From b36612b863c8f5dce738f6e2b7ae9b8bd6116b2d Mon Sep 17 00:00:00 2001 From: Petr Mladek Date: Fri, 11 Oct 2019 16:21:34 +0200 Subject: tracing: Initialize iter->seq after zeroing in tracing_read_pipe() [ Upstream commit d303de1fcf344ff7c15ed64c3f48a991c9958775 ] A customer reported the following softlockup: [899688.160002] NMI watchdog: BUG: soft lockup - CPU#0 stuck for 22s! [test.sh:16464] [899688.160002] CPU: 0 PID: 16464 Comm: test.sh Not tainted 4.12.14-6.23-azure #1 SLE12-SP4 [899688.160002] RIP: 0010:up_write+0x1a/0x30 [899688.160002] Kernel panic - not syncing: softlockup: hung tasks [899688.160002] RIP: 0010:up_write+0x1a/0x30 [899688.160002] RSP: 0018:ffffa86784d4fde8 EFLAGS: 00000257 ORIG_RAX: ffffffffffffff12 [899688.160002] RAX: ffffffff970fea00 RBX: 0000000000000001 RCX: 0000000000000000 [899688.160002] RDX: ffffffff00000001 RSI: 0000000000000080 RDI: ffffffff970fea00 [899688.160002] RBP: ffffffffffffffff R08: ffffffffffffffff R09: 0000000000000000 [899688.160002] R10: 0000000000000000 R11: 0000000000000000 R12: ffff8b59014720d8 [899688.160002] R13: ffff8b59014720c0 R14: ffff8b5901471090 R15: ffff8b5901470000 [899688.160002] tracing_read_pipe+0x336/0x3c0 [899688.160002] __vfs_read+0x26/0x140 [899688.160002] vfs_read+0x87/0x130 [899688.160002] SyS_read+0x42/0x90 [899688.160002] do_syscall_64+0x74/0x160 It caught the process in the middle of trace_access_unlock(). There is no loop. So, it must be looping in the caller tracing_read_pipe() via the "waitagain" label. Crashdump analyze uncovered that iter->seq was completely zeroed at this point, including iter->seq.seq.size. It means that print_trace_line() was never able to print anything and there was no forward progress. The culprit seems to be in the code: /* reset all but tr, trace, and overruns */ memset(&iter->seq, 0, sizeof(struct trace_iterator) - offsetof(struct trace_iterator, seq)); It was added by the commit 53d0aa773053ab182877 ("ftrace: add logic to record overruns"). It was v2.6.27-rc1. It was the time when iter->seq looked like: struct trace_seq { unsigned char buffer[PAGE_SIZE]; unsigned int len; }; There was no "size" variable and zeroing was perfectly fine. The solution is to reinitialize the structure after or without zeroing. Link: http://lkml.kernel.org/r/20191011142134.11997-1-pmladek@suse.com Signed-off-by: Petr Mladek Signed-off-by: Steven Rostedt (VMware) Signed-off-by: Sasha Levin --- kernel/trace/trace.c | 1 + 1 file changed, 1 insertion(+) (limited to 'kernel') diff --git a/kernel/trace/trace.c b/kernel/trace/trace.c index c6e4e3e7f685..6176dc89b32c 100644 --- a/kernel/trace/trace.c +++ b/kernel/trace/trace.c @@ -4803,6 +4803,7 @@ waitagain: sizeof(struct trace_iterator) - offsetof(struct trace_iterator, seq)); cpumask_clear(iter->started); + trace_seq_init(&iter->seq); iter->pos = -1; trace_event_read_lock(); -- cgit v1.2.3 From 87fb5df321742e5d58156f9d06646e7ad48798ab Mon Sep 17 00:00:00 2001 From: Petr Vorel Date: Fri, 8 Nov 2019 16:51:16 +0100 Subject: alarmtimer: Change remaining ENOTSUPP to EOPNOTSUPP Fix backport of commit f18ddc13af981ce3c7b7f26925f099e7c6929aba upstream. Update backport to change ENOTSUPP to EOPNOTSUPP in alarm_timer_{del,set}(), which were removed in f2c45807d3992fe0f173f34af9c347d907c31686 in v4.13-rc1. Fixes: c22df8ea7c5831d6fdca2f6f136f0d32d7064ff9 Signed-off-by: Petr Vorel Acked-by: Thadeu Lima de Souza Cascardo Signed-off-by: Greg Kroah-Hartman --- kernel/time/alarmtimer.