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[Linux-stable-mirror] [PATCH] PM / OPP: list_del_rcu should be used in function _remove_list_dev

by Chunyan Zhang

From: Vincent Wang <vincent.wang(a)spreadtrum.com> list_del_rcu() should be used to replace list_del() in the function _remove_list_dev(), since the opp is a rcu protected pointer. For example, on an ARM big.Little platform of spreadtrum, there are little cluster, big cluster and gpu using pm_opp. And the opp_table of big cluster will be removed when big cluster is removed, which is implemented in the cpufreq driver. Sometimes an issue maybe occur: [ 237.647758] c0 Unable to handle kernel paging request at virtual address dead000000000110 [ 237.647776] c0 pgd = ffffffc073e78000 [ 237.647786] c0 [dead000000000110] *pgd=0000000000000000, *pud=0000000000000000 [ 237.647808] c0 Internal error: Oops: 96000004 [#1] PREEMPT SMP [ 237.653535] c0 Modules linked in: sprdwl_ng(O) mtty marlin2_fm mali_kbase(O) [ 237.653569] c0 CPU: 0 PID: 38 Comm: kworker/u12:1 Tainted: G S W O 4.4.83+ #1 [ 237.653578] c0 Hardware name: Spreadtrum SP9850KHsmt 1h10 Board (DT) [ 237.653594] c0 Workqueue: devfreq_wq devfreq_monitor [ 237.653605] c0 task: ffffffc0babd0d80 task.stack: ffffffc0badbc000 [ 237.653619] c0 PC is at _find_device_opp+0x58/0xac [ 237.653629] c0 LR is at dev_pm_opp_find_freq_ceil+0x2c/0xb8 [ 237.921294] c0 Call trace: [ 237.921425] c0 [<ffffff80085362b0>] _find_device_opp+0x58/0xac [ 237.921437] c0 [<ffffff8008536560>] dev_pm_opp_find_freq_ceil+0x2c/0xb8 [ 237.921452] c0 [<ffffff80088760f4>] devfreq_recommended_opp+0x54/0x7c [ 237.921494] c0 [<ffffff8000b6a96c>] kbase_wait_write_flush+0x164/0x358 [mali_kbase] [ 237.921504] c0 [<ffffff800887485c>] update_devfreq+0x8c/0xf8 [ 237.921514] c0 [<ffffff80088749e4>] devfreq_monitor+0x34/0x94 [ 237.921529] c0 [<ffffff80080bd75c>] process_one_work+0x154/0x458 [ 237.921539] c0 [<ffffff80080be428>] worker_thread+0x134/0x4a4 [ 237.921551] c0 [<ffffff80080c4bec>] kthread+0xdc/0xf0 [ 237.921564] c0 [<ffffff8008085f20>] ret_from_fork+0x10/0x30 Cc: stable <stable(a)vger.kernel.org> # 4.4 Signed-off-by: Vincent Wang <vincent.wang(a)spreadtrum.com> Signed-off-by: Chunyan Zhang <chunyan.zhang(a)spreadtrum.com> Acked-by: Viresh Kumar <viresh.kumar(a)linaro.org> --- This patch is for 4.4 stable branch only. Once this patch accepted, I can cook a similar patch for 4.9 stable branch. This fix can't be done to upstream kernel as the OPP code doesn't use RCUs anymore. --- drivers/base/power/opp/core.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/drivers/base/power/opp/core.c b/drivers/base/power/opp/core.c index db6e7e5..e0eac53 100644 --- a/drivers/base/power/opp/core.c +++ b/drivers/base/power/opp/core.c @@ -463,7 +463,7 @@ static void _kfree_list_dev_rcu(struct rcu_head *head) static void _remove_list_dev(struct device_list_opp *list_dev, struct device_opp *dev_opp) { - list_del(&list_dev->node); + list_del_rcu(&list_dev->node); call_srcu(&dev_opp->srcu_head.srcu, &list_dev->rcu_head, _kfree_list_dev_rcu); } -- 1.9.1

