x86: unify chunks of kernel/process*.c
With x86-32 and -64 using the same mechanism for managing the tss io permissions bitmap, large chunks of process*.c are trivially unifyable, including: - exit_thread - flush_thread - __switch_to_xtra (along with tsc enable/disable) and as bonus pickups: - sys_fork - sys_vfork (Note: asmlinkage expands to empty on x86-64) Signed-off-by: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
This commit is contained in:
Jeremy Fitzhardinge
Ingo Molnar
parent
db949bba3c
commit
389d1fb11e
4 changed files with 192 additions and 361 deletions
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@ -20,6 +20,8 @@
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struct task_struct; /* one of the stranger aspects of C forward declarations */
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struct task_struct *__switch_to(struct task_struct *prev,
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struct task_struct *next);
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void __switch_to_xtra(struct task_struct *prev_p, struct task_struct *next_p,
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struct tss_struct *tss);
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#ifdef CONFIG_X86_32
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@ -1,8 +1,8 @@
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#include <linux/errno.h>
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#include <linux/kernel.h>
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#include <linux/mm.h>
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#include <asm/idle.h>
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#include <linux/smp.h>
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#include <linux/prctl.h>
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#include <linux/slab.h>
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#include <linux/sched.h>
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#include <linux/module.h>
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@ -11,6 +11,9 @@
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#include <linux/ftrace.h>
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#include <asm/system.h>
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#include <asm/apic.h>
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#include <asm/idle.h>
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#include <asm/uaccess.h>
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#include <asm/i387.h>
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unsigned long idle_halt;
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EXPORT_SYMBOL(idle_halt);
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@ -55,6 +58,192 @@ void arch_task_cache_init(void)
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SLAB_PANIC, NULL);
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}
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/*
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* Free current thread data structures etc..
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*/
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void exit_thread(void)
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{
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struct task_struct *me = current;
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struct thread_struct *t = &me->thread;
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if (me->thread.io_bitmap_ptr) {
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struct tss_struct *tss = &per_cpu(init_tss, get_cpu());
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kfree(t->io_bitmap_ptr);
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t->io_bitmap_ptr = NULL;
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clear_thread_flag(TIF_IO_BITMAP);
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/*
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* Careful, clear this in the TSS too:
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*/
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memset(tss->io_bitmap, 0xff, t->io_bitmap_max);
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t->io_bitmap_max = 0;
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put_cpu();
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}
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ds_exit_thread(current);
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}
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void flush_thread(void)
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{
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struct task_struct *tsk = current;
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#ifdef CONFIG_X86_64
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if (test_tsk_thread_flag(tsk, TIF_ABI_PENDING)) {
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clear_tsk_thread_flag(tsk, TIF_ABI_PENDING);
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if (test_tsk_thread_flag(tsk, TIF_IA32)) {
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clear_tsk_thread_flag(tsk, TIF_IA32);
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} else {
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set_tsk_thread_flag(tsk, TIF_IA32);
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current_thread_info()->status |= TS_COMPAT;
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}
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}
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#endif
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clear_tsk_thread_flag(tsk, TIF_DEBUG);
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tsk->thread.debugreg0 = 0;
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tsk->thread.debugreg1 = 0;
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tsk->thread.debugreg2 = 0;
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tsk->thread.debugreg3 = 0;
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tsk->thread.debugreg6 = 0;
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tsk->thread.debugreg7 = 0;
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memset(tsk->thread.tls_array, 0, sizeof(tsk->thread.tls_array));
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/*
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* Forget coprocessor state..
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*/
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tsk->fpu_counter = 0;
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clear_fpu(tsk);
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clear_used_math();
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}
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static void hard_disable_TSC(void)
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{
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write_cr4(read_cr4() | X86_CR4_TSD);
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}
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void disable_TSC(void)
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{
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preempt_disable();
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if (!test_and_set_thread_flag(TIF_NOTSC))
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/*
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* Must flip the CPU state synchronously with
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* TIF_NOTSC in the current running context.
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*/
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hard_disable_TSC();
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preempt_enable();
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}
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static void hard_enable_TSC(void)
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{
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write_cr4(read_cr4() & ~X86_CR4_TSD);
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}
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static void enable_TSC(void)
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{
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preempt_disable();
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if (test_and_clear_thread_flag(TIF_NOTSC))
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/*
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* Must flip the CPU state synchronously with
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* TIF_NOTSC in the current running context.
