December 2017 - Linux-stable-mirror

[Linux-stable-mirror] Patch "x86/mm: Optimize RESTORE_CR3" has been added to the 4.14-stable tree

by gregkh＠linuxfoundation.org

This is a note to let you know that I've just added the patch titled x86/mm: Optimize RESTORE_CR3 to the 4.14-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: x86-mm-optimize-restore_cr3.patch and it can be found in the queue-4.14 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 21e94459110252d41b45c0c8ba50fd72a664d50c Mon Sep 17 00:00:00 2001 From: Peter Zijlstra <peterz(a)infradead.org> Date: Mon, 4 Dec 2017 15:08:00 +0100 Subject: x86/mm: Optimize RESTORE_CR3 From: Peter Zijlstra <peterz(a)infradead.org> commit 21e94459110252d41b45c0c8ba50fd72a664d50c upstream. Most NMI/paranoid exceptions will not in fact change pagetables and would thus not require TLB flushing, however RESTORE_CR3 uses flushing CR3 writes. Restores to kernel PCIDs can be NOFLUSH, because we explicitly flush the kernel mappings and now that we track which user PCIDs need flushing we can avoid those too when possible. This does mean RESTORE_CR3 needs an additional scratch_reg, luckily both sites have plenty available. Signed-off-by: Peter Zijlstra (Intel) <peterz(a)infradead.org> Signed-off-by: Thomas Gleixner <tglx(a)linutronix.de> Cc: Andy Lutomirski <luto(a)kernel.org> Cc: Boris Ostrovsky <boris.ostrovsky(a)oracle.com> Cc: Borislav Petkov <bp(a)alien8.de> Cc: Brian Gerst <brgerst(a)gmail.com> Cc: Dave Hansen <dave.hansen(a)linux.intel.com> Cc: David Laight <David.Laight(a)aculab.com> Cc: Denys Vlasenko <dvlasenk(a)redhat.com> Cc: Eduardo Valentin <eduval(a)amazon.com> Cc: Greg KH <gregkh(a)linuxfoundation.org> Cc: H. Peter Anvin <hpa(a)zytor.com> Cc: Josh Poimboeuf <jpoimboe(a)redhat.com> Cc: Juergen Gross <jgross(a)suse.com> Cc: Linus Torvalds <torvalds(a)linux-foundation.org> Cc: Peter Zijlstra <peterz(a)infradead.org> Cc: Will Deacon <will.deacon(a)arm.com> Cc: aliguori(a)amazon.com Cc: daniel.gruss(a)iaik.tugraz.at Cc: hughd(a)google.com Cc: keescook(a)google.com Signed-off-by: Ingo Molnar <mingo(a)kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh(a)linuxfoundation.org> --- arch/x86/entry/calling.h | 30 ++++++++++++++++++++++++++++-- arch/x86/entry/entry_64.S | 4 ++-- 2 files changed, 30 insertions(+), 4 deletions(-) --- a/arch/x86/entry/calling.h +++ b/arch/x86/entry/calling.h @@ -281,8 +281,34 @@ For 32-bit we have the following convent .Ldone_\@: .endm -.macro RESTORE_CR3 save_reg:req +.macro RESTORE_CR3 scratch_reg:req save_reg:req ALTERNATIVE "jmp .Lend_\@", "", X86_FEATURE_PTI + + ALTERNATIVE "jmp .Lwrcr3_\@", "", X86_FEATURE_PCID + + /* + * KERNEL pages can always resume with NOFLUSH as we do + * explicit flushes. + */ + bt $X86_CR3_PTI_SWITCH_BIT, \save_reg + jnc .Lnoflush_\@ + + /* + * Check if there's a pending flush for the user ASID we're + * about to set. + */ + movq \save_reg, \scratch_reg + andq $(0x7FF), \scratch_reg + bt \scratch_reg, THIS_CPU_user_pcid_flush_mask + jnc .Lnoflush_\@ + + btr \scratch_reg, THIS_CPU_user_pcid_flush_mask + jmp .Lwrcr3_\@ + +.Lnoflush_\@: + SET_NOFLUSH_BIT \save_reg + +.Lwrcr3_\@: /* * The CR3 write could be avoided when not changing its value, * but would require a CR3 read *and* a scratch register. @@ -301,7 +327,7 @@ For 32-bit we have the following convent .endm .macro SAVE_AND_SWITCH_TO_KERNEL_CR3 scratch_reg:req save_reg:req .endm -.macro RESTORE_CR3 save_reg:req +.macro RESTORE_CR3 scratch_reg:req save_reg:req .endm #endif --- a/arch/x86/entry/entry_64.S +++ b/arch/x86/entry/entry_64.S @@ -1288,7 +1288,7 @@ ENTRY(paranoid_exit) testl %ebx, %ebx /* swapgs needed? */ jnz .Lparanoid_exit_no_swapgs TRACE_IRQS_IRETQ - RESTORE_CR3 save_reg=%r14 + RESTORE_CR3 scratch_reg=%rbx save_reg=%r14 SWAPGS_UNSAFE_STACK jmp .Lparanoid_exit_restore .Lparanoid_exit_no_swapgs: @@ -1730,7 +1730,7 @@ end_repeat_nmi: movq $-1, %rsi call do_nmi - RESTORE_CR3 save_reg=%r14 + RESTORE_CR3 scratch_reg=%r15 save_reg=%r14 testl %ebx, %ebx /* swapgs needed? */ jnz nmi_restore Patches currently in stable-queue which might be from peterz(a)infradead.org are queue-4.14/x86-mm-pti-allow-nx-poison-to-be-set-in-p4d-pgd.patch queue-4.14/x86-dumpstack-indicate-in-oops-whether-pti-is-configured-and-enabled.patch queue-4.14/x86-mm-clarify-the-whole-asid-kernel-pcid-user-pcid-naming.patch queue-4.14/x86-mm-abstract-switching-cr3.patch queue-4.14/x86-mm-optimize-restore_cr3.patch queue-4.14/x86-mm-pti-force-entry-through-trampoline-when-pti-active.patch queue-4.14/x86-entry-align-entry-text-section-to-pmd-boundary.patch queue-4.14/x86-mm-64-make-a-full-pgd-entry-size-hole-in-the-memory-map.patch queue-4.14/x86-cpu_entry_area-add-debugstore-entries-to-cpu_entry_area.patch queue-4.14/x86-mm-pti-share-entry-text-pmd.patch queue-4.14/x86-ldt-make-the-ldt-mapping-ro.patch queue-4.14/x86-mm-dump_pagetables-check-user-space-page-table-for-wx-pages.patch queue-4.14/x86-pti-map-the-vsyscall-page-if-needed.patch queue-4.14/x86-mm-pti-disable-global-pages-if-page_table_isolation-y.patch queue-4.14/x86-mm-dump_pagetables-allow-dumping-current-pagetables.patch queue-4.14/x86-mm-pti-add-infrastructure-for-page-table-isolation.patch queue-4.14/x86-cpufeatures-add-x86_bug_cpu_insecure.patch queue-4.14/x86-mm-use-fix-pcid-to-optimize-user-kernel-switches.patch queue-4.14/x86-mm-use-invpcid-for-__native_flush_tlb_single.patch queue-4.14/x86-mm-pti-prepare-the-x86-entry-assembly-code-for-entry-exit-cr3-switching.patch queue-4.14/x86-mm-allow-flushing-for-future-asid-switches.patch queue-4.14/x86-mm-pti-add-kconfig.patch queue-4.14/x86-mm-pti-add-mapping-helper-functions.patch queue-4.14/x86-mm-pti-map-espfix-into-user-space.patch queue-4.14/x86-mm-pti-share-cpu_entry_area-with-user-space-page-tables.patch queue-4.14/x86-mm-pti-add-functions-to-clone-kernel-pmds.patch queue-4.14/x86-pti-add-the-pti-cmdline-option-and-documentation.patch queue-4.14/x86-events-intel-ds-map-debug-buffers-in-cpu_entry_area.patch queue-4.14/x86-mm-pti-allocate-a-separate-user-pgd.patch queue-4.14/x86-pti-put-the-ldt-in-its-own-pgd-if-pti-is-on.patch queue-4.14/x86-mm-pti-populate-user-pgd.patch queue-4.14/x86-mm-dump_pagetables-add-page-table-directory-to-the-debugfs-vfs-hierarchy.patch

6 years, 6 months

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[Linux-stable-mirror] Patch "x86/mm/dump_pagetables: Check user space page table for WX pages" has been added to the 4.14-stable tree