7 years, 3 months

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[Linux-stable-mirror] Patch "objtool: Detect jumps to retpoline thunks" 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 objtool: Detect jumps to retpoline thunks 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: objtool-detect-jumps-to-retpoline-thunks.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 39b735332cb8b33a27c28592d969e4016c86c3ea Mon Sep 17 00:00:00 2001 From: Josh Poimboeuf <jpoimboe(a)redhat.com> Date: Thu, 11 Jan 2018 21:46:23 +0000 Subject: objtool: Detect jumps to retpoline thunks From: Josh Poimboeuf <jpoimboe(a)redhat.com> commit 39b735332cb8b33a27c28592d969e4016c86c3ea upstream. A direct jump to a retpoline thunk is really an indirect jump in disguise. Change the objtool instruction type accordingly. Objtool needs to know where indirect branches are so it can detect switch statement jump tables. This fixes a bunch of warnings with CONFIG_RETPOLINE like: arch/x86/events/intel/uncore_nhmex.o: warning: objtool: nhmex_rbox_msr_enable_event()+0x44: sibling call from callable instruction with modified stack frame kernel/signal.o: warning: objtool: copy_siginfo_to_user()+0x91: sibling call from callable instruction with modified stack frame ... Signed-off-by: Josh Poimboeuf <jpoimboe(a)redhat.com> Signed-off-by: David Woodhouse <dwmw(a)amazon.co.uk> Signed-off-by: Thomas Gleixner <tglx(a)linutronix.de> Cc: gnomes(a)lxorguk.ukuu.org.uk Cc: Rik van Riel <riel(a)redhat.com> Cc: Andi Kleen <ak(a)linux.intel.com> Cc: thomas.lendacky(a)amd.com Cc: Peter Zijlstra <peterz(a)infradead.org> Cc: Linus Torvalds <torvalds(a)linux-foundation.org> Cc: Jiri Kosina <jikos(a)kernel.org> Cc: Andy Lutomirski <luto(a)amacapital.net> Cc: Dave Hansen <dave.hansen(a)intel.com> Cc: Kees Cook <keescook(a)google.com> Cc: Tim Chen <tim.c.chen(a)linux.intel.com> Cc: Greg Kroah-Hartman <gregkh(a)linux-foundation.org> Cc: Paul Turner <pjt(a)google.com> Link: https://lkml.kernel.org/r/1515707194-20531-2-git-send-email-dwmw@amazon.co.… Signed-off-by: Greg Kroah-Hartman <gregkh(a)linuxfoundation.org> --- tools/objtool/check.c | 7 +++++++ 1 file changed, 7 insertions(+) --- a/tools/objtool/check.c +++ b/tools/objtool/check.c @@ -456,6 +456,13 @@ static int add_jump_destinations(struct } else if (rela->sym->sec->idx) { dest_sec = rela->sym->sec; dest_off = rela->sym->sym.st_value + rela->addend + 4; + } else if (strstr(rela->sym->name, "_indirect_thunk_")) { + /* + * Retpoline jumps are really dynamic jumps in + * disguise, so convert them accordingly. + */ + insn->type = INSN_JUMP_DYNAMIC; + continue; } else { /* sibling call */ insn->jump_dest = 0; Patches currently in stable-queue which might be from jpoimboe(a)redhat.com are queue-4.14/x86-spectre-add-boot-time-option-to-select-spectre-v2-mitigation.patch queue-4.14/objtool-detect-jumps-to-retpoline-thunks.patch queue-4.14/objtool-allow-alternatives-to-be-ignored.patch queue-4.14/x86-retpoline-add-initial-retpoline-support.patch

7 years, 3 months

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[Linux-stable-mirror] Patch "objtool: Allow alternatives to be ignored" 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 objtool: Allow alternatives to be ignored 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: objtool-allow-alternatives-to-be-ignored.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 258c76059cece01bebae098e81bacb1af2edad17 Mon Sep 17 00:00:00 2001 From: Josh Poimboeuf <jpoimboe(a)redhat.com> Date: Thu, 11 Jan 2018 21:46:24 +0000 Subject: objtool: Allow alternatives to be ignored From: Josh Poimboeuf <jpoimboe(a)redhat.com> commit 258c76059cece01bebae098e81bacb1af2edad17 upstream. Getting objtool to understand retpolines is going to be a bit of a challenge. For now, take advantage of the fact that retpolines are patched in with alternatives. Just read the original (sane) non-alternative instruction, and ignore the patched-in retpoline. This allows objtool to understand the control flow *around* the retpoline, even if it can't yet follow what's inside. This means the ORC unwinder will fail to unwind from inside a retpoline, but will work fine otherwise. Signed-off-by: Josh Poimboeuf <jpoimboe(a)redhat.com> Signed-off-by: David Woodhouse <dwmw(a)amazon.co.uk> Signed-off-by: Thomas Gleixner <tglx(a)linutronix.de> Cc: gnomes(a)lxorguk.ukuu.org.uk Cc: Rik van Riel <riel(a)redhat.com> Cc: Andi Kleen <ak(a)linux.intel.com> Cc: thomas.lendacky(a)amd.com Cc: Peter Zijlstra <peterz(a)infradead.org> Cc: Linus Torvalds <torvalds(a)linux-foundation.org> Cc: Jiri Kosina <jikos(a)kernel.org> Cc: Andy Lutomirski <luto(a)amacapital.net> Cc: Dave Hansen <dave.hansen(a)intel.com> Cc: Kees Cook <keescook(a)google.com> Cc: Tim Chen <tim.c.chen(a)linux.intel.com> Cc: Greg Kroah-Hartman <gregkh(a)linux-foundation.org> Cc: Paul Turner <pjt(a)google.com> Link: https://lkml.kernel.org/r/1515707194-20531-3-git-send-email-dwmw@amazon.co.… Signed-off-by: Greg Kroah-Hartman <gregkh(a)linuxfoundation.org> --- tools/objtool/check.c | 62 +++++++++++++++++++++++++++++++++++++++++++++----- tools/objtool/check.h | 2 - 2 files changed, 57 insertions(+), 7 deletions(-) --- a/tools/objtool/check.c +++ b/tools/objtool/check.c @@ -428,6 +428,40 @@ static void add_ignores(struct objtool_f } /* + * FIXME: For now, just ignore any alternatives which add retpolines. This is + * a temporary hack, as it doesn't allow ORC to unwind from inside a retpoline. + * But it at least allows objtool to understand the control flow *around* the + * retpoline. + */ +static int add_nospec_ignores(struct objtool_file *file) +{ + struct section *sec; + struct rela *rela; + struct instruction *insn; + + sec = find_section_by_name(file->elf, ".rela.discard.nospec"); + if (!sec) + return 0; + + list_for_each_entry(rela, &sec->rela_list, list) { + if (rela->sym->type != STT_SECTION) { + WARN("unexpected relocation symbol type in %s", sec->name); + return -1; + } + + insn = find_insn(file, rela->sym->sec, rela->addend); + if (!insn) { + WARN("bad .discard.nospec entry"); + return -1; + } + + insn->ignore_alts = true; + } + + return 0; +} + +/* * Find the destination instructions for all jumps. */ static int add_jump_destinations(struct objtool_file *file) @@ -509,11 +543,18 @@ static int add_call_destinations(struct dest_off = insn->offset + insn->len + insn->immediate; insn->call_dest = find_symbol_by_offset(insn->sec, dest_off); + /* + * FIXME: Thanks to retpolines, it's now considered + * normal for a function to call within itself. So + * disable this warning for now. + */ +#if 0 if (!insn->call_dest) { WARN_FUNC("can't find call dest symbol at offset 0x%lx", insn->sec, insn->offset, dest_off); return -1; } +#endif } else if (rela->sym->type == STT_SECTION) { insn->call_dest = find_symbol_by_offset(rela->sym->sec, rela->addend+4); @@ -678,12 +719,6 @@ static int add_special_section_alts(stru return ret; list_for_each_entry_safe(special_alt, tmp, &special_alts, list) { - alt = malloc(sizeof(*alt)); - if (!alt) { - WARN("malloc failed"); - ret = -1; - goto out; - } orig_insn = find_insn(file, special_alt->orig_sec, special_alt->orig_off); @@ -694,6 +729,10 @@ static int add_special_section_alts(stru goto out; } + /* Ignore retpoline alternatives. */ + if (orig_insn->ignore_alts) + continue; + new_insn = NULL; if (!special_alt->group || special_alt->new_len) { new_insn = find_insn(file, special_alt->new_sec, @@ -719,6 +758,13 @@ static int add_special_section_alts(stru goto out; } + alt = malloc(sizeof(*alt)); + if (!alt) { + WARN("malloc failed"); + ret = -1; + goto out; + } + alt->insn = new_insn; list_add_tail(&alt->list, &orig_insn->alts); @@ -1035,6 +1081,10 @@ static int decode_sections(struct objtoo add_ignores(file); + ret = add_nospec_ignores(file); + if (ret) + return ret; + ret = add_jump_destinations(file); if (ret) return ret; --- a/tools/objtool/check.h +++ b/tools/objtool/check.h @@ -44,7 +44,7 @@ struct instruction { unsigned int len; unsigned char type; unsigned long immediate; - bool alt_group, visited, dead_end, ignore, hint, save, restore; + bool alt_group, visited, dead_end, ignore, hint, save, restore, ignore_alts; struct symbol *call_dest; struct instruction *jump_dest; struct list_head alts; Patches currently in stable-queue which might be from jpoimboe(a)redhat.com are queue-4.14/x86-spectre-add-boot-time-option-to-select-spectre-v2-mitigation.patch queue-4.14/objtool-detect-jumps-to-retpoline-thunks.patch queue-4.14/objtool-allow-alternatives-to-be-ignored.patch queue-4.14/x86-retpoline-add-initial-retpoline-support.patch

