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Commit cd144573 authored by Michael Neuling's avatar Michael Neuling Committed by Benjamin Herrenschmidt
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powerpc: Dynamically calculate the dabrx based on kernel/user/hypervisor 



Currently we mark the DABRX to interrupt on all matches
(hypervisor/kernel/user and then filter in software.  We can be a lot
smarter now that we can set the DABRX dynamically.

This sets the DABRX based on the flags passed by the user.

Signed-off-by: default avatarMichael Neuling <mikey@neuling.org>
Signed-off-by: default avatarBenjamin Herrenschmidt <benh@kernel.crashing.org>
parent 4474ef05

arch/powerpc/include/asm/hw_breakpoint.h

+1 −0
Original line number Diff line number Diff line
@@ -28,6 +28,7 @@ 


struct arch_hw_breakpoint {

	unsigned long	address;

	unsigned long	dabrx;

	int		type;

	u8		len; /* length of the target data symbol */

	bool		extraneous_interrupt;

arch/powerpc/kernel/hw_breakpoint.c

+11 −4
Original line number Diff line number Diff line
@@ -73,7 +73,7 @@ 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_dabr(info->address | info->type | DABR_TRANSLATION, DABRX_ALL);

		set_dabr(info->address | info->type | DABR_TRANSLATION, info->dabrx);



	return 0;

}
@@ -170,6 +170,13 @@ int arch_validate_hwbkpt_settings(struct perf_event *bp) 


	info->address = bp->attr.bp_addr;

	info->len = bp->attr.bp_len;

	info->dabrx = DABRX_ALL;

	if (bp->attr.exclude_user)

		info->dabrx &= ~DABRX_USER;

	if (bp->attr.exclude_kernel)

		info->dabrx &= ~DABRX_KERNEL;

	if (bp->attr.exclude_hv)

		info->dabrx &= ~DABRX_HYP;



	/*

	 * Since breakpoint length can be a maximum of HW_BREAKPOINT_LEN(8)
@@ -197,7 +204,7 @@ 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_dabr(info->address | info->type | DABR_TRANSLATION, DABRX_ALL);

	set_dabr(info->address | info->type | DABR_TRANSLATION, info->dabrx);

	tsk->thread.last_hit_ubp = NULL;

}
@@ -281,7 +288,7 @@ int __kprobes hw_breakpoint_handler(struct die_args *args) 
	if (!info->extraneous_interrupt)

		perf_bp_event(bp, regs);



	set_dabr(info->address | info->type | DABR_TRANSLATION, DABRX_ALL);

	set_dabr(info->address | info->type | DABR_TRANSLATION, info->dabrx);

out:

	rcu_read_unlock();

	return rc;
@@ -313,7 +320,7 @@ int __kprobes single_step_dabr_instruction(struct die_args *args) 
	if (!info->extraneous_interrupt)

		perf_bp_event(bp, regs);



	set_dabr(info->address | info->type | DABR_TRANSLATION, DABRX_ALL);

	set_dabr(info->address | info->type | DABR_TRANSLATION, info->dabrx);

	current->thread.last_hit_ubp = NULL;



	/*

arch/powerpc/platforms/pseries/setup.c

+1 −1
Original line number Diff line number Diff line
@@ -425,7 +425,7 @@ static int pseries_set_xdabr(unsigned long dabr, unsigned long dabrx) 
	if (dabrx == 0 && dabr == 0)

		dabrx = DABRX_USER;

	/* PAPR says we can only set kernel and user bits */

	dabrx &= H_DABRX_KERNEL | H_DABRX_USER;

	dabrx &= DABRX_KERNEL | DABRX_USER;



	return plpar_hcall_norets(H_SET_XDABR, dabr, dabrx);

}