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Message-Id: <20071121223951.2A6F526F8BE@magilla.localdomain>
Date: Wed, 21 Nov 2007 14:39:51 -0800 (PST)
From: Roland McGrath <roland@...hat.com>
To: Zachary Amsden <zach@...are.com>
Cc: Andrew Morton <akpm@...ux-foundation.org>,
Thomas Gleixner <tglx@...utronix.de>,
Ingo Molnar <mingo@...hat.com>,
"H. Peter Anvin" <hpa@...or.com>, linux-kernel@...r.kernel.org
Subject: [replacement PATCH 6/6] x86: TLS cleanup
This consolidates the four different places that implemented the same
encoding magic for the GDT-slot 32-bit TLS support. The old tls32.c was
renamed and is now only slightly modified to be the shared implementation.
Signed-off-by: Roland McGrath <roland@...hat.com>
---
arch/x86/ia32/ia32entry.S | 4 +-
arch/x86/kernel/Makefile_32 | 1 +
arch/x86/kernel/process_32.c | 143 ++----------------------------------------
arch/x86/kernel/process_64.c | 3 +-
arch/x86/kernel/ptrace_32.c | 91 +++------------------------
arch/x86/kernel/ptrace_64.c | 26 +++-----
arch/x86/kernel/tls.c | 97 +++++++++++-----------------
include/asm-x86/ia32.h | 6 --
include/asm-x86/ptrace.h | 11 +++
9 files changed, 80 insertions(+), 302 deletions(-)
diff --git a/arch/x86/ia32/ia32entry.S b/arch/x86/ia32/ia32entry.S
index df588f0..0a71fa9 100644
--- a/arch/x86/ia32/ia32entry.S
+++ b/arch/x86/ia32/ia32entry.S
@@ -644,8 +644,8 @@ ia32_sys_call_table:
.quad compat_sys_futex /* 240 */
.quad compat_sys_sched_setaffinity
.quad compat_sys_sched_getaffinity
- .quad sys32_set_thread_area
- .quad sys32_get_thread_area
+ .quad sys_set_thread_area
+ .quad sys_get_thread_area
.quad compat_sys_io_setup /* 245 */
.quad sys_io_destroy
.quad compat_sys_io_getevents
diff --git a/arch/x86/kernel/Makefile_32 b/arch/x86/kernel/Makefile_32
index a7bc93c..e660584 100644
--- a/arch/x86/kernel/Makefile_32
+++ b/arch/x86/kernel/Makefile_32
@@ -10,6 +10,7 @@ obj-y := process_32.o signal_32.o entry_32.o traps_32.o irq_32.o \
pci-dma_32.o i386_ksyms_32.o i387_32.o bootflag.o e820_32.o\
quirks.o i8237.o topology.o alternative.o i8253.o tsc_32.o
+obj-y += tls.o
obj-$(CONFIG_STACKTRACE) += stacktrace.o
obj-y += cpu/
obj-y += acpi/
diff --git a/arch/x86/kernel/process_32.c b/arch/x86/kernel/process_32.c
index 7b89958..ebbbfc5 100644
--- a/arch/x86/kernel/process_32.c
+++ b/arch/x86/kernel/process_32.c
@@ -480,33 +480,16 @@ int copy_thread(int nr, unsigned long clone_flags, unsigned long esp,
set_tsk_thread_flag(p, TIF_IO_BITMAP);
}
+ err = 0;
+
/*
* Set a new TLS for the child thread?
