Commit 4a8a9379 authored by Ravi Bangoria's avatar Ravi Bangoria Committed by Michael Ellerman
Browse files

powerpc/watchpoint: Provide DAWR number to __set_breakpoint 



Introduce new parameter 'nr' to __set_breakpoint() which indicates
which DAWR should be programed. Also convert current_brk variable
to an array.

Signed-off-by: default avatarRavi Bangoria <ravi.bangoria@linux.ibm.com>
Signed-off-by: default avatarMichael Ellerman <mpe@ellerman.id.au>
Reviewed-by: default avatarMichael Neuling <mikey@neuling.org>
Link: https://lore.kernel.org/r/20200514111741.97993-7-ravi.bangoria@linux.ibm.com
parent a18b8346

arch/powerpc/include/asm/debug.h

+1 −1
Original line number Diff line number Diff line
@@ -45,7 +45,7 @@ static inline int debugger_break_match(struct pt_regs *regs) { return 0; } 
static inline int debugger_fault_handler(struct pt_regs *regs) { return 0; }

#endif



void __set_breakpoint(struct arch_hw_breakpoint *brk);

void __set_breakpoint(int nr, struct arch_hw_breakpoint *brk);

bool ppc_breakpoint_available(void);

#ifdef CONFIG_PPC_ADV_DEBUG_REGS

extern void do_send_trap(struct pt_regs *regs, unsigned long address,

arch/powerpc/include/asm/hw_breakpoint.h

+1 −1
Original line number Diff line number Diff line
@@ -85,7 +85,7 @@ static inline void hw_breakpoint_disable(void) 
	brk.len = 0;

	brk.hw_len = 0;

	if (ppc_breakpoint_available())

		__set_breakpoint(&brk);

		__set_breakpoint(0, &brk);

}

extern void thread_change_pc(struct task_struct *tsk, struct pt_regs *regs);

int hw_breakpoint_handler(struct die_args *args);

arch/powerpc/kernel/hw_breakpoint.c

+4 −4
Original line number Diff line number Diff line
@@ -64,7 +64,7 @@ int arch_install_hw_breakpoint(struct perf_event *bp) 
	 * If so, DABR will be populated in single_step_dabr_instruction().

	 */

	if (current->thread.last_hit_ubp != bp)

		__set_breakpoint(info);

		__set_breakpoint(0, info);



	return 0;

}
@@ -222,7 +222,7 @@ void thread_change_pc(struct task_struct *tsk, struct pt_regs *regs) 


	info = counter_arch_bp(tsk->thread.last_hit_ubp);

	regs->msr &= ~MSR_SE;

	__set_breakpoint(info);

	__set_breakpoint(0, info);

	tsk->thread.last_hit_ubp = NULL;

}
@@ -347,7 +347,7 @@ int hw_breakpoint_handler(struct die_args *args) 
	if (!(info->type & HW_BRK_TYPE_EXTRANEOUS_IRQ))

		perf_bp_event(bp, regs);



	__set_breakpoint(info);

	__set_breakpoint(0, info);

out:

	rcu_read_unlock();

	return rc;
@@ -380,7 +380,7 @@ static int single_step_dabr_instruction(struct die_args *args) 
	if (!(info->type & HW_BRK_TYPE_EXTRANEOUS_IRQ))

		perf_bp_event(bp, regs);



	__set_breakpoint(info);

	__set_breakpoint(0, info);

	current->thread.last_hit_ubp = NULL;



	/*

arch/powerpc/kernel/process.c

+7 −7
Original line number Diff line number Diff line
@@ -637,7 +637,7 @@ void do_break (struct pt_regs *regs, unsigned long address, 
}

#endif	/* CONFIG_PPC_ADV_DEBUG_REGS */



static DEFINE_PER_CPU(struct arch_hw_breakpoint, current_brk);

static DEFINE_PER_CPU(struct arch_hw_breakpoint, current_brk[HBP_NUM_MAX]);



#ifdef CONFIG_PPC_ADV_DEBUG_REGS

/*
@@ -714,7 +714,7 @@ EXPORT_SYMBOL_GPL(switch_booke_debug_regs); 
static void set_breakpoint(struct arch_hw_breakpoint *brk)

{

	preempt_disable();

	__set_breakpoint(brk);

	__set_breakpoint(0, brk);

	preempt_enable();

}
@@ -800,13 +800,13 @@ static inline int set_breakpoint_8xx(struct arch_hw_breakpoint *brk) 
	return 0;

}



void __set_breakpoint(struct arch_hw_breakpoint *brk)

void __set_breakpoint(int nr, struct arch_hw_breakpoint *brk)

{

	memcpy(this_cpu_ptr(&current_brk), brk, sizeof(*brk));

	memcpy(this_cpu_ptr(&current_brk[nr]), brk, sizeof(*brk));



	if (dawr_enabled())

		// Power8 or later

		set_dawr(0, brk);

		set_dawr(nr, brk);

	else if (IS_ENABLED(CONFIG_PPC_8xx))

		set_breakpoint_8xx(brk);

	else if (!cpu_has_feature(CPU_FTR_ARCH_207S))
@@ -1174,8 +1174,8 @@ struct task_struct *__switch_to(struct task_struct *prev, 
 * schedule DABR

 */

#ifndef CONFIG_HAVE_HW_BREAKPOINT

	if (unlikely(!hw_brk_match(this_cpu_ptr(&current_brk), &new->thread.hw_brk)))

		__set_breakpoint(&new->thread.hw_brk);

	if (unlikely(!hw_brk_match(this_cpu_ptr(&current_brk[0]), &new->thread.hw_brk)))

		__set_breakpoint(0, &new->thread.hw_brk);

#endif /* CONFIG_HAVE_HW_BREAKPOINT */

#endif

arch/powerpc/kernel/signal.c

+1 −1
Original line number Diff line number Diff line
@@ -272,7 +272,7 @@ static void do_signal(struct task_struct *tsk) 
	 * triggered inside the kernel.

	 */

	if (tsk->thread.hw_brk.address && tsk->thread.hw_brk.type)

		__set_breakpoint(&tsk->thread.hw_brk);

		__set_breakpoint(0, &tsk->thread.hw_brk);

#endif

	/* Re-enable the breakpoints for the signal stack */

	thread_change_pc(tsk, tsk->thread.regs);