by gregkh＠linuxfoundation.org

This is a note to let you know that I've just added the patch titled x86/mm/dump_pagetables: Check user space page table for WX pages to the 4.14-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: x86-mm-dump_pagetables-check-user-space-page-table-for-wx-pages.patch and it can be found in the queue-4.14 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 b4bf4f924b1d7bade38fd51b2e401d20d0956e4d Mon Sep 17 00:00:00 2001 From: Thomas Gleixner <tglx(a)linutronix.de> Date: Mon, 4 Dec 2017 15:08:05 +0100 Subject: x86/mm/dump_pagetables: Check user space page table for WX pages From: Thomas Gleixner <tglx(a)linutronix.de> commit b4bf4f924b1d7bade38fd51b2e401d20d0956e4d upstream. ptdump_walk_pgd_level_checkwx() checks the kernel page table for WX pages, but does not check the PAGE_TABLE_ISOLATION user space page table. Restructure the code so that dmesg output is selected by an explicit argument and not implicit via checking the pgd argument for !NULL. Add the check for the user space page table. Signed-off-by: Thomas Gleixner <tglx(a)linutronix.de> Cc: Andy Lutomirski <luto(a)kernel.org> Cc: Boris Ostrovsky <boris.ostrovsky(a)oracle.com> Cc: Borislav Petkov <bp(a)alien8.de> Cc: Brian Gerst <brgerst(a)gmail.com> Cc: Dave Hansen <dave.hansen(a)linux.intel.com> Cc: David Laight <David.Laight(a)aculab.com> Cc: Denys Vlasenko <dvlasenk(a)redhat.com> Cc: Eduardo Valentin <eduval(a)amazon.com> Cc: Greg KH <gregkh(a)linuxfoundation.org> Cc: H. Peter Anvin <hpa(a)zytor.com> Cc: Josh Poimboeuf <jpoimboe(a)redhat.com> Cc: Juergen Gross <jgross(a)suse.com> Cc: Linus Torvalds <torvalds(a)linux-foundation.org> Cc: Peter Zijlstra <peterz(a)infradead.org> Cc: Will Deacon <will.deacon(a)arm.com> Cc: aliguori(a)amazon.com Cc: daniel.gruss(a)iaik.tugraz.at Cc: hughd(a)google.com Cc: keescook(a)google.com Cc: linux-mm(a)kvack.org Signed-off-by: Ingo Molnar <mingo(a)kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh(a)linuxfoundation.org> --- arch/x86/include/asm/pgtable.h | 1 + arch/x86/mm/debug_pagetables.c | 2 +- arch/x86/mm/dump_pagetables.c | 30 +++++++++++++++++++++++++----- 3 files changed, 27 insertions(+), 6 deletions(-) --- a/arch/x86/include/asm/pgtable.h +++ b/arch/x86/include/asm/pgtable.h @@ -28,6 +28,7 @@ extern pgd_t early_top_pgt[PTRS_PER_PGD] int __init __early_make_pgtable(unsigned long address, pmdval_t pmd); void ptdump_walk_pgd_level(struct seq_file *m, pgd_t *pgd); +void ptdump_walk_pgd_level_debugfs(struct seq_file *m, pgd_t *pgd); void ptdump_walk_pgd_level_checkwx(void); #ifdef CONFIG_DEBUG_WX --- a/arch/x86/mm/debug_pagetables.c +++ b/arch/x86/mm/debug_pagetables.c @@ -5,7 +5,7 @@ static int ptdump_show(struct seq_file *m, void *v) { - ptdump_walk_pgd_level(m, NULL); + ptdump_walk_pgd_level_debugfs(m, NULL); return 0; } --- a/arch/x86/mm/dump_pagetables.c +++ b/arch/x86/mm/dump_pagetables.c @@ -476,7 +476,7 @@ static inline bool is_hypervisor_range(i } static void ptdump_walk_pgd_level_core(struct seq_file *m, pgd_t *pgd, - bool checkwx) + bool checkwx, bool dmesg) { #ifdef CONFIG_X86_64 pgd_t *start = (pgd_t *) &init_top_pgt; @@ -489,7 +489,7 @@ static void ptdump_walk_pgd_level_core(s if (pgd) { start = pgd; - st.to_dmesg = true; + st.to_dmesg = dmesg; } st.check_wx = checkwx; @@ -527,13 +527,33 @@ static void ptdump_walk_pgd_level_core(s void ptdump_walk_pgd_level(struct seq_file *m, pgd_t *pgd) { - ptdump_walk_pgd_level_core(m, pgd, false); + ptdump_walk_pgd_level_core(m, pgd, false, true); +} + +void ptdump_walk_pgd_level_debugfs(struct seq_file *m, pgd_t *pgd) +{ + ptdump_walk_pgd_level_core(m, pgd, false, false); +} +EXPORT_SYMBOL_GPL(ptdump_walk_pgd_level_debugfs); + +static void ptdump_walk_user_pgd_level_checkwx(void) +{ +#ifdef CONFIG_PAGE_TABLE_ISOLATION + pgd_t *pgd = (pgd_t *) &init_top_pgt; + + if (!static_cpu_has(X86_FEATURE_PTI)) + return; + + pr_info("x86/mm: Checking user space page tables\n"); + pgd = kernel_to_user_pgdp(pgd); + ptdump_walk_pgd_level_core(NULL, pgd, true, false); +#endif } -EXPORT_SYMBOL_GPL(ptdump_walk_pgd_level); void ptdump_walk_pgd_level_checkwx(void) { - ptdump_walk_pgd_level_core(NULL, NULL, true); + ptdump_walk_pgd_level_core(NULL, NULL, true, false); + ptdump_walk_user_pgd_level_checkwx(); } static int __init pt_dump_init(void) Patches currently in stable-queue which might be from tglx(a)linutronix.de are queue-4.14/x86-mm-pti-allow-nx-poison-to-be-set-in-p4d-pgd.patch queue-4.14/x86-dumpstack-indicate-in-oops-whether-pti-is-configured-and-enabled.patch queue-4.14/x86-mm-clarify-the-whole-asid-kernel-pcid-user-pcid-naming.patch queue-4.14/x86-mm-abstract-switching-cr3.patch queue-4.14/x86-mm-optimize-restore_cr3.patch queue-4.14/x86-mm-pti-force-entry-through-trampoline-when-pti-active.patch queue-4.14/x86-entry-align-entry-text-section-to-pmd-boundary.patch queue-4.14/x86-mm-64-make-a-full-pgd-entry-size-hole-in-the-memory-map.patch queue-4.14/x86-cpu_entry_area-add-debugstore-entries-to-cpu_entry_area.patch queue-4.14/x86-mm-pti-share-entry-text-pmd.patch queue-4.14/x86-ldt-make-the-ldt-mapping-ro.patch queue-4.14/x86-mm-dump_pagetables-check-user-space-page-table-for-wx-pages.patch queue-4.14/x86-pti-map-the-vsyscall-page-if-needed.patch queue-4.14/x86-mm-pti-disable-global-pages-if-page_table_isolation-y.patch queue-4.14/x86-mm-dump_pagetables-allow-dumping-current-pagetables.patch queue-4.14/x86-mm-pti-add-infrastructure-for-page-table-isolation.patch queue-4.14/x86-cpufeatures-add-x86_bug_cpu_insecure.patch queue-4.14/x86-mm-use-fix-pcid-to-optimize-user-kernel-switches.patch queue-4.14/x86-mm-use-invpcid-for-__native_flush_tlb_single.patch queue-4.14/x86-mm-pti-prepare-the-x86-entry-assembly-code-for-entry-exit-cr3-switching.patch queue-4.14/x86-mm-allow-flushing-for-future-asid-switches.patch queue-4.14/x86-mm-pti-add-kconfig.patch queue-4.14/x86-mm-pti-add-mapping-helper-functions.patch queue-4.14/x86-mm-pti-map-espfix-into-user-space.patch queue-4.14/x86-mm-pti-share-cpu_entry_area-with-user-space-page-tables.patch queue-4.14/x86-mm-pti-add-functions-to-clone-kernel-pmds.patch queue-4.14/x86-pti-add-the-pti-cmdline-option-and-documentation.patch queue-4.14/x86-events-intel-ds-map-debug-buffers-in-cpu_entry_area.patch queue-4.14/x86-mm-pti-allocate-a-separate-user-pgd.patch queue-4.14/x86-pti-put-the-ldt-in-its-own-pgd-if-pti-is-on.patch queue-4.14/x86-mm-pti-populate-user-pgd.patch queue-4.14/x86-mm-dump_pagetables-add-page-table-directory-to-the-debugfs-vfs-hierarchy.patch

6 years, 6 months

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[Linux-stable-mirror] Patch "x86/mm/dump_pagetables: Allow dumping current pagetables" has been added to the 4.14-stable tree