7 years, 3 months

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[Linux-stable-mirror] Patch "x86/tboot: Unbreak tboot with PTI enabled" 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/tboot: Unbreak tboot with PTI enabled 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-tboot-unbreak-tboot-with-pti-enabled.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 262b6b30087246abf09d6275eb0c0dc421bcbe38 Mon Sep 17 00:00:00 2001 From: Dave Hansen <dave.hansen(a)linux.intel.com> Date: Sat, 6 Jan 2018 18:41:14 +0100 Subject: x86/tboot: Unbreak tboot with PTI enabled From: Dave Hansen <dave.hansen(a)linux.intel.com> commit 262b6b30087246abf09d6275eb0c0dc421bcbe38 upstream. This is another case similar to what EFI does: create a new set of page tables, map some code at a low address, and jump to it. PTI mistakes this low address for userspace and mistakenly marks it non-executable in an effort to make it unusable for userspace. Undo the poison to allow execution. Fixes: 385ce0ea4c07 ("x86/mm/pti: Add Kconfig") Signed-off-by: Dave Hansen <dave.hansen(a)linux.intel.com> Signed-off-by: Andrea Arcangeli <aarcange(a)redhat.com> Signed-off-by: Thomas Gleixner <tglx(a)linutronix.de> Cc: Alan Cox <gnomes(a)lxorguk.ukuu.org.uk> Cc: Tim Chen <tim.c.chen(a)linux.intel.com> Cc: Jon Masters <jcm(a)redhat.com> Cc: Dave Hansen <dave.hansen(a)intel.com> Cc: Andi Kleen <andi(a)firstfloor.org> Cc: Jeff Law <law(a)redhat.com> Cc: Paolo Bonzini <pbonzini(a)redhat.com> Cc: Linus Torvalds <torvalds(a)linux-foundation.org> Cc: Greg Kroah-Hartman <gregkh(a)linux-foundation.org> Cc: David" <dwmw(a)amazon.co.uk> Cc: Nick Clifton <nickc(a)redhat.com> Link: https://lkml.kernel.org/r/20180108102805.GK25546@redhat.com Signed-off-by: Greg Kroah-Hartman <gregkh(a)linuxfoundation.org> --- arch/x86/kernel/tboot.c | 1 + 1 file changed, 1 insertion(+) --- a/arch/x86/kernel/tboot.c +++ b/arch/x86/kernel/tboot.c @@ -127,6 +127,7 @@ static int map_tboot_page(unsigned long p4d = p4d_alloc(&tboot_mm, pgd, vaddr); if (!p4d) return -1; + pgd->pgd &= ~_PAGE_NX; pud = pud_alloc(&tboot_mm, p4d, vaddr); if (!pud) return -1; Patches currently in stable-queue which might be from dave.hansen(a)linux.intel.com are queue-4.14/x86-pti-unbreak-efi-old_memmap.patch queue-4.14/x86-documentation-add-pti-description.patch queue-4.14/x86-tboot-unbreak-tboot-with-pti-enabled.patch