*/
- if (clone_flags & CLONE_SETTLS) {
- struct desc_struct *desc;
- struct user_desc info;
- int idx;
-
- err = -EFAULT;
- if (copy_from_user(&info, (void __user *)childregs->esi, sizeof(info)))
- goto out;
- err = -EINVAL;
- if (LDT_empty(&info))
- goto out;
-
- idx = info.entry_number;
- if (idx < GDT_ENTRY_TLS_MIN || idx > GDT_ENTRY_TLS_MAX)
- goto out;
-
- desc = p->thread.tls_array + idx - GDT_ENTRY_TLS_MIN;
- desc->a = LDT_entry_a(&info);
- desc->b = LDT_entry_b(&info);
- }
+ if (clone_flags & CLONE_SETTLS)
+ err = do_set_thread_area(p, -1,
+ (struct user_desc __user *)childregs->esi, 0);
- err = 0;
- out:
- if (err && p->thread.io_bitmap_ptr) {
+ if (err && p->thread.io_bitmap_ptr) {
kfree(p->thread.io_bitmap_ptr);
p->thread.io_bitmap_max = 0;
}
@@ -851,120 +834,6 @@ unsigned long get_wchan(struct task_struct *p)
return 0;
}
-/*
- * sys_alloc_thread_area: get a yet unused TLS descriptor index.
- */
-static int get_free_idx(void)
-{
- struct thread_struct *t = ¤t->thread;
- int idx;
-
- for (idx = 0; idx < GDT_ENTRY_TLS_ENTRIES; idx++)
- if (desc_empty(t->tls_array + idx))
- return idx + GDT_ENTRY_TLS_MIN;
- return -ESRCH;
-}
-
-/*
- * Set a given TLS descriptor:
- */
-asmlinkage int sys_set_thread_area(struct user_desc __user *u_info)
-{
- struct thread_struct *t = ¤t->thread;
- struct user_desc info;
- struct desc_struct *desc;
- int cpu, idx;
-
- if (copy_from_user(&info, u_info, sizeof(info)))
- return -EFAULT;
- idx = info.entry_number;
-
- /*
- * index -1 means the kernel should try to find and
- * allocate an empty descriptor:
- */
- if (idx == -1) {
- idx = get_free_idx();
- if (idx < 0)
- return idx;
- if (put_user(idx, &u_info->entry_number))
- return -EFAULT;
- }
-
- if (idx < GDT_ENTRY_TLS_MIN || idx > GDT_ENTRY_TLS_MAX)
- return -EINVAL;
-
- desc = t->tls_array + idx - GDT_ENTRY_TLS_MIN;
-
- /*
- * We must not get preempted while modifying the TLS.
- */
- cpu = get_cpu();
-
- if (LDT_empty(&info)) {
- desc->a = 0;
- desc->b = 0;
- } else {
- desc->a = LDT_entry_a(&info);
- desc->b = LDT_entry_b(&info);
- }
- load_TLS(t, cpu);
-
- put_cpu();
-
- return 0;
-}
-
-/*
- * Get the current Thread-Local Storage area:
- */
-
-#define GET_BASE(desc) ( \
- (((desc)->a >> 16) & 0x0000ffff) | \
- (((desc)->b << 16) & 0x00ff0000) | \
- ( (desc)->b & 0xff000000) )
-
-#define GET_LIMIT(desc) ( \
- ((desc)->a & 0x0ffff) | \
- ((desc)->b & 0xf0000) )
-
-#define GET_32BIT(desc) (((desc)->b >> 22) & 1)
-#define GET_CONTENTS(desc) (((desc)->b >> 10) & 3)
-#define GET_WRITABLE(desc) (((desc)->b >> 9) & 1)
-#define GET_LIMIT_PAGES(desc) (((desc)->b >> 23) & 1)
-#define GET_PRESENT(desc) (((desc)->b >> 15) & 1)
-#define GET_USEABLE(desc) (((desc)->b >> 20) & 1)
-
-asmlinkage int sys_get_thread_area(struct user_desc __user *u_info)
-{
- struct user_desc info;
- struct desc_struct *desc;
- int idx;
-
- if (get_user(idx, &u_info->entry_number))
- return -EFAULT;
- if (idx < GDT_ENTRY_TLS_MIN || idx > GDT_ENTRY_TLS_MAX)
