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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 2009-02-27 13:25:28 -08:00 committed by Ingo Molnar
parent db949bba3c
commit 389d1fb11e
4 changed files with 192 additions and 361 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

2
arch/x86/include/asm/system.h
View File

@ -20,6 +20,8 @@
struct task_struct; /* one of the stranger aspects of C forward declarations */ struct task_struct; /* one of the stranger aspects of C forward declarations */
struct task_struct *__switch_to(struct task_struct *prev, struct task_struct *__switch_to(struct task_struct *prev,
struct task_struct *next); struct task_struct *next);
void __switch_to_xtra(struct task_struct *prev_p, struct task_struct *next_p,
struct tss_struct *tss);
#ifdef CONFIG_X86_32 #ifdef CONFIG_X86_32

191
arch/x86/kernel/process.c
View File

@ -1,8 +1,8 @@
#include <linux/errno.h> #include <linux/errno.h>
#include <linux/kernel.h> #include <linux/kernel.h>
#include <linux/mm.h> #include <linux/mm.h>
#include <asm/idle.h>
#include <linux/smp.h> #include <linux/smp.h>
#include <linux/prctl.h>
#include <linux/slab.h> #include <linux/slab.h>
#include <linux/sched.h> #include <linux/sched.h>
#include <linux/module.h> #include <linux/module.h>
@ -11,6 +11,9 @@
#include <linux/ftrace.h> #include <linux/ftrace.h>
#include <asm/system.h> #include <asm/system.h>
#include <asm/apic.h> #include <asm/apic.h>
#include <asm/idle.h>
#include <asm/uaccess.h>
#include <asm/i387.h>
unsigned long idle_halt; unsigned long idle_halt;
EXPORT_SYMBOL(idle_halt); EXPORT_SYMBOL(idle_halt);
@ -55,6 +58,192 @@ void arch_task_cache_init(void)
SLAB_PANIC, NULL); SLAB_PANIC, NULL);
} }
/*
* Free current thread data structures etc..
*/
void exit_thread(void)
{
struct task_struct *me = current;
struct thread_struct *t = &me->thread;
if (me->thread.io_bitmap_ptr) {
struct tss_struct *tss = &per_cpu(init_tss, get_cpu());
kfree(t->io_bitmap_ptr);
t->io_bitmap_ptr = NULL;
clear_thread_flag(TIF_IO_BITMAP);
/*
* Careful, clear this in the TSS too:
*/
memset(tss->io_bitmap, 0xff, t->io_bitmap_max);
t->io_bitmap_max = 0;
put_cpu();
}
ds_exit_thread(current);
}
void flush_thread(void)
{
struct task_struct *tsk = current;
#ifdef CONFIG_X86_64
if (test_tsk_thread_flag(tsk, TIF_ABI_PENDING)) {
clear_tsk_thread_flag(tsk, TIF_ABI_PENDING);
if (test_tsk_thread_flag(tsk, TIF_IA32)) {
clear_tsk_thread_flag(tsk, TIF_IA32);
} else {
set_tsk_thread_flag(tsk, TIF_IA32);
current_thread_info()->status |= TS_COMPAT;
}
}
#endif
clear_tsk_thread_flag(tsk, TIF_DEBUG);
tsk->thread.debugreg0 = 0;
tsk->thread.debugreg1 = 0;
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();
}
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;
}
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)) {
set_debugreg(next->debugreg0, 0);
set_debugreg(next->debugreg1, 1);
set_debugreg(next->debugreg2, 2);
set_debugreg(next->debugreg3, 3);
/* no 4 and 5 */
set_debugreg(next->debugreg6, 6);
set_debugreg(next->debugreg7, 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);
}
}
int sys_fork(struct pt_regs *regs)
{
return do_fork(SIGCHLD, regs->sp, regs, 0, NULL, NULL);
}
/*
* 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.
*/
int sys_vfork(struct pt_regs *regs)
{
return do_fork(CLONE_VFORK | CLONE_VM | SIGCHLD, regs->sp, regs, 0,
NULL, NULL);
}
/* /*
* Idle related variables and functions * Idle related variables and functions
*/ */