7 years, 3 months

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[Linux-stable-mirror] Patch "x86/mm/pti: Remove dead logic in pti_user_pagetable_walk*()" 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/pti: Remove dead logic in pti_user_pagetable_walk*() 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-pti-remove-dead-logic-in-pti_user_pagetable_walk.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 8d56eff266f3e41a6c39926269c4c3f58f881a8e Mon Sep 17 00:00:00 2001 From: Jike Song <albcamus(a)gmail.com> Date: Tue, 9 Jan 2018 00:03:41 +0800 Subject: x86/mm/pti: Remove dead logic in pti_user_pagetable_walk*() From: Jike Song <albcamus(a)gmail.com> commit 8d56eff266f3e41a6c39926269c4c3f58f881a8e upstream. The following code contains dead logic: 162 if (pgd_none(*pgd)) { 163 unsigned long new_p4d_page = __get_free_page(gfp); 164 if (!new_p4d_page) 165 return NULL; 166 167 if (pgd_none(*pgd)) { 168 set_pgd(pgd, __pgd(_KERNPG_TABLE | __pa(new_p4d_page))); 169 new_p4d_page = 0; 170 } 171 if (new_p4d_page) 172 free_page(new_p4d_page); 173 } There can't be any difference between two pgd_none(*pgd) at L162 and L167, so it's always false at L171. Dave Hansen explained: Yes, the double-test was part of an optimization where we attempted to avoid using a global spinlock in the fork() path. We would check for unallocated mid-level page tables without the lock. The lock was only taken when we needed to *make* an entry to avoid collisions. Now that it is all single-threaded, there is no chance of a collision, no need for a lock, and no need for the re-check. As all these functions are only called during init, mark them __init as well. Fixes: 03f4424f348e ("x86/mm/pti: Add functions to clone kernel PMDs") Signed-off-by: Jike Song <albcamus(a)gmail.com> Signed-off-by: Thomas Gleixner <tglx(a)linutronix.de> Cc: Alan Cox <gnomes(a)lxorguk.ukuu.org.uk> Cc: Andi Kleen <ak(a)linux.intel.com> Cc: Tom Lendacky <thomas.lendacky(a)amd.com> Cc: Peter Zijlstra <peterz(a)infradead.org> Cc: Tim Chen <tim.c.chen(a)linux.intel.com> Cc: Jiri Koshina <jikos(a)kernel.org> Cc: Dave Hansen <dave.hansen(a)intel.com> Cc: Borislav Petkov <bp(a)alien8.de> Cc: Kees Cook <keescook(a)google.com> Cc: Andi Lutomirski <luto(a)amacapital.net> Cc: Linus Torvalds <torvalds(a)linux-foundation.org> Cc: Greg KH <gregkh(a)linux-foundation.org> Cc: David Woodhouse <dwmw(a)amazon.co.uk> Cc: Paul Turner <pjt(a)google.com> Link: https://lkml.kernel.org/r/20180108160341.3461-1-albcamus@gmail.com Signed-off-by: Greg Kroah-Hartman <gregkh(a)linuxfoundation.org> --- arch/x86/mm/pti.c | 32 ++++++-------------------------- 1 file changed, 6 insertions(+), 26 deletions(-) --- a/arch/x86/mm/pti.c +++ b/arch/x86/mm/pti.c @@ -149,7 +149,7 @@ pgd_t __pti_set_user_pgd(pgd_t *pgdp, pg * * Returns a pointer to a P4D on success, or NULL on failure. */ -static p4d_t *pti_user_pagetable_walk_p4d(unsigned long address) +static __init p4d_t *pti_user_pagetable_walk_p4d(unsigned long address) { pgd_t *pgd = kernel_to_user_pgdp(pgd_offset_k(address)); gfp_t gfp = (GFP_KERNEL | __GFP_NOTRACK | __GFP_ZERO); @@ -164,12 +164,7 @@ static p4d_t *pti_user_pagetable_walk_p4 if (!new_p4d_page) return NULL; - if (pgd_none(*pgd)) { - set_pgd(pgd, __pgd(_KERNPG_TABLE | __pa(new_p4d_page))); - new_p4d_page = 0; - } - if (new_p4d_page) - free_page(new_p4d_page); + set_pgd(pgd, __pgd(_KERNPG_TABLE | __pa(new_p4d_page))); } BUILD_BUG_ON(pgd_large(*pgd) != 0); @@ -182,7 +177,7 @@ static p4d_t *pti_user_pagetable_walk_p4 * * Returns a pointer to a PMD on success, or NULL on failure. */ -static pmd_t *pti_user_pagetable_walk_pmd(unsigned long address) +static __init pmd_t *pti_user_pagetable_walk_pmd(unsigned long address) { gfp_t gfp = (GFP_KERNEL | __GFP_NOTRACK | __GFP_ZERO); p4d_t *p4d = pti_user_pagetable_walk_p4d(address); @@ -194,12 +189,7 @@ static pmd_t *pti_user_pagetable_walk_pm if (!new_pud_page) return NULL; - if (p4d_none(*p4d)) { - set_p4d(p4d, __p4d(_KERNPG_TABLE | __pa(new_pud_page))); - new_pud_page = 0; - } - if (new_pud_page) - free_page(new_pud_page); + set_p4d(p4d, __p4d(_KERNPG_TABLE | __pa(new_pud_page))); } pud = pud_offset(p4d, address); @@ -213,12 +203,7 @@ static pmd_t *pti_user_pagetable_walk_pm if (!new_pmd_page) return NULL; - if (pud_none(*pud)) { - set_pud(pud, __pud(_KERNPG_TABLE | __pa(new_pmd_page))); - new_pmd_page = 0; - } - if (new_pmd_page) - free_page(new_pmd_page); + set_pud(pud, __pud(_KERNPG_TABLE | __pa(new_pmd_page))); } return pmd_offset(pud, address); @@ -251,12 +236,7 @@ static __init pte_t *pti_user_pagetable_ if (!new_pte_page) return NULL; - if (pmd_none(*pmd)) { - set_pmd(pmd, __pmd(_KERNPG_TABLE | __pa(new_pte_page))); - new_pte_page = 0; - } - if (new_pte_page) - free_page(new_pte_page); + set_pmd(pmd, __pmd(_KERNPG_TABLE | __pa(new_pte_page))); } pte = pte_offset_kernel(pmd, address); Patches currently in stable-queue which might be from albcamus(a)gmail.com are queue-4.14/x86-mm-pti-remove-dead-logic-in-pti_user_pagetable_walk.patch