- return -EINVAL;
-
- memset(&info, 0, sizeof(info));
-
- desc = current->thread.tls_array + idx - GDT_ENTRY_TLS_MIN;
-
- info.entry_number = idx;
- info.base_addr = GET_BASE(desc);
- info.limit = GET_LIMIT(desc);
- info.seg_32bit = GET_32BIT(desc);
- info.contents = GET_CONTENTS(desc);
- info.read_exec_only = !GET_WRITABLE(desc);
- info.limit_in_pages = GET_LIMIT_PAGES(desc);
- info.seg_not_present = !GET_PRESENT(desc);
- info.useable = GET_USEABLE(desc);
-
- if (copy_to_user(u_info, &info, sizeof(info)))
- return -EFAULT;
- return 0;
-}
-
unsigned long arch_align_stack(unsigned long sp)
{
if (!(current->personality & ADDR_NO_RANDOMIZE) && randomize_va_space)
diff --git a/arch/x86/kernel/process_64.c b/arch/x86/kernel/process_64.c
index b8d131d..3fdbf78 100644
--- a/arch/x86/kernel/process_64.c
+++ b/arch/x86/kernel/process_64.c
@@ -513,7 +513,8 @@ int copy_thread(int nr, unsigned long clone_flags, unsigned long rsp,
if (clone_flags & CLONE_SETTLS) {
#ifdef CONFIG_IA32_EMULATION
if (test_thread_flag(TIF_IA32))
- err = ia32_child_tls(p, childregs);
+ err = do_set_thread_area(p, -1,
+ (struct user_desc __user *)childregs->rsi, 0);
else
#endif
err = do_arch_prctl(p, ARCH_SET_FS, childregs->r8);
diff --git a/arch/x86/kernel/ptrace_32.c b/arch/x86/kernel/ptrace_32.c
index ff5431c..39a94a0 100644
--- a/arch/x86/kernel/ptrace_32.c
+++ b/arch/x86/kernel/ptrace_32.c
@@ -276,85 +276,6 @@ void ptrace_disable(struct task_struct *child)
clear_tsk_thread_flag(child, TIF_SYSCALL_EMU);
}
-/*
- * Perform get_thread_area on behalf of the traced child.
- */
-static int
-ptrace_get_thread_area(struct task_struct *child,
- int idx, struct user_desc __user *user_desc)
-{
- struct user_desc info;
- struct desc_struct *desc;
-
-/*
- * Get the current Thread-Local Storage area:
- */
-
-#define GET_BASE(desc) ( \
- (((desc)->a >> 16) & 0x0000ffff) | \
- (((desc)->b << 16) & 0x00ff0000) | \
- ( (desc)->b & 0xff000000) )
-
-#define GET_LIMIT(desc) ( \
- ((desc)->a & 0x0ffff) | \
- ((desc)->b & 0xf0000) )
-
-#define GET_32BIT(desc) (((desc)->b >> 22) & 1)
-#define GET_CONTENTS(desc) (((desc)->b >> 10) & 3)
-#define GET_WRITABLE(desc) (((desc)->b >> 9) & 1)
-#define GET_LIMIT_PAGES(desc) (((desc)->b >> 23) & 1)
-#define GET_PRESENT(desc) (((desc)->b >> 15) & 1)
-#define GET_USEABLE(desc) (((desc)->b >> 20) & 1)
-
- if (idx < GDT_ENTRY_TLS_MIN || idx > GDT_ENTRY_TLS_MAX)
- return -EINVAL;
-
- desc = child->thread.tls_array + idx - GDT_ENTRY_TLS_MIN;
-
- info.entry_number = idx;
- info.base_addr = GET_BASE(desc);
- info.limit = GET_LIMIT(desc);
- info.seg_32bit = GET_32BIT(desc);
- info.contents = GET_CONTENTS(desc);
- info.read_exec_only = !GET_WRITABLE(desc);
- info.limit_in_pages = GET_LIMIT_PAGES(desc);
- info.seg_not_present = !GET_PRESENT(desc);
- info.useable = GET_USEABLE(desc);
-
- if (copy_to_user(user_desc, &info, sizeof(info)))
- return -EFAULT;
-
- return 0;
-}
-
-/*
- * Perform set_thread_area on behalf of the traced child.