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*/
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hard_enable_TSC();
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preempt_enable();
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}
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int get_tsc_mode(unsigned long adr)
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{
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unsigned int val;
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if (test_thread_flag(TIF_NOTSC))
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val = PR_TSC_SIGSEGV;
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else
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val = PR_TSC_ENABLE;
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return put_user(val, (unsigned int __user *)adr);
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}
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int set_tsc_mode(unsigned int val)
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{
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if (val == PR_TSC_SIGSEGV)
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disable_TSC();
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else if (val == PR_TSC_ENABLE)
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enable_TSC();
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else
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return -EINVAL;
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return 0;
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}
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void __switch_to_xtra(struct task_struct *prev_p, struct task_struct *next_p,
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struct tss_struct *tss)
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{
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struct thread_struct *prev, *next;
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prev = &prev_p->thread;
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next = &next_p->thread;
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if (test_tsk_thread_flag(next_p, TIF_DS_AREA_MSR) ||
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test_tsk_thread_flag(prev_p, TIF_DS_AREA_MSR))
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ds_switch_to(prev_p, next_p);
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else if (next->debugctlmsr != prev->debugctlmsr)
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update_debugctlmsr(next->debugctlmsr);
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if (test_tsk_thread_flag(next_p, TIF_DEBUG)) {
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set_debugreg(next->debugreg0, 0);
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set_debugreg(next->debugreg1, 1);
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set_debugreg(next->debugreg2, 2);
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set_debugreg(next->debugreg3, 3);
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/* no 4 and 5 */
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set_debugreg(next->debugreg6, 6);
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set_debugreg(next->debugreg7, 7);
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}
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if (test_tsk_thread_flag(prev_p, TIF_NOTSC) ^
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test_tsk_thread_flag(next_p, TIF_NOTSC)) {
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/* prev and next are different */
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if (test_tsk_thread_flag(next_p, TIF_NOTSC))
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hard_disable_TSC();
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else
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hard_enable_TSC();
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}
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if (test_tsk_thread_flag(next_p, TIF_IO_BITMAP)) {
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/*
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* Copy the relevant range of the IO bitmap.
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* Normally this is 128 bytes or less:
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*/
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memcpy(tss->io_bitmap, next->io_bitmap_ptr,
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max(prev->io_bitmap_max, next->io_bitmap_max));
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} else if (test_tsk_thread_flag(prev_p, TIF_IO_BITMAP)) {
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/*
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* Clear any possible leftover bits:
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*/
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memset(tss->io_bitmap, 0xff, prev->io_bitmap_max);
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}
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}
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int sys_fork(struct pt_regs *regs)
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{
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return do_fork(SIGCHLD, regs->sp, regs, 0, NULL, NULL);
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}
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/*
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* This is trivial, and on the face of it looks like it
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* could equally well be done in user mode.
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*
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* Not so, for quite unobvious reasons - register pressure.
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* In user mode vfork() cannot have a stack frame, and if
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* done by calling the "clone()" system call directly, you
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* do not have enough call-clobbered registers to hold all
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* the information you need.
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*/
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int sys_vfork(struct pt_regs *regs)
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{
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return do_fork(CLONE_VFORK | CLONE_VM | SIGCHLD, regs->sp, regs, 0,
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NULL, NULL);
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}
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/*
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* Idle related variables and functions
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*/
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@ -230,52 +230,6 @@ int kernel_thread(int (*fn)(void *), void *arg, unsigned long flags)
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}
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EXPORT_SYMBOL(kernel_thread);
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/*
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* Free current thread data structures etc..
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*/
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void exit_thread(void)
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{
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/* The process may have allocated an io port bitmap... nuke it. */
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if (unlikely(test_thread_flag(TIF_IO_BITMAP))) {
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struct task_struct *tsk = current;
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struct thread_struct *t = &tsk->thread;
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int cpu = get_cpu();
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struct tss_struct *tss = &per_cpu(init_tss, cpu);
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kfree(t->io_bitmap_ptr);
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t->io_bitmap_ptr = NULL;
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clear_thread_flag(TIF_IO_BITMAP);
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/*
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* Careful, clear this in the TSS too:
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*/
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memset(tss->io_bitmap, 0xff, t->io_bitmap_max);
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t->io_bitmap_max = 0;
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put_cpu();
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}
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ds_exit_thread(current);
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}
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void flush_thread(void)
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{
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struct task_struct *tsk = current;
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tsk->thread.debugreg0 = 0;
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tsk->thread.debugreg1 = 0;
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tsk->thread.debugreg2 = 0;
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tsk->thread.debugreg3 = 0;
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tsk->thread.debugreg6 = 0;
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tsk->thread.debugreg7 = 0;
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memset(tsk->thread.tls_array, 0, sizeof(tsk->thread.tls_array));
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clear_tsk_thread_flag(tsk, TIF_DEBUG);
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/*
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* Forget coprocessor state..