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) (limited to 'kernel') diff --git a/kernel/time/alarmtimer.c b/kernel/time/alarmtimer.c index 70aef327b6e8..015d432bcb08 100644 --- a/kernel/time/alarmtimer.c +++ b/kernel/time/alarmtimer.c @@ -573,7 +573,7 @@ static void alarm_timer_get(struct k_itimer *timr, static int alarm_timer_del(struct k_itimer *timr) { if (!rtcdev) - return -ENOTSUPP; + return -EOPNOTSUPP; if (alarm_try_to_cancel(&timr->it.alarm.alarmtimer) < 0) return TIMER_RETRY; @@ -597,7 +597,7 @@ static int alarm_timer_set(struct k_itimer *timr, int flags, ktime_t exp; if (!rtcdev) - return -ENOTSUPP; + return -EOPNOTSUPP; if (flags & ~TIMER_ABSTIME) return -EINVAL; -- cgit v1.2.3 From bbf66e0d4239f43434816e7d58746edc2e344257 Mon Sep 17 00:00:00 2001 From: "Eric W. Biederman" Date: Thu, 19 Jul 2018 19:47:27 -0500 Subject: signal: Always ignore SIGKILL and SIGSTOP sent to the global init [ Upstream commit 86989c41b5ea08776c450cb759592532314a4ed6 ] If the first process started (aka /sbin/init) receives a SIGKILL it will panic the system if it is delivered. Making the system unusable and undebugable. It isn't much better if the first process started receives SIGSTOP. So always ignore SIGSTOP and SIGKILL sent to init. This is done in a separate clause in sig_task_ignored as force_sig_info can clear SIG_UNKILLABLE and this protection should work even then. Reviewed-by: Thomas Gleixner Signed-off-by: "Eric W. Biederman" Signed-off-by: Sasha Levin --- kernel/signal.c | 4 ++++ 1 file changed, 4 insertions(+) (limited to 'kernel') diff --git a/kernel/signal.c b/kernel/signal.c index 072fd152ab01..3095b2309876 100644 --- a/kernel/signal.c +++ b/kernel/signal.c @@ -71,6 +71,10 @@ static int sig_task_ignored(struct task_struct *t, int sig, bool force) handler = sig_handler(t, sig); + /* SIGKILL and SIGSTOP may not be sent to the global init */ + if (unlikely(is_global_init(t) && sig_kernel_only(sig))) + return true; + if (unlikely(t->signal->flags & SIGNAL_UNKILLABLE) && handler == SIG_DFL && !(force && sig_kernel_only(sig))) return 1; -- cgit v1.2.3 From dc9c09f5edc5aeaa1e04bc63b15c56b81bb6ee92 Mon Sep 17 00:00:00 2001 From: "Eric W. Biederman" Date: Thu, 19 Jul 2018 20:33:53 -0500 Subject: signal: Properly deliver SIGILL from uprobes [ Upstream commit 55a3235fc71bf34303e34a95eeee235b2d2a35dd ] For userspace to tell the difference between a random signal and an exception, the exception must include siginfo information. Using SEND_SIG_FORCED for SIGILL is thus wrong, and it will result in userspace seeing si_code == SI_USER (like a random signal) instead of si_code == SI_KERNEL or a more specific si_code as all exceptions deliver. Therefore replace force_sig_info(SIGILL, SEND_SIG_FORCE, current) with force_sig(SIG_ILL, current) which gets this right and is shorter and easier to type. Fixes: 014940bad8e4 ("uprobes/x86: Send SIGILL if arch_uprobe_post_xol() fails") Fixes: 0b5256c7f173 ("uprobes: Send SIGILL if handle_trampoline() fails") Reviewed-by: Thomas Gleixner Signed-off-by: "Eric W. Biederman" Signed-off-by: Sasha Levin --- kernel/events/uprobes.