable-mirror] Patch "kaiser: kaiser_flush_tlb_on_return_to_user() check PCID" 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: kaiser_flush_tlb_on_return_to_user() check PCID 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-kaiser_flush_tlb_on_return_to_user-check-pcid.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 18:43:06 -0700 Subject: kaiser: kaiser_flush_tlb_on_return_to_user() check PCID From: Hugh Dickins <hughd(a)google.com> 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(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 | 4 ++-- arch/x86/mm/kaiser.c | 6 +++--- arch/x86/mm/tlb.c | 8 ++++---- 3 files changed, 9 insertions(+), 9 deletions(-) --- a/arch/x86/include/asm/tlbflush.h +++ b/arch/x86/include/asm/tlbflush.h @@ -157,7 +157,7 @@ static inline void __native_flush_tlb(vo * 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(); @@ -216,7 +216,7 @@ static inline void __native_flush_tlb_si */ 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; --- a/arch/x86/mm/kaiser.c +++ b/arch/x86/mm/kaiser.c @@ -436,12 +436,12 @@ 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); --- a/arch/x86/mm/tlb.c +++ b/arch/x86/mm/tlb.c @@ -39,7 +39,7 @@ 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. @@ -50,10 +50,10 @@ 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(); } 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

1
0
0 0

[Linux-stable-mirror] Patch "kaiser: KAISER depends on SMP" 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: KAISER depends on SMP 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-kaiser-depends-on-smp.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: Wed, 13 Sep 2017 14:03:10 -0700 Subject: kaiser: KAISER depends on SMP From: Hugh Dickins <hughd(a)google.com> It is absurd that KAISER should depend on SMP, but apparently nobody has tried a UP build before: which breaks on implicit declaration of function 'per_cpu_offset' in arch/x86/mm/kaiser.c. Now, you would expect that to be trivially fixed up; but looking at the System.map when that block is #ifdef'ed out of kaiser_init(), I see that in a UP build __per_cpu_user_mapped_end is precisely at __per_cpu_user_mapped_start, and the items carefully gathered into that section for user-mapping on SMP, dispersed elsewhere on UP. So, some other kind of section assignment will be needed on UP, but implementing that is not a priority: just make KAISER depend on SMP for now. Also inserted a blank line before the option, tidied up the brief Kconfig help message, and added an "If unsure, Y". 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> --- security/Kconfig | 10 ++++++---- 1 file changed, 6 insertions(+), 4 deletions(-) --- a/security/Kconfig +++ b/security/Kconfig @@ -30,14 +30,16 @@ config SECURITY model will be used. If you are unsure how to answer this question, answer N. + config KAISER bool "Remove the kernel mapping in user mode" default y - depends on X86_64 - depends on !PARAVIRT + depends on X86_64 && SMP && !PARAVIRT help - This enforces a strict kernel and user space isolation in order to close - hardware side channels on kernel address information. + This enforces a strict kernel and user space isolation, in order + to close hardware side channels on kernel address information. + + If you are unsure how to answer this question, answer Y. config KAISER_REAL_SWITCH bool "KAISER: actually switch page tables" 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

1
0
0 0

[Linux-stable-mirror] Patch "kaiser: fix unlikely error in alloc_ldt_struct()" 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: fix unlikely error in alloc_ldt_struct() 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-fix-unlikely-error-in-alloc_ldt_struct.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, 4 Dec 2017 20:13:35 -0800 Subject: kaiser: fix unlikely error in alloc_ldt_struct() From: Hugh Dickins <hughd(a)google.com> An error from kaiser_add_mapping() here is not at all likely, but Eric Biggers rightly points out that __free_ldt_struct() relies on new_ldt->size being initialized: move that up. 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/kernel/ldt.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) --- a/arch/x86/kernel/ldt.c +++ b/arch/x86/kernel/ldt.c @@ -79,11 +79,11 @@ static struct ldt_struct *alloc_ldt_stru ret = kaiser_add_mapping((unsigned long)new_ldt->entries, alloc_size, __PAGE_KERNEL); + new_ldt->size = size; if (ret) { __free_ldt_struct(new_ldt); return NULL; } - new_ldt->size = size; return new_ldt; } 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

