From d11a69873d9a7435fe6a48531e165ab80a8b1221 Mon Sep 17 00:00:00 2001 From: Tomislav Novak Date: Mon, 5 Jun 2023 12:19:23 -0700 Subject: hw_breakpoint: fix single-stepping when using bpf_overflow_handler Arm platforms use is_default_overflow_handler() to determine if the hw_breakpoint code should single-step over the breakpoint trigger or let the custom handler deal with it. Since bpf_overflow_handler() currently isn't recognized as a default handler, attaching a BPF program to a PERF_TYPE_BREAKPOINT event causes it to keep firing (the instruction triggering the data abort exception is never skipped). For example: # bpftrace -e 'watchpoint:0x10000:4:w { print("hit") }' -c ./test Attaching 1 probe... hit hit [...] ^C (./test performs a single 4-byte store to 0x10000) This patch replaces the check with uses_default_overflow_handler(), which accounts for the bpf_overflow_handler() case by also testing if one of the perf_event_output functions gets invoked indirectly, via orig_default_handler. Signed-off-by: Tomislav Novak Tested-by: Samuel Gosselin # arm64 Reviewed-by: Catalin Marinas Acked-by: Alexei Starovoitov Link: https://lore.kernel.org/linux-arm-kernel/20220923203644.2731604-1-tnovak@fb.com/ Link: https://lore.kernel.org/r/20230605191923.1219974-1-tnovak@meta.com Signed-off-by: Will Deacon --- arch/arm64/kernel/hw_breakpoint.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) (limited to 'arch/arm64') diff --git a/arch/arm64/kernel/hw_breakpoint.c b/arch/arm64/kernel/hw_breakpoint.c index db2a1861bb97..35225632d70a 100644 --- a/arch/arm64/kernel/hw_breakpoint.c +++ b/arch/arm64/kernel/hw_breakpoint.c @@ -654,7 +654,7 @@ static int breakpoint_handler(unsigned long unused, unsigned long esr, perf_bp_event(bp, regs); /* Do we need to handle the stepping? */ - if (is_default_overflow_handler(bp)) + if (uses_default_overflow_handler(bp)) step = 1; unlock: rcu_read_unlock(); @@ -733,7 +733,7 @@ static u64 get_distance_from_watchpoint(unsigned long addr, u64 val, static int watchpoint_report(struct perf_event *wp, unsigned long addr, struct pt_regs *regs) { - int step = is_default_overflow_handler(wp); + int step = uses_default_overflow_handler(wp); struct arch_hw_breakpoint *info = counter_arch_bp(wp); info->trigger = addr; -- cgit v1.2.3 From 1aa3d0274a4aac338ee45a3dfc3b17c944bcc2bc Mon Sep 17 00:00:00 2001 From: Anshuman Khandual Date: Thu, 17 Aug 2023 11:24:03 +0530 Subject: arm_pmu: acpi: Add a representative platform device for TRBE ACPI TRBE does not have a HID for identification which could create and add a platform device into the platform bus. Also without a platform device, it cannot be probed and bound to a platform driver. This creates a dummy platform device for TRBE after ascertaining that ACPI provides required interrupts uniformly across all cpus on the system. This device gets created inside drivers/perf/arm_pmu_acpi.c to accommodate TRBE being built as a module. Cc: Catalin Marinas Cc: Will Deacon Cc: Mark Rutland Cc: linux-arm-kernel@lists.infradead.org Cc: linux-kernel@vger.kernel.org Signed-off-by: Anshuman Khandual Link: https://lore.kernel.org/r/20230817055405.249630-3-anshuman.khandual@arm.com Signed-off-by: Will Deacon --- arch/arm64/include/asm/acpi.h | 3 +++ drivers/perf/arm_pmu_acpi.c | 35 +++++++++++++++++++++++++++++++++++ include/linux/perf/arm_pmu.h | 1 + 3 files changed, 39 insertions(+) (limited to 'arch/arm64') diff --git a/arch/arm64/include/asm/acpi.h b/arch/arm64/include/asm/acpi.h index bd68e1b7f29f..4d537d56eb84 100644 --- a/arch/arm64/include/asm/acpi.h +++ b/arch/arm64/include/asm/acpi.h @@ -42,6 +42,9 @@ #define ACPI_MADT_GICC_SPE (offsetof(struct acpi_madt_generic_interrupt, \ spe_interrupt) + sizeof(u16)) +#define ACPI_MADT_GICC_TRBE (offsetof(struct acpi_madt_generic_interrupt, \ + trbe_interrupt) + sizeof(u16)) + /* Basic configuration for ACPI */ #ifdef CONFIG_ACPI pgprot_t __acpi_get_mem_attribute(phys_addr_t addr); diff --git a/drivers/perf/arm_pmu_acpi.c b/drivers/perf/arm_pmu_acpi.c index 48bd62d3993e..05dda19c5359 100644 --- a/drivers/perf/arm_pmu_acpi.c +++ b/drivers/perf/arm_pmu_acpi.c @@ -163,6 +163,40 @@ static inline void arm_spe_acpi_register_device(void) } #endif /* CONFIG_ARM_SPE_PMU */ +#if IS_ENABLED(CONFIG_CORESIGHT_TRBE) +static struct resource trbe_resources[] = { + { + /* irq */ + .flags = IORESOURCE_IRQ, + } +}; + +static struct platform_device trbe_dev = { + .name = ARMV8_TRBE_PDEV_NAME, + .id = -1, + .resource = trbe_resources, + .num_resources = ARRAY_SIZE(trbe_resources) +}; + +static u16 arm_trbe_parse_gsi(struct acpi_madt_generic_interrupt *gicc) +{ + return gicc->trbe_interrupt; +} + +static void arm_trbe_acpi_register_device(void) +{ + int ret = arm_acpi_register_pmu_device(&trbe_dev, ACPI_MADT_GICC_TRBE, + arm_trbe_parse_gsi); + if (ret) + pr_warn("ACPI: TRBE: Unable to register device\n"); +} +#else +static inline void arm_trbe_acpi_register_device(void) +{ + +} +#endif /* CONFIG_CORESIGHT_TRBE */ + static int arm_pmu_acpi_parse_irqs(void) { int irq, cpu, irq_cpu, err; @@ -398,6 +432,7 @@ static int arm_pmu_acpi_init(void) return 0; arm_spe_acpi_register_device(); + arm_trbe_acpi_register_device(); return 0; } diff --git a/include/linux/perf/arm_pmu.h b/include/linux/perf/arm_pmu.h index a0801f68762b..143fbc10ecfe 100644 --- a/include/linux/perf/arm_pmu.h +++ b/include/linux/perf/arm_pmu.h @@ -187,5 +187,6 @@ void armpmu_free_irq(int irq, int cpu); #endif /* CONFIG_ARM_PMU */ #define ARMV8_SPE_PDEV_NAME "arm,spe-v1" +#define ARMV8_TRBE_PDEV_NAME "arm,trbe" #endif /* __ARM_PMU_H__ */ -- cgit v1.2.3