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) (limited to 'kernel') diff --git a/kernel/events/uprobes.c b/kernel/events/uprobes.c index aad43c88a668..8cad3cd92e23 100644 --- a/kernel/events/uprobes.c +++ b/kernel/events/uprobes.c @@ -1836,7 +1836,7 @@ static void handle_trampoline(struct pt_regs *regs) sigill: uprobe_warn(current, "handle uretprobe, sending SIGILL."); - force_sig_info(SIGILL, SEND_SIG_FORCED, current); + force_sig(SIGILL, current); } @@ -1952,7 +1952,7 @@ static void handle_singlestep(struct uprobe_task *utask, struct pt_regs *regs) if (unlikely(err)) { uprobe_warn(current, "execute the probed insn, sending SIGILL."); - force_sig_info(SIGILL, SEND_SIG_FORCED, current); + force_sig(SIGILL, current); } } -- cgit v1.2.3 From b99fc345d90878bd4adbabdb2cb5800e30e11ff5 Mon Sep 17 00:00:00 2001 From: Masami Hiramatsu Date: Tue, 11 Sep 2018 19:21:09 +0900 Subject: kprobes: Don't call BUG_ON() if there is a kprobe in use on free list [ Upstream commit cbdd96f5586151e48317d90a403941ec23f12660 ] Instead of calling BUG_ON(), if we find a kprobe in use on free kprobe list, just remove it from the list and keep it on kprobe hash list as same as other in-use kprobes. Signed-off-by: Masami Hiramatsu Cc: Anil S Keshavamurthy Cc: David S . Miller Cc: Linus Torvalds Cc: Naveen N . Rao Cc: Peter Zijlstra Cc: Thomas Gleixner Link: http://lkml.kernel.org/r/153666126882.21306.10738207224288507996.stgit@devbox Signed-off-by: Ingo Molnar Signed-off-by: Sasha Levin --- kernel/kprobes.c | 8 +++++++- 1 file changed, 7 insertions(+), 1 deletion(-) (limited to 'kernel') diff --git a/kernel/kprobes.c b/kernel/kprobes.c index fdde50d39a46..f59f49bc2a5d 100644 --- a/kernel/kprobes.c +++ b/kernel/kprobes.c @@ -514,8 +514,14 @@ static void do_free_cleaned_kprobes(void) struct optimized_kprobe *op, *tmp; list_for_each_entry_safe(op, tmp, &freeing_list, list) { - BUG_ON(!kprobe_unused(&op->kp)); list_del_init(&op->list); + if (WARN_ON_ONCE(!kprobe_unused(&op->kp))) { + /* + * This must not happen, but if there is a kprobe + * still in use, keep it on kprobes hash list. + */ + continue; + } free_aggr_kprobe(&op->kp); } } -- cgit v1.2.3 From 55b2c1ccb82143be1ed9e1922976dbe63917fe68 Mon Sep 17 00:00:00 2001 From: He Zhe Date: Sun, 30 Sep 2018 00:45:53 +0800 Subject: printk: Give error on attempt to set log buffer length to over 2G [ Upstream commit e6fe3e5b7d16e8f146a4ae7fe481bc6e97acde1e ] The current printk() is ready to handle log buffer size up to 2G. Give an explicit error for users who want to use larger log buffer. Also fix printk formatting to show the 2G as a positive number. Link: http://lkml.kernel.org/r/20181008135916.gg4kkmoki5bgtco5@pathway.suse.cz Cc: rostedt@goodmis.org Cc: linux-kernel@vger.kernel.org Suggested-by: Sergey Senozhatsky Signed-off-by: He Zhe Reviewed-by: Sergey Senozhatsky [pmladek: Fixed to the really safe limit 2GB.] Signed-off-by: Petr Mladek Signed-off-by: Sasha Levin --- kernel/printk/printk.c | 18 ++++++++++++------ 1 file changed, 12 insertions(+), 6 deletions(-) (limited to 'kernel') diff --git a/kernel/printk/printk.c b/kernel/printk/printk.c index 5a1b2a914b4e..699c18c9d763 100644 --- a/kernel/printk/printk.c +++ b/kernel/printk/printk.c @@ -279,6 +279,7 @@ static u32 clear_idx; #define LOG_ALIGN __alignof__(struct printk_log) #endif #define __LOG_BUF_LEN (1 << CONFIG_LOG_BUF_SHIFT) +#define LOG_BUF_LEN_MAX (u32)(1 << 31) static char __log_buf[__LOG_BUF_LEN] __aligned(LOG_ALIGN); static char *log_buf = __log_buf; static u32 log_buf_len = __LOG_BUF_LEN; @@ -870,18 +871,23 @@ void log_buf_kexec_setup(void) static unsigned long __initdata new_log_buf_len; /* we practice scaling the ring buffer by powers of 2 */ -static void __init log_buf_len_update(unsigned size) +static void __init log_buf_len_update(u64 size) { + if (size > (u64)LOG_BUF_LEN_MAX) { + size = (u64)LOG_BUF_LEN_MAX; + pr_err("log_buf over 2G is not supported.