diff options
| -rw-r--r-- | arch/mips/kernel/process.c | 43 | ||||
| -rw-r--r-- | arch/mips/kernel/traps.c | 1 | ||||
| -rw-r--r-- | arch/mips/mm/ioremap.c | 37 |
3 files changed, 55 insertions, 26 deletions
diff --git a/arch/mips/kernel/process.c b/arch/mips/kernel/process.c index 8d85046adcc8..9670e70139fd 100644 --- a/arch/mips/kernel/process.c +++ b/arch/mips/kernel/process.c @@ -29,6 +29,7 @@ #include <linux/kallsyms.h> #include <linux/random.h> #include <linux/prctl.h> +#include <linux/nmi.h> #include <asm/asm.h> #include <asm/bootinfo.h> @@ -655,28 +656,42 @@ unsigned long arch_align_stack(unsigned long sp) return sp & ALMASK; } -static void arch_dump_stack(void *info) +static DEFINE_PER_CPU(call_single_data_t, backtrace_csd); +static struct cpumask backtrace_csd_busy; + +static void handle_backtrace(void *info) { - struct pt_regs *regs; + nmi_cpu_backtrace(get_irq_regs()); + cpumask_clear_cpu(smp_processor_id(), &backtrace_csd_busy); +} - regs = get_irq_regs(); +static void raise_backtrace(cpumask_t *mask) +{ + call_single_data_t *csd; + int cpu; - if (regs) - show_regs(regs); + for_each_cpu(cpu, mask) { + /* + * If we previously sent an IPI to the target CPU & it hasn't + * cleared its bit in the busy cpumask then it didn't handle + * our previous IPI & it's not safe for us to reuse the + * call_single_data_t. + */ + if (cpumask_test_and_set_cpu(cpu, &backtrace_csd_busy)) { + pr_warn("Unable to send backtrace IPI to CPU%u - perhaps it hung?\n", + cpu); + continue; + } - dump_stack(); + csd = &per_cpu(backtrace_csd, cpu); + csd->func = handle_backtrace; + smp_call_function_single_async(cpu, csd); + } } void arch_trigger_cpumask_backtrace(const cpumask_t *mask, bool exclude_self) { - long this_cpu = get_cpu(); - - if (cpumask_test_cpu(this_cpu, mask) && !exclude_self) - dump_stack(); - - smp_call_function_many(mask, arch_dump_stack, NULL, 1); - - put_cpu(); + nmi_trigger_cpumask_backtrace(mask, exclude_self, raise_backtrace); } int mips_get_process_fp_mode(struct task_struct *task) diff --git a/arch/mips/kernel/traps.c b/arch/mips/kernel/traps.c index d67fa74622ee..8d505a21396e 100644 --- a/arch/mips/kernel/traps.c +++ b/arch/mips/kernel/traps.c @@ -351,6 +351,7 @@ static void __show_regs(const struct pt_regs *regs) void show_regs(struct pt_regs *regs) { __show_regs((struct pt_regs *)regs); + dump_stack(); } void show_registers(struct pt_regs *regs) diff --git a/arch/mips/mm/ioremap.c b/arch/mips/mm/ioremap.c index 1986e09fb457..1601d90b087b 100644 --- a/arch/mips/mm/ioremap.c +++ b/arch/mips/mm/ioremap.c @@ -9,6 +9,7 @@ #include <linux/export.h> #include <asm/addrspace.h> #include <asm/byteorder.h> +#include <linux/ioport.h> #include <linux/sched.h> #include <linux/slab.h> #include <linux/vmalloc.h> @@ -98,6 +99,20 @@ static int remap_area_pages(unsigned long address, phys_addr_t phys_addr, return error; } +static int __ioremap_check_ram(unsigned long start_pfn, unsigned long nr_pages, + void *arg) +{ + unsigned long i; + + for (i = 0; i < nr_pages; i++) { + if (pfn_valid(start_pfn + i) && + !PageReserved(pfn_to_page(start_pfn + i))) + return 1; + } + + return 0; +} + /* * Generic mapping function (not visible outside): */ @@ -116,8 +131,8 @@ static int remap_area_pages(unsigned long address, phys_addr_t phys_addr, void __iomem * __ioremap(phys_addr_t phys_addr, phys_addr_t size, unsigned long flags) { + unsigned long offset, pfn, last_pfn; struct vm_struct * area; - unsigned long offset; phys_addr_t last_addr; void * addr; @@ -137,18 +152,16 @@ void __iomem * __ioremap(phys_addr_t phys_addr, phys_addr_t size, unsigned long return (void __iomem *) CKSEG1ADDR(phys_addr); /* - * Don't allow anybody to remap normal RAM that we're using.. + * Don't allow anybody to remap RAM that may be allocated by the page + * allocator, since that could lead to races & data clobbering. */ - if (phys_addr < virt_to_phys(high_memory)) { - char *t_addr, *t_end; - struct page *page; - - t_addr = __va(phys_addr); - t_end = t_addr + (size - 1); - - for(page = virt_to_page(t_addr); page <= virt_to_page(t_end); page++) - if(!PageReserved(page)) - return NULL; + pfn = PFN_DOWN(phys_addr); + last_pfn = PFN_DOWN(last_addr); + if (walk_system_ram_range(pfn, last_pfn - pfn + 1, NULL, + __ioremap_check_ram) == 1) { + WARN_ONCE(1, "ioremap on RAM at %pa - %pa\n", + &phys_addr, &last_addr); + return NULL; } /* |