by gregkh＠linuxfoundation.org

This is a note to let you know that I've just added the patch titled x86/mm/dump_pagetables: Allow dumping current pagetables to the 4.14-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: x86-mm-dump_pagetables-allow-dumping-current-pagetables.patch and it can be found in the queue-4.14 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 a4b51ef6552c704764684cef7e753162dc87c5fa Mon Sep 17 00:00:00 2001 From: Thomas Gleixner <tglx(a)linutronix.de> Date: Mon, 4 Dec 2017 15:08:06 +0100 Subject: x86/mm/dump_pagetables: Allow dumping current pagetables From: Thomas Gleixner <tglx(a)linutronix.de> commit a4b51ef6552c704764684cef7e753162dc87c5fa upstream. Add two debugfs files which allow to dump the pagetable of the current task. current_kernel dumps the regular page table. This is the page table which is normally shared between kernel and user space. If kernel page table isolation is enabled this is the kernel space mapping. If kernel page table isolation is enabled the second file, current_user, dumps the user space page table. These files allow to verify the resulting page tables for page table isolation, but even in the normal case its useful to be able to inspect user space page tables of current for debugging purposes. Signed-off-by: Thomas Gleixner <tglx(a)linutronix.de> Cc: Andy Lutomirski <luto(a)kernel.org> Cc: Boris Ostrovsky <boris.ostrovsky(a)oracle.com> Cc: Borislav Petkov <bp(a)alien8.de> Cc: Brian Gerst <brgerst(a)gmail.com> Cc: Dave Hansen <dave.hansen(a)linux.intel.com> Cc: David Laight <David.Laight(a)aculab.com> Cc: Denys Vlasenko <dvlasenk(a)redhat.com> Cc: Eduardo Valentin <eduval(a)amazon.com> Cc: Greg KH <gregkh(a)linuxfoundation.org> Cc: H. Peter Anvin <hpa(a)zytor.com> Cc: Josh Poimboeuf <jpoimboe(a)redhat.com> Cc: Juergen Gross <jgross(a)suse.com> Cc: Linus Torvalds <torvalds(a)linux-foundation.org> Cc: Peter Zijlstra <peterz(a)infradead.org> Cc: Will Deacon <will.deacon(a)arm.com> Cc: aliguori(a)amazon.com Cc: daniel.gruss(a)iaik.tugraz.at Cc: hughd(a)google.com Cc: keescook(a)google.com Cc: linux-mm(a)kvack.org Signed-off-by: Ingo Molnar <mingo(a)kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh(a)linuxfoundation.org> --- arch/x86/include/asm/pgtable.h | 2 - arch/x86/mm/debug_pagetables.c | 71 ++++++++++++++++++++++++++++++++++++++--- arch/x86/mm/dump_pagetables.c | 6 ++- 3 files changed, 73 insertions(+), 6 deletions(-) --- a/arch/x86/include/asm/pgtable.h +++ b/arch/x86/include/asm/pgtable.h @@ -28,7 +28,7 @@ extern pgd_t early_top_pgt[PTRS_PER_PGD] int __init __early_make_pgtable(unsigned long address, pmdval_t pmd); void ptdump_walk_pgd_level(struct seq_file *m, pgd_t *pgd); -void ptdump_walk_pgd_level_debugfs(struct seq_file *m, pgd_t *pgd); +void ptdump_walk_pgd_level_debugfs(struct seq_file *m, pgd_t *pgd, bool user); void ptdump_walk_pgd_level_checkwx(void); #ifdef CONFIG_DEBUG_WX --- a/arch/x86/mm/debug_pagetables.c +++ b/arch/x86/mm/debug_pagetables.c @@ -5,7 +5,7 @@ static int ptdump_show(struct seq_file *m, void *v) { - ptdump_walk_pgd_level_debugfs(m, NULL); + ptdump_walk_pgd_level_debugfs(m, NULL, false); return 0; } @@ -22,7 +22,57 @@ static const struct file_operations ptdu .release = single_release, }; -static struct dentry *dir, *pe; +static int ptdump_show_curknl(struct seq_file *m, void *v) +{ + if (current->mm->pgd) { + down_read(&current->mm->mmap_sem); + ptdump_walk_pgd_level_debugfs(m, current->mm->pgd, false); + up_read(&current->mm->mmap_sem); + } + return 0; +} + +static int ptdump_open_curknl(struct inode *inode, struct file *filp) +{ + return single_open(filp, ptdump_show_curknl, NULL); +} + +static const struct file_operations ptdump_curknl_fops = { + .owner = THIS_MODULE, + .open = ptdump_open_curknl, + .read = seq_read, + .llseek = seq_lseek, + .release = single_release, +}; + +#ifdef CONFIG_PAGE_TABLE_ISOLATION +static struct dentry *pe_curusr; + +static int ptdump_show_curusr(struct seq_file *m, void *v) +{ + if (current->mm->pgd) { + down_read(&current->mm->mmap_sem); + ptdump_walk_pgd_level_debugfs(m, current->mm->pgd, true); + up_read(&current->mm->mmap_sem); + } + return 0; +} + +static int ptdump_open_curusr(struct inode *inode, struct file *filp) +{ + return single_open(filp, ptdump_show_curusr, NULL); +} + +static const struct file_operations ptdump_curusr_fops = { + .owner = THIS_MODULE, + .open = ptdump_open_curusr, + .read = seq_read, + .llseek = seq_lseek, + .release = single_release, +}; +#endif + +static struct dentry *dir, *pe_knl, *pe_curknl; static int __init pt_dump_debug_init(void) { @@ -30,9 +80,22 @@ static int __init pt_dump_debug_init(voi if (!dir) return -ENOMEM; - pe = debugfs_create_file("kernel", 0400, dir, NULL, &ptdump_fops); - if (!pe) + pe_knl = debugfs_create_file("kernel", 0400, dir, NULL, + &ptdump_fops); + if (!pe_knl) + goto err; + + pe_curknl = debugfs_create_file("current_kernel", 0400, + dir, NULL, &ptdump_curknl_fops); + if (!pe_curknl) + goto err; + +#ifdef CONFIG_PAGE_TABLE_ISOLATION + pe_curusr = debugfs_create_file("current_user", 0400, + dir, NULL, &ptdump_curusr_fops); + if (!pe_curusr) goto err; +#endif return 0; err: debugfs_remove_recursive(dir); --- a/arch/x86/mm/dump_pagetables.c +++ b/arch/x86/mm/dump_pagetables.c @@ -530,8 +530,12 @@ void ptdump_walk_pgd_level(struct seq_fi ptdump_walk_pgd_level_core(m, pgd, false, true); } -void ptdump_walk_pgd_level_debugfs(struct seq_file *m, pgd_t *pgd) +void ptdump_walk_pgd_level_debugfs(struct seq_file *m, pgd_t *pgd, bool user) { +#ifdef CONFIG_PAGE_TABLE_ISOLATION + if (user && static_cpu_has(X86_FEATURE_PTI)) + pgd = kernel_to_user_pgdp(pgd); +#endif ptdump_walk_pgd_level_core(m, pgd, false, false); } EXPORT_SYMBOL_GPL(ptdump_walk_pgd_level_debugfs); Patches currently in stable-queue which might be from tglx(a)linutronix.de are queue-4.14/x86-mm-pti-allow-nx-poison-to-be-set-in-p4d-pgd.patch queue-4.14/x86-dumpstack-indicate-in-oops-whether-pti-is-configured-and-enabled.patch queue-4.14/x86-mm-clarify-the-whole-asid-kernel-pcid-user-pcid-naming.patch queue-4.14/x86-mm-abstract-switching-cr3.patch queue-4.14/x86-mm-optimize-restore_cr3.patch queue-4.14/x86-mm-pti-force-entry-through-trampoline-when-pti-active.patch queue-4.14/x86-entry-align-entry-text-section-to-pmd-boundary.patch queue-4.14/x86-mm-64-make-a-full-pgd-entry-size-hole-in-the-memory-map.patch queue-4.14/x86-cpu_entry_area-add-debugstore-entries-to-cpu_entry_area.patch queue-4.14/x86-mm-pti-share-entry-text-pmd.patch queue-4.14/x86-ldt-make-the-ldt-mapping-ro.patch queue-4.14/x86-mm-dump_pagetables-check-user-space-page-table-for-wx-pages.patch queue-4.14/x86-pti-map-the-vsyscall-page-if-needed.patch queue-4.14/x86-mm-pti-disable-global-pages-if-page_table_isolation-y.patch queue-4.14/x86-mm-dump_pagetables-allow-dumping-current-pagetables.patch queue-4.14/x86-mm-pti-add-infrastructure-for-page-table-isolation.patch queue-4.14/x86-cpufeatures-add-x86_bug_cpu_insecure.patch queue-4.14/x86-mm-use-fix-pcid-to-optimize-user-kernel-switches.patch queue-4.14/x86-mm-use-invpcid-for-__native_flush_tlb_single.patch queue-4.14/x86-mm-pti-prepare-the-x86-entry-assembly-code-for-entry-exit-cr3-switching.patch queue-4.14/x86-mm-allow-flushing-for-future-asid-switches.patch queue-4.14/x86-mm-pti-add-kconfig.patch queue-4.14/x86-mm-pti-add-mapping-helper-functions.patch queue-4.14/x86-mm-pti-map-espfix-into-user-space.patch queue-4.14/x86-mm-pti-share-cpu_entry_area-with-user-space-page-tables.patch queue-4.14/x86-mm-pti-add-functions-to-clone-kernel-pmds.patch queue-4.14/x86-pti-add-the-pti-cmdline-option-and-documentation.patch queue-4.14/x86-events-intel-ds-map-debug-buffers-in-cpu_entry_area.patch queue-4.14/x86-mm-pti-allocate-a-separate-user-pgd.patch queue-4.14/x86-pti-put-the-ldt-in-its-own-pgd-if-pti-is-on.patch queue-4.14/x86-mm-pti-populate-user-pgd.patch queue-4.14/x86-mm-dump_pagetables-add-page-table-directory-to-the-debugfs-vfs-hierarchy.patch

6 years, 6 months

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[Linux-stable-mirror] Patch "x86/mm/dump_pagetables: Add page table directory to the debugfs VFS hierarchy" has been added to the 4.14-stable tree

by gregkh＠linuxfoundation.org

This is a note to let you know that I've just added the patch titled x86/mm/dump_pagetables: Add page table directory to the debugfs VFS hierarchy to the 4.14-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: x86-mm-dump_pagetables-add-page-table-directory-to-the-debugfs-vfs-hierarchy.patch and it can be found in the queue-4.14 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 75298aa179d56cd64f54e58a19fffc8ab922b4c0 Mon Sep 17 00:00:00 2001 From: Borislav Petkov <bp(a)suse.de> Date: Mon, 4 Dec 2017 15:08:04 +0100 Subject: x86/mm/dump_pagetables: Add page table directory to the debugfs VFS hierarchy From: Borislav Petkov <bp(a)suse.de> commit 75298aa179d56cd64f54e58a19fffc8ab922b4c0 upstream. The upcoming support for dumping the kernel and the user space page tables of the current process would create more random files in the top level debugfs directory. Add a page table directory and move the existing file to it. Signed-off-by: Borislav Petkov <bp(a)suse.de> Signed-off-by: Thomas Gleixner <tglx(a)linutronix.de> Cc: Andy Lutomirski <luto(a)kernel.org> Cc: Boris Ostrovsky <boris.ostrovsky(a)oracle.com> Cc: Borislav Petkov <bp(a)alien8.de> Cc: Brian Gerst <brgerst(a)gmail.com> Cc: Dave Hansen <dave.hansen(a)linux.intel.com> Cc: David Laight <David.Laight(a)aculab.com> Cc: Denys Vlasenko <dvlasenk(a)redhat.com> Cc: Eduardo Valentin <eduval(a)amazon.com> Cc: Greg KH <gregkh(a)linuxfoundation.org> Cc: H. Peter Anvin <hpa(a)zytor.com> Cc: Josh Poimboeuf <jpoimboe(a)redhat.com> Cc: Juergen Gross <jgross(a)suse.com> Cc: Linus Torvalds <torvalds(a)linux-foundation.org> Cc: Peter Zijlstra <peterz(a)infradead.org> Cc: Will Deacon <will.deacon(a)arm.com> Cc: aliguori(a)amazon.com Cc: daniel.gruss(a)iaik.tugraz.at Cc: hughd(a)google.com Cc: keescook(a)google.com Signed-off-by: Ingo Molnar <mingo(a)kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh(a)linuxfoundation.org> --- arch/x86/mm/debug_pagetables.c | 15 ++++++++++----- 1 file changed, 10 insertions(+), 5 deletions(-) --- a/arch/x86/mm/debug_pagetables.c +++ b/arch/x86/mm/debug_pagetables.c @@ -22,21 +22,26 @@ static const struct file_operations ptdu .release = single_release, }; -static struct dentry *pe; +static struct dentry *dir, *pe; static int __init pt_dump_debug_init(void) { - pe = debugfs_create_file("kernel_page_tables", S_IRUSR, NULL, NULL, - &ptdump_fops); - if (!pe) + dir = debugfs_create_dir("page_tables", NULL); + if (!dir) return -ENOMEM; + pe = debugfs_create_file("kernel", 0400, dir, NULL, &ptdump_fops); + if (!pe) + goto err; return 0; +err: + debugfs_remove_recursive(dir); + return -ENOMEM; } static void __exit pt_dump_debug_exit(void) { - debugfs_remove_recursive(pe); + debugfs_remove_recursive(dir); } module_init(pt_dump_debug_init); Patches currently in stable-queue which might be from bp(a)suse.de are queue-4.14/x86-mm-pti-allow-nx-poison-to-be-set-in-p4d-pgd.patch queue-4.14/x86-mm-pti-force-entry-through-trampoline-when-pti-active.patch queue-4.14/x86-mm-pti-disable-global-pages-if-page_table_isolation-y.patch queue-4.14/x86-mm-pti-add-infrastructure-for-page-table-isolation.patch queue-4.14/x86-mm-pti-prepare-the-x86-entry-assembly-code-for-entry-exit-cr3-switching.patch queue-4.14/x86-pti-add-the-pti-cmdline-option-and-documentation.patch queue-4.14/x86-mm-pti-allocate-a-separate-user-pgd.patch queue-4.14/x86-mm-pti-populate-user-pgd.patch queue-4.14/x86-mm-dump_pagetables-add-page-table-directory-to-the-debugfs-vfs-hierarchy.patch

