From: Ravi Bangoria <ravi.bangoria@linux.ibm.com>
To: mpe@ellerman.id.au, mikey@neuling.org
Cc: apopple@linux.ibm.com, paulus@samba.org, npiggin@gmail.com,
christophe.leroy@c-s.fr, naveen.n.rao@linux.vnet.ibm.com,
peterz@infradead.org, jolsa@kernel.org, oleg@redhat.com,
fweisbec@gmail.com, mingo@kernel.org,
linuxppc-dev@lists.ozlabs.org, linux-kernel@vger.kernel.org,
ravi.bangoria@linux.ibm.com
Subject: [PATCH v6 10/16] powerpc/watchpoint: Use loop for thread_struct->ptrace_bps
Date: Thu, 14 May 2020 16:47:35 +0530 [thread overview]
Message-ID: <20200514111741.97993-11-ravi.bangoria@linux.ibm.com> (raw)
In-Reply-To: <20200514111741.97993-1-ravi.bangoria@linux.ibm.com>
ptrace_bps is already an array of size HBP_NUM_MAX. But we use
hardcoded index 0 while fetching/updating it. Convert such code
to loop over array.
ptrace interface to use multiple watchpoint remains same. eg:
two PPC_PTRACE_SETHWDEBUG calls will create two watchpoint if
underneath hw supports it.
Signed-off-by: Ravi Bangoria <ravi.bangoria@linux.ibm.com>
Reviewed-by: Michael Neuling <mikey@neuling.org>
---
arch/powerpc/kernel/hw_breakpoint.c | 7 ++++--
arch/powerpc/kernel/process.c | 6 ++++-
arch/powerpc/kernel/ptrace/ptrace-noadv.c | 28 +++++++++++++++++------
3 files changed, 31 insertions(+), 10 deletions(-)
diff --git a/arch/powerpc/kernel/hw_breakpoint.c b/arch/powerpc/kernel/hw_breakpoint.c
index f5472402c06d..917cca73dbc3 100644
--- a/arch/powerpc/kernel/hw_breakpoint.c
+++ b/arch/powerpc/kernel/hw_breakpoint.c
@@ -420,10 +420,13 @@ NOKPROBE_SYMBOL(hw_breakpoint_exceptions_notify);
*/
void flush_ptrace_hw_breakpoint(struct task_struct *tsk)
{
+ int i;
struct thread_struct *t = &tsk->thread;
- unregister_hw_breakpoint(t->ptrace_bps[0]);
- t->ptrace_bps[0] = NULL;
+ for (i = 0; i < nr_wp_slots(); i++) {
+ unregister_hw_breakpoint(t->ptrace_bps[i]);
+ t->ptrace_bps[i] = NULL;
+ }
}
void hw_breakpoint_pmu_read(struct perf_event *bp)
diff --git a/arch/powerpc/kernel/process.c b/arch/powerpc/kernel/process.c
index d94d8925711c..77ec1299e2fd 100644
--- a/arch/powerpc/kernel/process.c
+++ b/arch/powerpc/kernel/process.c
@@ -1604,6 +1604,9 @@ int copy_thread_tls(unsigned long clone_flags, unsigned long usp,
void (*f)(void);
unsigned long sp = (unsigned long)task_stack_page(p) + THREAD_SIZE;
struct thread_info *ti = task_thread_info(p);
+#ifdef CONFIG_HAVE_HW_BREAKPOINT
+ int i;
+#endif
klp_init_thread_info(p);
@@ -1663,7 +1666,8 @@ int copy_thread_tls(unsigned long clone_flags, unsigned long usp,
p->thread.ksp_limit = (unsigned long)end_of_stack(p);
#endif
#ifdef CONFIG_HAVE_HW_BREAKPOINT
- p->thread.ptrace_bps[0] = NULL;
+ for (i = 0; i < nr_wp_slots(); i++)
+ p->thread.ptrace_bps[i] = NULL;
#endif
p->thread.fp_save_area = NULL;
diff --git a/arch/powerpc/kernel/ptrace/ptrace-noadv.c b/arch/powerpc/kernel/ptrace/ptrace-noadv.c
index 0dbb35392dd2..08cb8c1b504c 100644
--- a/arch/powerpc/kernel/ptrace/ptrace-noadv.c
+++ b/arch/powerpc/kernel/ptrace/ptrace-noadv.c
@@ -168,6 +168,19 @@ int ptrace_set_debugreg(struct task_struct *task, unsigned long addr, unsigned l
return 0;
}
+#ifdef CONFIG_HAVE_HW_BREAKPOINT
+static int find_empty_ptrace_bp(struct thread_struct *thread)
+{
+ int i;
+
+ for (i = 0; i < nr_wp_slots(); i++) {
+ if (!thread->ptrace_bps[i])
+ return i;
+ }
+ return -1;
+}
+#endif
+
