sparc64: clear syscall_noerror on the entry to syscall, not on the exit

Move that sucker to just before TI_FPDEPTH and replace stb with sth in
etrap_save().  Take current_ds to its old place, so that we don't push
wsaved into TI_... flags.  That allows to lose clearing syscall_noerror
on return from syscall.

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

9 files changed, 29 insertions, 30 deletions

diff --git a/arch/sparc/include/asm/ptrace.h b/arch/sparc/include/asm/ptrace.h
index 0c6f6b068289..5b6019e327e5 100644
--- a/arch/sparc/include/asm/ptrace.h
+++ b/arch/sparc/include/asm/ptrace.h
@@ -44,9 +44,7 @@ struct global_reg_snapshot {
 };
 extern struct global_reg_snapshot global_reg_snapshot[NR_CPUS];
 
-#define force_successful_syscall_return()           \
-do {    current_thread_info()->syscall_noerror = 1; \
-} while (0)
+#define force_successful_syscall_return() set_thread_noerror(1)
 #define user_mode(regs) (!((regs)->tstate & TSTATE_PRIV))
 #define instruction_pointer(regs) ((regs)->tpc)
 #define instruction_pointer_set(regs, val) ((regs)->tpc = (val))
diff --git a/arch/sparc/include/asm/switch_to_64.h b/arch/sparc/include/asm/switch_to_64.h
index 7923c4a2be38..cad36f56fa03 100644
--- a/arch/sparc/include/asm/switch_to_64.h
+++ b/arch/sparc/include/asm/switch_to_64.h
@@ -23,7 +23,7 @@ do {	flush_tlb_pending();						\
         /* If you are tempted to conditionalize the following */        \
         /* so that ASI is only written if it changes, think again. */   \
         __asm__ __volatile__("wr %%g0, %0, %%asi"                       \
-        : : "r" (__thread_flag_byte_ptr(task_thread_info(next))[TI_FLAG_BYTE_CURRENT_DS]));\
+        : : "r" (task_thread_info(next)->current_ds));\
         trap_block[current_thread_info()->cpu].thread =                 \
                 task_thread_info(next);                                 \
         __asm__ __volatile__(                                           \
diff --git a/arch/sparc/include/asm/thread_info_64.h b/arch/sparc/include/asm/thread_info_64.h
index 4e2276631081..ea2ba22d595a 100644
--- a/arch/sparc/include/asm/thread_info_64.h
+++ b/arch/sparc/include/asm/thread_info_64.h
@@ -14,12 +14,12 @@
 #define TI_FLAG_FAULT_CODE_SHIFT        56
 #define TI_FLAG_BYTE_WSTATE             1
 #define TI_FLAG_WSTATE_SHIFT            48
-#define TI_FLAG_BYTE_CWP                2
-#define TI_FLAG_CWP_SHIFT               40
-#define TI_FLAG_BYTE_CURRENT_DS         3
-#define TI_FLAG_CURRENT_DS_SHIFT        32
-#define TI_FLAG_BYTE_FPDEPTH            4
-#define TI_FLAG_FPDEPTH_SHIFT           24
+#define TI_FLAG_BYTE_NOERROR            2
+#define TI_FLAG_BYTE_NOERROR_SHIFT      40
+#define TI_FLAG_BYTE_FPDEPTH            3
+#define TI_FLAG_FPDEPTH_SHIFT           32
+#define TI_FLAG_BYTE_CWP                4
+#define TI_FLAG_CWP_SHIFT               24
 #define TI_FLAG_BYTE_WSAVED             5
 #define TI_FLAG_WSAVED_SHIFT            16
 
@@ -47,7 +47,7 @@ struct thread_info {
         struct exec_domain      *exec_domain;
         int                     preempt_count;  /* 0 => preemptable, <0 => BUG */
         __u8                    new_child;
-        __u8                    syscall_noerror;
+        __u8                    current_ds;
         __u16                   cpu;
 
