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This defines the get_desc_base function in asm-x86/desc_64.h to match the
one in desc_32.h. If these two files ever get merged together, this
function could be the same in both.
Signed-off-by: Roland McGrath <roland@redhat.com>
diff --git a/include/asm-x86/desc_64.h b/include/asm-x86/desc_64.h
index 7d9c938..70bd72f 100644
--- a/include/asm-x86/desc_64.h
+++ b/include/asm-x86/desc_64.h
@@ -199,6 +199,16 @@ static inline void load_LDT(mm_context_t *pc)
extern struct desc_ptr idt_descr;
+static inline unsigned long get_desc_base(const void *ptr)
+{
+ const u32 *desc = ptr;
+ unsigned long base;
+ base = ((desc[0] >> 16) & 0x0000ffff) |
+ ((desc[1] << 16) & 0x00ff0000) |
+ (desc[1] & 0xff000000);
+ return base;
+}
+
#endif /* !__ASSEMBLY__ */
#endif
-
This changes a couple of places to use the get_desc_base function.
They were duplicating the same calculation with different equivalent code.
Signed-off-by: Roland McGrath <roland@redhat.com>
diff --git a/arch/x86/ia32/tls32.c b/arch/x86/ia32/tls32.c
index 1cc4340..5291596 100644
--- a/arch/x86/ia32/tls32.c
+++ b/arch/x86/ia32/tls32.c
@@ -85,11 +85,6 @@ asmlinkage long sys32_set_thread_area(struct user_desc __user *u_info)
* 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) )
@@ -117,7 +112,7 @@ int do_get_thread_area(struct thread_struct *t, struct user_desc __user *u_info)
memset(&info, 0, sizeof(struct user_desc));
info.entry_number = idx;
- info.base_addr = GET_BASE(desc);
+ info.base_addr = get_desc_base(desc);
info.limit = GET_LIMIT(desc);
info.seg_32bit = GET_32BIT(desc);
info.contents = GET_CONTENTS(desc);
diff --git a/arch/x86/kernel/process_64.c b/arch/x86/kernel/process_64.c
index 6309b27..b8d131d 100644
--- a/arch/x86/kernel/process_64.c
+++ b/arch/x86/kernel/process_64.c
@@ -453,11 +453,7 @@ static inline void set_32bit_tls(struct task_struct *t, int tls, u32 addr)
static inline u32 read_32bit_tls(struct task_struct *t, int tls)
{
- struct desc_struct *desc = (void *)t->thread.tls_array;
- desc += tls;
- return desc->base0 |
- (((u32)desc->base1) << 16) |
- (((u32)desc->base2) << 24);
+ return get_desc_base(&t->thread.tls_array[tls]);
}
/*
-
Are you sure there still aren't more of these things floating around? I recall ptrace and process.c even having one at one point, hopefully they are all gone. Nice cleanups, Zach -
The fs_base and gs_base fields are available in user_regs_struct. But reading these via ptrace (PTRACE_GETREGS or PTRACE_PEEKUSR) does not give a reliably useful value. The thread_struct fields are 0 when do_arch_prctl decided to use a GDT slot instead of MSR_FS_BASE, which it does for a value under 1<<32. This changes ptrace access to fs_base and gs_base to work like PTRACE_ARCH_PRCTL does. That is, it reads the base address that user-mode memory access using the fs/gs instruction prefixes will use, regardless of how it's being implemented in the kernel. The MSR vs GDT is an implementation detail that is pretty much hidden from userland in the actual using, and there is no reason that ptrace should give the internal implementation picture rather than the user-mode semantic picture. In the case of setting the value, this can implicitly change the fsindex/gsindex value (also separately in user_regs_struct), which is what happens when the thread calls arch_prctl itself. In a PTRACE_SETREGS, the fs_base change will come after the fsindex change due to the order of the struct, and so a change the debugger made to fs_base will have the effect intended, another part of the user_regs_struct will now differ when read back from what the debugger wrote. This makes PTRACE_ARCH_PRCTL obsolete. We could consider declaring it deprecated and removing it one day, though there is no hurry. For the foreseeable future, debuggers have to assume an old kernel that does not report reliable fs_base/gs_base values in user_regs_struct and stick to PTRACE_ARCH_PRCTL anyway. Signed-off-by: Roland McGrath <roland@redhat.com> diff --git a/arch/x86/kernel/ptrace_64.c b/arch/x86/kernel/ptrace_64.c index 607085f..3ff7ddc 100644 --- a/arch/x86/kernel/ptrace_64.c +++ b/arch/x86/kernel/ptrace_64.c @@ -22,6 +22,7 @@ #include <asm/pgtable.h> #include <asm/system.h> #include <asm/processor.h> +#include <asm/prctl.h> #include <asm/i387.h> #include <asm/debugreg.h> #include <asm/ldt.h> @@ ...
