Commit a5c1cb63 authored Nov 12, 2014 by Chen Gang Committed by Chris Metcalf Nov 12, 2014

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>

parent f4743673

arch/tile/kernel/kgdb.c

+1 −5

Original line number	Diff line number	Diff line
		@@ -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;
		}

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