\n"); + } + if (size) size = roundup_pow_of_two(size); if (size > log_buf_len) - new_log_buf_len = size; + new_log_buf_len = (unsigned long)size; } /* save requested log_buf_len since it's too early to process it */ static int __init log_buf_len_setup(char *str) { - unsigned int size; + u64 size; if (!str) return -EINVAL; @@ -951,7 +957,7 @@ void __init setup_log_buf(int early) } if (unlikely(!new_log_buf)) { - pr_err("log_buf_len: %ld bytes not available\n", + pr_err("log_buf_len: %lu bytes not available\n", new_log_buf_len); return; } @@ -964,8 +970,8 @@ void __init setup_log_buf(int early) memcpy(log_buf, __log_buf, __LOG_BUF_LEN); raw_spin_unlock_irqrestore(&logbuf_lock, flags); - pr_info("log_buf_len: %d bytes\n", log_buf_len); - pr_info("early log buf free: %d(%d%%)\n", + pr_info("log_buf_len: %u bytes\n", log_buf_len); + pr_info("early log buf free: %u(%u%%)\n", free, (free * 100) / __LOG_BUF_LEN); } -- cgit v1.2.3 From ee49574a110592204b7565362ac2066f27bdb1d3 Mon Sep 17 00:00:00 2001 From: Sergey Senozhatsky Date: Wed, 10 Oct 2018 20:33:08 +0900 Subject: printk: fix integer overflow in setup_log_buf() [ Upstream commit d2130e82e9454304e9b91ba9da551b5989af8c27 ] The way we calculate logbuf free space percentage overflows signed integer: int free; free = __LOG_BUF_LEN - log_next_idx; pr_info("early log buf free: %u(%u%%)\n", free, (free * 100) / __LOG_BUF_LEN); We support LOG_BUF_LEN of up to 1<<25 bytes. Since setup_log_buf() is called during early init, logbuf is mostly empty, so __LOG_BUF_LEN - log_next_idx is close to 1<<25. Thus when we multiply it by 100, we overflow signed integer value range: 100 is 2^6 + 2^5 + 2^2. Example, booting with LOG_BUF_LEN 1<<25 and log_buf_len=2G boot param: [ 0.075317] log_buf_len: -2147483648 bytes [ 0.075319] early log buf free: 33549896(-28%) Make "free" unsigned integer and use appropriate printk() specifier. Link: http://lkml.kernel.org/r/20181010113308.9337-1-sergey.senozhatsky@gmail.com To: Steven Rostedt Cc: linux-kernel@vger.kernel.org Cc: Sergey Senozhatsky Signed-off-by: Sergey Senozhatsky Signed-off-by: Petr Mladek Signed-off-by: Sasha Levin --- kernel/printk/printk.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'kernel') diff --git a/kernel/printk/printk.c b/kernel/printk/printk.c index 699c18c9d763..e53a976ca28e 100644 --- a/kernel/printk/printk.c +++ b/kernel/printk/printk.c @@ -937,7 +937,7 @@ void __init setup_log_buf(int early) { unsigned long flags; char *new_log_buf; - int free; + unsigned int free; if (log_buf != __log_buf) return; -- cgit v1.2.3 From e26e9e270b96021ff23be7bab3c64deebb89aabb Mon Sep 17 00:00:00 2001 From: Valentin Schneider Date: Wed, 26 Sep 2018 16:12:07 +0100 Subject: sched/fair: Don't increase sd->balance_interval on newidle balance [ Upstream commit 3f130a37c442d5c4d66531b240ebe9abfef426b5 ] When load_balance() fails to move some load because of task affinity, we end up increasing sd->balance_interval to delay the next periodic balance in the hopes that next time we look, that annoying pinned task(s) will be gone. However, idle_balance() pays no attention to