- */
-static int
-ptrace_set_thread_area(struct task_struct *child,
- int idx, struct user_desc __user *user_desc)
-{
- struct user_desc info;
- struct desc_struct *desc;
-
- if (copy_from_user(&info, user_desc, sizeof(info)))
- return -EFAULT;
-
- if (idx < GDT_ENTRY_TLS_MIN || idx > GDT_ENTRY_TLS_MAX)
- return -EINVAL;
-
- desc = child->thread.tls_array + idx - GDT_ENTRY_TLS_MIN;
- if (LDT_empty(&info)) {
- desc->a = 0;
- desc->b = 0;
- } else {
- desc->a = LDT_entry_a(&info);
- desc->b = LDT_entry_b(&info);
- }
-
- return 0;
-}
-
long arch_ptrace(struct task_struct *child, long request, long addr, long data)
{
struct user * dummy = NULL;
@@ -601,13 +522,17 @@ long arch_ptrace(struct task_struct *child, long request, long addr, long data)
}
case PTRACE_GET_THREAD_AREA:
- ret = ptrace_get_thread_area(child, addr,
- (struct user_desc __user *) data);
+ if (addr < 0)
+ return -EIO;
+ ret = do_get_thread_area(child, addr,
+ (struct user_desc __user *) data);
break;
case PTRACE_SET_THREAD_AREA:
- ret = ptrace_set_thread_area(child, addr,
- (struct user_desc __user *) data);
+ if (addr < 0)
+ return -EIO;
+ ret = do_set_thread_area(child, addr,
+ (struct user_desc __user *) data, 0);
break;
default:
diff --git a/arch/x86/kernel/ptrace_64.c b/arch/x86/kernel/ptrace_64.c
index 3ff7ddc..07de75d 100644
--- a/arch/x86/kernel/ptrace_64.c
+++ b/arch/x86/kernel/ptrace_64.c
@@ -474,23 +474,19 @@ long arch_ptrace(struct task_struct *child, long request, long addr, long data)
64bit debugger to fully examine them too. Better
don't use it against 64bit processes, use
PTRACE_ARCH_PRCTL instead. */
- case PTRACE_SET_THREAD_AREA: {
- struct user_desc __user *p;
- int old;
- p = (struct user_desc __user *)data;
- get_user(old, &p->entry_number);
- put_user(addr, &p->entry_number);
- ret = do_set_thread_area(&child->thread, p);
- put_user(old, &p->entry_number);
- break;
case PTRACE_GET_THREAD_AREA:
- p = (struct user_desc __user *)data;
- get_user(old, &p->entry_number);
- put_user(addr, &p->entry_number);
- ret = do_get_thread_area(&child->thread, p);
- put_user(old, &p->entry_number);
+ if (addr < 0)
+ return -EIO;
+ ret = do_get_thread_area(child, addr,
+ (struct user_desc __user *) data);
+
+ break;
+ case PTRACE_SET_THREAD_AREA:
+ if (addr < 0)
+ return -EIO;
+ ret = do_set_thread_area(child, addr,
+ (struct user_desc __user *) data, 0);
break;
- }
#endif
/* normal 64bit interface to access TLS data.