7 years, 3 months

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[Linux-stable-mirror] Patch "x86/cpu: Implement CPU vulnerabilites sysfs functions" 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/cpu: Implement CPU vulnerabilites sysfs functions 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-cpu-implement-cpu-vulnerabilites-sysfs-functions.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 61dc0f555b5c761cdafb0ba5bd41ecf22d68a4c4 Mon Sep 17 00:00:00 2001 From: Thomas Gleixner <tglx(a)linutronix.de> Date: Sun, 7 Jan 2018 22:48:01 +0100 Subject: x86/cpu: Implement CPU vulnerabilites sysfs functions From: Thomas Gleixner <tglx(a)linutronix.de> commit 61dc0f555b5c761cdafb0ba5bd41ecf22d68a4c4 upstream. Implement the CPU vulnerabilty show functions for meltdown, spectre_v1 and spectre_v2. Signed-off-by: Thomas Gleixner <tglx(a)linutronix.de> Reviewed-by: Greg Kroah-Hartman <gregkh(a)linuxfoundation.org> Reviewed-by: Konrad Rzeszutek Wilk <konrad.wilk(a)oracle.com> Cc: Peter Zijlstra <peterz(a)infradead.org> Cc: Will Deacon <will.deacon(a)arm.com> Cc: Dave Hansen <dave.hansen(a)intel.com> Cc: Linus Torvalds <torvalds(a)linuxfoundation.org> Cc: Borislav Petkov <bp(a)alien8.de> Cc: David Woodhouse <dwmw(a)amazon.co.uk> Link: https://lkml.kernel.org/r/20180107214913.177414879@linutronix.de Signed-off-by: Greg Kroah-Hartman <gregkh(a)linuxfoundation.org> --- arch/x86/Kconfig | 1 + arch/x86/kernel/cpu/bugs.c | 29 +++++++++++++++++++++++++++++ 2 files changed, 30 insertions(+) --- a/arch/x86/Kconfig +++ b/arch/x86/Kconfig @@ -89,6 +89,7 @@ config X86 select GENERIC_CLOCKEVENTS_MIN_ADJUST select GENERIC_CMOS_UPDATE select GENERIC_CPU_AUTOPROBE + select GENERIC_CPU_VULNERABILITIES select GENERIC_EARLY_IOREMAP select GENERIC_FIND_FIRST_BIT select GENERIC_IOMAP --- a/arch/x86/kernel/cpu/bugs.c +++ b/arch/x86/kernel/cpu/bugs.c @@ -10,6 +10,7 @@ */ #include <linux/init.h> #include <linux/utsname.h> +#include <linux/cpu.h> #include <asm/bugs.h> #include <asm/processor.h> #include <asm/processor-flags.h> @@ -60,3 +61,31 @@ void __init check_bugs(void) set_memory_4k((unsigned long)__va(0), 1); #endif } + +#ifdef CONFIG_SYSFS +ssize_t cpu_show_meltdown(struct device *dev, + struct device_attribute *attr, char *buf) +{ + if (!boot_cpu_has_bug(X86_BUG_CPU_MELTDOWN)) + return sprintf(buf, "Not affected\n"); + if (boot_cpu_has(X86_FEATURE_PTI)) + return sprintf(buf, "Mitigation: PTI\n"); + return sprintf(buf, "Vulnerable\n"); +} + +ssize_t cpu_show_spectre_v1(struct device *dev, + struct device_attribute *attr, char *buf) +{ + if (!boot_cpu_has_bug(X86_BUG_SPECTRE_V1)) + return sprintf(buf, "Not affected\n"); + return sprintf(buf, "Vulnerable\n"); +} + +ssize_t cpu_show_spectre_v2(struct device *dev, + struct device_attribute *attr, char *buf) +{ + if (!boot_cpu_has_bug(X86_BUG_SPECTRE_V2)) + return sprintf(buf, "Not affected\n"); + return sprintf(buf, "Vulnerable\n"); +} +#endif Patches currently in stable-queue which might be from tglx(a)linutronix.de are queue-4.14/x86-pti-unbreak-efi-old_memmap.patch queue-4.14/x86-cpufeatures-add-x86_bug_spectre_v.patch queue-4.14/x86-microcode-intel-extend-bdw-late-loading-with-a-revision-check.patch queue-4.14/membarrier-disable-preemption-when-calling-smp_call_function_many.patch queue-4.14/x86-mm-pti-remove-dead-logic-in-pti_user_pagetable_walk.patch queue-4.14/sysfs-cpu-fix-typos-in-vulnerability-documentation.patch queue-4.14/x86-cpu-amd-make-lfence-a-serializing-instruction.patch queue-4.14/x86-documentation-add-pti-description.patch queue-4.14/x86-acpi-handle-sci-interrupts-above-legacy-space-gracefully.patch queue-4.14/x86-cpu-implement-cpu-vulnerabilites-sysfs-functions.patch queue-4.14/x86-tboot-unbreak-tboot-with-pti-enabled.patch queue-4.14/sysfs-cpu-add-vulnerability-folder.patch queue-4.14/x86-acpi-reduce-code-duplication-in-mp_override_legacy_irq.patch queue-4.14/x86-alternatives-fix-optimize_nops-checking.patch queue-4.14/x86-cpu-amd-use-lfence_rdtsc-in-preference-to-mfence_rdtsc.patch queue-4.14/kdump-write-correct-address-of-mem_section-into-vmcoreinfo.patch