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*/
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tsk->fpu_counter = 0;
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clear_fpu(tsk);
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clear_used_math();
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}
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void release_thread(struct task_struct *dead_task)
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{
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BUG_ON(dead_task->mm);
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@ -363,112 +317,6 @@ start_thread(struct pt_regs *regs, unsigned long new_ip, unsigned long new_sp)
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}
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EXPORT_SYMBOL_GPL(start_thread);
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static void hard_disable_TSC(void)
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{
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write_cr4(read_cr4() | X86_CR4_TSD);
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}
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void disable_TSC(void)
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{
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preempt_disable();
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if (!test_and_set_thread_flag(TIF_NOTSC))
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/*
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* Must flip the CPU state synchronously with
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* TIF_NOTSC in the current running context.
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*/
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hard_disable_TSC();
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preempt_enable();
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}
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static void hard_enable_TSC(void)
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{
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write_cr4(read_cr4() & ~X86_CR4_TSD);
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}
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static void enable_TSC(void)
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{
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preempt_disable();
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if (test_and_clear_thread_flag(TIF_NOTSC))
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/*
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* Must flip the CPU state synchronously with
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* TIF_NOTSC in the current running context.
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*/
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hard_enable_TSC();
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preempt_enable();
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}
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int get_tsc_mode(unsigned long adr)
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{
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unsigned int val;
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if (test_thread_flag(TIF_NOTSC))
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val = PR_TSC_SIGSEGV;
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else
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val = PR_TSC_ENABLE;
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return put_user(val, (unsigned int __user *)adr);
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}
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int set_tsc_mode(unsigned int val)
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{
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if (val == PR_TSC_SIGSEGV)
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disable_TSC();
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else if (val == PR_TSC_ENABLE)
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enable_TSC();
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else
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return -EINVAL;
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return 0;
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}
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static noinline void
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__switch_to_xtra(struct task_struct *prev_p, struct task_struct *next_p,
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struct tss_struct *tss)
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{
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struct thread_struct *prev, *next;
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prev = &prev_p->thread;
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next = &next_p->thread;
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if (test_tsk_thread_flag(next_p, TIF_DS_AREA_MSR) ||
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test_tsk_thread_flag(prev_p, TIF_DS_AREA_MSR))
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ds_switch_to(prev_p, next_p);
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else if (next->debugctlmsr != prev->debugctlmsr)
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update_debugctlmsr(next->debugctlmsr);
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if (test_tsk_thread_flag(next_p, TIF_DEBUG)) {
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set_debugreg(next->debugreg0, 0);
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set_debugreg(next->debugreg1, 1);
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set_debugreg(next->debugreg2, 2);
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set_debugreg(next->debugreg3, 3);
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/* no 4 and 5 */
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set_debugreg(next->debugreg6, 6);
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set_debugreg(next->debugreg7, 7);
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}
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if (test_tsk_thread_flag(prev_p, TIF_NOTSC) ^
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test_tsk_thread_flag(next_p, TIF_NOTSC)) {
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/* prev and next are different */
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if (test_tsk_thread_flag(next_p, TIF_NOTSC))
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hard_disable_TSC();
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else
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hard_enable_TSC();
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}
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if (test_tsk_thread_flag(next_p, TIF_IO_BITMAP)) {
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/*
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* Copy the relevant range of the IO bitmap.
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* Normally this is 128 bytes or less:
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*/
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memcpy(tss->io_bitmap, next->io_bitmap_ptr,
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max(prev->io_bitmap_max, next->io_bitmap_max));
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} else if (test_tsk_thread_flag(prev_p, TIF_IO_BITMAP)) {
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/*
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* Clear any possible leftover bits:
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*/
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memset(tss->io_bitmap, 0xff, prev->io_bitmap_max);
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}
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}
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/*
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* switch_to(x,yn) should switch tasks from x to y.