static int find_empty_hw_brk(struct thread_struct *thread)
{
int i;
@@ -217,8 +230,9 @@ long ppc_set_hwdebug(struct task_struct *child, struct ppc_hw_breakpoint *bp_inf
len = 1;
else
return -EINVAL;
- bp = thread->ptrace_bps[0];
- if (bp)
+
+ i = find_empty_ptrace_bp(thread);
+ if (i < 0)
return -ENOSPC;
/* Create a new breakpoint request if one doesn't exist already */
@@ -228,13 +242,13 @@ long ppc_set_hwdebug(struct task_struct *child, struct ppc_hw_breakpoint *bp_inf
arch_bp_generic_fields(brk.type, &attr.bp_type);
bp = register_user_hw_breakpoint(&attr, ptrace_triggered, NULL, child);
- thread->ptrace_bps[0] = bp;
+ thread->ptrace_bps[i] = bp;
if (IS_ERR(bp)) {
- thread->ptrace_bps[0] = NULL;
+ thread->ptrace_bps[i] = NULL;
return PTR_ERR(bp);
}
- return 1;
+ return i + 1;
#endif /* CONFIG_HAVE_HW_BREAKPOINT */
if (bp_info->addr_mode != PPC_BREAKPOINT_MODE_EXACT)
@@ -263,10 +277,10 @@ long ppc_del_hwdebug(struct task_struct *child, long data)
return -EINVAL;
#ifdef CONFIG_HAVE_HW_BREAKPOINT
- bp = thread->ptrace_bps[0];
+ bp = thread->ptrace_bps[data - 1];
if (bp) {
unregister_hw_breakpoint(bp);
- thread->ptrace_bps[0] = NULL;
+ thread->ptrace_bps[data - 1] = NULL;
} else {
ret = -ENOENT;
}
--
2.26.2
next prev parent reply other threads:[~2020-05-14 11:18 UTC|newest]
Thread overview: 18+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-05-14 11:17 [PATCH v6 00/16] powerpc/watchpoint: Preparation for more than one watchpoint Ravi Bangoria
2020-05-14 11:17 ` [PATCH v6 01/16] powerpc/watchpoint: Rename current DAWR macros Ravi Bangoria
2020-05-14 11:17 ` [PATCH v6 02/16] powerpc/watchpoint: Add SPRN macros for second DAWR Ravi Bangoria
2020-05-14 11:17 ` [PATCH v6 03/16] powerpc/watchpoint: Introduce function to get nr watchpoints dynamically Ravi Bangoria
2020-05-14 11:17 ` [PATCH v6 04/16] powerpc/watchpoint/ptrace: Return actual num of available watchpoints Ravi Bangoria
2020-05-14 11:17 ` [PATCH v6 05/16] powerpc/watchpoint: Provide DAWR number to set_dawr Ravi Bangoria
2020-05-14 11:17 ` [PATCH v6 06/16] powerpc/watchpoint: Provide DAWR number to __set_breakpoint Ravi Bangoria
2020-05-14 11:17 ` [PATCH v6 07/16] powerpc/watchpoint: Get watchpoint count dynamically while disabling them Ravi Bangoria
2020-05-14 11:17 ` [PATCH v6 08/16] powerpc/watchpoint: Disable all available watchpoints when !dawr_force_enable Ravi Bangoria
2020-05-14 11:17 ` [PATCH v6 09/16] powerpc/watchpoint: Convert thread_struct->hw_brk to an array Ravi Bangoria
2020-05-14 11:17 ` Ravi Bangoria [this message]
2020-05-14 11:17 ` [PATCH v6 11/16] powerpc/watchpoint: Introduce is_ptrace_bp() function Ravi Bangoria
2020-05-14 11:17 ` [PATCH v6 12/16] powerpc/watchpoint: Use builtin ALIGN*() macros Ravi Bangoria
2020-05-14 11:17 ` [PATCH v6 13/16] powerpc/watchpoint: Prepare handler to handle more than one watcnhpoint Ravi Bangoria
2020-05-14 11:17 ` [PATCH v6 14/16] powerpc/watchpoint: Don't allow concurrent perf and ptrace events Ravi Bangoria
2020-05-14 11:17 ` [PATCH v6 15/16] powerpc/watchpoint/xmon: Don't allow breakpoint overwriting Ravi Bangoria
2020-05-14 11:17 ` [PATCH v6 16/16] powerpc/watchpoint/xmon: Support 2nd DAWR Ravi Bangoria
2020-05-20 11:00 ` [PATCH v6 00/16] powerpc/watchpoint: Preparation for more than one watchpoint Michael Ellerman
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