6 years, 6 months

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[Linux-stable-mirror] Patch "x86/mm: Clarify the whole ASID/kernel PCID/user PCID naming" has been added to the 4.14-stable tree

by gregkh＠linuxfoundation.org

This is a note to let you know that I've just added the patch titled x86/mm: Clarify the whole ASID/kernel PCID/user PCID naming to the 4.14-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: x86-mm-clarify-the-whole-asid-kernel-pcid-user-pcid-naming.patch and it can be found in the queue-4.14 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 0a126abd576ebc6403f063dbe20cf7416c9d9393 Mon Sep 17 00:00:00 2001 From: Peter Zijlstra <peterz(a)infradead.org> Date: Tue, 5 Dec 2017 13:34:53 +0100 Subject: x86/mm: Clarify the whole ASID/kernel PCID/user PCID naming From: Peter Zijlstra <peterz(a)infradead.org> commit 0a126abd576ebc6403f063dbe20cf7416c9d9393 upstream. Ideally we'd also use sparse to enforce this separation so it becomes much more difficult to mess up. Signed-off-by: Peter Zijlstra (Intel) <peterz(a)infradead.org> Signed-off-by: Thomas Gleixner <tglx(a)linutronix.de> Cc: Andy Lutomirski <luto(a)kernel.org> Cc: Boris Ostrovsky <boris.ostrovsky(a)oracle.com> Cc: Borislav Petkov <bp(a)alien8.de> Cc: Brian Gerst <brgerst(a)gmail.com> Cc: Dave Hansen <dave.hansen(a)linux.intel.com> Cc: David Laight <David.Laight(a)aculab.com> Cc: Denys Vlasenko <dvlasenk(a)redhat.com> Cc: Eduardo Valentin <eduval(a)amazon.com> Cc: Greg KH <gregkh(a)linuxfoundation.org> Cc: H. Peter Anvin <hpa(a)zytor.com> Cc: Josh Poimboeuf <jpoimboe(a)redhat.com> Cc: Juergen Gross <jgross(a)suse.com> Cc: Linus Torvalds <torvalds(a)linux-foundation.org> Cc: Peter Zijlstra <peterz(a)infradead.org> Cc: Will Deacon <will.deacon(a)arm.com> Cc: aliguori(a)amazon.com Cc: daniel.gruss(a)iaik.tugraz.at Cc: hughd(a)google.com Cc: keescook(a)google.com Cc: linux-mm(a)kvack.org Signed-off-by: Ingo Molnar <mingo(a)kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh(a)linuxfoundation.org> --- arch/x86/include/asm/tlbflush.h | 55 +++++++++++++++++++++++++++++++--------- 1 file changed, 43 insertions(+), 12 deletions(-) --- a/arch/x86/include/asm/tlbflush.h +++ b/arch/x86/include/asm/tlbflush.h @@ -13,16 +13,33 @@ #include <asm/pti.h> #include <asm/processor-flags.h> -static inline u64 inc_mm_tlb_gen(struct mm_struct *mm) -{ - /* - * Bump the generation count. This also serves as a full barrier - * that synchronizes with switch_mm(): callers are required to order - * their read of mm_cpumask after their writes to the paging - * structures. - */ - return atomic64_inc_return(&mm->context.tlb_gen); -} +/* + * The x86 feature is called PCID (Process Context IDentifier). It is similar + * to what is traditionally called ASID on the RISC processors. + * + * We don't use the traditional ASID implementation, where each process/mm gets + * its own ASID and flush/restart when we run out of ASID space. + * + * Instead we have a small per-cpu array of ASIDs and cache the last few mm's + * that came by on this CPU, allowing cheaper switch_mm between processes on + * this CPU. + * + * We end up with different spaces for different things. To avoid confusion we + * use different names for each of them: + * + * ASID - [0, TLB_NR_DYN_ASIDS-1] + * the canonical identifier for an mm + * + * kPCID - [1, TLB_NR_DYN_ASIDS] + * the value we write into the PCID part of CR3; corresponds to the + * ASID+1, because PCID 0 is special. + * + * uPCID - [2048 + 1, 2048 + TLB_NR_DYN_ASIDS] + * for KPTI each mm has two address spaces and thus needs two + * PCID values, but we can still do with a single ASID denomination + * for each mm. Corresponds to kPCID + 2048. + * + */ /* There are 12 bits of space for ASIDS in CR3 */ #define CR3_HW_ASID_BITS 12 @@ -41,7 +58,7 @@ static inline u64 inc_mm_tlb_gen(struct /* * ASIDs are zero-based: 0->MAX_AVAIL_ASID are valid. -1 below to account - * for them being zero-based. Another -1 is because ASID 0 is reserved for + * for them being zero-based. Another -1 is because PCID 0 is reserved for * use by non-PCID-aware users. */ #define MAX_ASID_AVAILABLE ((1 << CR3_AVAIL_PCID_BITS) - 2) @@ -52,6 +69,9 @@ static inline u64 inc_mm_tlb_gen(struct */ #define TLB_NR_DYN_ASIDS 6 +/* + * Given @asid, compute kPCID + */ static inline u16 kern_pcid(u16 asid) { VM_WARN_ON_ONCE(asid > MAX_ASID_AVAILABLE); @@ -86,7 +106,7 @@ static inline u16 kern_pcid(u16 asid) } /* - * The user PCID is just the kernel one, plus the "switch bit". + * Given @asid, compute uPCID */ static inline u16 user_pcid(u16 asid) { @@ -484,6 +504,17 @@ static inline void flush_tlb_page(struct void native_flush_tlb_others(const struct cpumask *cpumask, const struct flush_tlb_info *info); +static inline u64 inc_mm_tlb_gen(struct mm_struct *mm) +{ + /* + * Bump the generation count. This also serves as a full barrier + * that synchronizes with switch_mm(): callers are required to order + * their read of mm_cpumask after their writes to the paging + * structures. + */ + return atomic64_inc_return(&mm->context.tlb_gen); +} + static inline void arch_tlbbatch_add_mm(struct arch_tlbflush_unmap_batch *batch, struct mm_struct *mm) { Patches currently in stable-queue which might be from peterz(a)infradead.org are queue-4.14/x86-mm-pti-allow-nx-poison-to-be-set-in-p4d-pgd.patch queue-4.14/x86-dumpstack-indicate-in-oops-whether-pti-is-configured-and-enabled.patch queue-4.14/x86-mm-clarify-the-whole-asid-kernel-pcid-user-pcid-naming.patch queue-4.14/x86-mm-abstract-switching-cr3.patch queue-4.14/x86-mm-optimize-restore_cr3.patch queue-4.14/x86-mm-pti-force-entry-through-trampoline-when-pti-active.patch queue-4.14/x86-entry-align-entry-text-section-to-pmd-boundary.patch queue-4.14/x86-mm-64-make-a-full-pgd-entry-size-hole-in-the-memory-map.patch queue-4.14/x86-cpu_entry_area-add-debugstore-entries-to-cpu_entry_area.patch queue-4.14/x86-mm-pti-share-entry-text-pmd.patch queue-4.14/x86-ldt-make-the-ldt-mapping-ro.patch queue-4.14/x86-mm-dump_pagetables-check-user-space-page-table-for-wx-pages.patch queue-4.14/x86-pti-map-the-vsyscall-page-if-needed.patch queue-4.14/x86-mm-pti-disable-global-pages-if-page_table_isolation-y.patch queue-4.14/x86-mm-dump_pagetables-allow-dumping-current-pagetables.patch queue-4.14/x86-mm-pti-add-infrastructure-for-page-table-isolation.patch queue-4.14/x86-cpufeatures-add-x86_bug_cpu_insecure.patch queue-4.14/x86-mm-use-fix-pcid-to-optimize-user-kernel-switches.patch queue-4.14/x86-mm-use-invpcid-for-__native_flush_tlb_single.patch queue-4.14/x86-mm-pti-prepare-the-x86-entry-assembly-code-for-entry-exit-cr3-switching.patch queue-4.14/x86-mm-allow-flushing-for-future-asid-switches.patch queue-4.14/x86-mm-pti-add-kconfig.patch queue-4.14/x86-mm-pti-add-mapping-helper-functions.patch queue-4.14/x86-mm-pti-map-espfix-into-user-space.patch queue-4.14/x86-mm-pti-share-cpu_entry_area-with-user-space-page-tables.patch queue-4.14/x86-mm-pti-add-functions-to-clone-kernel-pmds.patch queue-4.14/x86-pti-add-the-pti-cmdline-option-and-documentation.patch queue-4.14/x86-events-intel-ds-map-debug-buffers-in-cpu_entry_area.patch queue-4.14/x86-mm-pti-allocate-a-separate-user-pgd.patch queue-4.14/x86-pti-put-the-ldt-in-its-own-pgd-if-pti-is-on.patch queue-4.14/x86-mm-pti-populate-user-pgd.patch queue-4.14/x86-mm-dump_pagetables-add-page-table-directory-to-the-debugfs-vfs-hierarchy.patch

6 years, 6 months

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[Linux-stable-mirror] Patch "x86/mm: Allow flushing for future ASID switches" has been added to the 4.14-stable tree