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@ -582,11 +430,6 @@ __switch_to(struct task_struct *prev_p, struct task_struct *next_p)
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return prev_p;
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}
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int sys_fork(struct pt_regs *regs)
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{
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return do_fork(SIGCHLD, regs->sp, regs, 0, NULL, NULL);
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}
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int sys_clone(struct pt_regs *regs)
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{
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unsigned long clone_flags;
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@ -602,21 +445,6 @@ int sys_clone(struct pt_regs *regs)
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return do_fork(clone_flags, newsp, regs, 0, parent_tidptr, child_tidptr);
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}
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/*
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* This is trivial, and on the face of it looks like it
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* could equally well be done in user mode.
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*
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* Not so, for quite unobvious reasons - register pressure.
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* In user mode vfork() cannot have a stack frame, and if
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* done by calling the "clone()" system call directly, you
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* do not have enough call-clobbered registers to hold all
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* the information you need.
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*/
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int sys_vfork(struct pt_regs *regs)
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{
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return do_fork(CLONE_VFORK | CLONE_VM | SIGCHLD, regs->sp, regs, 0, NULL, NULL);
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}
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/*
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* sys_execve() executes a new program.
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*/
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@ -237,61 +237,6 @@ void show_regs(struct pt_regs *regs)
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show_trace(NULL, regs, (void *)(regs + 1), regs->bp);
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}
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/*
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* Free current thread data structures etc..
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*/
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void exit_thread(void)
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{
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struct task_struct *me = current;
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struct thread_struct *t = &me->thread;
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if (me->thread.io_bitmap_ptr) {
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struct tss_struct *tss = &per_cpu(init_tss, get_cpu());
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kfree(t->io_bitmap_ptr);
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t->io_bitmap_ptr = NULL;
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clear_thread_flag(TIF_IO_BITMAP);
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/*
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* Careful, clear this in the TSS too:
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*/
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memset(tss->io_bitmap, 0xff, t->io_bitmap_max);
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t->io_bitmap_max = 0;
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put_cpu();
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}
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ds_exit_thread(current);
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}
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void flush_thread(void)
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{
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struct task_struct *tsk = current;
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if (test_tsk_thread_flag(tsk, TIF_ABI_PENDING)) {
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clear_tsk_thread_flag(tsk, TIF_ABI_PENDING);
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if (test_tsk_thread_flag(tsk, TIF_IA32)) {
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clear_tsk_thread_flag(tsk, TIF_IA32);
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} else {
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set_tsk_thread_flag(tsk, TIF_IA32);
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current_thread_info()->status |= TS_COMPAT;
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}
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}
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clear_tsk_thread_flag(tsk, TIF_DEBUG);
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tsk->thread.debugreg0 = 0;
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tsk->thread.debugreg1 = 0;
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tsk->thread.debugreg2 = 0;
|
||||
tsk->thread.debugreg3 = 0;
|
||||
tsk->thread.debugreg6 = 0;
|
||||
tsk->thread.debugreg7 = 0;
|
||||
memset(tsk->thread.tls_array, 0, sizeof(tsk->thread.tls_array));
|
||||
/*
|
||||
* Forget coprocessor state..
|
||||
*/
|
||||
tsk->fpu_counter = 0;
|
||||
clear_fpu(tsk);
|
||||
clear_used_math();
|
||||
}
|
||||
|
||||
void release_thread(struct task_struct *dead_task)
|
||||
{
|
||||
if (dead_task->mm) {
|
||||
|
|
@ -425,118 +370,6 @@ start_thread(struct pt_regs *regs, unsigned long new_ip, unsigned long new_sp)
|
|||
}
|
||||
EXPORT_SYMBOL_GPL(start_thread);
|
||||
|
||||
static void hard_disable_TSC(void)
|
||||
{
|
||||
write_cr4(read_cr4() | X86_CR4_TSD);
|
||||
}
|
||||
|
||||
void disable_TSC(void)
|
||||
{
|
||||
preempt_disable();
|
||||
if (!test_and_set_thread_flag(TIF_NOTSC))
|
||||
/*
|
||||
* Must flip the CPU state synchronously with
|
||||
* TIF_NOTSC in the current running context.