         unsigned long           *utraps;
@@ -74,9 +74,9 @@ struct thread_info {
 #define TI_FAULT_CODE   (TI_FLAGS + TI_FLAG_BYTE_FAULT_CODE)
 #define TI_WSTATE       (TI_FLAGS + TI_FLAG_BYTE_WSTATE)
 #define TI_CWP          (TI_FLAGS + TI_FLAG_BYTE_CWP)
-#define TI_CURRENT_DS   (TI_FLAGS + TI_FLAG_BYTE_CURRENT_DS)
 #define TI_FPDEPTH      (TI_FLAGS + TI_FLAG_BYTE_FPDEPTH)
 #define TI_WSAVED       (TI_FLAGS + TI_FLAG_BYTE_WSAVED)
+#define TI_SYS_NOERROR  (TI_FLAGS + TI_FLAG_BYTE_NOERROR)
 #define TI_FPSAVED      0x00000010
 #define TI_KSP          0x00000018
 #define TI_FAULT_ADDR   0x00000020
@@ -84,7 +84,7 @@ struct thread_info {
 #define TI_EXEC_DOMAIN  0x00000030
 #define TI_PRE_COUNT    0x00000038
 #define TI_NEW_CHILD    0x0000003c
-#define TI_SYS_NOERROR  0x0000003d
+#define TI_CURRENT_DS   0x0000003d
 #define TI_CPU          0x0000003e
 #define TI_UTRAPS       0x00000040
 #define TI_REG_WINDOW   0x00000048
@@ -121,7 +121,7 @@ struct thread_info {
 #define INIT_THREAD_INFO(tsk)                           \
 {                                                       \
         .task           =       &tsk,                   \
-        .flags          = ((unsigned long)ASI_P) << TI_FLAG_CURRENT_DS_SHIFT,   \
+        .current_ds     =       ASI_P,                  \
         .exec_domain    =       &default_exec_domain,   \
         .preempt_count  =       INIT_PREEMPT_COUNT,     \
         .restart_block  = {                             \
@@ -153,13 +153,12 @@ register struct thread_info *current_thread_info_reg asm("g6");
 #define set_thread_wstate(val)          (__cur_thread_flag_byte_ptr[TI_FLAG_BYTE_WSTATE] = (val))
 #define get_thread_cwp()                (__cur_thread_flag_byte_ptr[TI_FLAG_BYTE_CWP])
 #define set_thread_cwp(val)             (__cur_thread_flag_byte_ptr[TI_FLAG_BYTE_CWP] = (val))
-#define get_thread_current_ds()         (__cur_thread_flag_byte_ptr[TI_FLAG_BYTE_CURRENT_DS])
-#define set_thread_current_ds(val)      (__cur_thread_flag_byte_ptr[TI_FLAG_BYTE_CURRENT_DS] = (val))
+#define get_thread_noerror()            (__cur_thread_flag_byte_ptr[TI_FLAG_BYTE_NOERROR])
+#define set_thread_noerror(val)         (__cur_thread_flag_byte_ptr[TI_FLAG_BYTE_NOERROR] = (val))
 #define get_thread_fpdepth()            (__cur_thread_flag_byte_ptr[TI_FLAG_BYTE_FPDEPTH])
 #define set_thread_fpdepth(val)         (__cur_thread_flag_byte_ptr[TI_FLAG_BYTE_FPDEPTH] = (val))
 #define get_thread_wsaved()             (__cur_thread_flag_byte_ptr[TI_FLAG_BYTE_WSAVED])
 #define set_thread_wsaved(val)          (__cur_thread_flag_byte_ptr[TI_FLAG_BYTE_WSAVED] = (val))
-
 #endif /* !(__ASSEMBLY__) */
 
 /*
diff --git a/arch/sparc/include/asm/uaccess_64.h b/arch/sparc/include/asm/uaccess_64.h
index 73083e1d38d9..e562d3caee57 100644
--- a/arch/sparc/include/asm/uaccess_64.h
+++ b/arch/sparc/include/asm/uaccess_64.h
@@ -38,14 +38,14 @@
 #define VERIFY_READ     0
 #define VERIFY_WRITE    1
 
-#define get_fs() ((mm_segment_t) { get_thread_current_ds() })
+#define get_fs() ((mm_segment_t){(current_thread_info()->current_ds)})
 #define get_ds() (KERNEL_DS)
 
 #define segment_eq(a,b)  ((a).seg == (b).seg)
 
 #define set_fs(val)                                                             \
 do {                                                                            \
-        set_thread_current_ds((val).seg);                                       \
+        current_thread_info()->current_ds =(val).seg;                           \
         __asm__ __volatile__ ("wr %%g0, %0, %%asi" : : "r" ((val).seg));        \
 } while(0)
 
diff --git a/arch/sparc/kernel/etrap_64.S b/arch/sparc/kernel/etrap_64.S
index 786b185e6e3f..1276ca2567ba 100644
--- a/arch/sparc/kernel/etrap_64.S
+++ b/arch/sparc/kernel/etrap_64.S
@@ -92,8 +92,10 @@ etrap_save:	save	%g2, -STACK_BIAS, %sp
                 rdpr    %wstate, %g2
                 wrpr    %g0, 0, %canrestore
                 sll     %g2, 3, %g2
+
+                /* Set TI_SYS_FPDEPTH to 1 and clear TI_SYS_NOERROR.  */
                 mov     1, %l5
-                stb     %l5, [%l6 + TI_FPDEPTH]
+                sth     %l5, [%l6 + TI_SYS_NOERROR]
 