7 years, 3 months

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[Linux-stable-mirror] Patch "x86/cpu/AMD: Use LFENCE_RDTSC in preference to MFENCE_RDTSC" 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/cpu/AMD: Use LFENCE_RDTSC in preference to MFENCE_RDTSC 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-cpu-amd-use-lfence_rdtsc-in-preference-to-mfence_rdtsc.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 9c6a73c75864ad9fa49e5fa6513e4c4071c0e29f Mon Sep 17 00:00:00 2001 From: Tom Lendacky <thomas.lendacky(a)amd.com> Date: Mon, 8 Jan 2018 16:09:32 -0600 Subject: x86/cpu/AMD: Use LFENCE_RDTSC in preference to MFENCE_RDTSC From: Tom Lendacky <thomas.lendacky(a)amd.com> commit 9c6a73c75864ad9fa49e5fa6513e4c4071c0e29f upstream. With LFENCE now a serializing instruction, use LFENCE_RDTSC in preference to MFENCE_RDTSC. However, since the kernel could be running under a hypervisor that does not support writing that MSR, read the MSR back and verify that the bit has been set successfully. If the MSR can be read and the bit is set, then set the LFENCE_RDTSC feature, otherwise set the MFENCE_RDTSC feature. Signed-off-by: Tom Lendacky <thomas.lendacky(a)amd.com> Signed-off-by: Thomas Gleixner <tglx(a)linutronix.de> Reviewed-by: Reviewed-by: Borislav Petkov <bp(a)suse.de> Cc: Peter Zijlstra <peterz(a)infradead.org> Cc: Tim Chen <tim.c.chen(a)linux.intel.com> Cc: Dave Hansen <dave.hansen(a)intel.com> Cc: Borislav Petkov <bp(a)alien8.de> Cc: Dan Williams <dan.j.williams(a)intel.com> Cc: Linus Torvalds <torvalds(a)linux-foundation.org> Cc: Greg Kroah-Hartman <gregkh(a)linux-foundation.org> Cc: David Woodhouse <dwmw(a)amazon.co.uk> Cc: Paul Turner <pjt(a)google.com> Link: https://lkml.kernel.org/r/20180108220932.12580.52458.stgit@tlendack-t1.amdo… Signed-off-by: Greg Kroah-Hartman <gregkh(a)linuxfoundation.org> --- arch/x86/include/asm/msr-index.h | 1 + arch/x86/kernel/cpu/amd.c | 18 ++++++++++++++++-- 2 files changed, 17 insertions(+), 2 deletions(-) --- a/arch/x86/include/asm/msr-index.h +++ b/arch/x86/include/asm/msr-index.h @@ -354,6 +354,7 @@ #define MSR_FAM10H_NODE_ID 0xc001100c #define MSR_F10H_DECFG 0xc0011029 #define MSR_F10H_DECFG_LFENCE_SERIALIZE_BIT 1 +#define MSR_F10H_DECFG_LFENCE_SERIALIZE BIT_ULL(MSR_F10H_DECFG_LFENCE_SERIALIZE_BIT) /* K8 MSRs */ #define MSR_K8_TOP_MEM1 0xc001001a --- a/arch/x86/kernel/cpu/amd.c +++ b/arch/x86/kernel/cpu/amd.c @@ -829,6 +829,9 @@ static void init_amd(struct cpuinfo_x86 set_cpu_cap(c, X86_FEATURE_K8); if (cpu_has(c, X86_FEATURE_XMM2)) { + unsigned long long val; + int ret; + /* * A serializing LFENCE has less overhead than MFENCE, so * use it for execution serialization. On families which @@ -839,8 +842,19 @@ static void init_amd(struct cpuinfo_x86 msr_set_bit(MSR_F10H_DECFG, MSR_F10H_DECFG_LFENCE_SERIALIZE_BIT); - /* MFENCE stops RDTSC speculation */ - set_cpu_cap(c, X86_FEATURE_MFENCE_RDTSC); + /* + * Verify that the MSR write was successful (could be running + * under a hypervisor) and only then assume that LFENCE is + * serializing. + */ + ret = rdmsrl_safe(MSR_F10H_DECFG, &val); + if (!ret && (val & MSR_F10H_DECFG_LFENCE_SERIALIZE)) { + /* A serializing LFENCE stops RDTSC speculation */ + set_cpu_cap(c, X86_FEATURE_LFENCE_RDTSC); + } else { + /* MFENCE stops RDTSC speculation */ + set_cpu_cap(c, X86_FEATURE_MFENCE_RDTSC); + } } /* Patches currently in stable-queue which might be from thomas.lendacky(a)amd.com are queue-4.14/kvm-vmx-scrub-hardware-gprs-at-vm-exit.patch queue-4.14/x86-mm-pti-remove-dead-logic-in-pti_user_pagetable_walk.patch queue-4.14/x86-cpu-amd-make-lfence-a-serializing-instruction.patch queue-4.14/x86-alternatives-fix-optimize_nops-checking.patch queue-4.14/x86-cpu-amd-use-lfence_rdtsc-in-preference-to-mfence_rdtsc.patch

