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>
Signed-off-by: Chris Metcalf <cmetcalf@ezchip.com>
This commit is contained in:
Chen Gang 2014-11-12 10:11:31 +08:00 committed by Chris Metcalf
parent f47436734d
commit a5c1cb63dd

View File

@ -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;
}