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-rw-r--r--arch/x86/kernel/ptrace.c74
-rw-r--r--include/linux/hw_breakpoint.h36
-rw-r--r--kernel/hw_breakpoint.c87
3 files changed, 75 insertions, 122 deletions
diff --git a/arch/x86/kernel/ptrace.c b/arch/x86/kernel/ptrace.c
index 75e0cd847bd6..2941b32ea666 100644
--- a/arch/x86/kernel/ptrace.c
+++ b/arch/x86/kernel/ptrace.c
@@ -593,6 +593,34 @@ static unsigned long ptrace_get_dr7(struct perf_event *bp[])
return dr7;
}
+static struct perf_event *
+ptrace_modify_breakpoint(struct perf_event *bp, int len, int type,
+ struct task_struct *tsk)
+{
+ int err;
+ int gen_len, gen_type;
+ DEFINE_BREAKPOINT_ATTR(attr);
+
+ /*
+ * We shoud have at least an inactive breakpoint at this
+ * slot. It means the user is writing dr7 without having
+ * written the address register first
+ */
+ if (!bp)
+ return ERR_PTR(-EINVAL);
+
+ err = arch_bp_generic_fields(len, type, &gen_len, &gen_type);
+ if (err)
+ return ERR_PTR(err);
+
+ attr = bp->attr;
+ attr.bp_len = gen_len;
+ attr.bp_type = gen_type;
+ attr.disabled = 0;
+
+ return modify_user_hw_breakpoint(bp, &attr, bp->callback, tsk);
+}
+
/*
* Handle ptrace writes to debug register 7.
*/
@@ -603,7 +631,6 @@ static int ptrace_write_dr7(struct task_struct *tsk, unsigned long data)
int i, orig_ret = 0, rc = 0;
int enabled, second_pass = 0;
unsigned len, type;
- int gen_len, gen_type;
struct perf_event *bp;
data &= ~DR_CONTROL_RESERVED;
@@ -634,33 +661,12 @@ restore:
continue;
}
- /*
- * We shoud have at least an inactive breakpoint at this
- * slot. It means the user is writing dr7 without having
- * written the address register first
- */
- if (!bp) {
- rc = -EINVAL;
- break;
- }
-
- rc = arch_bp_generic_fields(len, type, &gen_len, &gen_type);
- if (rc)
- break;
-
- /*
- * This is a temporary thing as bp is unregistered/registered
- * to simulate modification
- */
- bp = modify_user_hw_breakpoint(bp, bp->attr.bp_addr, gen_len,
- gen_type, bp->callback,
- tsk, true);
- thread->ptrace_bps[i] = NULL;
+ bp = ptrace_modify_breakpoint(bp, len, type, tsk);
/* Incorrect bp, or we have a bug in bp API */
if (IS_ERR(bp)) {
rc = PTR_ERR(bp);
- bp = NULL;
+ thread->ptrace_bps[i] = NULL;
break;
}
thread->ptrace_bps[i] = bp;
@@ -707,24 +713,26 @@ static int ptrace_set_breakpoint_addr(struct task_struct *tsk, int nr,
{
struct perf_event *bp;
struct thread_struct *t = &tsk->thread;
+ DEFINE_BREAKPOINT_ATTR(attr);
if (!t->ptrace_bps[nr]) {
/*
* Put stub len and type to register (reserve) an inactive but
* correct bp
*/
- bp = register_user_hw_breakpoint(addr, HW_BREAKPOINT_LEN_1,
- HW_BREAKPOINT_W,
- ptrace_triggered, tsk,
- false);
+ attr.bp_addr = addr;
+ attr.bp_len = HW_BREAKPOINT_LEN_1;
+ attr.bp_type = HW_BREAKPOINT_W;
+ attr.disabled = 1;
+
+ bp = register_user_hw_breakpoint(&attr, ptrace_triggered, tsk);
} else {
bp = t->ptrace_bps[nr];
t->ptrace_bps[nr] = NULL;