by gregkh＠linuxfoundation.org

This is a note to let you know that I've just added the patch titled x86/mm: Allow flushing for future ASID switches to the 4.14-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: x86-mm-allow-flushing-for-future-asid-switches.patch and it can be found in the queue-4.14 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 2ea907c4fe7b78e5840c1dc07800eae93248cad1 Mon Sep 17 00:00:00 2001 From: Dave Hansen <dave.hansen(a)linux.intel.com> Date: Mon, 4 Dec 2017 15:07:57 +0100 Subject: x86/mm: Allow flushing for future ASID switches From: Dave Hansen <dave.hansen(a)linux.intel.com> commit 2ea907c4fe7b78e5840c1dc07800eae93248cad1 upstream. If changing the page tables in such a way that an invalidation of all contexts (aka. PCIDs / ASIDs) is required, they can be actively invalidated by: 1. INVPCID for each PCID (works for single pages too). 2. Load CR3 with each PCID without the NOFLUSH bit set 3. Load CR3 with the NOFLUSH bit set for each and do INVLPG for each address. But, none of these are really feasible since there are ~6 ASIDs (12 with PAGE_TABLE_ISOLATION) at the time that invalidation is required. Instead of actively invalidating them, invalidate the *current* context and also mark the cpu_tlbstate _quickly_ to indicate future invalidation to be required. At the next context-switch, look for this indicator ('invalidate_other' being set) invalidate all of the cpu_tlbstate.ctxs[] entries. This ensures that any future context switches will do a full flush of the TLB, picking up the previous changes. [ tglx: Folded more fixups from Peter ] Signed-off-by: Dave Hansen <dave.hansen(a)linux.intel.com> Signed-off-by: Peter Zijlstra (Intel) <peterz(a)infradead.org> Signed-off-by: Thomas Gleixner <tglx(a)linutronix.de> Cc: Andy Lutomirski <luto(a)kernel.org> Cc: Boris Ostrovsky <boris.ostrovsky(a)oracle.com> Cc: Borislav Petkov <bp(a)alien8.de> Cc: Brian Gerst <brgerst(a)gmail.com> Cc: David Laight <David.Laight(a)aculab.com> Cc: Denys Vlasenko <dvlasenk(a)redhat.com> Cc: Eduardo Valentin <eduval(a)amazon.com> Cc: Greg KH <gregkh(a)linuxfoundation.org> Cc: H. Peter Anvin <hpa(a)zytor.com> Cc: Josh Poimboeuf <jpoimboe(a)redhat.com> Cc: Juergen Gross <jgross(a)suse.com> Cc: Linus Torvalds <torvalds(a)linux-foundation.org> Cc: Peter Zijlstra <peterz(a)infradead.org> Cc: Will Deacon <will.deacon(a)arm.com> Cc: aliguori(a)amazon.com Cc: daniel.gruss(a)iaik.tugraz.at Cc: hughd(a)google.com Cc: keescook(a)google.com Signed-off-by: Ingo Molnar <mingo(a)kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh(a)linuxfoundation.org> --- arch/x86/include/asm/tlbflush.h | 37 +++++++++++++++++++++++++++++-------- arch/x86/mm/tlb.c | 35 +++++++++++++++++++++++++++++++++++ 2 files changed, 64 insertions(+), 8 deletions(-) --- a/arch/x86/include/asm/tlbflush.h +++ b/arch/x86/include/asm/tlbflush.h @@ -135,6 +135,17 @@ struct tlb_state { bool is_lazy; /* + * If set we changed the page tables in such a way that we + * needed an invalidation of all contexts (aka. PCIDs / ASIDs). + * This tells us to go invalidate all the non-loaded ctxs[] + * on the next context switch. + * + * The current ctx was kept up-to-date as it ran and does not + * need to be invalidated. + */ + bool invalidate_other; + + /* * Access to this CR4 shadow and to H/W CR4 is protected by * disabling interrupts when modifying either one. */ @@ -212,6 +223,14 @@ static inline unsigned long cr4_read_sha } /* + * Mark all other ASIDs as invalid, preserves the current. + */ +static inline void invalidate_other_asid(void) +{ + this_cpu_write(cpu_tlbstate.invalidate_other, true); +} + +/* * Save some of cr4 feature set we're using (e.g. Pentium 4MB * enable and PPro Global page enable), so that any CPU's that boot * up after us can get the correct flags. This should only be used @@ -298,14 +317,6 @@ static inline void __flush_tlb_all(void) */ __flush_tlb(); } - - /* - * 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 - * we might fail to flush kernel translations for other cached ASIDs. - * - * To avoid this issue, we force PCID off if PGE is off. - */ } /* @@ -315,6 +326,16 @@ static inline void __flush_tlb_one(unsig { count_vm_tlb_event(NR_TLB_LOCAL_FLUSH_ONE); __flush_tlb_single(addr); + + if (!static_cpu_has(X86_FEATURE_PTI)) + return; + + /* + * __flush_tlb_single() will have cleared the TLB entry for this ASID, + * but since kernel space is replicated across all, we must also + * invalidate all others. + */ + invalidate_other_asid(); } #define TLB_FLUSH_ALL -1UL --- a/arch/x86/mm/tlb.c +++ b/arch/x86/mm/tlb.c @@ -28,6 +28,38 @@ * Implement flush IPI by CALL_FUNCTION_VECTOR, Alex Shi */ +/* + * We get here when we do something requiring a TLB invalidation + * but could not go invalidate all of the contexts. We do the + * necessary invalidation by clearing out the 'ctx_id' which + * forces a TLB flush when the context is loaded. + */ +void clear_asid_other(void) +{ + u16 asid; + + /* + * This is only expected to be set if we have disabled + * kernel _PAGE_GLOBAL pages. + */ + if (!static_cpu_has(X86_FEATURE_PTI)) { + WARN_ON_ONCE(1); + return; + } + + for (asid = 0; asid < TLB_NR_DYN_ASIDS; asid++) { + /* Do not need to flush the current asid */ + if (asid == this_cpu_read(cpu_tlbstate.loaded_mm_asid)) + continue; + /* + * Make sure the next time we go to switch to + * this asid, we do a flush: + */ + this_cpu_write(cpu_tlbstate.ctxs[asid].ctx_id, 0); + } + this_cpu_write(cpu_tlbstate.invalidate_other, false); +} + atomic64_t last_mm_ctx_id = ATOMIC64_INIT(1); @@ -42,6 +74,9 @@ static void choose_new_asid(struct mm_st return; } + if (this_cpu_read(cpu_tlbstate.invalidate_other)) + clear_asid_other(); + for (asid = 0; asid < TLB_NR_DYN_ASIDS; asid++) { if (this_cpu_read(cpu_tlbstate.ctxs[asid].ctx_id) != next->context.ctx_id) Patches currently in stable-queue which might be from dave.hansen(a)linux.intel.com are queue-4.14/x86-mm-pti-allow-nx-poison-to-be-set-in-p4d-pgd.patch queue-4.14/x86-dumpstack-indicate-in-oops-whether-pti-is-configured-and-enabled.patch queue-4.14/x86-mm-clarify-the-whole-asid-kernel-pcid-user-pcid-naming.patch queue-4.14/x86-mm-abstract-switching-cr3.patch queue-4.14/x86-mm-optimize-restore_cr3.patch queue-4.14/x86-mm-pti-force-entry-through-trampoline-when-pti-active.patch queue-4.14/x86-entry-align-entry-text-section-to-pmd-boundary.patch queue-4.14/x86-mm-64-make-a-full-pgd-entry-size-hole-in-the-memory-map.patch queue-4.14/x86-cpu_entry_area-add-debugstore-entries-to-cpu_entry_area.patch queue-4.14/x86-mm-pti-share-entry-text-pmd.patch queue-4.14/x86-ldt-make-the-ldt-mapping-ro.patch queue-4.14/x86-mm-dump_pagetables-check-user-space-page-table-for-wx-pages.patch queue-4.14/x86-pti-map-the-vsyscall-page-if-needed.patch queue-4.14/x86-mm-pti-disable-global-pages-if-page_table_isolation-y.patch queue-4.14/x86-mm-dump_pagetables-allow-dumping-current-pagetables.patch queue-4.14/x86-mm-pti-add-infrastructure-for-page-table-isolation.patch queue-4.14/x86-cpufeatures-add-x86_bug_cpu_insecure.patch queue-4.14/x86-mm-use-fix-pcid-to-optimize-user-kernel-switches.patch queue-4.14/x86-mm-use-invpcid-for-__native_flush_tlb_single.patch queue-4.14/x86-mm-pti-prepare-the-x86-entry-assembly-code-for-entry-exit-cr3-switching.patch queue-4.14/x86-mm-allow-flushing-for-future-asid-switches.patch queue-4.14/x86-mm-pti-add-kconfig.patch queue-4.14/x86-mm-pti-add-mapping-helper-functions.patch queue-4.14/x86-mm-pti-map-espfix-into-user-space.patch queue-4.14/x86-mm-pti-share-cpu_entry_area-with-user-space-page-tables.patch queue-4.14/x86-mm-pti-add-functions-to-clone-kernel-pmds.patch queue-4.14/x86-pti-add-the-pti-cmdline-option-and-documentation.patch queue-4.14/x86-events-intel-ds-map-debug-buffers-in-cpu_entry_area.patch queue-4.14/x86-mm-pti-allocate-a-separate-user-pgd.patch queue-4.14/x86-pti-put-the-ldt-in-its-own-pgd-if-pti-is-on.patch queue-4.14/x86-mm-pti-populate-user-pgd.patch queue-4.14/x86-mm-dump_pagetables-add-page-table-directory-to-the-debugfs-vfs-hierarchy.patch

6 years, 6 months

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[Linux-stable-mirror] Patch "x86/mm: Abstract switching CR3" has been added to the 4.14-stable tree

