From mboxrd@z Thu Jan 1 00:00:00 1970 From: Guenter Roeck Subject: Re: [RFC][PATCH v3 00/33] timers: Use timer_shutdown*() before freeing timers Date: Fri, 4 Nov 2022 16:34:40 -0700 Message-ID: <20221104233440.GA2443898@roeck-us.net> References: <20221104054053.431922658@goodmis.org> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Return-path: DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20210112; h=in-reply-to:content-disposition:mime-version:references:message-id :subject:cc:to:from:date:sender:from:to:cc:subject:date:message-id :reply-to; bh=6hvd6urNEa2bZ2TTknP5YJ+H72Ja2eceUu/0SfBV1dc=; b=Jg8jucXtBJP8myrTJM3z0Wltiv65Ikg/KpM2vg9+TBoUW8c9U6W60sIjrbQ9g2FcCc 31LubanrKiS7Sxd3jWqCYjN51E7mjzHAKTsl2yG3a+PmWqITk6B5s+HGczlPeMYiJFrb vBZoQtVDG0kLRBI424jNNGG2b2bDrcM9K1WztoTH0rQVEK4L8GAlPvrCSGnj6IlV9xUa XQ46HitYNVXogafALOjhYHs25Hj1J/FbNvVDg+CD68rFnvYhDXkugu2K8l076C7M7TZq Qr6xjmcHk7Gk4pAipfE4FkxiMKzRcyJTcom7FrkAkJoEkKmmujHBgxhv3f/neLNWJFlx 4OcQ== Content-Disposition: inline In-Reply-To: <20221104054053.431922658-nx8X9YLhiw1AfugRpC6u6w@public.gmane.org> List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: drbd-dev-bounces-cunTk1MwBs8qoQakbn7OcQ@public.gmane.org Errors-To: drbd-dev-bounces-cunTk1MwBs8qoQakbn7OcQ@public.gmane.org To: Steven Rostedt Cc: alsa-devel-K7yf7f+aM1XWsZ/bQMPhNw@public.gmane.org, linux-staging-cunTk1MwBs/YUNznpcFYbw@public.gmane.org, linux-doc-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, dri-devel-PD4FTy7X32lNgt0PjOBp9y5qC8QIuHrW@public.gmane.org, linaro-mm-sig-cunTk1MwBs8s++Sfvej+rw@public.gmane.org, Thomas Gleixner , linux-leds-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, drbd-dev-cunTk1MwBs8qoQakbn7OcQ@public.gmane.org, linux-s390-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, linux-nilfs-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, linux-scsi-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, linux-sh-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, linux-atm-general-5NWGOfrQmneRv+LV9MX5uipxlwaOVQ5f@public.gmane.org, linux-afs-IAPFreCvJWM7uuMidbF8XUB+6BGkLq7r@public.gmane.org, lvs-devel-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, linux-acpi-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, coreteam-Cap9r6Oaw4JrovVCs/uTlw@public.gmane.org, intel-wired-lan-qjLDD68F18P21nG7glBr7A@public.gmane.org, linux-input-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, tipc-discussion-5NWGOfrQmneRv+LV9MX5uipxlwaOVQ5f@public.gmane.org, linux-ext4-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, linux-media-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, bridge-cunTk1MwBs9QetFLy7KEm3xJsTq8ys+cHZ5vskTnxNA@public.gmane.org, linux-pm-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, intel-gfx-PD4FTy7X32lNgt0PjOBp9y5qC8QIuHrW@public.gmane.org, rcu-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, cgroups-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, openipmi-developer-5NWGOfrQmneRv+LV9MX5uipxlwaOVQ5f@public.gmane.org, Anna-Maria Gleixner On Fri, Nov 04, 2022 at 01:40:53AM -0400, Steven Rostedt wrote: > > Back in April, I posted an RFC patch set to help mitigate a common issue > where a timer gets armed just before it is freed, and when the timer > goes off, it crashes in the timer code without any evidence of who the > culprit was. I got side tracked and never finished up on that patch set. > Since this type of crash is still our #1 crash we are seeing in the field, > it has become a priority again to finish it. > After applying the patches attached below, everything compiles for me, and there are no crashes. There are still various warnings, most in networking. I know I need to apply some patch(es) to fix the networking warnings, but I didn't entirely understand what exactly to apply, so I didn't try. Complete logs are at https://kerneltests.org/builders, on the bottom half of the page (qemu tests, in the 'testing' column). Guenter --- Warnings: ODEBUG: free active (active state 0) object type: timer_list hint: tcp_write_timer+0x0/0x1d0 