|
||||
*/
|
||||
hard_disable_TSC();
|
||||
preempt_enable();
|
||||
}
|
||||
|
||||
static void hard_enable_TSC(void)
|
||||
{
|
||||
write_cr4(read_cr4() & ~X86_CR4_TSD);
|
||||
}
|
||||
|
||||
static 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;
|
||||
}
|
||||
|
||||
/*
|
||||
* This special macro can be used to load a debugging register
|
||||
*/
|
||||
#define loaddebug(thread, r) set_debugreg(thread->debugreg ## r, r)
|
||||
|
||||
static inline void __switch_to_xtra(struct task_struct *prev_p,
|
||||
struct task_struct *next_p,
|
||||
struct tss_struct *tss)
|
||||
{
|
||||
struct thread_struct *prev, *next;
|
||||
|
||||
prev = &prev_p->thread,
|
||||
next = &next_p->thread;
|
||||
|
||||
if (test_tsk_thread_flag(next_p, TIF_DS_AREA_MSR) ||
|
||||
test_tsk_thread_flag(prev_p, TIF_DS_AREA_MSR))
|
||||
ds_switch_to(prev_p, next_p);
|
||||
else if (next->debugctlmsr != prev->debugctlmsr)
|
||||
update_debugctlmsr(next->debugctlmsr);
|
||||
|
||||
if (test_tsk_thread_flag(next_p, TIF_DEBUG)) {
|
||||
loaddebug(next, 0);
|
||||
loaddebug(next, 1);
|
||||
loaddebug(next, 2);
|
||||
loaddebug(next, 3);
|
||||
/* no 4 and 5 */
|
||||
loaddebug(next, 6);
|
||||
loaddebug(next, 7);
|
||||
}
|
||||
|
||||
if (test_tsk_thread_flag(prev_p, TIF_NOTSC) ^
|
||||
test_tsk_thread_flag(next_p, TIF_NOTSC)) {
|
||||
/* prev and next are different */
|
||||
if (test_tsk_thread_flag(next_p, TIF_NOTSC))
|
||||
hard_disable_TSC();
|
||||
else
|
||||
hard_enable_TSC();
|
||||
}
|
||||
|
||||
if (test_tsk_thread_flag(next_p, TIF_IO_BITMAP)) {
|
||||
/*
|
||||
* Copy the relevant range of the IO bitmap.
|
||||
* Normally this is 128 bytes or less:
|
||||
*/
|
||||
memcpy(tss->io_bitmap, next->io_bitmap_ptr,
|
||||
max(prev->io_bitmap_max, next->io_bitmap_max));
|
||||
} else if (test_tsk_thread_flag(prev_p, TIF_IO_BITMAP)) {
|
||||
/*
|
||||
* Clear any possible leftover bits:
|
||||
*/
|
||||
memset(tss->io_bitmap, 0xff, prev->io_bitmap_max);
|
||||
}
|
||||
}
|
||||
|
||||
/*
|
||||
* switch_to(x,y) should switch tasks from x to y.
|
||||
*
|
||||
|
|
@ -694,11 +527,6 @@ void set_personality_64bit(void)
|
|||
current->personality &= ~READ_IMPLIES_EXEC;
|
||||
}
|
||||
|
||||
asmlinkage long sys_fork(struct pt_regs *regs)
|
||||
{
|
||||
return do_fork(SIGCHLD, regs->sp, regs, 0, NULL, NULL);
|
||||
}
|
||||
|
||||
asmlinkage long
|
||||
sys_clone(unsigned long clone_flags, unsigned long newsp,
|
||||
void __user *parent_tid, void __user *child_tid, struct pt_regs *regs)
|
||||
|
|
@ -708,22 +536,6 @@ sys_clone(unsigned long clone_flags, unsigned long newsp,
|
|||
return do_fork(clone_flags, newsp, regs, 0, parent_tid, child_tid);
|
||||
}
|
||||
|
||||
/*
|
||||
* This is trivial, and on the face of it looks like it
|
||||
* could equally well be done in user mode.
|
||||
*
|
||||
* Not so, for quite unobvious reasons - register pressure.
|
||||
* In user mode vfork() cannot have a stack frame, and if
|
||||
* done by calling the "clone()" system call directly, you
|
||||
* do not have enough call-clobbered registers to hold all
|
||||
* the information you need.
|
||||
*/
|
||||
asmlinkage long sys_vfork(struct pt_regs *regs)
|
||||
{
|
||||
return do_fork(CLONE_VFORK | CLONE_VM | SIGCHLD, regs->sp, regs, 0,
|
||||
NULL, NULL);
|
||||
}
|
||||
|
||||
unsigned long get_wchan(struct task_struct *p)
|
||||
{
|
||||
unsigned long stack;
|
||||
|
|
|
|||
Loading…
Reference in a new issue