x86/uaccess: Move thread_info::uaccess_err and thread_info::sig_on_uaccess_err to thread_struct

struct thread_info is a legacy mess.  To prepare for its partial removal,
move the uaccess control fields out -- they're straightforward.

Signed-off-by: Andy Lutomirski <luto@kernel.org>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Brian Gerst <brgerst@gmail.com>
Cc: Denys Vlasenko <dvlasenk@redhat.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Josh Poimboeuf <jpoimboe@redhat.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: http://lkml.kernel.org/r/d0ac4d01c8e4d4d756264604e47445d5acc7900e.1468527351.git.luto@kernel.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>

6 files changed, 10 insertions, 9 deletions

diff --git a/arch/x86/entry/vsyscall/vsyscall_64.c b/arch/x86/entry/vsyscall/vsyscall_64.c
index 174c2549939d..3aba2b043050 100644
--- a/arch/x86/entry/vsyscall/vsyscall_64.c
+++ b/arch/x86/entry/vsyscall/vsyscall_64.c
@@ -221,8 +221,8 @@ bool emulate_vsyscall(struct pt_regs *regs, unsigned long address)
          * With a real vsyscall, page faults cause SIGSEGV.  We want to
          * preserve that behavior to make writing exploits harder.
          */
-        prev_sig_on_uaccess_error = current_thread_info()->sig_on_uaccess_error;
-        current_thread_info()->sig_on_uaccess_error = 1;
+        prev_sig_on_uaccess_error = current->thread.sig_on_uaccess_error;
+        current->thread.sig_on_uaccess_error = 1;
 
         ret = -EFAULT;
         switch (vsyscall_nr) {
@@ -243,7 +243,7 @@ bool emulate_vsyscall(struct pt_regs *regs, unsigned long address)
                 break;
         }
 
-        current_thread_info()->sig_on_uaccess_error = prev_sig_on_uaccess_error;
+        current->thread.sig_on_uaccess_error = prev_sig_on_uaccess_error;
 
 check_fault:
         if (ret == -EFAULT) {
diff --git a/arch/x86/include/asm/processor.h b/arch/x86/include/asm/processor.h
index 62c6cc3cc5d3..f53ae57bd985 100644
--- a/arch/x86/include/asm/processor.h
+++ b/arch/x86/include/asm/processor.h
@@ -419,6 +419,9 @@ struct thread_struct {
         /* Max allowed port in the bitmap, in bytes: */
         unsigned                io_bitmap_max;
 
+        unsigned int            sig_on_uaccess_error:1;
+        unsigned int            uaccess_err:1;  /* uaccess failed */
+
         /* Floating point and extended processor state */
         struct fpu              fpu;
         /*
diff --git a/arch/x86/include/asm/thread_info.h b/arch/x86/include/asm/thread_info.h
index 30c133ac05cd..7c47bb659ecd 100644
--- a/arch/x86/include/asm/thread_info.h
+++ b/arch/x86/include/asm/thread_info.h
@@ -58,8 +58,6 @@ struct thread_info {
         __u32                   status;         /* thread synchronous flags */
         __u32                   cpu;            /* current CPU */
         mm_segment_t            addr_limit;
-        unsigned int            sig_on_uaccess_error:1;
-        unsigned int            uaccess_err:1;  /* uaccess failed */
 };
 
 #define INIT_THREAD_INFO(tsk)                   \
diff --git a/arch/x86/include/asm/uaccess.h b/arch/x86/include/asm/uaccess.h
index d40ec723f799..8f66e5655c23 100644
--- a/arch/x86/include/asm/uaccess.h
+++ b/arch/x86/include/asm/uaccess.h
@@ -487,13 +487,13 @@ struct __large_struct { unsigned long buf[100]; };
  * uaccess_try and catch
  */
 #define uaccess_try     do {                                            \
-        current_thread_info()->uaccess_err = 0;                         \
+        current->thread.uaccess_err = 0;                                \
         __uaccess_begin();                                              \
         barrier();
 
 #define uaccess_catch(err)                                              \
         __uaccess_end();                                                \
-        (err) |= (current_thread_info()->uaccess_err ? -EFAULT : 0);    \
+        (err) |= (current->thread.uaccess_err ? -EFAULT : 0);           \
 } while (0)
 
 /**
diff --git a/arch/x86/mm/extable.c b/arch/x86/mm/extable.c
index 4bb53b89f3c5..0f90cc218d04 100644
--- a/arch/x86/mm/extable.c
+++ b/arch/x86/mm/extable.c
@@ -37,7 +37,7 @@ bool ex_handler_ext(const struct exception_table_entry *fixup,
                    struct pt_regs *regs, int trapnr)
 {
         /* Special hack for uaccess_err */
-        current_thread_info()->uaccess_err = 1;
+        current->thread.uaccess_err = 1;
         regs->ip = ex_fixup_addr(fixup);
         return true;
 }
diff --git a/arch/x86/mm/fault.c b/arch/x86/mm/fault.c
index ca44e2e7fd00..69be03d4aca6 100644
--- a/arch/x86/mm/fault.c
+++ b/arch/x86/mm/fault.c
@@ -737,7 +737,7 @@ no_context(struct pt_regs *regs, unsigned long error_code,
                  * In this case we need to make sure we're not recursively
                  * faulting through the emulate_vsyscall() logic.
                  */
-                if (current_thread_info()->sig_on_uaccess_error && signal) {
+                if (current->thread.sig_on_uaccess_error && signal) {
                         tsk->thread.trap_nr = X86_TRAP_PF;
                         tsk->thread.error_code = error_code | PF_USER;
                         tsk->thread.cr2 = address;