From 034dd340b08be1f2f0477ad16131d609f9dbd53c Mon Sep 17 00:00:00 2001 From: Linus Torvalds Date: Sun, 30 Aug 2026 09:22:00 -0700 Subject: Merge tag 'trace-v7.3-2' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace Pull tracing fixes from Steven Rostedt: - Fix error output of boot instance creation failure Currently if a boot instance creation fails, instead of printing out the name of the instance that failed, it prints "(null)". That is because it prints "cur_str" that had already been processed by strsep(). Print the saved name instead. While at it, print the error code of the failure. - Fix use-after-free for same named historgrams Histograms can be named so that they can be used in multiple events. But if the named histogram has a variable attached, the second event that uses the named histogram which duplicates it and needs to free the original after duplication leaves the old variable in place and still visible. If another histogram uses than variable, it will use the stale one which will try to reference the freed duplicate histogram and crash the kernel. Free the duplicate variables along with the duplicated histogram data. - Check return value of kthread_run() in event self test The events self tests uses a kthread for testing but does not check if it succeeded in creating a kthread. If the kthread creation were to fail, the code will still try to call kthread_stop() on the error returned. - Fix race between reading trace_pipe and updating subbuffer size If a user is reading the trace_pipe file at the same time they update the ring buffer sub-buffer size, can cause the trace_pipe read to read stale data. Add trace_access_lock() around updating the ring buffer sub-buffer size. - Fix eventfs_inode on failure path in creation of the events directory In the creation of the "events" directory, if after allocating the eventfs_inode a failure is detected, it calls cleanup_ei() which calls free_ei(). The free_ei() will test if eventfs_inode being freed has no children. It is a bug if it does. But on the failure case of the creation of the "events" directory, the children lists have not yet been initialized and the free will trigger a warning because list_empty() on an uninitialized list returns false. Move the initialization into init_ei() where it makes more sense and makes sure that a created eventfs_inode has its lists initialized upon creation. - Check return value of kthread_run() in ftrace direct sample code The sample code that shows how to use the ftrace direct calls does not test the return of kthread_run() to see if it succeeds. Return a failure if the kthread_run() doesn't succeed. - Clear user events state on fork in case of alloc failure On fork, the child gets a pointer to the parent's user events state. It makes a copy of it then updates the child's pointer to it. But if the allocation fails, the duplication function leaves the child with a pointer to its parent's descriptor. When the child cleans up its data, it will free the parent's descriptor while the parent is still using it. In the duplication function, set the child's user_event_mm to NULL before testing if the allocation succeeded, and when it exits it will not free the parent's descriptor. - Fix retry exhaustion in simple ring buffer reader swap simple_ring_buffer_swap_reader_page() starts with retry set to 8 and post-decrements it only after a failed link replacement. On the final attempt, a successful replacement leaves retry at zero, while a failed replacement leaves it at -1. But the check for success expects the retry value to be non-zero and exits with an error on zero. This is the opposite result. Fix it. - Fail