7 years, 3 months

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[Linux-stable-mirror] Patch "x86/cpu/AMD: Make LFENCE a serializing instruction" 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/cpu/AMD: Make LFENCE a serializing instruction 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-cpu-amd-make-lfence-a-serializing-instruction.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 e4d0e84e490790798691aaa0f2e598637f1867ec Mon Sep 17 00:00:00 2001 From: Tom Lendacky <thomas.lendacky(a)amd.com> Date: Mon, 8 Jan 2018 16:09:21 -0600 Subject: x86/cpu/AMD: Make LFENCE a serializing instruction From: Tom Lendacky <thomas.lendacky(a)amd.com> commit e4d0e84e490790798691aaa0f2e598637f1867ec upstream. To aid in speculation control, make LFENCE a serializing instruction since it has less overhead than MFENCE. This is done by setting bit 1 of MSR 0xc0011029 (DE_CFG). Some families that support LFENCE do not have this MSR. For these families, the LFENCE instruction is already serializing. Signed-off-by: Tom Lendacky <thomas.lendacky(a)amd.com> Signed-off-by: Thomas Gleixner <tglx(a)linutronix.de> Reviewed-by: Reviewed-by: Borislav Petkov <bp(a)suse.de> Cc: Peter Zijlstra <peterz(a)infradead.org> Cc: Tim Chen <tim.c.chen(a)linux.intel.com> Cc: Dave Hansen <dave.hansen(a)intel.com> Cc: Borislav Petkov <bp(a)alien8.de> Cc: Dan Williams <dan.j.williams(a)intel.com> Cc: Linus Torvalds <torvalds(a)linux-foundation.org> Cc: Greg Kroah-Hartman <gregkh(a)linux-foundation.org> Cc: David Woodhouse <dwmw(a)amazon.co.uk> Cc: Paul Turner <pjt(a)google.com> Link: https://lkml.kernel.org/r/20180108220921.12580.71694.stgit@tlendack-t1.amdo… Signed-off-by: Greg Kroah-Hartman <gregkh(a)linuxfoundation.org> --- arch/x86/include/asm/msr-index.h | 2 ++ arch/x86/kernel/cpu/amd.c | 10 ++++++++++ 2 files changed, 12 insertions(+) --- a/arch/x86/include/asm/msr-index.h +++ b/arch/x86/include/asm/msr-index.h @@ -352,6 +352,8 @@ #define FAM10H_MMIO_CONF_BASE_MASK 0xfffffffULL #define FAM10H_MMIO_CONF_BASE_SHIFT 20 #define MSR_FAM10H_NODE_ID 0xc001100c +#define MSR_F10H_DECFG 0xc0011029 +#define MSR_F10H_DECFG_LFENCE_SERIALIZE_BIT 1 /* K8 MSRs */ #define MSR_K8_TOP_MEM1 0xc001001a --- a/arch/x86/kernel/cpu/amd.c +++ b/arch/x86/kernel/cpu/amd.c @@ -829,6 +829,16 @@ static void init_amd(struct cpuinfo_x86 set_cpu_cap(c, X86_FEATURE_K8); if (cpu_has(c, X86_FEATURE_XMM2)) { + /* + * A serializing LFENCE has less overhead than MFENCE, so + * use it for execution serialization. On families which + * don't have that MSR, LFENCE is already serializing. + * msr_set_bit() uses the safe accessors, too, even if the MSR + * is not present. + */ + msr_set_bit(MSR_F10H_DECFG, + MSR_F10H_DECFG_LFENCE_SERIALIZE_BIT); + /* MFENCE stops RDTSC speculation */ set_cpu_cap(c, X86_FEATURE_MFENCE_RDTSC); } Patches currently in stable-queue which might be from thomas.lendacky(a)amd.com are queue-4.14/kvm-vmx-scrub-hardware-gprs-at-vm-exit.patch queue-4.14/x86-mm-pti-remove-dead-logic-in-pti_user_pagetable_walk.patch queue-4.14/x86-cpu-amd-make-lfence-a-serializing-instruction.patch queue-4.14/x86-alternatives-fix-optimize_nops-checking.patch queue-4.14/x86-cpu-amd-use-lfence_rdtsc-in-preference-to-mfence_rdtsc.patch

