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authorChris Metcalf <cmetcalf@ezchip.com>2016-01-25 23:05:34 +0300
committerChris Metcalf <cmetcalf@ezchip.com>2016-03-02 23:19:44 +0300
commit77ef8f5177599efd0cedeb52c1950c1bd73fa5e3 (patch)
treeb6091bf407bc008da5fd6e68d4eaca4d543efe58 /arch
parent81f70ba233d5f660e1ea5fe23260ee323af5d53a (diff)
downloadlinux-77ef8f5177599efd0cedeb52c1950c1bd73fa5e3.tar.xz
tile kgdb: fix bug in copy to gdb regs, and optimize memset
David Binderman pointed out that we were doing a full memset() of the gdb register buffer and then doing a memcpy() to it that was almost as big. This commit optimizes that by only doing a memset() of the registers that are intended to be zero. While making this change I noticed that we were not copying the link register (LR, number 55) due to a fencepost error in commit f419e6f63c5a ("arch: tile: kernel: kgdb.c: Use memcpy() instead of pointer copy one by one"), and I've corrected that as well. Reported-by: David Binderman <dcb314@hotmail.com> Signed-off-by: Chris Metcalf <cmetcalf@ezchip.com>
Diffstat (limited to 'arch')
-rw-r--r--arch/tile/kernel/kgdb.c8
1 files changed, 4 insertions, 4 deletions
diff --git a/arch/tile/kernel/kgdb.c b/arch/tile/kernel/kgdb.c
index a506c2c28943..6ad99925900e 100644
--- a/arch/tile/kernel/kgdb.c
+++ b/arch/tile/kernel/kgdb.c
@@ -126,15 +126,15 @@ void
sleeping_thread_to_gdb_regs(unsigned long *gdb_regs, struct task_struct *task)
{
struct pt_regs *thread_regs;
+ const int NGPRS = TREG_LAST_GPR + 1;
if (task == NULL)
return;
- /* Initialize to zero. */
- memset(gdb_regs, 0, NUMREGBYTES);
-
thread_regs = task_pt_regs(task);
- memcpy(gdb_regs, thread_regs, TREG_LAST_GPR * sizeof(unsigned long));
+ memcpy(gdb_regs, thread_regs, NGPRS * sizeof(unsigned long));
+ memset(&gdb_regs[NGPRS], 0,
+ (TILEGX_PC_REGNUM - NGPRS) * sizeof(unsigned long));
gdb_regs[TILEGX_PC_REGNUM] = thread_regs->pc;
gdb_regs[TILEGX_FAULTNUM_REGNUM] = thread_regs->faultnum;
}