Works just like arch_prctl, except that the arguments
diff --git a/arch/x86/kernel/tls.c b/arch/x86/kernel/tls.c
index 5291596..0a1a744 100644
--- a/arch/x86/kernel/tls.c
+++ b/arch/x86/kernel/tls.c
@@ -19,31 +19,34 @@ static int get_free_idx(void)
int idx;
for (idx = 0; idx < GDT_ENTRY_TLS_ENTRIES; idx++)
- if (desc_empty((struct n_desc_struct *)(t->tls_array) + idx))
+ if (desc_empty(&t->tls_array[idx]))
return idx + GDT_ENTRY_TLS_MIN;
return -ESRCH;
}
/*
* Set a given TLS descriptor:
- * When you want addresses > 32bit use arch_prctl()
*/
-int do_set_thread_area(struct thread_struct *t, struct user_desc __user *u_info)
+int do_set_thread_area(struct task_struct *p, int idx,
+ struct user_desc __user *u_info,
+ int can_allocate)
{
+ struct thread_struct *t = &p->thread;
struct user_desc info;
- struct n_desc_struct *desc;
- int cpu, idx;
+ u32 *desc;
+ int cpu;
if (copy_from_user(&info, u_info, sizeof(info)))
return -EFAULT;
- idx = info.entry_number;
+ if (idx == -1)
+ idx = info.entry_number;
/*
* index -1 means the kernel should try to find and
* allocate an empty descriptor:
*/
- if (idx == -1) {
+ if (idx == -1 && can_allocate) {
idx = get_free_idx();
if (idx < 0)
return idx;
@@ -54,7 +57,7 @@ int do_set_thread_area(struct thread_struct *t, struct user_desc __user *u_info)
if (idx < GDT_ENTRY_TLS_MIN || idx > GDT_ENTRY_TLS_MAX)
return -EINVAL;
- desc = ((struct n_desc_struct *)t->tls_array) + idx - GDT_ENTRY_TLS_MIN;
+ desc = (u32 *) &t->tls_array[idx - GDT_ENTRY_TLS_MIN];
/*
* We must not get preempted while modifying the TLS.
@@ -62,11 +65,11 @@ int do_set_thread_area(struct thread_struct *t, struct user_desc __user *u_info)
cpu = get_cpu();
if (LDT_empty(&info)) {
- desc->a = 0;
- desc->b = 0;
+ desc[0] = 0;
+ desc[1] = 0;
} else {
- desc->a = LDT_entry_a(&info);
- desc->b = LDT_entry_b(&info);
+ desc[0] = LDT_entry_a(&info);
+ desc[1] = LDT_entry_b(&info);
}
if (t == ¤t->thread)
load_TLS(t, cpu);
@@ -75,9 +78,9 @@ int do_set_thread_area(struct thread_struct *t, struct user_desc __user *u_info)
return 0;
}
-asmlinkage long sys32_set_thread_area(struct user_desc __user *u_info)
+asmlinkage int sys_set_thread_area(struct user_desc __user *u_info)
{
- return do_set_thread_area(¤t->thread, u_info);
+ return do_set_thread_area(current, -1, u_info, 1);
}
@@ -86,33 +89,34 @@ asmlinkage long sys32_set_thread_area(struct user_desc __user *u_info)
*/
#define GET_LIMIT(desc) ( \
- ((desc)->a & 0x0ffff) | \
- ((desc)->b & 0xf0000) )
-
-#define GET_32BIT(desc) (((desc)->b >> 22) & 1)
-#define GET_CONTENTS(desc) (((desc)->b >> 10) & 3)
-#define GET_WRITABLE(desc) (((desc)->b >> 9) & 1)
-#define GET_LIMIT_PAGES(desc) (((desc)->b >> 23) & 1)
-#define GET_PRESENT(desc) (((desc)->b >> 15) & 1)
-#define GET_USEABLE(desc) (((desc)->b >> 20) & 1)
-#define GET_LONGMODE(desc) (((desc)->b >> 21) & 1)
-
-int do_get_thread_area(struct thread_struct *t, struct user_desc __user *u_info)
+ ((desc)[0] & 0x0ffff) | \
+ ((desc)[1] & 0xf0000) )
+
+#define GET_32BIT(desc) (((desc)[1] >> 22) & 1)
+#define GET_CONTENTS(desc) (((desc)[1] >> 10) & 3)
+#define GET_WRITABLE(desc) (((desc)[1] >> 9) & 1)
+#define GET_LIMIT_PAGES(desc) (((desc)[1] >> 23) & 1)
+#define GET_PRESENT(desc) (((desc)[1] >> 15) & 1)
+#define GET_USEABLE(desc) (((desc)[1] >> 20) & 1)