This replaces the desc_empty macro with an inline. It now handles
easily any of the four different types used between 32/64 code to
refer to these 8 bytes. It's identical in both asm-x86/processor_64.h
and asm-x86/processor_32.h, so if these files ever get merged this
function can be in the common code.
This also removes the desc_equal macro because nothing uses it.
Signed-off-by: Roland McGrath <roland@redhat.com>
diff --git a/include/asm-x86/processor_32.h b/include/asm-x86/processor_32.h
index 13976b0..34e8063 100644
--- a/include/asm-x86/processor_32.h
+++ b/include/asm-x86/processor_32.h
@@ -30,11 +30,12 @@ struct desc_struct {
unsigned long a,b;
};
-#define desc_empty(desc) \
- (!((desc)->a | (desc)->b))
+static inline int desc_empty(const void *ptr)
+{
+ const u32 *desc = ptr;
+ return !(desc[0] | desc[1]);
+}
-#define desc_equal(desc1, desc2) \
- (((desc1)->a == (desc2)->a) && ((desc1)->b == (desc2)->b))
/*
* Default implementation of macro that returns current
* instruction pointer ("program counter").
diff --git a/include/asm-x86/processor_64.h b/include/asm-x86/processor_64.h
index e4f1997..2dd739a 100644
--- a/include/asm-x86/processor_64.h
+++ b/include/asm-x86/processor_64.h
@@ -32,11 +32,11 @@
#define VIP_MASK 0x00100000 /* virtual interrupt pending */
#define ID_MASK 0x00200000
-#define desc_empty(desc) \
- (!((desc)->a | (desc)->b))
-
-#define desc_equal(desc1, desc2) \
- (((desc1)->a == (desc2)->a) && ((desc1)->b == (desc2)->b))
+static inline int desc_empty(const void *ptr)
+{
+ const u32 *desc = ptr;
+ return !(desc[0] | desc[1]);
+}
/*
* Default implementation of macro that returns current
-
This consolidates the four different places that implemented the same
encoding magic for the GDT-slot 32-bit TLS support. The old tls32.c is
renamed and only slightly modified to be the shared implementation guts.
Signed-off-by: Roland McGrath <roland@redhat.com>
diff --git a/arch/x86/ia32/Makefile b/arch/x86/ia32/Makefile
index e2edda2..3c8b746 100644
--- a/arch/x86/ia32/Makefile
+++ b/arch/x86/ia32/Makefile
@@ -2,7 +2,7 @@
# Makefile for the ia32 kernel emulation subsystem.
#
-obj-$(CONFIG_IA32_EMULATION) := ia32entry.o sys_ia32.o ia32_signal.o tls32.o \
+obj-$(CONFIG_IA32_EMULATION) := ia32entry.o sys_ia32.o ia32_signal.o \
ia32_binfmt.o fpu32.o ptrace32.o syscall32.o syscall32_syscall.o \
mmap32.o
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/ia32/tls32.c b/arch/x86/ia32/tls32.c
deleted file mode 100644
index 5291596..0000000
--- a/arch/x86/ia32/tls32.c
+++ /dev/null
@@ -1,158 +0,0 @@
-#include <linux/kernel.h>
-#include <linux/errno.h>
-#include <linux/sched.h>
-#include <linux/user.h>
-
-#include <asm/uaccess.h>
-#include <asm/desc.h>
-#include <asm/system.h>
-#include <asm/ldt.h>
-#include <asm/processor.h>
-#include <asm/proto.h>
-
-/*
- * sys_alloc_thread_area: get a yet unused TLS descriptor index.