7 years, 3 months

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[Linux-stable-mirror] Patch "x86/alternatives: Fix optimize_nops() checking" 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/alternatives: Fix optimize_nops() checking 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-alternatives-fix-optimize_nops-checking.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 612e8e9350fd19cae6900cf36ea0c6892d1a0dca Mon Sep 17 00:00:00 2001 From: Borislav Petkov <bp(a)suse.de> Date: Wed, 10 Jan 2018 12:28:16 +0100 Subject: x86/alternatives: Fix optimize_nops() checking From: Borislav Petkov <bp(a)suse.de> commit 612e8e9350fd19cae6900cf36ea0c6892d1a0dca upstream. The alternatives code checks only the first byte whether it is a NOP, but with NOPs in front of the payload and having actual instructions after it breaks the "optimized' test. Make sure to scan all bytes before deciding to optimize the NOPs in there. Reported-by: David Woodhouse <dwmw2(a)infradead.org> Signed-off-by: Borislav Petkov <bp(a)suse.de> Signed-off-by: Thomas Gleixner <tglx(a)linutronix.de> Cc: Tom Lendacky <thomas.lendacky(a)amd.com> Cc: Andi Kleen <ak(a)linux.intel.com> Cc: Tim Chen <tim.c.chen(a)linux.intel.com> Cc: Peter Zijlstra <peterz(a)infradead.org> Cc: Jiri Kosina <jikos(a)kernel.org> Cc: Dave Hansen <dave.hansen(a)intel.com> Cc: Andi Kleen <andi(a)firstfloor.org> Cc: Andrew Lutomirski <luto(a)kernel.org> Cc: Linus Torvalds <torvalds(a)linux-foundation.org> Cc: Greg Kroah-Hartman <gregkh(a)linux-foundation.org> Cc: Paul Turner <pjt(a)google.com> Link: https://lkml.kernel.org/r/20180110112815.mgciyf5acwacphkq@pd.tnic Signed-off-by: Greg Kroah-Hartman <gregkh(a)linuxfoundation.org> --- arch/x86/kernel/alternative.c | 7 +++++-- 1 file changed, 5 insertions(+), 2 deletions(-) --- a/arch/x86/kernel/alternative.c +++ b/arch/x86/kernel/alternative.c @@ -344,9 +344,12 @@ done: static void __init_or_module noinline optimize_nops(struct alt_instr *a, u8 *instr) { unsigned long flags; + int i; - if (instr[0] != 0x90) - return; + for (i = 0; i < a->padlen; i++) { + if (instr[i] != 0x90) + return; + } local_irq_save(flags); add_nops(instr + (a->instrlen - a->padlen), a->padlen); Patches currently in stable-queue which might be from bp(a)suse.de are queue-4.14/x86-microcode-intel-extend-bdw-late-loading-with-a-revision-check.patch queue-4.14/x86-cpu-amd-make-lfence-a-serializing-instruction.patch queue-4.14/x86-alternatives-fix-optimize_nops-checking.patch queue-4.14/x86-cpu-amd-use-lfence_rdtsc-in-preference-to-mfence_rdtsc.patch

7 years, 3 months

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[Linux-stable-mirror] Patch "sysfs/cpu: Fix typos in vulnerability documentation" 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 sysfs/cpu: Fix typos in vulnerability documentation 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: sysfs-cpu-fix-typos-in-vulnerability-documentation.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 9ecccfaa7cb5249bd31bdceb93fcf5bedb8a24d8 Mon Sep 17 00:00:00 2001 From: David Woodhouse <dwmw(a)amazon.co.uk> Date: Tue, 9 Jan 2018 15:02:51 +0000 Subject: sysfs/cpu: Fix typos in vulnerability documentation From: David Woodhouse <dwmw(a)amazon.co.uk> commit 9ecccfaa7cb5249bd31bdceb93fcf5bedb8a24d8 upstream. Fixes: 87590ce6e ("sysfs/cpu: Add vulnerability folder") Signed-off-by: David Woodhouse <dwmw(a)amazon.co.uk> Signed-off-by: Thomas Gleixner <tglx(a)linutronix.de> Signed-off-by: Greg Kroah-Hartman <gregkh(a)linuxfoundation.org> --- Documentation/ABI/testing/sysfs-devices-system-cpu | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) --- a/Documentation/ABI/testing/sysfs-devices-system-cpu +++ b/Documentation/ABI/testing/sysfs-devices-system-cpu @@ -378,7 +378,7 @@ What: /sys/devices/system/cpu/vulnerabi /sys/devices/system/cpu/vulnerabilities/meltdown /sys/devices/system/cpu/vulnerabilities/spectre_v1 /sys/devices/system/cpu/vulnerabilities/spectre_v2 -Date: Januar 2018 +Date: January 2018 Contact: Linux kernel mailing list <linux-kernel(a)vger.kernel.org> Description: Information about CPU vulnerabilities @@ -388,4 +388,4 @@ Description: Information about CPU vulne "Not affected" CPU is not affected by the vulnerability "Vulnerable" CPU is affected and no mitigation in effect - "Mitigation: $M" CPU is affetcted and mitigation $M is in effect + "Mitigation: $M" CPU is affected and mitigation $M is in effect Patches currently in stable-queue which might be from dwmw(a)amazon.co.uk are queue-4.14/x86-cpufeatures-add-x86_bug_spectre_v.patch queue-4.14/x86-mm-pti-remove-dead-logic-in-pti_user_pagetable_walk.patch queue-4.14/sysfs-cpu-fix-typos-in-vulnerability-documentation.patch queue-4.14/x86-cpu-amd-make-lfence-a-serializing-instruction.patch queue-4.14/x86-cpu-implement-cpu-vulnerabilites-sysfs-functions.patch queue-4.14/x86-tboot-unbreak-tboot-with-pti-enabled.patch queue-4.14/sysfs-cpu-add-vulnerability-folder.patch queue-4.14/x86-cpu-amd-use-lfence_rdtsc-in-preference-to-mfence_rdtsc.patch

7 years, 3 months

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