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Diffstat (limited to 'arch/x86/kernel/process_32.c')
-rw-r--r--arch/x86/kernel/process_32.c138
1 files changed, 81 insertions, 57 deletions
diff --git a/arch/x86/kernel/process_32.c b/arch/x86/kernel/process_32.c
index be3c7a299f02..7adad088e373 100644
--- a/arch/x86/kernel/process_32.c
+++ b/arch/x86/kernel/process_32.c
@@ -36,6 +36,7 @@
#include <linux/personality.h>
#include <linux/tick.h>
#include <linux/percpu.h>
+#include <linux/prctl.h>
#include <asm/uaccess.h>
#include <asm/pgtable.h>
@@ -45,7 +46,6 @@
#include <asm/processor.h>
#include <asm/i387.h>
#include <asm/desc.h>
-#include <asm/vm86.h>
#ifdef CONFIG_MATH_EMULATION
#include <asm/math_emu.h>
#endif
@@ -82,7 +82,6 @@ unsigned long thread_saved_pc(struct task_struct *tsk)
*/
void (*pm_idle)(void);
EXPORT_SYMBOL(pm_idle);
-static DEFINE_PER_CPU(unsigned int, cpu_idle_state);
void disable_hlt(void)
{
@@ -114,20 +113,13 @@ void default_idle(void)
local_irq_disable();
if (!need_resched()) {
- ktime_t t0, t1;
- u64 t0n, t1n;
-
- t0 = ktime_get();
- t0n = ktime_to_ns(t0);
safe_halt(); /* enables interrupts racelessly */
local_irq_disable();
- t1 = ktime_get();
- t1n = ktime_to_ns(t1);
- sched_clock_idle_wakeup_event(t1n - t0n);
}
local_irq_enable();
current_thread_info()->status |= TS_POLLING;
} else {
+ local_irq_enable();
/* loop is done by the caller */
cpu_relax();
}
@@ -143,6 +135,7 @@ EXPORT_SYMBOL(default_idle);
*/
static void poll_idle(void)
{
+ local_irq_enable();
cpu_relax();
}
@@ -190,9 +183,6 @@ void cpu_idle(void)
while (!need_resched()) {
void (*idle)(void);
- if (__get_cpu_var(cpu_idle_state))
- __get_cpu_var(cpu_idle_state) = 0;
-
check_pgt_cache();
rmb();
idle = pm_idle;
@@ -220,40 +210,19 @@ static void do_nothing(void *unused)
{
}
+/*
+ * cpu_idle_wait - Used to ensure that all the CPUs discard old value of
+ * pm_idle and update to new pm_idle value. Required while changing pm_idle
+ * handler on SMP systems.
+ *
+ * Caller must have changed pm_idle to the new value before the call. Old
+ * pm_idle value will not be used by any CPU after the return of this function.
+ */
void cpu_idle_wait(void)
{
- unsigned int cpu, this_cpu = get_cpu();
- cpumask_t map, tmp = current->cpus_allowed;
-
- set_cpus_allowed(current, cpumask_of_cpu(this_cpu));
- put_cpu();
-
- cpus_clear(map);
- for_each_online_cpu(cpu) {
- per_cpu(cpu_idle_state, cpu) = 1;
- cpu_set(cpu, map);
- }
-
- __get_cpu_var(cpu_idle_state) = 0;
-
- wmb();
- do {
- ssleep(1);
- for_each_online_cpu(cpu) {
- if (cpu_isset(cpu, map) && !per_cpu(cpu_idle_state, cpu))
- cpu_clear(cpu, map);
- }
- cpus_and(map, map, cpu_online_map);
- /*
- * We waited 1 sec, if a CPU still did not call idle
- * it may be because it is in idle and not waking up
- * because it has nothing to do.
- * Give all the remaining CPUS a kick.
