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authorLinus Torvalds <torvalds@linux-foundation.org>2015-04-14 21:03:26 -0700
committerLinus Torvalds <torvalds@linux-foundation.org>2015-04-14 21:03:26 -0700
commitbb0fd7ab0986105765d11baa82e619c618a235aa (patch)
tree6a0585ece827e1025aa48819959d02155a871be9 /arch/arm/kernel/process.c
parentbdfa54dfd9eea001274dbcd622657a904fe43b81 (diff)
parent4b2f8838479eb2abe042e094f7d2cced6d5ea772 (diff)
Merge branch 'for-linus' of git://ftp.arm.linux.org.uk/~rmk/linux-arm
Pull ARM updates from Russell King: "Included in this update are both some long term fixes and some new features. Fixes: - An integer overflow in the calculation of ELF_ET_DYN_BASE. - Avoiding OOMs for high-order IOMMU allocations - SMP requires the data cache to be enabled for synchronisation primitives to work, so prevent the CPU_DCACHE_DISABLE option being visible on SMP builds. - A bug going back 10+ years in the noMMU ARM94* CPU support code, where it corrupts registers. Found by folk getting Linux running on their cameras. - Versatile Express needs an errata workaround enabled for CPU hot-unplug to work. Features: - Clean up module linker by handling out of range relocations separately from relocation cases we don't handle. - Fix a long term bug in the pci_mmap_page_range() code, which we hope won't impact userspace (we hope there's no users of the existing broken interface.) - Don't map DMA coherent allocations when we don't have a MMU. - Drop experimental status for SMP_ON_UP. - Warn when DT doesn't specify ePAPR mandatory cache properties. - Add documentation concerning how we find the start of physical memory for AUTO_ZRELADDR kernels, detailing why we have chosen the mask and the implications of changing it. - Updates from Ard Biesheuvel to address some issues with large kernels (such as allyesconfig) failing to link. - Allow hibernation to work on modern (ARMv7) CPUs - this appears to have never worked in the past on these CPUs. - Enable IRQ_SHOW_LEVEL, which changes the /proc/interrupts output format (hopefully without userspace breaking... let's hope that if it causes someone a problem, they tell us.) - Fix tegra-ahb DT offsets. - Rework ARM errata 643719 code (and ARMv7 flush_cache_louis()/ flush_dcache_all()) code to be more efficient, and enable this errata workaround by default for ARMv7+SMP CPUs. This complements the Versatile Express fix above. - Rework ARMv7 context code for errata 430973, so that only Cortex A8 CPUs are impacted by the branch target buffer flush when this errata is enabled. Also update the help text to indicate that all r1p* A8 CPUs are impacted. - Switch ARM to the generic show_mem() implementation, it conveys all the information which we were already reporting. - Prevent slow timer sources being used for udelay() - timers running at less than 1MHz are not useful for this, and can cause udelay() to return immediately, without any wait. Using such a slow timer is silly. - VDSO support for 32-bit ARM, mainly for gettimeofday() using the ARM architected timer. - Perf support for Scorpion performance monitoring units" vdso semantic conflict fixed up as per linux-next. * 'for-linus' of git://ftp.arm.linux.org.uk/~rmk/linux-arm: (52 commits) ARM: update errata 430973 documentation to cover Cortex A8 r1p* ARM: ensure delay timer has sufficient accuracy for delays ARM: switch to use the generic show_mem() implementation ARM: proc-v7: avoid errata 430973 workaround for non-Cortex A8 CPUs ARM: enable ARM errata 643719 workaround by default ARM: cache-v7: optimise test for Cortex A9 r0pX devices ARM: cache-v7: optimise branches in v7_flush_cache_louis ARM: cache-v7: consolidate initialisation of cache level index ARM: cache-v7: shift CLIDR to extract appropriate field before masking ARM: cache-v7: use movw/movt instructions ARM: allow 16-bit instructions in ALT_UP() ARM: proc-arm94*.S: fix setup function ARM: vexpress: fix CPU hotplug with CT9x4 tile. ARM: 8276/1: Make CPU_DCACHE_DISABLE depend on !SMP ARM: 8335/1: Documentation: DT bindings: Tegra AHB: document the legacy base address ARM: 8334/1: amba: tegra-ahb: detect and correct bogus base address ARM: 8333/1: amba: tegra-ahb: fix register offsets in the macros ARM: 8339/1: Enable CONFIG_GENERIC_IRQ_SHOW_LEVEL ARM: 8338/1: kexec: Relax SMP validation to improve DT compatibility ARM: 8337/1: mm: Do not invoke OOM for higher order IOMMU DMA allocations ...