- */
-static int get_free_idx(void)
-{
- struct thread_struct *t = &current->thread;
- int idx;
-
- for (idx = 0; idx < GDT_ENTRY_TLS_ENTRIES; idx++)
- if (desc_empty((struct n_desc_struct *)(t->tls_array) + idx))
- return idx + ...Cool patchset. One minor nit: Please do not put stuff into proto.h anymore. I'm I pull it into the x86 git tree and look for a better place for do_[sg]et_thread_area() Thanks, tglx -
That was the other redundant definition, thanks. I had a bit of trouble verifying correctness here because of much brownian motion. Any possibility of a pure movement / fixup separation to make it easier on the eyes? Zach -
Yeah, sorry about that. It was late and the whole TLS thing was a sudden afterthought while I was in the middle of doing something else, so I didn't feel like slicing up the patch any more. And in my tree, GIT didn't even do so great a job with noticing this rename. I'll send a replacement. Thanks, Roland -
This renames arch/x86/ia32/tls32.c to arch/x86/kernel/tls.c, which does
nothing now but paves the way to consolidate this code for 32-bit too.
Signed-off-by: Roland McGrath <roland@redhat.com>
---
arch/x86/ia32/Makefile | 2 +-
arch/x86/ia32/tls32.c | 158 -------------------------------------------
arch/x86/kernel/Makefile_64 | 2 +
arch/x86/kernel/tls.c | 158 +++++++++++++++++++++++++++++++++++++++++++
4 files changed, 161 insertions(+), 159 deletions(-)
diff --git a/arch/x86/ia32/Makefile b/arch/x86/ia32/Makefile
index e2edda2..3c8b746 100644
--- a/arch/x86/ia32/Makefile
+++ b/arch/x86/ia32/Makefile
@@ -2,7 +2,7 @@
# Makefile for the ia32 kernel emulation subsystem.
#
-obj-$(CONFIG_IA32_EMULATION) := ia32entry.o sys_ia32.o ia32_signal.o tls32.o \
+obj-$(CONFIG_IA32_EMULATION) := ia32entry.o sys_ia32.o ia32_signal.o \
ia32_binfmt.o fpu32.o ptrace32.o syscall32.o syscall32_syscall.o \
mmap32.o
diff --git a/arch/x86/ia32/tls32.c b/arch/x86/ia32/tls32.c
deleted file mode 100644
index 5291596..0000000
--- a/arch/x86/ia32/tls32.c
+++ /dev/null
@@ -1,158 +0,0 @@
-#include <linux/kernel.h>
-#include <linux/errno.h>
-#include <linux/sched.h>
-#include <linux/user.h>
-
-#include <asm/uaccess.h>
-#include <asm/desc.h>
-#include <asm/system.h>
-#include <asm/ldt.h>
-#include <asm/processor.h>
-#include <asm/proto.h>
-
-/*
- * sys_alloc_thread_area: get a yet unused TLS descriptor index.
- */
-static int get_free_idx(void)
-{
- struct thread_struct *t = &current->thread;
- int idx;
-
- for (idx = 0; idx < GDT_ENTRY_TLS_ENTRIES; idx++)
- if (desc_empty((struct n_desc_struct *)(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)
-{
- struct user_desc info;
- struct n_desc_struct *desc;
- int cpu, idx;
-
- if ...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@redhat.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 ...