lkml.org 
[lkml]   [2014]   [Nov]   [1]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
Patch in this message
/
Date
From
Subject[PATCH] arch: tile: kernel: kgdb.c: Use memcpy() instead of pointer copy one by one
Not only memcpy() is faster than pointer copy, but also let code more
clearer and simple, which can avoid compiling warning (the original
implementation copy registers by exceeding member array border).

The related warning (with allmodconfig under tile):

CC arch/tile/kernel/kgdb.o
arch/tile/kernel/kgdb.c: In function 'sleeping_thread_to_gdb_regs':
arch/tile/kernel/kgdb.c:140:31: warning: iteration 53u invokes undefined behavior [-Waggressive-loop-optimizations]
*(ptr++) = thread_regs->regs[reg];
^
arch/tile/kernel/kgdb.c:139:2: note: containing loop
for (reg = 0; reg <= TREG_LAST_GPR; reg++)
^

Signed-off-by: Chen Gang <gang.chen.5i5j@gmail.com>
---
arch/tile/kernel/kgdb.c | 6 +-----
1 file changed, 1 insertion(+), 5 deletions(-)

diff --git a/arch/tile/kernel/kgdb.c b/arch/tile/kernel/kgdb.c
index 4cd8838..ff5335a 100644
--- a/arch/tile/kernel/kgdb.c
+++ b/arch/tile/kernel/kgdb.c
@@ -125,9 +125,7 @@ int dbg_set_reg(int regno, void *mem, struct pt_regs *regs)
void
sleeping_thread_to_gdb_regs(unsigned long *gdb_regs, struct task_struct *task)
{
- int reg;
struct pt_regs *thread_regs;
- unsigned long *ptr = gdb_regs;

if (task == NULL)
return;
@@ -136,9 +134,7 @@ sleeping_thread_to_gdb_regs(unsigned long *gdb_regs, struct task_struct *task)
memset(gdb_regs, 0, NUMREGBYTES);

thread_regs = task_pt_regs(task);
- for (reg = 0; reg <= TREG_LAST_GPR; reg++)
- *(ptr++) = thread_regs->regs[reg];
-
+ memcpy(gdb_regs, thread_regs, TREG_LAST_GPR * sizeof(unsigned long));
gdb_regs[TILEGX_PC_REGNUM] = thread_regs->pc;
gdb_regs[TILEGX_FAULTNUM_REGNUM] = thread_regs->faultnum;
}
--
1.9.3

\
 
 \ /
  Last update: 2014-11-01 14:21    [W:0.045 / U:79.860 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site