                 wrpr    %g3, 0, %otherwin
                 wrpr    %g2, 0, %wstate
@@ -152,7 +154,9 @@ etrap_save:	save	%g2, -STACK_BIAS, %sp
                 add     %l6, TI_FPSAVED + 1, %l4
                 srl     %l5, 1, %l3
                 add     %l5, 2, %l5
-                stb     %l5, [%l6 + TI_FPDEPTH]
+
+                /* Set TI_SYS_FPDEPTH to %l5 and clear TI_SYS_NOERROR.  */
+                sth     %l5, [%l6 + TI_SYS_NOERROR]
                 ba,pt   %xcc, 2b
                  stb    %g0, [%l4 + %l3]
                 nop
diff --git a/arch/sparc/kernel/process_64.c b/arch/sparc/kernel/process_64.c
index fcaa59421126..4c864c796507 100644
--- a/arch/sparc/kernel/process_64.c
+++ b/arch/sparc/kernel/process_64.c
@@ -557,9 +557,8 @@ int copy_thread(unsigned long clone_flags, unsigned long sp,
                             (THREAD_SIZE - child_stack_sz));
         memcpy(child_trap_frame, parent_sf, child_stack_sz);
 
-        t->flags = (t->flags & ~((0xffUL << TI_FLAG_CWP_SHIFT) |
-                                 (0xffUL << TI_FLAG_CURRENT_DS_SHIFT))) |
-                (((regs->tstate + 1) & TSTATE_CWP) << TI_FLAG_CWP_SHIFT);
+        __thread_flag_byte_ptr(t)[TI_FLAG_BYTE_CWP] = 
+                (regs->tstate + 1) & TSTATE_CWP;
         t->new_child = 1;
         t->ksp = ((unsigned long) child_trap_frame) - STACK_BIAS;
         t->kregs = (struct pt_regs *) (child_trap_frame +
@@ -575,7 +574,7 @@ int copy_thread(unsigned long clone_flags, unsigned long sp,
                 t->kregs->u_regs[UREG_FP] =
                   ((unsigned long) child_sf) - STACK_BIAS;
 
-                t->flags |= ((long)ASI_P << TI_FLAG_CURRENT_DS_SHIFT);
+                t->current_ds = ASI_P;
                 t->kregs->u_regs[UREG_G6] = (unsigned long) t;
                 t->kregs->u_regs[UREG_G4] = (unsigned long) t->task;
         } else {
@@ -584,7 +583,7 @@ int copy_thread(unsigned long clone_flags, unsigned long sp,
                         regs->u_regs[UREG_FP] &= 0x00000000ffffffffUL;
                 }
                 t->kregs->u_regs[UREG_FP] = sp;
-                t->flags |= ((long)ASI_AIUS << TI_FLAG_CURRENT_DS_SHIFT);
+                t->current_ds = ASI_AIUS;
                 if (sp != regs->u_regs[UREG_FP]) {
                         unsigned long csp;
 
diff --git a/arch/sparc/kernel/syscalls.S b/arch/sparc/kernel/syscalls.S
index 7f5f65d0b3fd..b0ac10306425 100644
--- a/arch/sparc/kernel/syscalls.S
+++ b/arch/sparc/kernel/syscalls.S
@@ -222,7 +222,6 @@ ret_sys_call:
         ldx     [%sp + PTREGS_OFF + PT_V9_TNPC], %l1 ! pc = npc
 
 2:
-        stb     %g0, [%g6 + TI_SYS_NOERROR]
         /* System call success, clear Carry condition code. */
         andn    %g3, %g2, %g3
 3:
diff --git a/arch/sparc/kernel/traps_64.c b/arch/sparc/kernel/traps_64.c
index b66a77968f35..e7ecf1507d90 100644
--- a/arch/sparc/kernel/traps_64.c
+++ b/arch/sparc/kernel/traps_64.c
@@ -2688,8 +2688,8 @@ void __init trap_init(void)
                      TI_PRE_COUNT != offsetof(struct thread_info,
                                               preempt_count) ||
                      TI_NEW_CHILD != offsetof(struct thread_info, new_child) ||
-                     TI_SYS_NOERROR != offsetof(struct thread_info,
-                                                syscall_noerror) ||
+                     TI_CURRENT_DS != offsetof(struct thread_info,
+                                                current_ds) ||
                      TI_RESTART_BLOCK != offsetof(struct thread_info,
                                                   restart_block) ||
                      TI_KUNA_REGS != offsetof(struct thread_info,
diff --git a/arch/sparc/mm/init_64.c b/arch/sparc/mm/init_64.c
index 9e28a118e6a4..85be1ca539b2 100644
--- a/arch/sparc/mm/init_64.c
+++ b/arch/sparc/mm/init_64.c
@@ -624,7 +624,7 @@ static void __init inherit_prom_mappings(void)
 void prom_world(int enter)
 {
         if (!enter)
-                set_fs((mm_segment_t) { get_thread_current_ds() });
+                set_fs(get_fs());
 
         __asm__ __volatile__("flushw");
 }