nicely when the remote swap_reader_page() returns an error Currently, if the swap_reader_page() of a remote buffer fails, it triggers a WARN_ON_ONCE() and continues normally. Instead, have it exit with an error and a pr_warn() print instead of a full WARNING. * tag 'trace-v7.3-2' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace: ring-buffer: Stop remote reader update when page swap fails tracing: Fix retry exhaustion in simple ring buffer reader swap tracing/user_events: Clear copied tracing state before fork duplication samples/ftrace: Fix kthread_stop() on ERR_PTR in ftrace-direct-multi-modify samples/ftrace: Fix kthread_stop() on ERR_PTR in ftrace-direct-modify eventfs: Initialize ei->children and ei->list in init_ei() tracing: Fix use-after-free in trace_pipe read on sub-buffer order change tracing: Fix crash passing ERR_PTR to kthread_stop() tracing: Fix use-after-free with same-name named triggers tracing: Fix logged instance name on creation failure --- drivers/clocksource/timer-pxa.c | 227 ++++++++++++++++++++++++++++++++++++++++ 1 file changed, 227 insertions(+) create mode 100644 drivers/clocksource/timer-pxa.c (limited to 'drivers/clocksource/timer-pxa.c') diff --git a/drivers/clocksource/timer-pxa.c b/drivers/clocksource/timer-pxa.c new file mode 100644 index 000000000..7ad0e5adb --- /dev/null +++ b/drivers/clocksource/timer-pxa.c @@ -0,0 +1,227 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * arch/arm/mach-pxa/time.c + * + * PXA clocksource, clockevents, and OST interrupt handlers. + * Copyright (c) 2007 by Bill Gatliff . + * + * Derived from Nicolas Pitre's PXA timer handler Copyright (c) 2001 + * by MontaVista Software, Inc. (Nico, your code rocks!) + */ + +#include +#include +#include +#include +#include +#include +#include +#include +#include + +#include + +#include + +#define OSMR0 0x00 /* OS Timer 0 Match Register */ +#define OSMR1 0x04 /* OS Timer 1 Match Register */ +#define OSMR2 0x08 /* OS Timer 2 Match Register */ +#define OSMR3 0x0C /* OS Timer 3 Match Register */ + +#define OSCR 0x10 /* OS Timer Counter Register */ +#define OSSR 0x14 /* OS Timer Status Register */ +#define OWER 0x18 /* OS Timer Watchdog Enable Register */ +#define OIER 0x1C /* OS Timer Interrupt Enable Register */ + +#define OSSR_M3 (1 << 3) /* Match status channel 3 */ +#define OSSR_M2 (1 << 2) /* Match status channel 2 */ +#define OSSR_M1 (1 << 1) /* Match status channel 1 */ +#define OSSR_M0 (1 << 0) /* Match status channel 0 */ + +#define OIER_E0 (1 << 0) /* Interrupt enable channel 0 */ + +/* + * This is PXA's sched_clock implementation. This has a resolution + * of at least 308 ns and a maximum value of 208 days. + * + * The return value is guaranteed to be monotonic in that range as + * long as there is always less than 582 seconds between successive + * calls to sched_clock() which should always be the case in practice. + */ + +#define timer_readl(reg) readl_relaxed(timer_base + (reg)) +#define timer_writel(val, reg) writel_relaxed((val), timer_base + (reg)) + +static void __iomem *timer_base; + +static u64 notrace pxa_read_sched_clock(void) +{ + return timer_readl(OSCR); +} + + +#define MIN_OSCR_DELTA 16 + +static irqreturn_t +pxa_ost0_interrupt(int irq, void *dev_id) +{ + struct clock_event_device *c = dev_id; + + /* Disarm the compare/match, signal the event. */ + timer_writel(timer_readl(OIER) & ~OIER_E0, OIER); + timer_writel(OSSR_M0, OSSR); + c->event_handler(c); + + return IRQ_HANDLED; +} + +static int +pxa_osmr0_set_next_event(unsigned long delta, struct clock_event_device *dev) +{ + unsigned long next, oscr; + + timer_writel(timer_readl(OIER) | OIER_E0, OIER); + next = timer_readl(OSCR) + delta; + timer_writel(next, OSMR0); + oscr = timer_readl(OSCR); + + return (signed)(next - oscr) <= MIN_OSCR_DELTA ? -ETIME : 0; +} + +static int pxa_osmr0_shutdown(struct clock_event_device *evt) +{ + /* initializing, released, or preparing for suspend */ + timer_writel(timer_readl(OIER) & ~OIER_E0, OIER); + timer_writel(OSSR_M0, OSSR); + return 0; +} + +#ifdef CONFIG_PM +static unsigned long osmr[4], oier, oscr; + +static void pxa_timer_suspend(struct clock_event_device *cedev) +{ + osmr[0] = timer_readl(OSMR0); + osmr[1] = timer_readl(OSMR1); + osmr[2] = timer_readl(OSMR2); + osmr[3] = timer_readl(OSMR3); + oier = timer_readl(OIER); + oscr = timer_readl(OSCR); +} + +static void pxa_timer_resume(struct clock_event_device *cedev) +{ + /* + * Ensure that we have at least MIN_OSCR_DELTA between match + * register 0 and the OSCR, to guarantee that we will receive + * the one-shot timer interrupt. We adjust OSMR0 in preference + * to OSCR to guarantee that OSCR is monotonically incrementing. + */ + if (osmr[0] - oscr < MIN_OSCR_DELTA) + osmr[0] += MIN_OSCR_DELTA; + + timer_writel(osmr[0], OSMR0); + timer_writel(osmr[1], OSMR1); + timer_writel(osmr[2], OSMR2); + timer_writel(osmr[3], OSMR3); + timer_writel(oier, OIER); + timer_writel(oscr, OSCR); +} +#else +#define pxa_timer_suspend NULL +#define pxa_timer_resume NULL +#endif + +static struct clock_event_device ckevt_pxa_osmr0 = { + .name = "osmr0", + .features = CLOCK_EVT_FEAT_ONESHOT, + .rating = 200, + .set_next_event = pxa_osmr0_set_next_event, + .set_state_shutdown = pxa_osmr0_shutdown, + .set_state_oneshot = pxa_osmr0_shutdown, + .suspend = pxa_timer_suspend, + .resume = pxa_timer_resume, +}; + +static int __init pxa_timer_common_init(int irq, unsigned long clock_tick_rate) +{ + int ret; + + timer_writel(0, OIER); + timer_writel(OSSR_M0 | OSSR_M1 | OSSR_M2 | OSSR_M3, OSSR); + + sched_clock_register(pxa_read_sched_clock, 32, clock_tick_rate); + + ckevt_pxa_osmr0.cpumask = cpumask_of(0); + + ret = request_irq(irq, pxa_ost0_interrupt, IRQF_TIMER | IRQF_IRQPOLL, + "ost0", &ckevt_pxa_osmr0); + if (ret) { + pr_err("Failed to setup irq\n"); + return ret; + } + + ret = clocksource_mmio_init(timer_base + OSCR, "oscr0", clock_tick_rate, 200, + 32, clocksource_mmio_readl_up); + if (ret) { + pr_err("Failed to init clocksource\n"); + return ret; + } + + clockevents_config_and_register(&ckevt_pxa_osmr0, clock_tick_rate, + MIN_OSCR_DELTA * 2, 0x7fffffff); + + return 0; +} + +static int __init pxa_timer_dt_init(struct device_node *np) +{ + struct clk *clk; + int irq, ret; + + /* timer registers are shared with watchdog timer */ + timer_base = of_iomap(np, 0); + if (!timer_base) { + pr_err("%pOFn: unable to map resource\n", np); + return -ENXIO; + } + + clk = of_clk_get(np, 0); + if (IS_ERR(clk)) { + pr_crit("%pOFn: unable to get clk\n", np); + return PTR_ERR(clk); + } + + ret = clk_prepare_enable(clk); + if (ret) { + pr_crit("Failed to prepare clock\n"); + return ret; + } + + /* we are only interested in OS-timer0 irq */ + irq = irq_of_parse_and_map(np, 0); + if (irq <= 0) { + pr_crit("%pOFn: unable to parse OS-timer0 irq\n", np); + return -EINVAL; + } + + return pxa_timer_common_init(irq, clk_get_rate(clk)); +} +TIMER_OF_DECLARE(pxa_timer, "marvell,pxa-timer", pxa_timer_dt_init); + +/* + * Legacy timer init for non device-tree boards. + */ +void __init pxa_timer_nodt_init(int irq, void __iomem *base) +{ + struct clk *clk; + + timer_base = base; + clk = clk_get(NULL, "OSTIMER0"); + if (clk && !IS_ERR(clk)) { + clk_prepare_enable(clk); + pxa_timer_common_init(irq, clk_get_rate(clk)); + } else { + pr_crit("%s: unable to get clk\n", __func__); + } +} -- cgit v1.3.1