1
0
0 0

[Linux-stable-mirror] Patch "kaiser: fix regs to do_nmi() ifndef CONFIG_KAISER" 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: fix regs to do_nmi() ifndef CONFIG_KAISER 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-fix-regs-to-do_nmi-ifndef-config_kaiser.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: Thu, 21 Sep 2017 20:39:56 -0700 Subject: kaiser: fix regs to do_nmi() ifndef CONFIG_KAISER From: Hugh Dickins <hughd(a)google.com> pjt has observed that nmi's second (nmi_from_kernel) call to do_nmi() adjusted the %rdi regs arg, rightly when CONFIG_KAISER, but wrongly when not CONFIG_KAISER. Although the minimal change is to add an #ifdef CONFIG_KAISER around the addq line, that looks cluttered, and I prefer how the first call to do_nmi() handled it: prepare args in %rdi and %rsi before getting into the CONFIG_KAISER block, since it does not touch them at all. And while we're here, place the "#ifdef CONFIG_KAISER" that follows each, to enclose the "Unconditionally restore CR3" comment: matching how the "Unconditionally use kernel CR3" comment above is enclosed. 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 | 11 ++++++----- 1 file changed, 6 insertions(+), 5 deletions(-) --- a/arch/x86/entry/entry_64.S +++ b/arch/x86/entry/entry_64.S @@ -1297,12 +1297,13 @@ ENTRY(nmi) movq %rax, %cr3 #endif call do_nmi + +#ifdef CONFIG_KAISER /* * Unconditionally restore CR3. I know we return to * kernel code that needs user CR3, but do we ever return * to "user mode" where we need the kernel CR3? */ -#ifdef CONFIG_KAISER popq %rax mov %rax, %cr3 #endif @@ -1526,6 +1527,8 @@ end_repeat_nmi: SWAPGS xorl %ebx, %ebx 1: + movq %rsp, %rdi + movq $-1, %rsi #ifdef CONFIG_KAISER /* Unconditionally use kernel CR3 for do_nmi() */ /* %rax is saved above, so OK to clobber here */ @@ -1538,16 +1541,14 @@ end_repeat_nmi: #endif /* paranoidentry do_nmi, 0; without TRACE_IRQS_OFF */ - movq %rsp, %rdi - addq $8, %rdi /* point %rdi at ptregs, fixed up for CR3 */ - movq $-1, %rsi call do_nmi + +#ifdef CONFIG_KAISER /* * Unconditionally restore CR3. We might be returning to * kernel code that needs user CR3, like just just before * a sysret. */ -#ifdef CONFIG_KAISER popq %rax mov %rax, %cr3 #endif 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

