Messages in this thread | | | Subject | Re: [PATCH 09/15] powerpc/watchpoint: Convert thread_struct->hw_brk to an array | From | Christophe Leroy <> | Date | Tue, 17 Mar 2020 11:37:46 +0100 |
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Le 09/03/2020 à 09:58, Ravi Bangoria a écrit : > So far powerpc hw supported only one watchpoint. But Future Power > architecture is introducing 2nd DAWR. Convert thread_struct->hw_brk > into an array.
Looks like you are doing a lot more than that in this patch.
Should this patch be splitted in two parts ?
Christophe
> > Signed-off-by: Ravi Bangoria <ravi.bangoria@linux.ibm.com> > --- > arch/powerpc/include/asm/processor.h | 2 +- > arch/powerpc/kernel/process.c | 43 ++++++++++++++++++++-------- > arch/powerpc/kernel/ptrace.c | 42 ++++++++++++++++++++------- > arch/powerpc/kernel/ptrace32.c | 4 +-- > arch/powerpc/kernel/signal.c | 9 ++++-- > 5 files changed, 72 insertions(+), 28 deletions(-) > > diff --git a/arch/powerpc/include/asm/processor.h b/arch/powerpc/include/asm/processor.h > index 666b2825278c..57a8fac2e72b 100644 > --- a/arch/powerpc/include/asm/processor.h > +++ b/arch/powerpc/include/asm/processor.h > @@ -183,7 +183,7 @@ struct thread_struct { > */ > struct perf_event *last_hit_ubp; > #endif /* CONFIG_HAVE_HW_BREAKPOINT */ > - struct arch_hw_breakpoint hw_brk; /* info on the hardware breakpoint */ > + struct arch_hw_breakpoint hw_brk[HBP_NUM_MAX]; /* hardware breakpoint info */ > unsigned long trap_nr; /* last trap # on this thread */ > u8 load_slb; /* Ages out SLB preload cache entries */ > u8 load_fp; > diff --git a/arch/powerpc/kernel/process.c b/arch/powerpc/kernel/process.c > index f6bb2586fa5d..42ff62ef749c 100644 > --- a/arch/powerpc/kernel/process.c > +++ b/arch/powerpc/kernel/process.c > @@ -704,21 +704,25 @@ void switch_booke_debug_regs(struct debug_reg *new_debug) > EXPORT_SYMBOL_GPL(switch_booke_debug_regs); > #else /* !CONFIG_PPC_ADV_DEBUG_REGS */ > #ifndef CONFIG_HAVE_HW_BREAKPOINT > -static void set_breakpoint(struct arch_hw_breakpoint *brk) > +static void set_breakpoint(struct arch_hw_breakpoint *brk, int i) > { > preempt_disable(); > - __set_breakpoint(brk, 0); > + __set_breakpoint(brk, i); > preempt_enable(); > } > > static void set_debug_reg_defaults(struct thread_struct *thread) > { > - thread->hw_brk.address = 0; > - thread->hw_brk.type = 0; > - thread->hw_brk.len = 0; > - thread->hw_brk.hw_len = 0; > - if (ppc_breakpoint_available()) > - set_breakpoint(&thread->hw_brk); > + int i; > + > + for (i = 0; i < nr_wp_slots(); i++) { > + thread->hw_brk[i].address = 0; > + thread->hw_brk[i].type = 0; > + thread->hw_brk[i].len = 0; > + thread->hw_brk[i].hw_len = 0; > + if (ppc_breakpoint_available()) > + set_breakpoint(&thread->hw_brk[i], i); > + } > } > #endif /* !CONFIG_HAVE_HW_BREAKPOINT */ > #endif /* CONFIG_PPC_ADV_DEBUG_REGS */ > @@ -1141,6 +1145,24 @@ static inline void restore_sprs(struct thread_struct *old_thread, > thread_pkey_regs_restore(new_thread, old_thread); > } > > +#ifndef CONFIG_HAVE_HW_BREAKPOINT > +static void switch_hw_breakpoint(struct