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-rw-r--r--arch/arm/kernel/head-nommu.S2
-rw-r--r--arch/arm/mm/init.c9
-rw-r--r--arch/mips/kernel/process.c43
-rw-r--r--arch/mips/kernel/traps.c1
-rw-r--r--arch/mips/mm/ioremap.c37
5 files changed, 65 insertions, 27 deletions
diff --git a/arch/arm/kernel/head-nommu.S b/arch/arm/kernel/head-nommu.S
index dd546d65a383..7a9b86978ee1 100644
--- a/arch/arm/kernel/head-nommu.S
+++ b/arch/arm/kernel/head-nommu.S
@@ -177,7 +177,7 @@ M_CLASS(streq r3, [r12, #PMSAv8_MAIR1])
bic r0, r0, #CR_I
#endif
mcr p15, 0, r0, c1, c0, 0 @ write control reg
- isb
+ instr_sync
#elif defined (CONFIG_CPU_V7M)
#ifdef CONFIG_ARM_MPU
ldreq r3, [r12, MPU_CTRL]
diff --git a/arch/arm/mm/init.c b/arch/arm/mm/init.c
index c186474422f3..0cc8e04295a4 100644
--- a/arch/arm/mm/init.c
+++ b/arch/arm/mm/init.c
@@ -736,20 +736,29 @@ static int __mark_rodata_ro(void *unused)
return 0;
}
+static int kernel_set_to_readonly __read_mostly;
+
void mark_rodata_ro(void)
{
+ kernel_set_to_readonly = 1;
stop_machine(__mark_rodata_ro, NULL, NULL);
debug_checkwx();
}
void set_kernel_text_rw(void)
{
+ if (!kernel_set_to_readonly)
+ return;
+
set_section_perms(ro_perms, ARRAY_SIZE(ro_perms), false,
current->active_mm);
}
void set_kernel_text_ro(void)
{
+ if (!kernel_set_to_readonly)
+ return;
+
set_section_perms(ro_perms, ARRAY_SIZE(ro_perms), true,
current->active_mm);
}
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;
}
/*