Diffstat (limited to 'arch/arm/kernel/process.c')
-rw-r--r--arch/arm/kernel/process.c159
1 files changed, 14 insertions, 145 deletions
diff --git a/arch/arm/kernel/process.c b/arch/arm/kernel/process.c
index fdfa3a78ec8c..f192a2a41719 100644
--- a/arch/arm/kernel/process.c
+++ b/arch/arm/kernel/process.c
@@ -17,12 +17,9 @@
#include <linux/stddef.h>
#include <linux/unistd.h>
#include <linux/user.h>
-#include <linux/delay.h>
-#include <linux/reboot.h>
#include <linux/interrupt.h>
#include <linux/kallsyms.h>
#include <linux/init.h>
-#include <linux/cpu.h>
#include <linux/elfcore.h>
#include <linux/pm.h>
#include <linux/tick.h>
@@ -31,16 +28,14 @@
#include <linux/random.h>
#include <linux/hw_breakpoint.h>
#include <linux/leds.h>
-#include <linux/reboot.h>
-#include <asm/cacheflush.h>
-#include <asm/idmap.h>
#include <asm/processor.h>
#include <asm/thread_notify.h>
#include <asm/stacktrace.h>
#include <asm/system_misc.h>
#include <asm/mach/time.h>
#include <asm/tls.h>
+#include <asm/vdso.h>
#ifdef CONFIG_CC_STACKPROTECTOR
#include <linux/stackprotector.h>
@@ -59,69 +54,6 @@ static const char *isa_modes[] __maybe_unused = {
"ARM" , "Thumb" , "Jazelle", "ThumbEE"
};
-extern void call_with_stack(void (*fn)(void *), void *arg, void *sp);
-typedef void (*phys_reset_t)(unsigned long);
-
-/*
- * A temporary stack to use for CPU reset. This is static so that we
- * don't clobber it with the identity mapping. When running with this
- * stack, any references to the current task *will not work* so you
- * should really do as little as possible before jumping to your reset
- * code.
- */
-static u64 soft_restart_stack[16];
-
-static void __soft_restart(void *addr)
-{
- phys_reset_t phys_reset;
-
- /* Take out a flat memory mapping. */
- setup_mm_for_reboot();
-
- /* Clean and invalidate caches */
- flush_cache_all();
-
- /* Turn off caching */
- cpu_proc_fin();
-
- /* Push out any further dirty data, and ensure cache is empty */
- flush_cache_all();
-
- /* Switch to the identity mapping. */
- phys_reset = (phys_reset_t)(unsigned long)virt_to_phys(cpu_reset);
- phys_reset((unsigned long)addr);
-
- /* Should never get here. */
- BUG();
-}
-
-void soft_restart(unsigned long addr)
-{
- u64 *stack = soft_restart_stack + ARRAY_SIZE(soft_restart_stack);
-
- /* Disable interrupts first */
- raw_local_irq_disable();
- local_fiq_disable();
-
- /* Disable the L2 if we're the last man standing. */
- if (num_online_cpus() == 1)
- outer_disable();
-
- /* Change to the new stack and continue with the reset. */
- call_with_stack(__soft_restart, (void *)addr, (void *)stack);
-
- /* Should never get here. */
- BUG();
-}
-
-/*
- * Function pointers to optional machine specific functions
- */
-void (*pm_power_off)(void);
-EXPORT_SYMBOL(pm_power_off);
-
-void (*arm_pm_restart)(enum reboot_mode reboot_mode, const char *cmd);
-
/*
* This is our default idle handler.
*/
@@ -166,79 +98,6 @@ void arch_cpu_idle_dead(void)
}
#endif
-/*
- * Called by kexec, immediately prior to machine_kexec().
