On Fri, Oct 05, 2012 at 05:48:42PM -0400, David Miller wrote:
>
> Al, this change turns out to be broken.
>
> If you move the WSAVED byte down past bit 16, it runs into the bit
> mask we for the _TI_* flag bits down lower in the file.
Umm... Right you are. I wonder why I hadn't stepped into that while
testing that sucker... Could we simply move current_ds at the place
we'd cleared from noerror and take wsaved at its place? AFAICS, that
ought to work without any penalties. IOW, something like this:
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@xxxxxxxxxxxxxxxxxx>
diff --git a/arch/sparc/include/asm/ptrace.h b/arch/sparc/include/asm/ptrace.h
index fd9c3f2..22142aa 100644
--- a/arch/sparc/include/asm/ptrace.h
+++ b/arch/sparc/include/asm/ptrace.h
@@ -203,7 +203,7 @@ 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; \
+do { ((u8 *)¤t_thread_info()->flags)[TI_FLAG_BYTE_NOERROR] = 1; \
} while (0)
#define user_mode(regs) (!((regs)->tstate & TSTATE_PRIV))
#define instruction_pointer(regs) ((regs)->tpc)
diff --git a/arch/sparc/include/asm/thread_info_64.h b/arch/sparc/include/asm/thread_info_64.h
index cfa8c38..8531205 100644
--- a/arch/sparc/include/asm/thread_info_64.h
+++ b/arch/sparc/include/asm/thread_info_64.h
@@ -16,12 +16,12 @@
#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_WSAVED 5
-#define TI_FLAG_WSAVED_SHIFT 16
+#define TI_FLAG_BYTE_WSAVED 3
+#define TI_FLAG_WSAVED_SHIFT 32
+#define TI_FLAG_BYTE_NOERROR 4
+#define TI_FLAG_BYTE_NOERROR_SHIFT 24
+#define TI_FLAG_BYTE_FPDEPTH 5
+#define TI_FLAG_FPDEPTH_SHIFT 16
#include <asm/page.h>
@@ -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
@@ -153,8 +153,8 @@ 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_current_ds() (current_thread_info()->current_ds)
+#define set_thread_current_ds(val) (current_thread_info()->current_ds = (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])
diff --git a/arch/sparc/kernel/etrap_64.S b/arch/sparc/kernel/etrap_64.S
index 786b185..759a2d3 100644
--- a/arch/sparc/kernel/etrap_64.S
+++ b/arch/sparc/kernel/etrap_64.S
@@ -93,7 +93,7 @@ etrap_save: save %g2, -STACK_BIAS, %sp
wrpr %g0, 0, %canrestore
sll %g2, 3, %g2
mov 1, %l5
- stb %l5, [%l6 + TI_FPDEPTH]
+ sth %l5, [%l6 + TI_SYS_NOERROR] ! set fpdepth, clear noerror
wrpr %g3, 0, %otherwin
wrpr %g2, 0, %wstate
@@ -152,7 +152,7 @@ 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]
+ sth %l5, [%l6 + TI_SYS_NOERROR] ! set fpdepth, clear noerror
ba,pt %xcc, 2b
stb %g0, [%l4 + %l3]
nop
diff --git a/arch/sparc/kernel/syscalls.S b/arch/sparc/kernel/syscalls.S
index 1d7e274..ed277e2 100644
--- a/arch/sparc/kernel/syscalls.S
+++ b/arch/sparc/kernel/syscalls.S
@@ -221,8 +221,8 @@ ret_sys_call:
* was invoked.
*/
ldub [%g6 + TI_SYS_NOERROR], %l2
- brnz,a,pn %l2, 80f
- stb %g0, [%g6 + TI_SYS_NOERROR]
+ brnz,pn %l2, 80f
+ nop
cmp %o0, -ERESTART_RESTARTBLOCK
bgeu,pn %xcc, 1f
diff --git a/arch/sparc/kernel/traps_64.c b/arch/sparc/kernel/traps_64.c
index 3b05e66..b3c337c 100644
--- a/arch/sparc/kernel/traps_64.c
+++ b/arch/sparc/kernel/traps_64.c
@@ -2547,8 +2547,8 @@ 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,
--
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