172
arch/x86/kernel/process_32.c
View File

@ -230,52 +230,6 @@ int kernel_thread(int (*fn)(void *), void *arg, unsigned long flags)
} }
EXPORT_SYMBOL(kernel_thread); EXPORT_SYMBOL(kernel_thread);
/*
* Free current thread data structures etc..
*/
void exit_thread(void)
{
/* The process may have allocated an io port bitmap... nuke it. */
if (unlikely(test_thread_flag(TIF_IO_BITMAP))) {
struct task_struct *tsk = current;
struct thread_struct *t = &tsk->thread;
int cpu = get_cpu();
struct tss_struct *tss = &per_cpu(init_tss, cpu);
kfree(t->io_bitmap_ptr);
t->io_bitmap_ptr = NULL;
clear_thread_flag(TIF_IO_BITMAP);
/*
* Careful, clear this in the TSS too:
*/
memset(tss->io_bitmap, 0xff, t->io_bitmap_max);
t->io_bitmap_max = 0;
put_cpu();
}
ds_exit_thread(current);
}
void flush_thread(void)
{
struct task_struct *tsk = current;
tsk->thread.debugreg0 = 0;
tsk->thread.debugreg1 = 0;
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));
clear_tsk_thread_flag(tsk, TIF_DEBUG);
/*
* Forget coprocessor state..
*/
tsk->fpu_counter = 0;
clear_fpu(tsk);
clear_used_math();
}
void release_thread(struct task_struct *dead_task) void release_thread(struct task_struct *dead_task)
{ {
BUG_ON(dead_task->mm); BUG_ON(dead_task->mm);
@ -363,112 +317,6 @@ start_thread(struct pt_regs *regs, unsigned long new_ip, unsigned long new_sp)
} }
EXPORT_SYMBOL_GPL(start_thread); 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;
}
static noinline 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)) {
set_debugreg(next->debugreg0, 0);
set_debugreg(next->debugreg1, 1);
set_debugreg(next->debugreg2, 2);
set_debugreg(next->debugreg3, 3);
/* no 4 and 5 */
set_debugreg(next->debugreg6, 6);
set_debugreg(next->debugreg7, 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,yn) should switch tasks from x to y. * switch_to(x,yn) should switch tasks from x to y.
@ -582,11 +430,6 @@ __switch_to(struct task_struct *prev_p, struct task_struct *next_p)
return prev_p; return prev_p;
} }
int sys_fork(struct pt_regs *regs)
{
return do_fork(SIGCHLD, regs->sp, regs, 0, NULL, NULL);
}
int sys_clone(struct pt_regs *regs) int sys_clone(struct pt_regs *regs)
{ {
unsigned long clone_flags; unsigned long clone_flags;
@ -602,21 +445,6 @@ int sys_clone(struct pt_regs *regs)
return do_fork(clone_flags, newsp, regs, 0, parent_tidptr, child_tidptr); return do_fork(clone_flags, newsp, regs, 0, parent_tidptr, child_tidptr);
} }
/*
* 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.
*/
int sys_vfork(struct pt_regs *regs)
{
return do_fork(CLONE_VFORK | CLONE_VM | SIGCHLD, regs->sp, regs, 0, NULL, NULL);
}
/* /*
* sys_execve() executes a new program. * sys_execve() executes a new program.
*/ */

188
arch/x86/kernel/process_64.c
View File

@ -237,61 +237,6 @@ void show_regs(struct pt_regs *regs)
show_trace(NULL, regs, (void *)(regs + 1), regs->bp); show_trace(NULL, regs, (void *)(regs + 1), regs->bp);
} }
/*
* Free current thread data structures etc..
*/
void exit_thread(void)
{
struct task_struct *me = current;
struct thread_struct *t = &me->thread;
if (me->thread.io_bitmap_ptr) {
struct tss_struct *tss = &per_cpu(init_tss, get_cpu());
kfree(t->io_bitmap_ptr);
t->io_bitmap_ptr = NULL;
clear_thread_flag(TIF_IO_BITMAP);
/*
* Careful, clear this in the TSS too:
*/
memset(tss->io_bitmap, 0xff, t->io_bitmap_max);
t->io_bitmap_max = 0;
put_cpu();
}
ds_exit_thread(current);
}
void flush_thread(void)
{
struct task_struct *tsk = current;
if (test_tsk_thread_flag(tsk, TIF_ABI_PENDING)) {
clear_tsk_thread_flag(tsk, TIF_ABI_PENDING);
if (test_tsk_thread_flag(tsk, TIF_IA32)) {
clear_tsk_thread_flag(tsk, TIF_IA32);
} else {
set_tsk_thread_flag(tsk, TIF_IA32);
current_thread_info()->status |= TS_COMPAT;
}
}
clear_tsk_thread_flag(tsk, TIF_DEBUG);
tsk->thread.debugreg0 = 0;
tsk->thread.debugreg1 = 0;
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) void release_thread(struct task_struct *dead_task)
{ {
if (dead_task->mm) { 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); 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. * 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; 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 asmlinkage long
sys_clone(unsigned long clone_flags, unsigned long newsp, sys_clone(unsigned long clone_flags, unsigned long newsp,
void __user *parent_tid, void __user *child_tid, struct pt_regs *regs) 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); 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 get_wchan(struct task_struct *p)
{ {
unsigned long stack; unsigned long stack;