- bp = modify_user_hw_breakpoint(bp, addr, bp->attr.bp_len,
- bp->attr.bp_type,
- bp->callback,
- tsk,
- bp->attr.disabled);
+
+ attr = bp->attr;
+ attr.bp_addr = addr;
+ bp = modify_user_hw_breakpoint(bp, &attr, bp->callback, tsk);
}
/*
* CHECKME: the previous code returned -EIO if the addr wasn't a
diff --git a/include/linux/hw_breakpoint.h b/include/linux/hw_breakpoint.h
index c9f7f7c7b0e0..5da472e434b7 100644
--- a/include/linux/hw_breakpoint.h
+++ b/include/linux/hw_breakpoint.h
@@ -20,6 +20,14 @@ enum {
#ifdef CONFIG_HAVE_HW_BREAKPOINT
+/* As it's for in-kernel or ptrace use, we want it to be pinned */
+#define DEFINE_BREAKPOINT_ATTR(name) \
+struct perf_event_attr name = { \
+ .type = PERF_TYPE_BREAKPOINT, \
+ .size = sizeof(name), \
+ .pinned = 1, \
+};
+
static inline unsigned long hw_breakpoint_addr(struct perf_event *bp)
{
return bp->attr.bp_addr;
@@ -36,22 +44,16 @@ static inline int hw_breakpoint_len(struct perf_event *bp)
}
extern struct perf_event *
-register_user_hw_breakpoint(unsigned long addr,
- int len,
- int type,
+register_user_hw_breakpoint(struct perf_event_attr *attr,
perf_callback_t triggered,
- struct task_struct *tsk,
- bool active);
+ struct task_struct *tsk);
/* FIXME: only change from the attr, and don't unregister */
extern struct perf_event *
modify_user_hw_breakpoint(struct perf_event *bp,
- unsigned long addr,
- int len,
- int type,
+ struct perf_event_attr *attr,
perf_callback_t triggered,
- struct task_struct *tsk,
- bool active);
+ struct task_struct *tsk);
/*
* Kernel breakpoints are not associated with any particular thread.
@@ -89,20 +91,14 @@ static inline struct arch_hw_breakpoint *counter_arch_bp(struct perf_event *bp)
#else /* !CONFIG_HAVE_HW_BREAKPOINT */
static inline struct perf_event *
-register_user_hw_breakpoint(unsigned long addr,
- int len,
- int type,
+register_user_hw_breakpoint(struct perf_event_attr *attr,
perf_callback_t triggered,
- struct task_struct *tsk,
- bool active) { return NULL; }
+ struct task_struct *tsk) { return NULL; }
static inline struct perf_event *
modify_user_hw_breakpoint(struct perf_event *bp,
- unsigned long addr,
- int len,
- int type,
+ struct perf_event_attr *attr,
perf_callback_t triggered,
- struct task_struct *tsk,
- bool active) { return NULL; }
+ struct task_struct *tsk) { return NULL; }
static inline struct perf_event *
register_wide_hw_breakpoint_cpu(unsigned long addr,
int len,
diff --git a/kernel/hw_breakpoint.c b/kernel/hw_breakpoint.c
index 32e1018191be..2a47514f12fd 100644
--- a/kernel/hw_breakpoint.c
+++ b/kernel/hw_breakpoint.c
@@ -289,90 +289,32 @@ int register_perf_hw_breakpoint(struct perf_event *bp)
return __register_perf_hw_breakpoint(bp);
}
-/*
- * Register a breakpoint bound to a task and a given cpu.
- * If cpu is -1, the breakpoint is active for the task in every cpu
- * If the task is -1, the breakpoint is active for every tasks in the given
- * cpu.