by gregkh＠linuxfoundation.org

This is a note to let you know that I've just added the patch titled x86/mm: Abstract switching CR3 to the 4.14-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: x86-mm-abstract-switching-cr3.patch and it can be found in the queue-4.14 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 48e111982cda033fec832c6b0592c2acedd85d04 Mon Sep 17 00:00:00 2001 From: Dave Hansen <dave.hansen(a)linux.intel.com> Date: Mon, 4 Dec 2017 15:07:58 +0100 Subject: x86/mm: Abstract switching CR3 From: Dave Hansen <dave.hansen(a)linux.intel.com> commit 48e111982cda033fec832c6b0592c2acedd85d04 upstream. In preparation to adding additional PCID flushing, abstract the loading of a new ASID into CR3. [ PeterZ: Split out from big combo patch ] Signed-off-by: Dave Hansen <dave.hansen(a)linux.intel.com> Signed-off-by: Peter Zijlstra (Intel) <peterz(a)infradead.org> Signed-off-by: Thomas Gleixner <tglx(a)linutronix.de> Cc: Andy Lutomirski <luto(a)kernel.org> Cc: Boris Ostrovsky <boris.ostrovsky(a)oracle.com> Cc: Borislav Petkov <bp(a)alien8.de> Cc: Brian Gerst <brgerst(a)gmail.com> Cc: David Laight <David.Laight(a)aculab.com> Cc: Denys Vlasenko <dvlasenk(a)redhat.com> Cc: Eduardo Valentin <eduval(a)amazon.com> Cc: Greg KH <gregkh(a)linuxfoundation.org> Cc: H. Peter Anvin <hpa(a)zytor.com> Cc: Josh Poimboeuf <jpoimboe(a)redhat.com> Cc: Juergen Gross <jgross(a)suse.com> Cc: Linus Torvalds <torvalds(a)linux-foundation.org> Cc: Peter Zijlstra <peterz(a)infradead.org> Cc: Will Deacon <will.deacon(a)arm.com> Cc: aliguori(a)amazon.com Cc: daniel.gruss(a)iaik.tugraz.at Cc: hughd(a)google.com Cc: keescook(a)google.com Signed-off-by: Ingo Molnar <mingo(a)kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh(a)linuxfoundation.org> --- arch/x86/mm/tlb.c | 22 ++++++++++++++++++++-- 1 file changed, 20 insertions(+), 2 deletions(-) --- a/arch/x86/mm/tlb.c +++ b/arch/x86/mm/tlb.c @@ -100,6 +100,24 @@ static void choose_new_asid(struct mm_st *need_flush = true; } +static void load_new_mm_cr3(pgd_t *pgdir, u16 new_asid, bool need_flush) +{ + unsigned long new_mm_cr3; + + if (need_flush) { + new_mm_cr3 = build_cr3(pgdir, new_asid); + } else { + new_mm_cr3 = build_cr3_noflush(pgdir, new_asid); + } + + /* + * Caution: many callers of this function expect + * that load_cr3() is serializing and orders TLB + * fills with respect to the mm_cpumask writes. + */ + write_cr3(new_mm_cr3); +} + void leave_mm(int cpu) { struct mm_struct *loaded_mm = this_cpu_read(cpu_tlbstate.loaded_mm); @@ -230,7 +248,7 @@ void switch_mm_irqs_off(struct mm_struct if (need_flush) { this_cpu_write(cpu_tlbstate.ctxs[new_asid].ctx_id, next->context.ctx_id); this_cpu_write(cpu_tlbstate.ctxs[new_asid].tlb_gen, next_tlb_gen); - write_cr3(build_cr3(next->pgd, new_asid)); + load_new_mm_cr3(next->pgd, new_asid, true); /* * NB: This gets called via leave_mm() in the idle path @@ -243,7 +261,7 @@ void switch_mm_irqs_off(struct mm_struct trace_tlb_flush_rcuidle(TLB_FLUSH_ON_TASK_SWITCH, TLB_FLUSH_ALL); } else { /* The new ASID is already up to date. */ - write_cr3(build_cr3_noflush(next->pgd, new_asid)); + load_new_mm_cr3(next->pgd, new_asid, false); /* See above wrt _rcuidle. */ trace_tlb_flush_rcuidle(TLB_FLUSH_ON_TASK_SWITCH, 0); Patches currently in stable-queue which might be from dave.hansen(a)linux.intel.com are queue-4.14/x86-mm-pti-allow-nx-poison-to-be-set-in-p4d-pgd.patch queue-4.14/x86-dumpstack-indicate-in-oops-whether-pti-is-configured-and-enabled.patch queue-4.14/x86-mm-clarify-the-whole-asid-kernel-pcid-user-pcid-naming.patch queue-4.14/x86-mm-abstract-switching-cr3.patch queue-4.14/x86-mm-optimize-restore_cr3.patch queue-4.14/x86-mm-pti-force-entry-through-trampoline-when-pti-active.patch queue-4.14/x86-entry-align-entry-text-section-to-pmd-boundary.patch queue-4.14/x86-mm-64-make-a-full-pgd-entry-size-hole-in-the-memory-map.patch queue-4.14/x86-cpu_entry_area-add-debugstore-entries-to-cpu_entry_area.patch queue-4.14/x86-mm-pti-share-entry-text-pmd.patch queue-4.14/x86-ldt-make-the-ldt-mapping-ro.patch queue-4.14/x86-mm-dump_pagetables-check-user-space-page-table-for-wx-pages.patch queue-4.14/x86-pti-map-the-vsyscall-page-if-needed.patch queue-4.14/x86-mm-pti-disable-global-pages-if-page_table_isolation-y.patch queue-4.14/x86-mm-dump_pagetables-allow-dumping-current-pagetables.patch queue-4.14/x86-mm-pti-add-infrastructure-for-page-table-isolation.patch queue-4.14/x86-cpufeatures-add-x86_bug_cpu_insecure.patch queue-4.14/x86-mm-use-fix-pcid-to-optimize-user-kernel-switches.patch queue-4.14/x86-mm-use-invpcid-for-__native_flush_tlb_single.patch queue-4.14/x86-mm-pti-prepare-the-x86-entry-assembly-code-for-entry-exit-cr3-switching.patch queue-4.14/x86-mm-allow-flushing-for-future-asid-switches.patch queue-4.14/x86-mm-pti-add-kconfig.patch queue-4.14/x86-mm-pti-add-mapping-helper-functions.patch queue-4.14/x86-mm-pti-map-espfix-into-user-space.patch queue-4.14/x86-mm-pti-share-cpu_entry_area-with-user-space-page-tables.patch queue-4.14/x86-mm-pti-add-functions-to-clone-kernel-pmds.patch queue-4.14/x86-pti-add-the-pti-cmdline-option-and-documentation.patch queue-4.14/x86-events-intel-ds-map-debug-buffers-in-cpu_entry_area.patch queue-4.14/x86-mm-pti-allocate-a-separate-user-pgd.patch queue-4.14/x86-pti-put-the-ldt-in-its-own-pgd-if-pti-is-on.patch queue-4.14/x86-mm-pti-populate-user-pgd.patch queue-4.14/x86-mm-dump_pagetables-add-page-table-directory-to-the-debugfs-vfs-hierarchy.patch

6 years, 6 months

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[Linux-stable-mirror] Patch "x86/mm/64: Make a full PGD-entry size hole in the memory map" has been added to the 4.14-stable tree

by gregkh＠linuxfoundation.org

This is a note to let you know that I've just added the patch titled x86/mm/64: Make a full PGD-entry size hole in the memory map to the 4.14-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: x86-mm-64-make-a-full-pgd-entry-size-hole-in-the-memory-map.patch and it can be found in the queue-4.14 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 9f449772a3106bcdd4eb8fdeb281147b0e99fb30 Mon Sep 17 00:00:00 2001 From: Andy Lutomirski <luto(a)kernel.org> Date: Tue, 12 Dec 2017 07:56:44 -0800 Subject: x86/mm/64: Make a full PGD-entry size hole in the memory map From: Andy Lutomirski <luto(a)kernel.org> commit 9f449772a3106bcdd4eb8fdeb281147b0e99fb30 upstream. Shrink vmalloc space from 16384TiB to 12800TiB to enlarge the hole starting at 0xff90000000000000 to be a full PGD entry. A subsequent patch will use this hole for the pagetable isolation LDT alias. Signed-off-by: Andy Lutomirski <luto(a)kernel.org> Signed-off-by: Thomas Gleixner <tglx(a)linutronix.de> Cc: Borislav Petkov <bp(a)alien8.de> Cc: Brian Gerst <brgerst(a)gmail.com> Cc: Dave Hansen <dave.hansen(a)intel.com> Cc: Dave Hansen <dave.hansen(a)linux.intel.com> Cc: David Laight <David.Laight(a)aculab.com> Cc: H. Peter Anvin <hpa(a)zytor.com> Cc: Josh Poimboeuf <jpoimboe(a)redhat.com> Cc: Juergen Gross <jgross(a)suse.com> Cc: Kees Cook <keescook(a)chromium.org> Cc: Kirill A. Shutemov <kirill(a)shutemov.name> Cc: Linus Torvalds <torvalds(a)linux-foundation.org> Cc: Peter Zijlstra <peterz(a)infradead.org> Signed-off-by: Ingo Molnar <mingo(a)kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh(a)linuxfoundation.org> --- Documentation/x86/x86_64/mm.txt | 4 ++-- arch/x86/include/asm/pgtable_64_types.h | 4 ++-- 2 files changed, 4 insertions(+), 4 deletions(-) --- a/Documentation/x86/x86_64/mm.txt +++ b/Documentation/x86/x86_64/mm.txt @@ -29,8 +29,8 @@ Virtual memory map with 5 level page tab hole caused by [56:63] sign extension ff00000000000000 - ff0fffffffffffff (=52 bits) guard hole, reserved for hypervisor ff10000000000000 - ff8fffffffffffff (=55 bits) direct mapping of all phys. memory -ff90000000000000 - ff91ffffffffffff (=49 bits) hole -ff92000000000000 - ffd1ffffffffffff (=54 bits) vmalloc/ioremap space +ff90000000000000 - ff9fffffffffffff (=52 bits) hole +ffa0000000000000 - ffd1ffffffffffff (=54 bits) vmalloc/ioremap space (12800 TB) ffd2000000000000 - ffd3ffffffffffff (=49 bits) hole ffd4000000000000 - ffd5ffffffffffff (=49 bits) virtual memory map (512TB) ... unused hole ... --- a/arch/x86/include/asm/pgtable_64_types.h +++ b/arch/x86/include/asm/pgtable_64_types.h @@ -79,8 +79,8 @@ typedef struct { pteval_t pte; } pte_t; #define MAXMEM _AC(__AC(1, UL) << MAX_PHYSMEM_BITS, UL) #ifdef CONFIG_X86_5LEVEL -# define VMALLOC_SIZE_TB _AC(16384, UL) -# define __VMALLOC_BASE _AC(0xff92000000000000, UL) +# define VMALLOC_SIZE_TB _AC(12800, UL) +# define __VMALLOC_BASE _AC(0xffa0000000000000, UL) # define __VMEMMAP_BASE _AC(0xffd4000000000000, UL) #else # define VMALLOC_SIZE_TB _AC(32, UL) Patches currently in stable-queue which might be from luto(a)kernel.org are queue-4.14/x86-mm-pti-allow-nx-poison-to-be-set-in-p4d-pgd.patch queue-4.14/x86-dumpstack-indicate-in-oops-whether-pti-is-configured-and-enabled.patch queue-4.14/x86-mm-clarify-the-whole-asid-kernel-pcid-user-pcid-naming.patch queue-4.14/x86-mm-abstract-switching-cr3.patch queue-4.14/x86-mm-optimize-restore_cr3.patch queue-4.14/x86-mm-pti-force-entry-through-trampoline-when-pti-active.patch queue-4.14/x86-entry-align-entry-text-section-to-pmd-boundary.patch queue-4.14/x86-mm-64-make-a-full-pgd-entry-size-hole-in-the-memory-map.patch queue-4.14/x86-cpu_entry_area-add-debugstore-entries-to-cpu_entry_area.patch queue-4.14/x86-mm-pti-share-entry-text-pmd.patch queue-4.14/x86-ldt-make-the-ldt-mapping-ro.patch queue-4.14/x86-mm-dump_pagetables-check-user-space-page-table-for-wx-pages.patch queue-4.14/x86-pti-map-the-vsyscall-page-if-needed.patch queue-4.14/x86-mm-pti-disable-global-pages-if-page_table_isolation-y.patch queue-4.14/x86-mm-dump_pagetables-allow-dumping-current-pagetables.patch queue-4.14/x86-mm-pti-add-infrastructure-for-page-table-isolation.patch queue-4.14/x86-cpufeatures-add-x86_bug_cpu_insecure.patch queue-4.14/x86-mm-use-fix-pcid-to-optimize-user-kernel-switches.patch queue-4.14/x86-mm-use-invpcid-for-__native_flush_tlb_single.patch queue-4.14/x86-mm-pti-prepare-the-x86-entry-assembly-code-for-entry-exit-cr3-switching.patch queue-4.14/x86-mm-allow-flushing-for-future-asid-switches.patch queue-4.14/x86-mm-pti-add-kconfig.patch queue-4.14/x86-mm-pti-add-mapping-helper-functions.patch queue-4.14/x86-mm-pti-map-espfix-into-user-space.patch queue-4.14/x86-mm-pti-share-cpu_entry_area-with-user-space-page-tables.patch queue-4.14/x86-mm-pti-add-functions-to-clone-kernel-pmds.patch queue-4.14/x86-pti-add-the-pti-cmdline-option-and-documentation.patch queue-4.14/x86-events-intel-ds-map-debug-buffers-in-cpu_entry_area.patch queue-4.14/x86-mm-pti-allocate-a-separate-user-pgd.patch queue-4.14/x86-pti-put-the-ldt-in-its-own-pgd-if-pti-is-on.patch queue-4.14/x86-mm-pti-populate-user-pgd.patch queue-4.14/x86-mm-dump_pagetables-add-page-table-directory-to-the-debugfs-vfs-hierarchy.patch