+#define GET_LONGMODE(desc) (((desc)[1] >> 21) & 1)
+
+int do_get_thread_area(struct task_struct *p, int idx,
+ struct user_desc __user *u_info)
{
+ struct thread_struct *t = &p->thread;
struct user_desc info;
- struct n_desc_struct *desc;
- int idx;
+ u32 *desc;
- if (get_user(idx, &u_info->entry_number))
+ if (idx == -1 && get_user(idx, &u_info->entry_number))
return -EFAULT;
if (idx < GDT_ENTRY_TLS_MIN || idx > GDT_ENTRY_TLS_MAX)
return -EINVAL;
- desc = ((struct n_desc_struct *)t->tls_array) + idx - GDT_ENTRY_TLS_MIN;
+ desc = (u32 *) &t->tls_array[idx - GDT_ENTRY_TLS_MIN];
memset(&info, 0, sizeof(struct user_desc));
info.entry_number = idx;
- info.base_addr = get_desc_base(desc);
+ info.base_addr = get_desc_base((void *)desc);
info.limit = GET_LIMIT(desc);
info.seg_32bit = GET_32BIT(desc);
info.contents = GET_CONTENTS(desc);
@@ -120,39 +124,16 @@ int do_get_thread_area(struct thread_struct *t, struct user_desc __user *u_info)
info.limit_in_pages = GET_LIMIT_PAGES(desc);
info.seg_not_present = !GET_PRESENT(desc);
info.useable = GET_USEABLE(desc);
+#ifdef CONFIG_X86_64
info.lm = GET_LONGMODE(desc);
+#endif
if (copy_to_user(u_info, &info, sizeof(info)))
return -EFAULT;
return 0;
}
-asmlinkage long sys32_get_thread_area(struct user_desc __user *u_info)
-{
- return do_get_thread_area(¤t->thread, u_info);
-}
-
-
-int ia32_child_tls(struct task_struct *p, struct pt_regs *childregs)
+asmlinkage int sys_get_thread_area(struct user_desc __user *u_info)
{
- struct n_desc_struct *desc;
- struct user_desc info;
- struct user_desc __user *cp;
- int idx;
-
- cp = (void __user *)childregs->rsi;
- if (copy_from_user(&info, cp, sizeof(info)))
- return -EFAULT;
- if (LDT_empty(&info))
- return -EINVAL;
-
- idx = info.entry_number;
- if (idx < GDT_ENTRY_TLS_MIN || idx > GDT_ENTRY_TLS_MAX)
- return -EINVAL;
-
- desc = (struct n_desc_struct *)(p->thread.tls_array) + idx - GDT_ENTRY_TLS_MIN;
- desc->a = LDT_entry_a(&info);
- desc->b = LDT_entry_b(&info);
-
- return 0;
+ return do_get_thread_area(current, -1, u_info);
}
diff --git a/include/asm-x86/ia32.h b/include/asm-x86/ia32.h
index 0190b7c..aa97332 100644
--- a/include/asm-x86/ia32.h
+++ b/include/asm-x86/ia32.h
@@ -159,12 +159,6 @@ struct ustat32 {
#define IA32_STACK_TOP IA32_PAGE_OFFSET
#ifdef __KERNEL__
-struct user_desc;
-struct siginfo_t;
-int do_get_thread_area(struct thread_struct *t, struct user_desc __user *info);
-int do_set_thread_area(struct thread_struct *t, struct user_desc __user *info);
-int ia32_child_tls(struct task_struct *p, struct pt_regs *childregs);
-
struct linux_binprm;
extern int ia32_setup_arg_pages(struct linux_binprm *bprm,
unsigned long stack_top, int exec_stack);
diff --git a/include/asm-x86/ptrace.h b/include/asm-x86/ptrace.h
index 51ddb25..105d153 100644
--- a/include/asm-x86/ptrace.h
+++ b/include/asm-x86/ptrace.h
@@ -137,6 +137,17 @@ enum {
};
#endif /* __KERNEL__ */
#endif /* !__i386__ */
+
+#ifdef __KERNEL__
+
+struct user_desc;
+extern int do_get_thread_area(struct task_struct *p, int idx,
+ struct user_desc __user *info);
+extern int do_set_thread_area(struct task_struct *p, int idx,
+ struct user_desc __user *info, int can_allocate);
+
+#endif /* __KERNEL__ */
+
#endif /* !__ASSEMBLY__ */
#endif
-
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