sh: kgdb: Fill out sleeping_thread_to_gdb_regs() state.
Presently we're using a pretty dumbed-down implementation that copies
over register state visible from the thread info, leaving the bulk of the
switch_to state uncopied.
Given that we're also depending on register bank toggling for switch_to
optimization we ought to also explicitly zero out the GP regs that reside
in an alternate bank in order to prevent handing back garbage.
There are a few extra registers that we have state for in switch_to, so
copy those over while we're at it.
Signed-off-by: Paul Mundt <lethal@linux-sh.org>
diff --git a/arch/sh/kernel/kgdb.c b/arch/sh/kernel/kgdb.c
index d25b5ed..ba8e763 100644
--- a/arch/sh/kernel/kgdb.c
+++ b/arch/sh/kernel/kgdb.c
@@ -222,8 +222,31 @@
void sleeping_thread_to_gdb_regs(unsigned long *gdb_regs, struct task_struct *p)
{
+ struct pt_regs *thread_regs = task_pt_regs(p);
+ int reg;
+
+ /* Initialize to zero */
+ for (reg = 0; reg < DBG_MAX_REG_NUM; reg++)
+ gdb_regs[reg] = 0;
+
+ /*
+ * Copy out GP regs 8 to 14.
+ *
+ * switch_to() relies on SR.RB toggling, so regs 0->7 are banked
+ * and need privileged instructions to get to. The r15 value we
+ * fetch from the thread info directly.
+ */
+ for (reg = GDB_R8; reg < GDB_R15; reg++)
+ gdb_regs[reg] = thread_regs->regs[reg];
+
gdb_regs[GDB_R15] = p->thread.sp;
gdb_regs[GDB_PC] = p->thread.pc;
+
+ /*
+ * Additional registers we have context for
+ */
+ gdb_regs[GDB_PR] = thread_regs->pr;
+ gdb_regs[GDB_GBR] = thread_regs->gbr;
}
int kgdb_arch_handle_exception(int e_vector, int signo, int err_code,