1
0
0 0

[Linux-stable-mirror] Patch "kaiser: fix perf crashes" 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: fix perf crashes 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-fix-perf-crashes.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: Wed, 23 Aug 2017 14:21:14 -0700 Subject: kaiser: fix perf crashes From: Hugh Dickins <hughd(a)google.com> Avoid perf crashes: place debug_store in the user-mapped per-cpu area instead of allocating, and use page allocator plus kaiser_add_mapping() to keep the BTS and PEBS buffers user-mapped (that is, present in the user mapping, though visible only to kernel and hardware). The PEBS fixup buffer does not need this treatment. The need for a user-mapped struct debug_store showed up before doing any conscious perf testing: in a couple of kernel paging oopses on Westmere, implicating the debug_store offset of the per-cpu area. 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/kernel/cpu/perf_event_intel_ds.c | 57 +++++++++++++++++++++++------- 1 file changed, 45 insertions(+), 12 deletions(-) --- a/arch/x86/kernel/cpu/perf_event_intel_ds.c +++ b/arch/x86/kernel/cpu/perf_event_intel_ds.c @@ -2,11 +2,15 @@ #include <linux/types.h> #include <linux/slab.h> +#include <asm/kaiser.h> #include <asm/perf_event.h> #include <asm/insn.h> #include "perf_event.h" +static +DEFINE_PER_CPU_SHARED_ALIGNED_USER_MAPPED(struct debug_store, cpu_debug_store); + /* The size of a BTS record in bytes: */ #define BTS_RECORD_SIZE 24 @@ -268,6 +272,39 @@ void fini_debug_store_on_cpu(int cpu) static DEFINE_PER_CPU(void *, insn_buffer); +static void *dsalloc(size_t size, gfp_t flags, int node) +{ +#ifdef CONFIG_KAISER + unsigned int order = get_order(size); + struct page *page; + unsigned long addr; + + page = __alloc_pages_node(node, flags | __GFP_ZERO, order); + if (!page) + return NULL; + addr = (unsigned long)page_address(page); + if (kaiser_add_mapping(addr, size, __PAGE_KERNEL) < 0) { + __free_pages(page, order); + addr = 0; + } + return (void *)addr; +#else + return kmalloc_node(size, flags | __GFP_ZERO, node); +#endif +} + +static void dsfree(const void *buffer, size_t size) +{ +#ifdef CONFIG_KAISER + if (!buffer) + return; + kaiser_remove_mapping((unsigned long)buffer, size); + free_pages((unsigned long)buffer, get_order(size)); +#else + kfree(buffer); +#endif +} + static int alloc_pebs_buffer(int cpu) { struct debug_store *ds = per_cpu(cpu_hw_events, cpu).ds; @@ -278,7 +315,7 @@ static int alloc_pebs_buffer(int cpu) if (!x86_pmu.pebs) return 0; - buffer = kzalloc_node(x86_pmu.pebs_buffer_size, GFP_KERNEL, node); + buffer = dsalloc(x86_pmu.pebs_buffer_size, GFP_KERNEL, node); if (unlikely(!buffer)) return -ENOMEM; @@ -289,7 +326,7 @@ static int alloc_pebs_buffer(int cpu) if (x86_pmu.intel_cap.pebs_format < 2) { ibuffer = kzalloc_node(PEBS_FIXUP_SIZE, GFP_KERNEL, node); if (!ibuffer) { - kfree(buffer); + dsfree(buffer, x86_pmu.pebs_buffer_size); return -ENOMEM; } per_cpu(insn_buffer, cpu) = ibuffer; @@ -315,7 +352,8 @@ static void release_pebs_buffer(int cpu) kfree(per_cpu(insn_buffer, cpu)); per_cpu(insn_buffer, cpu) = NULL; - kfree((void *)(unsigned long)ds->pebs_buffer_base); + dsfree((void *)(unsigned long)ds->pebs_buffer_base, + x86_pmu.pebs_buffer_size); ds->pebs_buffer_base = 0; } @@ -329,7 +367,7 @@ static int alloc_bts_buffer(int cpu) if (!x86_pmu.bts) return 0; - buffer = kzalloc_node(BTS_BUFFER_SIZE, GFP_KERNEL | __GFP_NOWARN, node); + buffer = dsalloc(BTS_BUFFER_SIZE, GFP_KERNEL | __GFP_NOWARN, node); if (unlikely(!buffer)) { WARN_ONCE(1, "%s: BTS buffer allocation failure\n", __func__); return -ENOMEM; @@ -355,19 +393,15 @@ static void release_bts_buffer(int cpu) if (!ds || !x86_pmu.bts) return; - kfree((void *)(unsigned long)ds->bts_buffer_base); + dsfree((void *)(unsigned long)ds->bts_buffer_base, BTS_BUFFER_SIZE); ds->bts_buffer_base = 0; } static int alloc_ds_buffer(int cpu) { - int node = cpu_to_node(cpu); - struct debug_store *ds; - - ds = kzalloc_node(sizeof(*ds), GFP_KERNEL, node); - if (unlikely(!ds)) - return -ENOMEM; + struct debug_store *ds = per_cpu_ptr(&cpu_debug_store, cpu); + memset(ds, 0, sizeof(*ds)); per_cpu(cpu_hw_events, cpu).ds = ds; return 0; @@ -381,7 +415,6 @@ static void release_ds_buffer(int cpu) return; per_cpu(cpu_hw_events, cpu).ds = NULL; - kfree(ds); } void release_ds_buffers(void) 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