6 years, 6 months

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[Linux-stable-mirror] Patch "x86/ldt: Make the LDT mapping RO" has been added to the 4.14-stable tree

by gregkh＠linuxfoundation.org

This is a note to let you know that I've just added the patch titled x86/ldt: Make the LDT mapping RO to the 4.14-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: x86-ldt-make-the-ldt-mapping-ro.patch and it can be found in the queue-4.14 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 9f5cb6b32d9e0a3a7453222baaf15664d92adbf2 Mon Sep 17 00:00:00 2001 From: Thomas Gleixner <tglx(a)linutronix.de> Date: Fri, 15 Dec 2017 20:35:11 +0100 Subject: x86/ldt: Make the LDT mapping RO From: Thomas Gleixner <tglx(a)linutronix.de> commit 9f5cb6b32d9e0a3a7453222baaf15664d92adbf2 upstream. Now that the LDT mapping is in a known area when PAGE_TABLE_ISOLATION is enabled its a primary target for attacks, if a user space interface fails to validate a write address correctly. That can never happen, right? The SDM states: If the segment descriptors in the GDT or an LDT are placed in ROM, the processor can enter an indefinite loop if software or the processor attempts to update (write to) the ROM-based segment descriptors. To prevent this problem, set the accessed bits for all segment descriptors placed in a ROM. Also, remove operating-system or executive code that attempts to modify segment descriptors located in ROM. So its a valid approach to set the ACCESS bit when setting up the LDT entry and to map the table RO. Fixup the selftest so it can handle that new mode. Remove the manual ACCESS bit setter in set_tls_desc() as this is now pointless. Folded the patch from Peter Ziljstra. Signed-off-by: Thomas Gleixner <tglx(a)linutronix.de> Cc: Andy Lutomirski <luto(a)kernel.org> Cc: Borislav Petkov <bp(a)alien8.de> Cc: Dave Hansen <dave.hansen(a)linux.intel.com> Cc: H. Peter Anvin <hpa(a)zytor.com> Cc: Josh Poimboeuf <jpoimboe(a)redhat.com> Cc: Juergen Gross <jgross(a)suse.com> Cc: Linus Torvalds <torvalds(a)linux-foundation.org> Cc: Peter Zijlstra <peterz(a)infradead.org> Signed-off-by: Ingo Molnar <mingo(a)kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh(a)linuxfoundation.org> --- arch/x86/include/asm/desc.h | 2 ++ arch/x86/kernel/ldt.c | 7 ++++++- arch/x86/kernel/tls.c | 11 ++--------- tools/testing/selftests/x86/ldt_gdt.c | 3 +-- 4 files changed, 11 insertions(+), 12 deletions(-) --- a/arch/x86/include/asm/desc.h +++ b/arch/x86/include/asm/desc.h @@ -21,6 +21,8 @@ static inline void fill_ldt(struct desc_ desc->type = (info->read_exec_only ^ 1) << 1; desc->type |= info->contents << 2; + /* Set the ACCESS bit so it can be mapped RO */ + desc->type |= 1; desc->s = 1; desc->dpl = 0x3; --- a/arch/x86/kernel/ldt.c +++ b/arch/x86/kernel/ldt.c @@ -158,7 +158,12 @@ map_ldt_struct(struct mm_struct *mm, str ptep = get_locked_pte(mm, va, &ptl); if (!ptep) return -ENOMEM; - pte = pfn_pte(pfn, __pgprot(__PAGE_KERNEL & ~_PAGE_GLOBAL)); + /* + * Map it RO so the easy to find address is not a primary + * target via some kernel interface which misses a + * permission check. + */ + pte = pfn_pte(pfn, __pgprot(__PAGE_KERNEL_RO & ~_PAGE_GLOBAL)); set_pte_at(mm, va, ptep, pte); pte_unmap_unlock(ptep, ptl); } --- a/arch/x86/kernel/tls.c +++ b/arch/x86/kernel/tls.c @@ -93,17 +93,10 @@ static void set_tls_desc(struct task_str cpu = get_cpu(); while (n-- > 0) { - if (LDT_empty(info) || LDT_zero(info)) { + if (LDT_empty(info) || LDT_zero(info)) memset(desc, 0, sizeof(*desc)); - } else { + else fill_ldt(desc, info); - - /* - * Always set the accessed bit so that the CPU - * doesn't try to write to the (read-only) GDT. - */ - desc->type |= 1; - } ++info; ++desc; } --- a/tools/testing/selftests/x86/ldt_gdt.c +++ b/tools/testing/selftests/x86/ldt_gdt.c @@ -122,8 +122,7 @@ static void check_valid_segment(uint16_t * NB: Different Linux versions do different things with the * accessed bit in set_thread_area(). */ - if (ar != expected_ar && - (ldt || ar != (expected_ar | AR_ACCESSED))) { + if (ar != expected_ar && ar != (expected_ar | AR_ACCESSED)) { printf("[FAIL]\t%s entry %hu has AR 0x%08X but expected 0x%08X\n", (ldt ? "LDT" : "GDT"), index, ar, expected_ar); nerrs++; Patches currently in stable-queue which might be from tglx(a)linutronix.de are queue-4.14/x86-mm-pti-allow-nx-poison-to-be-set-in-p4d-pgd.patch queue-4.14/x86-dumpstack-indicate-in-oops-whether-pti-is-configured-and-enabled.patch queue-4.14/x86-mm-clarify-the-whole-asid-kernel-pcid-user-pcid-naming.patch queue-4.14/x86-mm-abstract-switching-cr3.patch queue-4.14/x86-mm-optimize-restore_cr3.patch queue-4.14/x86-mm-pti-force-entry-through-trampoline-when-pti-active.patch queue-4.14/x86-entry-align-entry-text-section-to-pmd-boundary.patch queue-4.14/x86-mm-64-make-a-full-pgd-entry-size-hole-in-the-memory-map.patch queue-4.14/x86-cpu_entry_area-add-debugstore-entries-to-cpu_entry_area.patch queue-4.14/x86-mm-pti-share-entry-text-pmd.patch queue-4.14/x86-ldt-make-the-ldt-mapping-ro.patch queue-4.14/x86-mm-dump_pagetables-check-user-space-page-table-for-wx-pages.patch queue-4.14/x86-pti-map-the-vsyscall-page-if-needed.patch queue-4.14/x86-mm-pti-disable-global-pages-if-page_table_isolation-y.patch queue-4.14/x86-mm-dump_pagetables-allow-dumping-current-pagetables.patch queue-4.14/x86-mm-pti-add-infrastructure-for-page-table-isolation.patch queue-4.14/x86-cpufeatures-add-x86_bug_cpu_insecure.patch queue-4.14/x86-mm-use-fix-pcid-to-optimize-user-kernel-switches.patch queue-4.14/x86-mm-use-invpcid-for-__native_flush_tlb_single.patch queue-4.14/x86-mm-pti-prepare-the-x86-entry-assembly-code-for-entry-exit-cr3-switching.patch queue-4.14/x86-mm-allow-flushing-for-future-asid-switches.patch queue-4.14/x86-mm-pti-add-kconfig.patch queue-4.14/x86-mm-pti-add-mapping-helper-functions.patch queue-4.14/x86-mm-pti-map-espfix-into-user-space.patch queue-4.14/x86-mm-pti-share-cpu_entry_area-with-user-space-page-tables.patch queue-4.14/x86-mm-pti-add-functions-to-clone-kernel-pmds.patch queue-4.14/x86-pti-add-the-pti-cmdline-option-and-documentation.patch queue-4.14/x86-events-intel-ds-map-debug-buffers-in-cpu_entry_area.patch queue-4.14/x86-mm-pti-allocate-a-separate-user-pgd.patch queue-4.14/x86-pti-put-the-ldt-in-its-own-pgd-if-pti-is-on.patch queue-4.14/x86-mm-pti-populate-user-pgd.patch queue-4.14/x86-mm-dump_pagetables-add-page-table-directory-to-the-debugfs-vfs-hierarchy.patch

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[Linux-stable-mirror] Patch "x86/events/intel/ds: Map debug buffers in cpu_entry_area" has been added to the 4.14-stable tree