from tcp_close -> __sk_destruct -> tcp_write_timer ODEBUG: free active (active state 0) object type: timer_list hint: tcp_keepalive_timer+0x0/0x4c0 from tcp_close -> __sk_destruct -> tcp_keepalive_timer -> __del_timer_sync ODEBUG: free active (active state 0) object type: timer_list hint: blk_rq_timed_out_timer+0x0/0x40 blk_free_queue_rcu -> blk_free_queue_rcu -> blk_rq_timed_out_timer --- Changes applied on top of patch set to fix build errors: diff --git a/arch/arm/mach-spear/time.c b/arch/arm/mach-spear/time.c index e979e2197f8e..5371c824786d 100644 --- a/arch/arm/mach-spear/time.c +++ b/arch/arm/mach-spear/time.c @@ -90,7 +90,7 @@ static void __init spear_clocksource_init(void) 200, 16, clocksource_mmio_readw_up); } -static inline void timer_shutdown(struct clock_event_device *evt) +static inline void spear_timer_shutdown(struct clock_event_device *evt) { u16 val = readw(gpt_base + CR(CLKEVT)); @@ -101,7 +101,7 @@ static inline void timer_shutdown(struct clock_event_device *evt) static int spear_shutdown(struct clock_event_device *evt) { - timer_shutdown(evt); + spear_timer_shutdown(evt); return 0; } @@ -111,7 +111,7 @@ static int spear_set_oneshot(struct clock_event_device *evt) u16 val; /* stop the timer */ - timer_shutdown(evt); + spear_timer_shutdown(evt); val = readw(gpt_base + CR(CLKEVT)); val |= CTRL_ONE_SHOT; @@ -126,7 +126,7 @@ static int spear_set_periodic(struct clock_event_device *evt) u16 val; /* stop the timer */ - timer_shutdown(evt); + spear_timer_shutdown(evt); period = clk_get_rate(gpt_clk) / HZ; period >>= CTRL_PRESCALER16; diff --git a/drivers/clocksource/arm_arch_timer.c b/drivers/clocksource/arm_arch_timer.c index a7ff77550e17..9c3420a0d19d 100644 --- a/drivers/clocksource/arm_arch_timer.c +++ b/drivers/clocksource/arm_arch_timer.c @@ -687,8 +687,8 @@ static irqreturn_t arch_timer_handler_virt_mem(int irq, void *dev_id) return timer_handler(ARCH_TIMER_MEM_VIRT_ACCESS, evt); } -static __always_inline int timer_shutdown(const int access, - struct clock_event_device *clk) +static __always_inline int arch_timer_shutdown(const int access, + struct clock_event_device *clk) { unsigned long ctrl; @@ -701,22 +701,22 @@ static __always_inline int timer_shutdown(const int access, static int arch_timer_shutdown_virt(struct clock_event_device *clk) { - return timer_shutdown(ARCH_TIMER_VIRT_ACCESS, clk); + return arch_timer_shutdown(ARCH_TIMER_VIRT_ACCESS, clk); } static int arch_timer_shutdown_phys(struct clock_event_device *clk) { - return timer_shutdown(ARCH_TIMER_PHYS_ACCESS, clk); + return arch_timer_shutdown(ARCH_TIMER_PHYS_ACCESS, clk); } static int arch_timer_shutdown_virt_mem(struct clock_event_device *clk) { - return timer_shutdown(ARCH_TIMER_MEM_VIRT_ACCESS, clk); + return arch_timer_shutdown(ARCH_TIMER_MEM_VIRT_ACCESS, clk); } static int arch_timer_shutdown_phys_mem(struct clock_event_device *clk) { - return timer_shutdown(ARCH_TIMER_MEM_PHYS_ACCESS, clk); + return arch_timer_shutdown(ARCH_TIMER_MEM_PHYS_ACCESS, clk); } static __always_inline void set_next_event(const int access, unsigned long evt, diff --git a/drivers/clocksource/timer-sp804.c b/drivers/clocksource/timer-sp804.c index e6a87f4af2b5..a3c38e1343f0 100644 --- a/drivers/clocksource/timer-sp804.c +++ b/drivers/clocksource/timer-sp804.c @@ -155,14 +155,14 @@ static irqreturn_t sp804_timer_interrupt(int irq, void *dev_id) return IRQ_HANDLED; } -static inline void timer_shutdown(struct clock_event_device *evt) +static inline void sp804_timer_shutdown(struct clock_event_device *evt) { writel(0, common_clkevt->ctrl); } static int sp804_shutdown(struct clock_event_device *evt) { - timer_shutdown(evt); + sp804_timer_shutdown(evt); return 0; } @@ -171,7 +171,7 @@ static int sp804_set_periodic(struct clock_event_device *evt) unsigned long ctrl = TIMER_CTRL_32BIT | TIMER_CTRL_IE | TIMER_CTRL_PERIODIC | TIMER_CTRL_ENABLE; - timer_shutdown(evt); + sp804_timer_shutdown(evt); writel(common_clkevt->reload, common_clkevt->load); writel(ctrl, common_clkevt->ctrl); return 0;