- *
- * This must completely disable all secondary CPUs; simply causing those CPUs
- * to execute e.g. a RAM-based pin loop is not sufficient. This allows the
- * kexec'd kernel to use any and all RAM as it sees fit, without having to
- * avoid any code or data used by any SW CPU pin loop. The CPU hotplug
- * functionality embodied in disable_nonboot_cpus() to achieve this.
- */
-void machine_shutdown(void)
-{
- disable_nonboot_cpus();
-}
-
-/*
- * Halting simply requires that the secondary CPUs stop performing any
- * activity (executing tasks, handling interrupts). smp_send_stop()
- * achieves this.
- */
-void machine_halt(void)
-{
- local_irq_disable();
- smp_send_stop();
-
- local_irq_disable();
- while (1);
-}
-
-/*
- * Power-off simply requires that the secondary CPUs stop performing any
- * activity (executing tasks, handling interrupts). smp_send_stop()
- * achieves this. When the system power is turned off, it will take all CPUs
- * with it.
- */
-void machine_power_off(void)
-{
- local_irq_disable();
- smp_send_stop();
-
- if (pm_power_off)
- pm_power_off();
-}
-
-/*
- * Restart requires that the secondary CPUs stop performing any activity
- * while the primary CPU resets the system. Systems with a single CPU can
- * use soft_restart() as their machine descriptor's .restart hook, since that
- * will cause the only available CPU to reset. Systems with multiple CPUs must
- * provide a HW restart implementation, to ensure that all CPUs reset at once.
- * This is required so that any code running after reset on the primary CPU
- * doesn't have to co-ordinate with other CPUs to ensure they aren't still
- * executing pre-reset code, and using RAM that the primary CPU's code wishes
- * to use. Implementing such co-ordination would be essentially impossible.
- */
-void machine_restart(char *cmd)
-{
- local_irq_disable();
- smp_send_stop();
-
- if (arm_pm_restart)
- arm_pm_restart(reboot_mode, cmd);
- else
- do_kernel_restart(cmd);
-
- /* Give a grace period for failure to restart of 1s */
- mdelay(1000);
-
- /* Whoops - the platform was unable to reboot. Tell the user! */
- printk("Reboot failed -- System halted\n");
- local_irq_disable();
- while (1);
-}
-
void __show_regs(struct pt_regs *regs)
{
unsigned long flags;
@@ -475,7 +334,7 @@ const char *arch_vma_name(struct vm_area_struct *vma)
}
/* If possible, provide a placement hint at a random offset from the
- * stack for the signal page.
+ * stack for the sigpage and vdso pages.
*/
static unsigned long sigpage_addr(const struct mm_struct *mm,
unsigned int npages)
@@ -519,6 +378,7 @@ int arch_setup_additional_pages(struct linux_binprm *bprm, int uses_interp)
{
struct mm_struct *mm = current->mm;
struct vm_area_struct *vma;
+ unsigned long npages;
unsigned long addr;
unsigned long hint;
int ret = 0;
@@ -528,9 +388,12 @@ int arch_setup_additional_pages(struct linux_binprm *bprm, int uses_interp)
if (!signal_page)
return -ENOMEM;
+ npages = 1; /* for sigpage */
+ npages += vdso_total_pages;
+
down_write(&mm->mmap_sem);
- hint = sigpage_addr(mm, 1);
- addr = get_unmapped_area(NULL, hint, PAGE_SIZE, 0, 0);
+ hint = sigpage_addr(mm, npages);
+ addr = get_unmapped_area(NULL, hint, npages << PAGE_SHIFT, 0, 0);
if (IS_ERR_VALUE(addr)) {
ret = addr;
goto up_fail;
@@ -547,6 +410,12 @@ int arch_setup_additional_pages(struct linux_binprm *bprm, int uses_interp)
mm->context.sigpage = addr;
+ /* Unlike the sigpage, failure to install the vdso is unlikely
+ * to be fatal to the process, so no error check needed
+ * here.
+ */
+ arm_install_vdso(mm, addr + PAGE_SIZE);
+
up_fail:
up_write(&mm->mmap_sem);
return ret;