backport some bugfix patches for mm/sched/kprobes modules.
Aili Yao (1): mm,hwpoison: return -EHWPOISON to denote that the page has already been poisoned
Pu Lehui (1): powerpc/kprobes: Fix kprobe Oops happens in booke
Tony Luck (1): mm/memory-failure: use a mutex to avoid memory_failure() races
Yu Jiahua (2): sched: Access control for sysctl_update_load_latency sched: Fix branch prediction error in static_key
arch/powerpc/kernel/kprobes.c | 3 ++- kernel/sched/fair.c | 5 ++++- mm/memory-failure.c | 40 ++++++++++++++++++++++------------- 3 files changed, 31 insertions(+), 17 deletions(-)
From: Tony Luck tony.luck@intel.com
mainline inclusion from mainline-v5.13 commit 171936ddaf97e6f4e1264f4128bb5cf15691339c category: bugfix bugzilla: 167325 https://gitee.com/openeuler/kernel/issues/I4DDEL
Reference: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?i...
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Patch series "mm,hwpoison: fix sending SIGBUS for Action Required MCE", v5.
I wrote this patchset to materialize what I think is the current allowable solution mentioned by the previous discussion [1]. I simply borrowed Tony's mutex patch and Aili's return code patch, then I queued another one to find error virtual address in the best effort manner. I know that this is not a perfect solution, but should work for some typical case.
[1]: https://lore.kernel.org/linux-mm/20210331192540.2141052f@alex-virtual-machin...
This patch (of 2):
There can be races when multiple CPUs consume poison from the same page. The first into memory_failure() atomically sets the HWPoison page flag and begins hunting for tasks that map this page. Eventually it invalidates those mappings and may send a SIGBUS to the affected tasks.
But while all that work is going on, other CPUs see a "success" return code from memory_failure() and so they believe the error has been handled and continue executing.
Fix by wrapping most of the internal parts of memory_failure() in a mutex.
[akpm@linux-foundation.org: make mf_mutex local to memory_failure()]
Link: https://lkml.kernel.org/r/20210521030156.2612074-1-nao.horiguchi@gmail.com Link: https://lkml.kernel.org/r/20210521030156.2612074-2-nao.horiguchi@gmail.com Signed-off-by: Tony Luck tony.luck@intel.com Signed-off-by: Naoya Horiguchi naoya.horiguchi@nec.com Reviewed-by: Borislav Petkov bp@suse.de Reviewed-by: Oscar Salvador osalvador@suse.de Cc: Aili Yao yaoaili@kingsoft.com Cc: Andy Lutomirski luto@kernel.org Cc: Borislav Petkov bp@alien8.de Cc: David Hildenbrand david@redhat.com Cc: Jue Wang juew@google.com Cc: stable@vger.kernel.org Signed-off-by: Andrew Morton akpm@linux-foundation.org Signed-off-by: Linus Torvalds torvalds@linux-foundation.org
Conflicts: mm/memory-failure.c Signed-off-by: Nanyong Sun sunnanyong@huawei.com Reviewed-by: Chen Wandun chenwandun@huawei.com Signed-off-by: Chen Jun chenjun102@huawei.com --- mm/memory-failure.c | 37 +++++++++++++++++++++++-------------- 1 file changed, 23 insertions(+), 14 deletions(-)
diff --git a/mm/memory-failure.c b/mm/memory-failure.c index d00d1b2e97da..8df59bb777a7 100644 --- a/mm/memory-failure.c +++ b/mm/memory-failure.c @@ -1329,8 +1329,9 @@ int memory_failure(unsigned long pfn, int flags) struct page *hpage; struct page *orig_head; struct dev_pagemap *pgmap; - int res; + int res = 0; unsigned long page_flags; + static DEFINE_MUTEX(mf_mutex);
if (!sysctl_memory_failure_recovery) panic("Memory failure on page %lx", pfn); @@ -1348,12 +1349,17 @@ int memory_failure(unsigned long pfn, int flags) return -ENXIO; }
- if (PageHuge(p)) - return memory_failure_hugetlb(pfn, flags); + mutex_lock(&mf_mutex); + + if (PageHuge(p)) { + res = memory_failure_hugetlb(pfn, flags); + goto unlock_mutex; + } + if (TestSetPageHWPoison(p)) { pr_err("Memory failure: %#lx: already hardware poisoned\n", pfn); - return 0; + goto unlock_mutex; }