- */
- smp_call_function_mask(map, do_nothing, NULL, 0);
- } while (!cpus_empty(map));
-
- set_cpus_allowed(current, tmp);
+ smp_mb();
+ /* kick all the CPUs so that they exit out of pm_idle */
+ smp_call_function(do_nothing, NULL, 0, 1);
}
EXPORT_SYMBOL_GPL(cpu_idle_wait);
@@ -273,8 +242,11 @@ void mwait_idle_with_hints(unsigned long ax, unsigned long cx)
__monitor((void *)&current_thread_info()->flags, 0, 0);
smp_mb();
if (!need_resched())
- __mwait(ax, cx);
- }
+ __sti_mwait(ax, cx);
+ else
+ local_irq_enable();
+ } else
+ local_irq_enable();
}
/* Default MONITOR/MWAIT with no hints, used for default C1 state */
@@ -357,7 +329,7 @@ void __show_registers(struct pt_regs *regs, int all)
init_utsname()->version);
printk("EIP: %04x:[<%08lx>] EFLAGS: %08lx CPU: %d\n",
- 0xffff & regs->cs, regs->ip, regs->flags,
+ (u16)regs->cs, regs->ip, regs->flags,
smp_processor_id());
print_symbol("EIP is at %s\n", regs->ip);
@@ -366,8 +338,7 @@ void __show_registers(struct pt_regs *regs, int all)
printk("ESI: %08lx EDI: %08lx EBP: %08lx ESP: %08lx\n",
regs->si, regs->di, regs->bp, sp);
printk(" DS: %04x ES: %04x FS: %04x GS: %04x SS: %04x\n",
- regs->ds & 0xffff, regs->es & 0xffff,
- regs->fs & 0xffff, gs, ss);
+ (u16)regs->ds, (u16)regs->es, (u16)regs->fs, gs, ss);
if (!all)
return;
@@ -538,11 +509,30 @@ int copy_thread(int nr, unsigned long clone_flags, unsigned long sp,
return err;
}
-#ifdef CONFIG_SECCOMP
+void
+start_thread(struct pt_regs *regs, unsigned long new_ip, unsigned long new_sp)
+{
+ __asm__("movl %0, %%gs" :: "r"(0));
+ regs->fs = 0;
+ set_fs(USER_DS);
+ regs->ds = __USER_DS;
+ regs->es = __USER_DS;
+ regs->ss = __USER_DS;
+ regs->cs = __USER_CS;
+ regs->ip = new_ip;
+ regs->sp = new_sp;
+ /*
+ * Free the old FP and other extended state
+ */
+ free_thread_xstate(current);
+}
+EXPORT_SYMBOL_GPL(start_thread);
+
static void hard_disable_TSC(void)
{
write_cr4(read_cr4() | X86_CR4_TSD);
}
+
void disable_TSC(void)
{
preempt_disable();
@@ -554,11 +544,47 @@ void disable_TSC(void)
hard_disable_TSC();
preempt_enable();
}
+
static void hard_enable_TSC(void)
{
write_cr4(read_cr4() & ~X86_CR4_TSD);
}
-#endif /* CONFIG_SECCOMP */
+
+void enable_TSC(void)
+{
+ preempt_disable();
+ if (test_and_clear_thread_flag(TIF_NOTSC))
+ /*
+ * Must flip the CPU state synchronously with
+ * TIF_NOTSC in the current running context.
+ */
+ hard_enable_TSC();
+ preempt_enable();
+}
+
+int get_tsc_mode(unsigned long adr)
+{
+ unsigned int val;
+
+ if (test_thread_flag(TIF_NOTSC))
+ val = PR_TSC_SIGSEGV;
+ else
+ val = PR_TSC_ENABLE;
+
+ return put_user(val, (unsigned int __user *)adr);
+}
+
+int set_tsc_mode(unsigned int val)
+{
+ if (val == PR_TSC_SIGSEGV)
+ disable_TSC();
+ else if (val == PR_TSC_ENABLE)
+ enable_TSC();
+ else
+ return -EINVAL;
+
+ return 0;
+}
static noinline void
__switch_to_xtra(struct task_struct *prev_p, struct task_struct *next_p,
@@ -575,12 +601,12 @@ __switch_to_xtra(struct task_struct *prev_p, struct task_struct *next_p,
/* we clear debugctl to make sure DS
* is not in use when we change it */
debugctl = 0;
- wrmsrl(MSR_IA32_DEBUGCTLMSR, 0);
+ update_debugctlmsr(0);
wrmsr(MSR_IA32_DS_AREA, next->ds_area_msr, 0);
}
if (next->debugctlmsr != debugctl)
- wrmsr(MSR_IA32_DEBUGCTLMSR, next->debugctlmsr, 0);
+ update_debugctlmsr(next->debugctlmsr);
if (test_tsk_thread_flag(next_p, TIF_DEBUG)) {
set_debugreg(next->debugreg0, 0);
@@ -592,7 +618,6 @@ __switch_to_xtra(struct task_struct *prev_p, struct task_struct *next_p,
set_debugreg(next->debugreg7, 7);
}
-#ifdef CONFIG_SECCOMP
if (test_tsk_thread_flag(prev_p, TIF_NOTSC) ^
test_tsk_thread_flag(next_p, TIF_NOTSC)) {
/* prev and next are different */
@@ -601,7 +626,6 @@ __switch_to_xtra(struct task_struct *prev_p, struct task_struct *next_p,
else
hard_enable_TSC();
}
-#endif
#ifdef X86_BTS
if (test_tsk_thread_flag(prev_p, TIF_BTS_TRACE_TS))
@@ -683,7 +707,7 @@ struct task_struct * __switch_to(struct task_struct *prev_p, struct task_struct
/* we're going to use this soon, after a few expensive things */
if (next_p->fpu_counter > 5)
- prefetch(&next->i387.fxsave);
+ prefetch(next->xstate);
/*
* Reload esp0.
generated by cgit v1.2.3 (git 2.46.0) at 2025-09-28 03:57:48 +0000