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authorAl Viro <viro@zeniv.linux.org.uk>2012-10-04 13:52:53 -0700
committerDavid S. Miller <davem@davemloft.net>2012-10-04 14:13:29 -0700
commit40138249c3b7a0762155216b963ec7fd4d09b5b4 (patch)
treebe0a2441aa7f7b3245e6de70cc4a8055031742f8 /arch/sparc
parentecefbd94b834fa32559d854646d777c56749ef1c (diff)
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sparc64: Rearrange thread info to cheaply clear syscall noerror state.
After fixing a couple of brainos, it even seems to work. What's done here is move of ->syscall_noerror right before FPDEPTH byte in ->flags and using sth to [%g6 + TI_SYS_NOERROR] instead of stb to [%g6 + TI_FPDEPTH] in both branches of etrap_save. AFAICS, that ought to be solid. Again, deciding what to do with now unused delay slot of branch on ->syscall_noerror and dealing with the order of tests in ret_from_sys is a separate question, but at least that way we don't have to clean ->syscall_noerror in there at all. AFAICS, it ought to be a clear win - sth is not going to cost more than stb on etrap_64.S side of things, and we are losing write on syscalls.S one. Signed-off-by: Al Viro <viro@zeniv.linux.org.uk> Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'arch/sparc')
-rw-r--r--arch/sparc/include/asm/ptrace.h4
-rw-r--r--arch/sparc/include/asm/thread_info_64.h16
-rw-r--r--arch/sparc/kernel/etrap_64.S8
-rw-r--r--arch/sparc/kernel/syscalls.S4
-rw-r--r--arch/sparc/kernel/traps_64.c2
5 files changed, 19 insertions, 15 deletions
diff --git a/arch/sparc/include/asm/ptrace.h b/arch/sparc/include/asm/ptrace.h
index fd9c3f2..eeed804 100644
--- a/arch/sparc/include/asm/ptrace.h
+++ b/arch/sparc/include/asm/ptrace.h
@@ -202,9 +202,7 @@ 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/thread_info_64.h b/arch/sparc/include/asm/thread_info_64.h
index cfa8c38..8511e5f 100644
--- a/arch/sparc/include/asm/thread_info_64.h
+++ b/arch/sparc/include/asm/thread_info_64.h
@@ -18,10 +18,12 @@
#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_NOERROR 4
+#define TI_FLAG_BYTE_NOERROR_SHIFT 24
+#define TI_FLAG_BYTE_FPDEPTH 5
+#define TI_FLAG_FPDEPTH_SHIFT 16
+#define TI_FLAG_BYTE_WSAVED 6
+#define TI_FLAG_WSAVED_SHIFT 8
#include <asm/page.h>
@@ -47,7 +49,7 @@ struct thread_info {
struct exec_domain *exec_domain;
int preempt_count; /* 0 => preemptable, <0 => BUG */
__u8 new_child;
- __u8 syscall_noerror;
+ __u8 __pad;
__u16 cpu;
unsigned long *utraps;
@@ -77,6 +79,7 @@ struct thread_info {
#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 +87,6 @@ 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_CPU 0x0000003e
#define TI_UTRAPS 0x00000040
#define TI_REG_WINDOW 0x00000048
@@ -155,6 +157,8 @@ register struct thread_info *current_thread_info_reg asm("g6");
#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])
diff --git a/arch/sparc/kernel/etrap_64.S b/arch/sparc/kernel/etrap_64.S
index 786b185..1276ca2 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/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 fa1f1d3..82af591 100644
--- a/arch/sparc/kernel/traps_64.c
+++ b/arch/sparc/kernel/traps_64.c
@@ -2547,8 +2547,6 @@ 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_RESTART_BLOCK != offsetof(struct thread_info,
restart_block) ||
TI_KUNA_REGS != offsetof(struct thread_info,
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