orig_head = hpage = compound_head(p); @@ -1373,17 +1379,18 @@ int memory_failure(unsigned long pfn, int flags) if (!(flags & MF_COUNT_INCREASED) && !get_hwpoison_page(p)) { if (is_free_buddy_page(p)) { action_result(pfn, MF_MSG_BUDDY, MF_DELAYED); - return 0; } else { action_result(pfn, MF_MSG_KERNEL_HIGH_ORDER, MF_IGNORED); - return -EBUSY; + res = -EBUSY; } + goto unlock_mutex; }
if (PageTransHuge(hpage)) { if (try_to_split_thp_page(p, "Memory Failure") < 0) { action_result(pfn, MF_MSG_UNSPLIT_THP, MF_IGNORED); - return -EBUSY; + res = -EBUSY; + goto unlock_mutex; } VM_BUG_ON_PAGE(!page_count(p), p); } @@ -1403,7 +1410,7 @@ int memory_failure(unsigned long pfn, int flags) action_result(pfn, MF_MSG_BUDDY, MF_DELAYED); else action_result(pfn, MF_MSG_BUDDY_2ND, MF_DELAYED); - return 0; + goto unlock_mutex; }
lock_page(p); @@ -1415,7 +1422,7 @@ int memory_failure(unsigned long pfn, int flags) if (PageCompound(p) && compound_head(p) != orig_head) { action_result(pfn, MF_MSG_DIFFERENT_COMPOUND, MF_IGNORED); res = -EBUSY; - goto out; + goto unlock_page; }
/* @@ -1435,14 +1442,14 @@ int memory_failure(unsigned long pfn, int flags) num_poisoned_pages_dec(); unlock_page(p); put_page(p); - return 0; + goto unlock_mutex; } if (hwpoison_filter(p)) { if (TestClearPageHWPoison(p)) num_poisoned_pages_dec(); unlock_page(p); put_page(p); - return 0; + goto unlock_mutex; }
/* @@ -1466,7 +1473,7 @@ int memory_failure(unsigned long pfn, int flags) if (!hwpoison_user_mappings(p, pfn, flags, &p)) { action_result(pfn, MF_MSG_UNMAP_FAILED, MF_IGNORED); res = -EBUSY; - goto out; + goto unlock_page; }
/* @@ -1475,13 +1482,15 @@ int memory_failure(unsigned long pfn, int flags) if (PageLRU(p) && !PageSwapCache(p) && p->mapping == NULL) { action_result(pfn, MF_MSG_TRUNCATED_LRU, MF_IGNORED); res = -EBUSY; - goto out; + goto unlock_page; }
identify_page_state: res = identify_page_state(pfn, p, page_flags); -out: +unlock_page: unlock_page(p); +unlock_mutex: + mutex_unlock(&mf_mutex); return res; } EXPORT_SYMBOL_GPL(memory_failure);
From: Aili Yao yaoaili@kingsoft.com
mainline inclusion from mainline-v5.13 commit 47af12bae17f99b5e77f8651cb7f3e1877610acf category: bugfix bugzilla: 167324 https://gitee.com/openeuler/kernel/issues/I4DDEL
Reference: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?i...
-------------------------------------------------
When memory_failure() is called with MF_ACTION_REQUIRED on the page that has already been hwpoisoned, memory_failure() could fail to send SIGBUS to the affected process, which results in infinite loop of MCEs.
Currently memory_failure() returns 0 if it's called for already hwpoisoned page, then the caller, kill_me_maybe(), could return without sending SIGBUS to current process. An action required MCE is raised when the current process accesses to the broken memory, so no SIGBUS means that the current process continues to run and access to the error page again soon, so running into MCE loop.
This issue can arise for example in the following scenarios:
- Two or more threads access to the poisoned page concurrently. If local MCE is enabled, MCE handler independently handles the MCE events. So there's a race among MCE events, and the second or latter threads fall into the situation in question.
- If there was a precedent memory error event and memory_failure() for the event failed to unmap the error page for some reason, the subsequent memory access to the error page triggers the MCE loop situation.
To fix the issue, make memory_failure() return an error code when the error page has already been hwpoisoned. This allows memory error handler to control how it sends signals to userspace. And make sure that any process touching a hwpoisoned page should get a SIGBUS even in "already hwpoisoned" path of memory_failure() as is done in page fault path.