1
0
0 0

[Linux-stable-mirror] Patch "kaiser: fix build and FIXME in alloc_ldt_struct()" 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: fix build and FIXME in alloc_ldt_struct() 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-fix-build-and-fixme-in-alloc_ldt_struct.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 17:09:44 -0700 Subject: kaiser: fix build and FIXME in alloc_ldt_struct() From: Hugh Dickins <hughd(a)google.com> Include linux/kaiser.h instead of asm/kaiser.h to build ldt.c without CONFIG_KAISER. kaiser_add_mapping() does already return an error code, so fix the FIXME. 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/kernel/ldt.c | 10 ++++------ 1 file changed, 4 insertions(+), 6 deletions(-) --- a/arch/x86/kernel/ldt.c +++ b/arch/x86/kernel/ldt.c @@ -16,9 +16,9 @@ #include <linux/slab.h> #include <linux/vmalloc.h> #include <linux/uaccess.h> +#include <linux/kaiser.h> #include <asm/ldt.h> -#include <asm/kaiser.h> #include <asm/desc.h> #include <asm/mmu_context.h> #include <asm/syscalls.h> @@ -49,7 +49,7 @@ static struct ldt_struct *alloc_ldt_stru { struct ldt_struct *new_ldt; int alloc_size; - int ret = 0; + int ret; if (size > LDT_ENTRIES) return NULL; @@ -77,10 +77,8 @@ static struct ldt_struct *alloc_ldt_stru return NULL; } - // FIXME: make kaiser_add_mapping() return an error code - // when it fails - kaiser_add_mapping((unsigned long)new_ldt->entries, alloc_size, - __PAGE_KERNEL); + ret = kaiser_add_mapping((unsigned long)new_ldt->entries, alloc_size, + __PAGE_KERNEL); if (ret) { __free_ldt_struct(new_ldt); return NULL; 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

1
0
0 0

[Linux-stable-mirror] Patch "kaiser: ENOMEM if kaiser_pagetable_walk() NULL" 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: ENOMEM if kaiser_pagetable_walk() NULL 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-enomem-if-kaiser_pagetable_walk-null.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 18:48:02 -0700 Subject: kaiser: ENOMEM if kaiser_pagetable_walk() NULL From: Hugh Dickins <hughd(a)google.com> kaiser_add_user_map() took no notice when kaiser_pagetable_walk() failed. And avoid its might_sleep() when atomic (though atomic at present unused). 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, 7 insertions(+), 3 deletions(-) --- a/arch/x86/mm/kaiser.c +++ b/arch/x86/mm/kaiser.c @@ -99,11 +99,11 @@ static pte_t *kaiser_pagetable_walk(unsi pgd_t *pgd = native_get_shadow_pgd(pgd_offset_k(address)); gfp_t gfp = (GFP_KERNEL | __GFP_NOTRACK | __GFP_ZERO); - might_sleep(); 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"); @@ -160,13 +160,17 @@ int kaiser_add_user_map(const void *__st unsigned long end_addr = PAGE_ALIGN(start_addr + size); unsigned long target_address; - for (;address < end_addr; address += PAGE_SIZE) { + for (; address < end_addr; address += PAGE_SIZE) { target_address = get_pa_from_mapping(address); if (target_address == -1) { ret = -EIO; break; } pte = kaiser_pagetable_walk(address, false); + if (!pte) { + ret = -ENOMEM; + break; + } if (pte_none(*pte)) { set_pte(pte, __pte(flags | target_address)); } else { 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

1
0
0 0

[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

1
0
0 0

[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

1
0
0 0

2025

2024

2023

2022

2021

2020

2019

2018

2017

Linux-stable-mirror