From 990cb8acf23cab19a2930f1ed5e7dc108f89079b Mon Sep 17 00:00:00 2001 From: Nicolas Pitre Date: Mon, 14 Jun 2010 16:27:19 -0400 Subject: [ARM] implement arch_randomize_brk() For this feature to take effect, CONFIG_COMPAT_BRK must be turned off. This can safely be turned off for any EABI user space versions. Signed-off-by: Nicolas Pitre --- arch/arm/kernel/process.c | 7 +++++++ 1 file changed, 7 insertions(+) (limited to 'arch/arm/kernel/process.c') diff --git a/arch/arm/kernel/process.c b/arch/arm/kernel/process.c index acf5e6fdb6dc..1c6eb7ed9642 100644 --- a/arch/arm/kernel/process.c +++ b/arch/arm/kernel/process.c @@ -28,6 +28,7 @@ #include #include #include +#include #include #include @@ -421,3 +422,9 @@ unsigned long get_wchan(struct task_struct *p) } while (count ++ < 16); return 0; } + +unsigned long arch_randomize_brk(struct mm_struct *mm) +{ + unsigned long range_end = mm->brk + 0x02000000; + return randomize_range(mm->brk, range_end, 0) ? : mm->brk; +} -- cgit v1.2.3 From c743f38013aeff58ef6252601e397b5ba281c633 Mon Sep 17 00:00:00 2001 From: Nicolas Pitre Date: Mon, 24 May 2010 23:55:42 -0400 Subject: ARM: initial stack protector (-fstack-protector) support This is the very basic stuff without the changing canary upon task switch yet. Just the Kconfig option and a constant canary value initialized at boot time. Signed-off-by: Nicolas Pitre --- arch/arm/kernel/process.c | 6 ++++++ 1 file changed, 6 insertions(+) (limited to 'arch/arm/kernel/process.c') diff --git a/arch/arm/kernel/process.c b/arch/arm/kernel/process.c index 1c6eb7ed9642..090ac9459da1 100644 --- a/arch/arm/kernel/process.c +++ b/arch/arm/kernel/process.c @@ -37,6 +37,12 @@ #include #include +#ifdef CONFIG_CC_STACKPROTECTOR +#include +unsigned long __stack_chk_guard __read_mostly; +EXPORT_SYMBOL(__stack_chk_guard); +#endif + static const char *processor_modes[] = { "USER_26", "FIQ_26" , "IRQ_26" , "SVC_26" , "UK4_26" , "UK5_26" , "UK6_26" , "UK7_26" , "UK8_26" , "UK9_26" , "UK10_26", "UK11_26", "UK12_26", "UK13_26", "UK14_26", "UK15_26", -- cgit v1.2.3 From ac78884e6d89714d18b32b5b7d574116ecfb7c88 Mon Sep 17 00:00:00 2001 From: Russell King Date: Sat, 10 Jul 2010 10:10:18 +0100 Subject: ARM: lockdep: fix unannotated irqs-on CPU: Testing write buffer coherency: ok ------------[ cut here ]------------ WARNING: at kernel/lockdep.c:3145 check_flags+0xcc/0x1dc() Modules linked in: [] (unwind_backtrace+0x0/0xf8) from [] (dump_stack+0x20/0x24) [] (dump_stack+0x20/0x24) from [] (warn_slowpath_common+0x58/0x70) [] (warn_slowpath_common+0x58/0x70) from [] (warn_slowpath_null+0x20/0x24) [] (warn_slowpath_null+0x20/0x24) from [] (check_flags+0xcc/0x1dc) [] (check_flags+0xcc/0x1dc) from [] (lock_acquire+0x50/0x140) [] (lock_acquire+0x50/0x140) from [] (_raw_spin_lock+0x50/0x88) [] (_raw_spin_lock+0x50/0x88) from [] (set_task_comm+0x2c/0x60) [] (set_task_comm+0x2c/0x60) from [] (kthreadd+0x30/0x108) [] (kthreadd+0x30/0x108) from [] (kernel_thread_exit+0x0/0x8) ---[ end trace 1b75b31a2719ed1c ]--- possible reason: unannotated irqs-on. irq event stamp: 3 hardirqs last enabled at (2): [] finish_task_switch+0x48/0xb0 hardirqs last disabled at (3): [] ret_slow_syscall+0xc/0x1c softirqs last enabled at (0): [] copy_process+0x394/0xe5c softirqs last disabled at (0): [<(null)>] (null) Fix this by ensuring that the lockdep interrupt state is manipulated in the appropriate places. We essentially treat userspace as an entirely separate environment which isn't relevant to lockdep (lockdep doesn't monitor userspace.) We don't tell lockdep that IRQs will be enabled in that environment. Instead, when creating kernel threads (which is a rare event compared to entering/leaving userspace) we have to update the lockdep state. Do this by starting threads with IRQs disabled, and in the kthread helper, tell lockdep that IRQs are enabled, and enable them. This provides lockdep with a consistent view of the current IRQ state in kernel space. This also revert portions of 0d928b0b616d1c5c5fe76019a87cba171ca91633 which didn't fix the problem. Tested-by: Ming Lei Signed-off-by: Russell King --- arch/arm/kernel/process.c | 23 ++++++++++++++--------- 1 file changed, 14 insertions(+), 9 deletions(-) (limited to 'arch/arm/kernel/process.c') diff --git a/arch/arm/kernel/process.c b/arch/arm/kernel/process.c index acf5e6fdb6dc..a4a9cc88bec7 100644 --- a/arch/arm/kernel/process.c +++ b/arch/arm/kernel/process.c @@ -351,17 +351,21 @@ EXPORT_SYMBOL(dump_fpu); /* * Shuffle the argument into the correct register before calling the - * thread function. r1 is the thread argument, r2 is the pointer to - * the thread function, and r3 points to the exit function. + * thread function. r4 is the thread argument, r5 is the pointer to + * the thread function, and r6 points to the exit function. */ extern void kernel_thread_helper(void); asm( ".pushsection .text\n" " .align\n" " .type kernel_thread_helper, #function\n" "kernel_thread_helper:\n" -" mov r0, r1\n" -" mov lr, r3\n" -" mov pc, r2\n" +#ifdef CONFIG_TRACE_IRQFLAGS +" bl trace_hardirqs_on\n" +#endif +" msr cpsr_c, r7\n" +" mov r0, r4\n" +" mov lr, r6\n" +" mov pc, r5\n" " .size kernel_thread_helper, . - kernel_thread_helper\n" " .popsection"); @@ -391,11 +395,12 @@ pid_t kernel_thread(int (*fn)(void *), void *arg, unsigned long flags) memset(®s, 0, sizeof(regs)); - regs.ARM_r1 = (unsigned long)arg; - regs.ARM_r2 = (unsigned long)fn; - regs.ARM_r3 = (unsigned long)kernel_thread_exit; + regs.ARM_r4 = (unsigned long)arg; + regs.ARM_r5 = (unsigned long)fn; + regs.ARM_r6 = (unsigned long)kernel_thread_exit; + regs.ARM_r7 = SVC_MODE | PSR_ENDSTATE | PSR_ISETSTATE; regs.ARM_pc = (unsigned long)kernel_thread_helper; - regs.ARM_cpsr = SVC_MODE | PSR_ENDSTATE | PSR_ISETSTATE; + regs.ARM_cpsr = regs.ARM_r7 | PSR_I_BIT; return do_fork(flags|CLONE_VM|CLONE_UNTRACED, 0, ®s, 0, NULL, NULL); } -- cgit v1.2.3 From 9ca03a21e320a6bf44559323527aba704bcc8772 Mon Sep 17 00:00:00 2001 From: Russell King Date: Mon, 26 Jul 2010 12:22:12 +0100 Subject: ARM: Factor out common code from cpu_proc_fin() All implementations of cpu_proc_fin() start by disabling interrupts and then flush caches. Rather than have every processors proc_fin() implementation do this, move it out into generic code - and move the cache flush past setup_mm_for_reboot() (so it can benefit from having caches still enabled.) This allows cpu_proc_fin() to become independent of the L1/L2 cache types, and eventually move the L2 cache flushing into the L2 support code. Signed-off-by: Russell King --- arch/arm/kernel/process.c | 17 +++++++++++++---- 1 file changed, 13 insertions(+), 4 deletions(-) (limited to 'arch/arm/kernel/process.c') diff --git a/arch/arm/kernel/process.c b/arch/arm/kernel/process.c index a4a9cc88bec7..aaf51159203a 100644 --- a/arch/arm/kernel/process.c +++ b/arch/arm/kernel/process.c @@ -29,6 +29,7 @@ #include #include +#include #include #include #include @@ -84,10 +85,9 @@ __setup("hlt", hlt_setup); void arm_machine_restart(char mode, const char *cmd) { - /* - * Clean and disable cache, and turn off interrupts - */ - cpu_proc_fin(); + /* Disable interrupts first */ + local_irq_disable(); + local_fiq_disable(); /* * Tell the mm system that we are going to reboot - @@ -96,6 +96,15 @@ void arm_machine_restart(char mode, const char *cmd) */ setup_mm_for_reboot(mode); + /* 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(); + /* * Now call the architecture specific reboot code. */ -- cgit v1.2.3 From 3d3f78d752bfada5b6041f2f7bd0833d8bdf7a4a Mon Sep 17 00:00:00 2001 From: Russell King Date: Mon, 26 Jul 2010 13:31:27 +0100 Subject: ARM: call machine_shutdown() from machine_halt(), etc x86 calls machine_shutdown() from the various machine_*() calls which take the machine down ready for halting, restarting, etc, and uses this to bring the system safely to a point where those actions can be performed. Such actions are stopping the secondary CPUs. So, change the ARM implementation of these to reflect what x86 does. This solves kexec problems on ARM SMP platforms, where the secondary CPUs were left running across the kexec call. Signed-off-by: Russell King --- arch/arm/kernel/process.c | 12 +++++++++++- 1 file changed, 11 insertions(+), 1 deletion(-) (limited to 'arch/arm/kernel/process.c') diff --git a/arch/arm/kernel/process.c b/arch/arm/kernel/process.c index aaf51159203a..2e2ec97cc50c 100644 --- a/arch/arm/kernel/process.c +++ b/arch/arm/kernel/process.c @@ -198,19 +198,29 @@ int __init reboot_setup(char *str) __setup("reboot=", reboot_setup); -void machine_halt(void) +void machine_shutdown(void) { +#ifdef CONFIG_SMP + smp_send_stop(); +#endif } +void machine_halt(void) +{ + machine_shutdown(); + while (1); +} void machine_power_off(void) { + machine_shutdown(); if (pm_power_off) pm_power_off(); } void machine_restart(char *cmd) { + machine_shutdown(); arm_pm_restart(reboot_mode, cmd); } -- cgit v1.2.3