Link: https://lkml.kernel.org/r/20210521030156.2612074-3-nao.horiguchi@gmail.com Signed-off-by: Aili Yao yaoaili@kingsoft.com Signed-off-by: Naoya Horiguchi naoya.horiguchi@nec.com Reviewed-by: Oscar Salvador osalvador@suse.de Cc: Andy Lutomirski luto@kernel.org Cc: Borislav Petkov bp@alien8.de Cc: Borislav Petkov bp@suse.de Cc: David Hildenbrand david@redhat.com Cc: Jue Wang juew@google.com Cc: Tony Luck tony.luck@intel.com Cc: stable@vger.kernel.org Signed-off-by: Andrew Morton akpm@linux-foundation.org Signed-off-by: Linus Torvalds torvalds@linux-foundation.org Signed-off-by: Nanyong Sun sunnanyong@huawei.com Reviewed-by: Chen Wandun chenwandun@huawei.com Signed-off-by: Chen Jun chenjun102@huawei.com --- mm/memory-failure.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-)
diff --git a/mm/memory-failure.c b/mm/memory-failure.c index 8df59bb777a7..c222d5a35338 100644 --- a/mm/memory-failure.c +++ b/mm/memory-failure.c @@ -1157,7 +1157,7 @@ static int memory_failure_hugetlb(unsigned long pfn, int flags) if (TestSetPageHWPoison(head)) { pr_err("Memory failure: %#lx: already hardware poisoned\n", pfn); - return 0; + return -EHWPOISON; }
num_poisoned_pages_inc(); @@ -1359,6 +1359,7 @@ int memory_failure(unsigned long pfn, int flags) if (TestSetPageHWPoison(p)) { pr_err("Memory failure: %#lx: already hardware poisoned\n", pfn); + res = -EHWPOISON; goto unlock_mutex; }
From: Yu Jiahua yujiahua1@huawei.com
hulk inclusion category: feature bugzilla: 175551 https://gitee.com/openeuler/kernel/issues/I4DDEL
--------------------------------
Add access control for sysctl_update_load_latency
Signed-off-by: Yu Jiahua yujiahua1@huawei.com Reviewed-by: Chen Hui judy.chenhui@huawei.com Signed-off-by: Chen Jun chenjun102@huawei.com --- kernel/sched/fair.c | 3 +++ 1 file changed, 3 insertions(+)
diff --git a/kernel/sched/fair.c b/kernel/sched/fair.c index 0183b177ee6b..96793d50c621 100644 --- a/kernel/sched/fair.c +++ b/kernel/sched/fair.c @@ -52,6 +52,9 @@ int sysctl_update_load_latency(struct ctl_table *table, int write, int latency = sysctl_load_tracking_latency; struct ctl_table t;
+ if (write && !capable(CAP_SYS_ADMIN)) + return -EPERM; + t = *table; t.data = &latency; t.extra1 = &min;
From: Yu Jiahua yujiahua1@huawei.com
hulk inclusion category: feature bugzilla: 175551 https://gitee.com/openeuler/kernel/issues/I4DDEL
--------
sched_blocked_averages is trun on in most cases, it should be static_branch_likely rather than static_branch_unlikely.
Signed-off-by: Yu Jiahua yujiahua1@huawei.com Reviewed-by: Chen Hui judy.chenhui@huawei.com Signed-off-by: Chen Jun chenjun102@huawei.com --- kernel/sched/fair.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/kernel/sched/fair.c b/kernel/sched/fair.c index 96793d50c621..bd42f8e9f5ad 100644 --- a/kernel/sched/fair.c +++ b/kernel/sched/fair.c @@ -8327,7 +8327,7 @@ static void update_blocked_averages(int cpu) update_rq_clock(rq);
#ifdef CONFIG_SCHED_OPTIMIZE_LOAD_TRACKING - if (!static_branch_unlikely(&sched_blocked_averages)) { + if (!static_branch_likely(&sched_blocked_averages)) { rq_unlock_irqrestore(rq, &rf); return; }
From: Pu Lehui pulehui@huawei.com
maillist inclusion category: bugfix bugzilla: 176149 https://gitee.com/openeuler/kernel/issues/I4DDEL
Reference: https://lore.kernel.org/lkml/20210809023658.218915-1-pulehui@huawei.com/
--------------------------------
When using kprobe on powerpc booke series processor, Oops happens as show bellow:
