Re: [PATCH v2 06/16] powerpc/watchpoint: Provide DAWR number to __set_breakpoint

From: Christophe Leroy
Date: Wed Apr 01 2020 - 03:03:42 EST



Le 01/04/2020 Ã 08:12, Ravi Bangoria a ÃcritÂ:
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: Ravi Bangoria <ravi.bangoria@xxxxxxxxxxxxx>
---
arch/powerpc/include/asm/debug.h | 2 +-
arch/powerpc/include/asm/hw_breakpoint.h | 2 +-
arch/powerpc/kernel/hw_breakpoint.c | 8 ++++----
arch/powerpc/kernel/process.c | 14 +++++++-------
arch/powerpc/kernel/signal.c | 2 +-
arch/powerpc/xmon/xmon.c | 2 +-
6 files changed, 15 insertions(+), 15 deletions(-)

diff --git a/arch/powerpc/include/asm/debug.h b/arch/powerpc/include/asm/debug.h
index 7756026b95ca..6228935a8b64 100644
--- a/arch/powerpc/include/asm/debug.h
+++ b/arch/powerpc/include/asm/debug.h
@@ -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(struct arch_hw_breakpoint *brk, int nr);

Same, I think it would make more sense to have nr as first argument.

Christophe


bool ppc_breakpoint_available(void);
#ifdef CONFIG_PPC_ADV_DEBUG_REGS
extern void do_send_trap(struct pt_regs *regs, unsigned long address,
diff --git a/arch/powerpc/include/asm/hw_breakpoint.h b/arch/powerpc/include/asm/hw_breakpoint.h
index 62549007c87a..4e4976c3248b 100644
--- a/arch/powerpc/include/asm/hw_breakpoint.h
+++ b/arch/powerpc/include/asm/hw_breakpoint.h
@@ -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(&brk, 0);
}
extern void thread_change_pc(struct task_struct *tsk, struct pt_regs *regs);
int hw_breakpoint_handler(struct die_args *args);
diff --git a/arch/powerpc/kernel/hw_breakpoint.c b/arch/powerpc/kernel/hw_breakpoint.c
index 4120349e2abe..7562f9ceb77e 100644
--- a/arch/powerpc/kernel/hw_breakpoint.c
+++ b/arch/powerpc/kernel/hw_breakpoint.c
@@ -63,7 +63,7 @@ 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(info, 0);
return 0;
}
@@ -221,7 +221,7 @@ 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(info, 0);
tsk->thread.last_hit_ubp = NULL;
}
@@ -346,7 +346,7 @@ 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(info, 0);
out:
rcu_read_unlock();
return rc;
@@ -379,7 +379,7 @@ 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(info, 0);
current->thread.last_hit_ubp = NULL;
/*
diff --git a/arch/powerpc/kernel/process.c b/arch/powerpc/kernel/process.c
index b548a584e465..e0275fcd0c55 100644
--- a/arch/powerpc/kernel/process.c
+++ b/arch/powerpc/kernel/process.c
@@ -630,7 +630,7 @@ 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
/*
@@ -707,7 +707,7 @@ EXPORT_SYMBOL_GPL(switch_booke_debug_regs);
static void set_breakpoint(struct arch_hw_breakpoint *brk)
{
preempt_disable();
- __set_breakpoint(brk);
+ __set_breakpoint(brk, 0);
preempt_enable();
}
@@ -793,13 +793,13 @@ static inline int set_breakpoint_8xx(struct arch_hw_breakpoint *brk)
return 0;
}
-void __set_breakpoint(struct arch_hw_breakpoint *brk)
+void __set_breakpoint(struct arch_hw_breakpoint *brk, int nr)
{
- 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(brk, 0);
+ set_dawr(brk, nr);
else if (IS_ENABLED(CONFIG_PPC_8xx))
set_breakpoint_8xx(brk);
else if (!cpu_has_feature(CPU_FTR_ARCH_207S))
@@ -1167,8 +1167,8 @@ 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(&new->thread.hw_brk, 0);
#endif /* CONFIG_HAVE_HW_BREAKPOINT */
#endif
diff --git a/arch/powerpc/kernel/signal.c b/arch/powerpc/kernel/signal.c
index d215f9554553..bbf237f072d4 100644
--- a/arch/powerpc/kernel/signal.c
+++ b/arch/powerpc/kernel/signal.c
@@ -129,7 +129,7 @@ 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(&tsk->thread.hw_brk, 0);
#endif
/* Re-enable the breakpoints for the signal stack */
thread_change_pc(tsk, tsk->thread.regs);
diff --git a/arch/powerpc/xmon/xmon.c b/arch/powerpc/xmon/xmon.c
index 75ca41c04dd1..508d353e7f06 100644
--- a/arch/powerpc/xmon/xmon.c
+++ b/arch/powerpc/xmon/xmon.c
@@ -935,7 +935,7 @@ static void insert_cpu_bpts(void)
brk.address = dabr.address;
brk.type = (dabr.enabled & HW_BRK_TYPE_DABR) | HW_BRK_TYPE_PRIV_ALL;
brk.len = DABR_MAX_LEN;
- __set_breakpoint(&brk);
+ __set_breakpoint(&brk, 0);
}
if (iabr)