task_struct *new) > +{ > + int i; > + > + for (i = 0; i < nr_wp_slots(); i++) { > + if (unlikely(!hw_brk_match(this_cpu_ptr(¤t_brk[i]), > + &new->thread.hw_brk[i]))) { > + __set_breakpoint(&new->thread.hw_brk[i], i); > + } > + } > +} > +#else > +static void switch_hw_breakpoint(struct task_struct *new) > +{ > +} > +#endif > + > struct task_struct *__switch_to(struct task_struct *prev, > struct task_struct *new) > { > @@ -1172,10 +1194,7 @@ struct task_struct *__switch_to(struct task_struct *prev, > * For PPC_BOOK3S_64, we use the hw-breakpoint interfaces that would > * schedule DABR > */ > -#ifndef CONFIG_HAVE_HW_BREAKPOINT > - if (unlikely(!hw_brk_match(this_cpu_ptr(¤t_brk[0]), &new->thread.hw_brk))) > - __set_breakpoint(&new->thread.hw_brk, 0); > -#endif /* CONFIG_HAVE_HW_BREAKPOINT */ > + switch_hw_breakpoint(new); > #endif > > /* > diff --git a/arch/powerpc/kernel/ptrace.c b/arch/powerpc/kernel/ptrace.c > index dd46e174dbe7..f6d7955fc61e 100644 > --- a/arch/powerpc/kernel/ptrace.c > +++ b/arch/powerpc/kernel/ptrace.c > @@ -2382,6 +2382,11 @@ void ptrace_triggered(struct perf_event *bp, > } > #endif /* CONFIG_HAVE_HW_BREAKPOINT */ > > +/* > + * ptrace_set_debugreg() fakes DABR and DABR is only one. So even if > + * internal hw supports more than one watchpoint, we support only one > + * watchpoint with this interface. > + */ > static int ptrace_set_debugreg(struct task_struct *task, unsigned long addr, > unsigned long data) > { > @@ -2451,7 +2456,7 @@ static int ptrace_set_debugreg(struct task_struct *task, unsigned long addr, > return ret; > } > thread->ptrace_bps[0] = bp; > - thread->hw_brk = hw_brk; > + thread->hw_brk[0] = hw_brk; > return 0; > } > > @@ -2473,7 +2478,7 @@ static int ptrace_set_debugreg(struct task_struct *task, unsigned long addr, > if (set_bp && (!ppc_breakpoint_available())) > return -ENODEV; > #endif /* CONFIG_HAVE_HW_BREAKPOINT */ > - task->thread.hw_brk = hw_brk; > + task->thread.hw_brk[0] = hw_brk; > #else /* CONFIG_PPC_ADV_DEBUG_REGS */ > /* As described above, it was assumed 3 bits were passed with the data > * address, but we will assume only the mode bits will be passed > @@ -2824,9 +2829,23 @@ static int set_dac_range(struct task_struct *child, > } > #endif /* CONFIG_PPC_ADV_DEBUG_DAC_RANGE */ > > +#ifndef CONFIG_PPC_ADV_DEBUG_REGS > +static int empty_hw_brk(struct thread_struct *thread) > +{ > + int i; > + > + for (i = 0; i < nr_wp_slots(); i++) { > + if (!thread->hw_brk[i].address) > + return i; > + } > + return -1; > +} > +#endif > + > static long ppc_set_hwdebug(struct task_struct *child, > struct ppc_hw_breakpoint *bp_info) > { > + int i; > #ifdef CONFIG_HAVE_HW_BREAKPOINT > int len = 0; > struct thread_struct *thread = &(child->thread); > @@ -2919,15 +2938,16 @@ static long ppc_set_hwdebug(struct task_struct *child, > if (bp_info->addr_mode != PPC_BREAKPOINT_MODE_EXACT) > return -EINVAL; > > - if (child->thread.hw_brk.address) > + i = empty_hw_brk(&child->thread); > + if (i < 0) > return -ENOSPC; > > if (!ppc_breakpoint_available()) > return -ENODEV; > > - child->thread.hw_brk = brk; > + child->thread.hw_brk[i] = brk; > > - return 1; > + return i + 1; > #endif /* !CONFIG_PPC_ADV_DEBUG_DVCS */ > } > > @@ -2955,7 +2975,7 @@ static long ppc_del_hwdebug(struct task_struct *child, long data) > } > return rc; > #else > - if (data != 1) > + if (data < 1 || data > nr_wp_slots()) > return -EINVAL; > > #ifdef CONFIG_HAVE_HW_BREAKPOINT > @@ -2967,11 +2987,11 @@ static long ppc_del_hwdebug(struct task_struct *child, long data) > ret = -ENOENT; > return ret; > #else /* CONFIG_HAVE_HW_BREAKPOINT */ > - if (child->thread.hw_brk.address == 0) > + if (child->thread.hw_brk[data - 1].address == 0) > return -ENOENT; > > - child->thread.hw_brk.address = 0; > - child->thread.hw_brk.type = 0; > + child->thread.hw_brk[data - 1].address = 0; > + child->thread.hw_brk[data - 1].type = 0; > #endif /* CONFIG_HAVE_HW_BREAKPOINT */ > > return 0; > @@ -3124,8 +3144,8 @@ long arch_ptrace(struct task_struct *child, long request, > #ifdef CONFIG_PPC_ADV_DEBUG_REGS > ret = put_user(child->thread.debug.dac1, datalp); > #else > - dabr_fake = ((child->thread.hw_brk.address & (~HW_BRK_TYPE_DABR)) | > - (child->thread.hw_brk.type & HW_BRK_TYPE_DABR)); > + dabr_fake = ((child->thread.hw_brk[0].address & (~HW_BRK_TYPE_DABR)) | > + (child->thread.hw_brk[0].type & HW_BRK_TYPE_DABR)); > ret = put_user(dabr_fake, datalp); > #endif > break; > diff --git a/arch/powerpc/kernel/ptrace32.c b/arch/powerpc/kernel/ptrace32.c > index f37eb53de1a1..e227cd320b46 100644 > --- a/arch/powerpc/kernel/ptrace32.c > +++ b/arch/powerpc/kernel/ptrace32.c > @@ -270,8 +270,8 @@ long compat_arch_ptrace(struct task_struct *child, compat_long_t request, > ret = put_user(child->thread.debug.dac1, (u32 __user *)data); > #else > dabr_fake = ( > - (child->thread.hw_brk.address & (~HW_BRK_TYPE_DABR)) | > - (child->thread.hw_brk.type & HW_BRK_TYPE_DABR)); > + (child->thread.hw_brk[0].address & (~HW_BRK_TYPE_DABR)) | > + (child->thread.hw_brk[0].type & HW_BRK_TYPE_DABR)); > ret = put_user(dabr_fake, (u32 __user *)data); > #endif > break; > diff --git a/arch/powerpc/kernel/signal.c b/arch/powerpc/kernel/signal.c > index 8bc6cc55420a..3116896e89a6 100644 > --- a/arch/powerpc/kernel/signal.c > +++ b/arch/powerpc/kernel/signal.c > @@ -107,6 +107,9 @@ static void do_signal(struct task_struct *tsk) > struct ksignal ksig = { .sig = 0 }; > int ret; > int is32 = is_32bit_task(); > +#ifndef CONFIG_PPC_ADV_DEBUG_REGS > + int i; > +#endif > > BUG_ON(tsk != current); > > @@ -128,8 +131,10 @@ static void do_signal(struct task_struct *tsk) > * user space. The DABR will have been cleared if it > * triggered inside the kernel. > */ > - if (tsk->thread.hw_brk.address && tsk->thread.hw_brk.type) > - __set_breakpoint(&tsk->thread.hw_brk, 0); > + for (i = 0; i < nr_wp_slots(); i++) { > + if (tsk->thread.hw_brk[i].address && tsk->thread.hw_brk[i].type) > + __set_breakpoint(&tsk->thread.hw_brk[i], i); > + } > #endif > /* Re-enable the breakpoints for the signal stack */ > thread_change_pc(tsk, tsk->thread.regs); >
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