/ # echo "p:myprobe do_nanosleep" > /sys/kernel/debug/tracing/kprobe_events / # echo 1 > /sys/kernel/debug/tracing/events/kprobes/myprobe/enable / # sleep 1 [ 50.076730] Oops: Exception in kernel mode, sig: 5 [#1] [ 50.077017] BE PAGE_SIZE=4K SMP NR_CPUS=24 QEMU e500 [ 50.077221] Modules linked in: [ 50.077462] CPU: 0 PID: 77 Comm: sleep Not tainted 5.14.0-rc4-00022-g251a1524293d #21 [ 50.077887] NIP: c0b9c4e0 LR: c00ebecc CTR: 00000000 [ 50.078067] REGS: c3883de0 TRAP: 0700 Not tainted (5.14.0-rc4-00022-g251a1524293d) [ 50.078349] MSR: 00029000 <CE,EE,ME> CR: 24000228 XER: 20000000 [ 50.078675] [ 50.078675] GPR00: c00ebdf0 c3883e90 c313e300 c3883ea0 00000001 00000000 c3883ecc 00000001 [ 50.078675] GPR08: c100598c c00ea250 00000004 00000000 24000222 102490c2 bff4180c 101e60d4 [ 50.078675] GPR16: 00000000 102454ac 00000040 10240000 10241100 102410f8 10240000 00500000 [ 50.078675] GPR24: 00000002 00000000 c3883ea0 00000001 00000000 0000c350 3b9b8d50 00000000 [ 50.080151] NIP [c0b9c4e0] do_nanosleep+0x0/0x190 [ 50.080352] LR [c00ebecc] hrtimer_nanosleep+0x14c/0x1e0 [ 50.080638] Call Trace: [ 50.080801] [c3883e90] [c00ebdf0] hrtimer_nanosleep+0x70/0x1e0 (unreliable) [ 50.081110] [c3883f00] [c00ec004] sys_nanosleep_time32+0xa4/0x110 [ 50.081336] [c3883f40] [c001509c] ret_from_syscall+0x0/0x28 [ 50.081541] --- interrupt: c00 at 0x100a4d08 [ 50.081749] NIP: 100a4d08 LR: 101b5234 CTR: 00000003 [ 50.081931] REGS: c3883f50 TRAP: 0c00 Not tainted (5.14.0-rc4-00022-g251a1524293d) [ 50.082183] MSR: 0002f902 <CE,EE,PR,FP,ME> CR: 24000222 XER: 00000000 [ 50.082457] [ 50.082457] GPR00: 000000a2 bf980040 1024b4d0 bf980084 bf980084 64000000 00555345 fefefeff [ 50.082457] GPR08: 7f7f7f7f 101e0000 00000069 00000003 28000422 102490c2 bff4180c 101e60d4 [ 50.082457] GPR16: 00000000 102454ac 00000040 10240000 10241100 102410f8 10240000 00500000 [ 50.082457] GPR24: 00000002 bf9803f4 10240000 00000000 00000000 100039e0 00000000 102444e8 [ 50.083789] NIP [100a4d08] 0x100a4d08 [ 50.083917] LR [101b5234] 0x101b5234 [ 50.084042] --- interrupt: c00 [ 50.084238] Instruction dump: [ 50.084483] 4bfffc40 60000000 60000000 60000000 9421fff0 39400402 914200c0 38210010 [ 50.084841] 4bfffc20 00000000 00000000 00000000 <7fe00008> 7c0802a6 7c892378 93c10048 [ 50.085487] ---[ end trace f6fffe98e2fa8f3e ]--- [ 50.085678] Trace/breakpoint trap
There is no real mode for booke arch and the MMU translation is always on. The corresponding MSR_IS/MSR_DS bit in booke is used to switch the address space, but not for real mode judgment.
Fixes: 21f8b2fa3ca5 ("powerpc/kprobes: Ignore traps that happened in real mode") Signed-off-by: Pu Lehui pulehui@huawei.com Signed-off-by: Michael Ellerman mpe@ellerman.id.au Link: https://lore.kernel.org/r/20210809023658.218915-1-pulehui@huawei.com Signed-off-by: Pu Lehui pulehui@huawei.com Reviewed-by: Kuohai Xu xukuohai@huawei.com Signed-off-by: Chen Jun chenjun102@huawei.com --- arch/powerpc/kernel/kprobes.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-)
diff --git a/arch/powerpc/kernel/kprobes.c b/arch/powerpc/kernel/kprobes.c index e8c2a6373157..00fafc8b249e 100644 --- a/arch/powerpc/kernel/kprobes.c +++ b/arch/powerpc/kernel/kprobes.c @@ -276,7 +276,8 @@ int kprobe_handler(struct pt_regs *regs) if (user_mode(regs)) return 0;
- if (!(regs->msr & MSR_IR) || !(regs->msr & MSR_DR)) + if (!IS_ENABLED(CONFIG_BOOKE) && + (!(regs->msr & MSR_IR) || !(regs->msr & MSR_DR))) return 0;
/*
-
Zheng Zengkai