sh: kgdb: Fill out sleeping_thread_to_gdb_regs() state. (10c5e4e1) · Commits · 戴 / test

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>

arch/sh/kernel/kgdb.c

+23 −0

Original line number	Diff line number	Diff line
		@@ -222,8 +222,31 @@ char dbg_get_reg(int regno, void mem, struct pt_regs *regs)

		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,

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