by gregkh＠linuxfoundation.org

This is a note to let you know that I've just added the patch titled x86/events/intel/ds: Map debug buffers in cpu_entry_area to the 4.14-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: x86-events-intel-ds-map-debug-buffers-in-cpu_entry_area.patch and it can be found in the queue-4.14 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 c1961a4631daef4aeabee8e368b1b13e8f173c91 Mon Sep 17 00:00:00 2001 From: Hugh Dickins <hughd(a)google.com> Date: Mon, 4 Dec 2017 15:07:50 +0100 Subject: x86/events/intel/ds: Map debug buffers in cpu_entry_area From: Hugh Dickins <hughd(a)google.com> commit c1961a4631daef4aeabee8e368b1b13e8f173c91 upstream. The BTS and PEBS buffers both have their virtual addresses programmed into the hardware. This means that any access to them is performed via the page tables. The times that the hardware accesses these are entirely dependent on how the performance monitoring hardware events are set up. In other words, there is no way for the kernel to tell when the hardware might access these buffers. To avoid perf crashes, place 'debug_store' allocate pages and map them into the cpu_entry_area. The PEBS fixup buffer does not need this treatment. [ tglx: Got rid of the kaiser_add_mapping() complication ] Signed-off-by: Hugh Dickins <hughd(a)google.com> Signed-off-by: Dave Hansen <dave.hansen(a)linux.intel.com> Signed-off-by: Thomas Gleixner <tglx(a)linutronix.de> Cc: Andy Lutomirski <luto(a)kernel.org> Cc: Boris Ostrovsky <boris.ostrovsky(a)oracle.com> Cc: Borislav Petkov <bp(a)alien8.de> Cc: Brian Gerst <brgerst(a)gmail.com> Cc: David Laight <David.Laight(a)aculab.com> Cc: Denys Vlasenko <dvlasenk(a)redhat.com> Cc: Eduardo Valentin <eduval(a)amazon.com> Cc: Greg KH <gregkh(a)linuxfoundation.org> Cc: H. Peter Anvin <hpa(a)zytor.com> Cc: Josh Poimboeuf <jpoimboe(a)redhat.com> Cc: Juergen Gross <jgross(a)suse.com> Cc: Linus Torvalds <torvalds(a)linux-foundation.org> Cc: Peter Zijlstra <peterz(a)infradead.org> Cc: Will Deacon <will.deacon(a)arm.com> Cc: aliguori(a)amazon.com Cc: daniel.gruss(a)iaik.tugraz.at Cc: keescook(a)google.com Signed-off-by: Ingo Molnar <mingo(a)kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh(a)linuxfoundation.org> --- arch/x86/events/intel/ds.c | 125 +++++++++++++++++++++++++++---------------- arch/x86/events/perf_event.h | 2 2 files changed, 82 insertions(+), 45 deletions(-) --- a/arch/x86/events/intel/ds.c +++ b/arch/x86/events/intel/ds.c @@ -3,6 +3,7 @@ #include <linux/types.h> #include <linux/slab.h> +#include <asm/cpu_entry_area.h> #include <asm/perf_event.h> #include <asm/insn.h> @@ -280,17 +281,52 @@ void fini_debug_store_on_cpu(int cpu) static DEFINE_PER_CPU(void *, insn_buffer); -static int alloc_pebs_buffer(int cpu) +static void ds_update_cea(void *cea, void *addr, size_t size, pgprot_t prot) { - struct debug_store *ds = per_cpu(cpu_hw_events, cpu).ds; + phys_addr_t pa; + size_t msz = 0; + + pa = virt_to_phys(addr); + for (; msz < size; msz += PAGE_SIZE, pa += PAGE_SIZE, cea += PAGE_SIZE) + cea_set_pte(cea, pa, prot); +} + +static void ds_clear_cea(void *cea, size_t size) +{ + size_t msz = 0; + + for (; msz < size; msz += PAGE_SIZE, cea += PAGE_SIZE) + cea_set_pte(cea, 0, PAGE_NONE); +} + +static void *dsalloc_pages(size_t size, gfp_t flags, int cpu) +{ + unsigned int order = get_order(size); int node = cpu_to_node(cpu); - int max; - void *buffer, *ibuffer; + struct page *page; + + page = __alloc_pages_node(node, flags | __GFP_ZERO, order); + return page ? page_address(page) : NULL; +} + +static void dsfree_pages(const void *buffer, size_t size) +{ + if (buffer) + free_pages((unsigned long)buffer, get_order(size)); +} + +static int alloc_pebs_buffer(int cpu) +{ + struct cpu_hw_events *hwev = per_cpu_ptr(&cpu_hw_events, cpu); + struct debug_store *ds = hwev->ds; + size_t bsiz = x86_pmu.pebs_buffer_size; + int max, node = cpu_to_node(cpu); + void *buffer, *ibuffer, *cea; if (!x86_pmu.pebs) return 0; - buffer = kzalloc_node(x86_pmu.pebs_buffer_size, GFP_KERNEL, node); + buffer = dsalloc_pages(bsiz, GFP_KERNEL, cpu); if (unlikely(!buffer)) return -ENOMEM; @@ -301,25 +337,27 @@ 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_pages(buffer, bsiz); return -ENOMEM; } per_cpu(insn_buffer, cpu) = ibuffer; } - - max = x86_pmu.pebs_buffer_size / x86_pmu.pebs_record_size; - - ds->pebs_buffer_base = (u64)(unsigned long)buffer; + hwev->ds_pebs_vaddr = buffer; + /* Update the cpu entry area mapping */ + cea = &get_cpu_entry_area(cpu)->cpu_debug_buffers.pebs_buffer; + ds->pebs_buffer_base = (unsigned long) cea; + ds_update_cea(cea, buffer, bsiz, PAGE_KERNEL); ds->pebs_index = ds->pebs_buffer_base; - ds->pebs_absolute_maximum = ds->pebs_buffer_base + - max * x86_pmu.pebs_record_size; - + max = x86_pmu.pebs_record_size * (bsiz / x86_pmu.pebs_record_size); + ds->pebs_absolute_maximum = ds->pebs_buffer_base + max; return 0; } static void release_pebs_buffer(int cpu) { - struct debug_store *ds = per_cpu(cpu_hw_events, cpu).ds; + struct cpu_hw_events *hwev = per_cpu_ptr(&cpu_hw_events, cpu); + struct debug_store *ds = hwev->ds; + void *cea; if (!ds || !x86_pmu.pebs) return; @@ -327,73 +365,70 @@ 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); + /* Clear the fixmap */ + cea = &get_cpu_entry_area(cpu)->cpu_debug_buffers.pebs_buffer; + ds_clear_cea(cea, x86_pmu.pebs_buffer_size); ds->pebs_buffer_base = 0; + dsfree_pages(hwev->ds_pebs_vaddr, x86_pmu.pebs_buffer_size); + hwev->ds_pebs_vaddr = NULL; } static int alloc_bts_buffer(int cpu) { - struct debug_store *ds = per_cpu(cpu_hw_events, cpu).ds; - int node = cpu_to_node(cpu); - int max, thresh; - void *buffer; + struct cpu_hw_events *hwev = per_cpu_ptr(&cpu_hw_events, cpu); + struct debug_store *ds = hwev->ds; + void *buffer, *cea; + int max; if (!x86_pmu.bts) return 0; - buffer = kzalloc_node(BTS_BUFFER_SIZE, GFP_KERNEL | __GFP_NOWARN, node); + buffer = dsalloc_pages(BTS_BUFFER_SIZE, GFP_KERNEL | __GFP_NOWARN, cpu); if (unlikely(!buffer)) { WARN_ONCE(1, "%s: BTS buffer allocation failure\n", __func__); return -ENOMEM; } - - max = BTS_BUFFER_SIZE / BTS_RECORD_SIZE; - thresh = max / 16; - - ds->bts_buffer_base = (u64)(unsigned long)buffer; + hwev->ds_bts_vaddr = buffer; + /* Update the fixmap */ + cea = &get_cpu_entry_area(cpu)->cpu_debug_buffers.bts_buffer; + ds->bts_buffer_base = (unsigned long) cea; + ds_update_cea(cea, buffer, BTS_BUFFER_SIZE, PAGE_KERNEL); ds->bts_index = ds->bts_buffer_base; - ds->bts_absolute_maximum = ds->bts_buffer_base + - max * BTS_RECORD_SIZE; - ds->bts_interrupt_threshold = ds->bts_absolute_maximum - - thresh * BTS_RECORD_SIZE; - + max = BTS_RECORD_SIZE * (BTS_BUFFER_SIZE / BTS_RECORD_SIZE); + ds->bts_absolute_maximum = ds->bts_buffer_base + max; + ds->bts_interrupt_threshold = ds->bts_absolute_maximum - (max / 16); return 0; } static void release_bts_buffer(int cpu) { - struct debug_store *ds = per_cpu(cpu_hw_events, cpu).ds; + struct cpu_hw_events *hwev = per_cpu_ptr(&cpu_hw_events, cpu); + struct debug_store *ds = hwev->ds; + void *cea; if (!ds || !x86_pmu.bts) return; - kfree((void *)(unsigned long)ds->bts_buffer_base); + /* Clear the fixmap */ + cea = &get_cpu_entry_area(cpu)->cpu_debug_buffers.bts_buffer; + ds_clear_cea(cea, BTS_BUFFER_SIZE); ds->bts_buffer_base = 0; + dsfree_pages(hwev->ds_bts_vaddr, BTS_BUFFER_SIZE); + hwev->ds_bts_vaddr = NULL; } 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 = &get_cpu_entry_area(cpu)->cpu_debug_store; + memset(ds, 0, sizeof(*ds)); per_cpu(cpu_hw_events, cpu).ds = ds; - return 0; } static void release_ds_buffer(int cpu) { - struct debug_store *ds = per_cpu(cpu_hw_events, cpu).ds; - - if (!ds) - return; - per_cpu(cpu_hw_events, cpu).ds = NULL; - kfree(ds); } void release_ds_buffers(void) --- a/arch/x86/events/perf_event.h +++ b/arch/x86/events/perf_event.h @@ -199,6 +199,8 @@ struct cpu_hw_events { * Intel DebugStore bits */ struct debug_store *ds; + void *ds_pebs_vaddr; + void *ds_bts_vaddr; u64 pebs_enabled; int n_pebs; int n_large_pebs; Patches currently in stable-queue which might be from hughd(a)google.com are queue-4.14/x86-mm-pti-allow-nx-poison-to-be-set-in-p4d-pgd.patch queue-4.14/x86-dumpstack-indicate-in-oops-whether-pti-is-configured-and-enabled.patch queue-4.14/x86-mm-clarify-the-whole-asid-kernel-pcid-user-pcid-naming.patch queue-4.14/x86-mm-abstract-switching-cr3.patch queue-4.14/x86-mm-optimize-restore_cr3.patch queue-4.14/x86-mm-pti-force-entry-through-trampoline-when-pti-active.patch queue-4.14/x86-entry-align-entry-text-section-to-pmd-boundary.patch queue-4.14/x86-cpu_entry_area-add-debugstore-entries-to-cpu_entry_area.patch queue-4.14/x86-mm-pti-share-entry-text-pmd.patch queue-4.14/x86-mm-dump_pagetables-check-user-space-page-table-for-wx-pages.patch queue-4.14/x86-mm-pti-disable-global-pages-if-page_table_isolation-y.patch queue-4.14/x86-mm-dump_pagetables-allow-dumping-current-pagetables.patch queue-4.14/x86-mm-pti-add-infrastructure-for-page-table-isolation.patch queue-4.14/x86-cpufeatures-add-x86_bug_cpu_insecure.patch queue-4.14/x86-mm-use-fix-pcid-to-optimize-user-kernel-switches.patch queue-4.14/x86-mm-use-invpcid-for-__native_flush_tlb_single.patch queue-4.14/x86-mm-pti-prepare-the-x86-entry-assembly-code-for-entry-exit-cr3-switching.patch queue-4.14/x86-mm-allow-flushing-for-future-asid-switches.patch queue-4.14/x86-mm-pti-add-kconfig.patch queue-4.14/x86-mm-pti-add-mapping-helper-functions.patch queue-4.14/x86-mm-pti-share-cpu_entry_area-with-user-space-page-tables.patch queue-4.14/x86-mm-pti-add-functions-to-clone-kernel-pmds.patch queue-4.14/x86-pti-add-the-pti-cmdline-option-and-documentation.patch queue-4.14/x86-events-intel-ds-map-debug-buffers-in-cpu_entry_area.patch queue-4.14/x86-mm-pti-allocate-a-separate-user-pgd.patch queue-4.14/x86-mm-pti-populate-user-pgd.patch queue-4.14/x86-mm-dump_pagetables-add-page-table-directory-to-the-debugfs-vfs-hierarchy.patch

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Linux-stable-mirror December 2017