Commit 303e6a9d authored by Ravi Bangoria's avatar Ravi Bangoria Committed by Michael Ellerman

powerpc/watchpoint: Convert thread_struct->hw_brk to an array

So far powerpc hw supported only one watchpoint. But Power10 is
introducing 2nd DAWR. Convert thread_struct->hw_brk into 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/20200514111741.97993-10-ravi.bangoria@linux.ibm.com
parent 22a214e4
......@@ -187,7 +187,7 @@ 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;
......
......@@ -711,21 +711,49 @@ 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(int i, struct arch_hw_breakpoint *brk)
{
preempt_disable();
__set_breakpoint(0, brk);
__set_breakpoint(i, brk);
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;
struct arch_hw_breakpoint null_brk = {0};
for (i = 0; i < nr_wp_slots(); i++) {
thread->hw_brk[i] = null_brk;
if (ppc_breakpoint_available())
set_breakpoint(i, &thread->hw_brk[i]);
}
}
static inline bool hw_brk_match(struct arch_hw_breakpoint *a,
struct arch_hw_breakpoint *b)
{
if (a->address != b->address)
return false;
if (a->type != b->type)
return false;
if (a->len != b->len)
return false;
/* no need to check hw_len. it's calculated from address and len */
return true;
}
static void switch_hw_breakpoint(struct task_struct *new)
{
int i;
for (i = 0; i < nr_wp_slots(); i++) {
if (likely(hw_brk_match(this_cpu_ptr(&current_brk[i]),
&new->thread.hw_brk[i])))
continue;
__set_breakpoint(i, &new->thread.hw_brk[i]);
}
}
#endif /* !CONFIG_HAVE_HW_BREAKPOINT */
#endif /* CONFIG_PPC_ADV_DEBUG_REGS */
......@@ -829,19 +857,6 @@ bool ppc_breakpoint_available(void)
}
EXPORT_SYMBOL_GPL(ppc_breakpoint_available);
static inline bool hw_brk_match(struct arch_hw_breakpoint *a,
struct arch_hw_breakpoint *b)
{
if (a->address != b->address)
return false;
if (a->type != b->type)
return false;
if (a->len != b->len)
return false;
/* no need to check hw_len. it's calculated from address and len */
return true;
}
#ifdef CONFIG_PPC_TRANSACTIONAL_MEM
static inline bool tm_enabled(struct task_struct *tsk)
......@@ -1174,8 +1189,7 @@ 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[0]), &new->thread.hw_brk)))
__set_breakpoint(0, &new->thread.hw_brk);
switch_hw_breakpoint(new);
#endif /* CONFIG_HAVE_HW_BREAKPOINT */
#endif
......
......@@ -67,11 +67,16 @@ int ptrace_get_debugreg(struct task_struct *child, unsigned long addr,
/* We only support one DABR and no IABRS at the moment */
if (addr > 0)
return -EINVAL;
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));
return put_user(dabr_fake, datalp);
}
/*
* 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.
*/
int ptrace_set_debugreg(struct task_struct *task, unsigned long addr, unsigned long data)
{
#ifdef CONFIG_HAVE_HW_BREAKPOINT
......@@ -137,7 +142,7 @@ int ptrace_set_debugreg(struct task_struct *task, unsigned long addr, unsigned l
return ret;
thread->ptrace_bps[0] = bp;
thread->hw_brk = hw_brk;
thread->hw_brk[0] = hw_brk;
return 0;
}
......@@ -159,12 +164,24 @@ int ptrace_set_debugreg(struct task_struct *task, unsigned long addr, unsigned l
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;
return 0;
}
static int find_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;
}
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;
......@@ -223,15 +240,16 @@ long ppc_set_hwdebug(struct task_struct *child, struct ppc_hw_breakpoint *bp_inf
if (bp_info->addr_mode != PPC_BREAKPOINT_MODE_EXACT)
return -EINVAL;
if (child->thread.hw_brk.address)
i = find_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;
}
long ppc_del_hwdebug(struct task_struct *child, long data)
......@@ -241,7 +259,7 @@ long ppc_del_hwdebug(struct task_struct *child, long data)
struct thread_struct *thread = &child->thread;
struct perf_event *bp;
#endif /* CONFIG_HAVE_HW_BREAKPOINT */
if (data != 1)
if (data < 1 || data > nr_wp_slots())
return -EINVAL;
#ifdef CONFIG_HAVE_HW_BREAKPOINT
......@@ -254,11 +272,11 @@ long ppc_del_hwdebug(struct task_struct *child, long data)
}
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;
......
......@@ -259,8 +259,8 @@ 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;
......
......@@ -265,15 +265,20 @@ static void do_signal(struct task_struct *tsk)
return; /* no signals delivered */
}
#ifndef CONFIG_PPC_ADV_DEBUG_REGS
/*
* Reenable the DABR before delivering the signal to
* 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(0, &tsk->thread.hw_brk);
#endif
if (!IS_ENABLED(CONFIG_PPC_ADV_DEBUG_REGS)) {
int i;
for (i = 0; i < nr_wp_slots(); i++) {
if (tsk->thread.hw_brk[i].address && tsk->thread.hw_brk[i].type)
__set_breakpoint(i, &tsk->thread.hw_brk[i]);
}
}
/* Re-enable the breakpoints for the signal stack */
thread_change_pc(tsk, tsk->thread.regs);
......
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