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

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>

diff --git a/arch/x86/entry/vsyscall/vsyscall_64.c b/arch/x86/entry/vsyscall/vsyscall_64.c
index 174c254..3aba2b0 100644 (file)
--- 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 62c6cc3..f53ae57 100644 (file)
--- 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 30c133a..7c47bb6 100644 (file)
--- 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 d40ec72..8f66e56 100644 (file)
--- 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 4bb53b8..0f90cc2 100644 (file)
--- 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 ca44e2e..69be03d 100644 (file)
--- 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;