sd->balance_interval, yet it will still lead to an increase in balance_interval in case of pinned tasks. If we're going through several newidle balances (e.g. we have a periodic task), this can lead to a huge increase of the balance_interval in a very small amount of time. To prevent that, don't increase the balance interval when going through a newidle balance. This is a similar approach to what is done in commit 58b26c4c0257 ("sched: Increment cache_nice_tries only on periodic lb"), where we disregard newidle balance and rely on periodic balance for more stable results. Signed-off-by: Valentin Schneider Signed-off-by: Peter Zijlstra (Intel) Cc: Dietmar.Eggemann@arm.com Cc: Linus Torvalds Cc: Peter Zijlstra Cc: Thomas Gleixner Cc: patrick.bellasi@arm.com Cc: vincent.guittot@linaro.org Link: http://lkml.kernel.org/r/1537974727-30788-2-git-send-email-valentin.schneider@arm.com Signed-off-by: Ingo Molnar Signed-off-by: Sasha Levin --- kernel/sched/fair.c | 13 +++++++++++-- 1 file changed, 11 insertions(+), 2 deletions(-) (limited to 'kernel') diff --git a/kernel/sched/fair.c b/kernel/sched/fair.c index cd2fb8384fbe..d012681fb1ab 100644 --- a/kernel/sched/fair.c +++ b/kernel/sched/fair.c @@ -7334,13 +7334,22 @@ out_all_pinned: sd->nr_balance_failed = 0; out_one_pinned: + ld_moved = 0; + + /* + * idle_balance() disregards balance intervals, so we could repeatedly + * reach this code, which would lead to balance_interval skyrocketting + * in a short amount of time. Skip the balance_interval increase logic + * to avoid that. + */ + if (env.idle == CPU_NEWLY_IDLE) + goto out; + /* tune up the balancing interval */ if (((env.flags & LBF_ALL_PINNED) && sd->balance_interval < MAX_PINNED_INTERVAL) || (sd->balance_interval < sd->max_interval)) sd->balance_interval *= 2; - - ld_moved = 0; out: return ld_moved; } -- cgit v1.2.3 From 044cc4e38cb940255b1b90e2685b760c5314f569 Mon Sep 17 00:00:00 2001 From: Richard Guy Briggs Date: Wed, 10 Oct 2018 16:22:57 -0400 Subject: audit: print empty EXECVE args [ Upstream commit ea956d8be91edc702a98b7fe1f9463e7ca8c42ab ] Empty executable arguments were being skipped when printing out the list of arguments in an EXECVE record, making it appear they were somehow lost. Include empty arguments as an itemized empty string. Reproducer: autrace /bin/ls "" "/etc" ausearch --start recent -m execve -i | grep EXECVE type=EXECVE msg=audit(10/03/2018 13:04:03.208:1391) : argc=3 a0=/bin/ls a2=/etc With fix: type=EXECVE msg=audit(10/03/2018 21:51:38.290:194) : argc=3 a0=/bin/ls a1= a2=/etc type=EXECVE msg=audit(1538617898.290:194): argc=3 a0="/bin/ls" a1="" a2="/etc" Passes audit-testsuite. GH issue tracker at https://github.com/linux-audit/audit-kernel/issues/99 Signed-off-by: Richard Guy Briggs [PM: cleaned up the commit metadata] Signed-off-by: Paul Moore Signed-off-by: Sasha Levin --- kernel/auditsc.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'kernel') diff --git a/kernel/auditsc.c b/kernel/auditsc.c index 0fe8b337291a..87c43c92fb7d 100644 --- a/kernel/auditsc.c +++ b/kernel/auditsc.c @@ -1093,7 +1093,7 @@ static void audit_log_execve_info(struct audit_context *context, } /* write as much as we can to the audit log */ - if (len_buf > 0) { + if (len_buf >= 0) { /* NOTE: some magic numbers here - basically if we * can't fit a reasonable amount of data into the * existing audit buffer, flush it and start with -- cgit v1.2.3