- */
-static struct perf_event *
-register_user_hw_breakpoint_cpu(unsigned long addr,
- int len,
- int type,
- perf_callback_t triggered,
- pid_t pid,
- int cpu,
- bool active)
-{
- struct perf_event_attr *attr;
- struct perf_event *bp;
-
- attr = kzalloc(sizeof(*attr), GFP_KERNEL);
- if (!attr)
- return ERR_PTR(-ENOMEM);
-
- attr->type = PERF_TYPE_BREAKPOINT;
- attr->size = sizeof(*attr);
- attr->bp_addr = addr;
- attr->bp_len = len;
- attr->bp_type = type;
- /*
- * Such breakpoints are used by debuggers to trigger signals when
- * we hit the excepted memory op. We can't miss such events, they
- * must be pinned.
- */
- attr->pinned = 1;
-
- if (!active)
- attr->disabled = 1;
-
- bp = perf_event_create_kernel_counter(attr, cpu, pid, triggered);
- kfree(attr);
-
- return bp;
-}
-
/**
* register_user_hw_breakpoint - register a hardware breakpoint for user space
- * @addr: is the memory address that triggers the breakpoint
- * @len: the length of the access to the memory (1 byte, 2 bytes etc...)
- * @type: the type of the access to the memory (read/write/exec)
+ * @attr: breakpoint attributes
* @triggered: callback to trigger when we hit the breakpoint
* @tsk: pointer to 'task_struct' of the process to which the address belongs
- * @active: should we activate it while registering it
- *
*/
struct perf_event *
-register_user_hw_breakpoint(unsigned long addr,
- int len,
- int type,
+register_user_hw_breakpoint(struct perf_event_attr *attr,
perf_callback_t triggered,
- struct task_struct *tsk,
- bool active)
+ struct task_struct *tsk)
{
- return register_user_hw_breakpoint_cpu(addr, len, type, triggered,
- tsk->pid, -1, active);
+ return perf_event_create_kernel_counter(attr, -1, tsk->pid, triggered);
}
EXPORT_SYMBOL_GPL(register_user_hw_breakpoint);
/**
* modify_user_hw_breakpoint - modify a user-space hardware breakpoint
* @bp: the breakpoint structure to modify
- * @addr: is the memory address that triggers the breakpoint
- * @len: the length of the access to the memory (1 byte, 2 bytes etc...)
- * @type: the type of the access to the memory (read/write/exec)
+ * @attr: new breakpoint attributes
* @triggered: callback to trigger when we hit the breakpoint
* @tsk: pointer to 'task_struct' of the process to which the address belongs
- * @active: should we activate it while registering it
*/
struct perf_event *
-modify_user_hw_breakpoint(struct perf_event *bp,
- unsigned long addr,
- int len,
- int type,
+modify_user_hw_breakpoint(struct perf_event *bp, struct perf_event_attr *attr,
perf_callback_t triggered,
- struct task_struct *tsk,
- bool active)
+ struct task_struct *tsk)
{
/*
* FIXME: do it without unregistering
@@ -381,8 +323,7 @@ modify_user_hw_breakpoint(struct perf_event *bp,
*/
unregister_hw_breakpoint(bp);
- return register_user_hw_breakpoint(addr, len, type, triggered,
- tsk, active);
+ return perf_event_create_kernel_counter(attr, -1, tsk->pid, triggered);
}
EXPORT_SYMBOL_GPL(modify_user_hw_breakpoint);
@@ -406,8 +347,16 @@ register_kernel_hw_breakpoint_cpu(unsigned long addr,
int cpu,
bool active)
{
- return register_user_hw_breakpoint_cpu(addr, len, type, triggered,
- -1, cpu, active);
+ DEFINE_BREAKPOINT_ATTR(attr);
+
+ attr.bp_addr = addr;
+ attr.bp_len = len;
+ attr.bp_type = type;
+
+ if (!active)
+ attr.disabled = 1;
+
+ return perf_event_create_kernel_counter(&attr, cpu, -1, triggered);
}
/**
generated by cgit v1.2.3 (git 2.39.1) at 2024-12-14 18:08:05 +0100