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authorThomas Gleixner <tglx@linutronix.de>2016-09-14 21:53:26 +0300
committerThomas Gleixner <tglx@linutronix.de>2016-09-14 21:53:26 +0300
commit16217dc79dbc599b110dda26d0421df47904bba4 (patch)
tree98df3c18b14284b8a6f8b04de12e0b7dde5a55fa /kernel/trace/bpf_trace.c
parentecb3f394c5dba897d215a5422f1b363e93e2ce4e (diff)
parent723344dd0b2aa10ef9d28fe7f35d594d3e64f0f9 (diff)
downloadlinux-16217dc79dbc599b110dda26d0421df47904bba4.tar.xz
Merge tag 'irqchip-4.9-1' of git://git.kernel.org/pub/scm/linux/kernel/git/maz/arm-platforms into irq/core
Merge the first drop of irqchip updates for 4.9 from Marc Zyngier: - ACPI IORT core code - IORT support for the GICv3 ITS - A few of GIC cleanups
Diffstat (limited to 'kernel/trace/bpf_trace.c')
-rw-r--r--kernel/trace/bpf_trace.c164
1 files changed, 115 insertions, 49 deletions
diff --git a/kernel/trace/bpf_trace.c b/kernel/trace/bpf_trace.c
index 26f603da7e26..b20438fdb029 100644
--- a/kernel/trace/bpf_trace.c
+++ b/kernel/trace/bpf_trace.c
@@ -81,6 +81,49 @@ static const struct bpf_func_proto bpf_probe_read_proto = {
.arg3_type = ARG_ANYTHING,
};
+static u64 bpf_probe_write_user(u64 r1, u64 r2, u64 r3, u64 r4, u64 r5)
+{
+ void *unsafe_ptr = (void *) (long) r1;
+ void *src = (void *) (long) r2;
+ int size = (int) r3;
+
+ /*
+ * Ensure we're in user context which is safe for the helper to
+ * run. This helper has no business in a kthread.
+ *
+ * access_ok() should prevent writing to non-user memory, but in
+ * some situations (nommu, temporary switch, etc) access_ok() does
+ * not provide enough validation, hence the check on KERNEL_DS.
+ */
+
+ if (unlikely(in_interrupt() ||
+ current->flags & (PF_KTHREAD | PF_EXITING)))
+ return -EPERM;
+ if (unlikely(segment_eq(get_fs(), KERNEL_DS)))
+ return -EPERM;
+ if (!access_ok(VERIFY_WRITE, unsafe_ptr, size))
+ return -EPERM;
+
+ return probe_kernel_write(unsafe_ptr, src, size);
+}
+
+static const struct bpf_func_proto bpf_probe_write_user_proto = {
+ .func = bpf_probe_write_user,
+ .gpl_only = true,
+ .ret_type = RET_INTEGER,
+ .arg1_type = ARG_ANYTHING,
+ .arg2_type = ARG_PTR_TO_STACK,
+ .arg3_type = ARG_CONST_STACK_SIZE,
+};
+
+static const struct bpf_func_proto *bpf_get_probe_write_proto(void)
+{
+ pr_warn_ratelimited("%s[%d] is installing a program with bpf_probe_write_user helper that may corrupt user memory!",
+ current->comm, task_pid_nr(current));
+
+ return &bpf_probe_write_user_proto;
+}
+
/*
* limited trace_printk()
* only %d %u %x %ld %lu %lx %lld %llu %llx %p %s conversion specifiers allowed
@@ -188,31 +231,35 @@ const struct bpf_func_proto *bpf_get_trace_printk_proto(void)
return &bpf_trace_printk_proto;
}
-static u64 bpf_perf_event_read(u64 r1, u64 index, u64 r3, u64 r4, u64 r5)
+static u64 bpf_perf_event_read(u64 r1, u64 flags, u64 r3, u64 r4, u64 r5)
{
struct bpf_map *map = (struct bpf_map *) (unsigned long) r1;
struct bpf_array *array = container_of(map, struct bpf_array, map);
+ unsigned int cpu = smp_processor_id();
+ u64 index = flags & BPF_F_INDEX_MASK;
+ struct bpf_event_entry *ee;
struct perf_event *event;
- struct file *file;
+ if (unlikely(flags & ~(BPF_F_INDEX_MASK)))
+ return -EINVAL;
+ if (index == BPF_F_CURRENT_CPU)
+ index = cpu;
if (unlikely(index >= array->map.max_entries))
return -E2BIG;
- file = READ_ONCE(array->ptrs[index]);
- if (unlikely(!file))
+ ee = READ_ONCE(array->ptrs[index]);
+ if (!ee)
return -ENOENT;
- event = file->private_data;
-
- /* make sure event is local and doesn't have pmu::count */
- if (event->oncpu != smp_processor_id() ||
- event->pmu->count)
- return -EINVAL;
-
+ event = ee->event;
if (unlikely(event->attr.type != PERF_TYPE_HARDWARE &&
event->attr.type != PERF_TYPE_RAW))
return -EINVAL;
+ /* make sure event is local and doesn't have pmu::count */
+ if (unlikely(event->oncpu != cpu || event->pmu->count))
+ return -EINVAL;
+
/*
* we don't know if the function is run successfully by the
* return value. It can be judged in other places, such as
@@ -229,47 +276,58 @@ static const struct bpf_func_proto bpf_perf_event_read_proto = {
.arg2_type = ARG_ANYTHING,
};
-static u64 bpf_perf_event_output(u64 r1, u64 r2, u64 flags, u64 r4, u64 size)
+static __always_inline u64
+__bpf_perf_event_output(struct pt_regs *regs, struct bpf_map *map,
+ u64 flags, struct perf_raw_record *raw)
{
- struct pt_regs *regs = (struct pt_regs *) (long) r1;
- struct bpf_map *map = (struct bpf_map *) (long) r2;
struct bpf_array *array = container_of(map, struct bpf_array, map);
+ unsigned int cpu = smp_processor_id();
u64 index = flags & BPF_F_INDEX_MASK;
- void *data = (void *) (long) r4;
struct perf_sample_data sample_data;
+ struct bpf_event_entry *ee;
struct perf_event *event;
- struct file *file;
- struct perf_raw_record raw = {
- .size = size,
- .data = data,
- };
- if (unlikely(flags & ~(BPF_F_INDEX_MASK)))
- return -EINVAL;
if (index == BPF_F_CURRENT_CPU)
- index = raw_smp_processor_id();
+ index = cpu;
if (unlikely(index >= array->map.max_entries))
return -E2BIG;
- file = READ_ONCE(array->ptrs[index]);
- if (unlikely(!file))
+ ee = READ_ONCE(array->ptrs[index]);
+ if (!ee)
return -ENOENT;
- event = file->private_data;
-
+ event = ee->event;
if (unlikely(event->attr.type != PERF_TYPE_SOFTWARE ||
event->attr.config != PERF_COUNT_SW_BPF_OUTPUT))
return -EINVAL;
- if (unlikely(event->oncpu != smp_processor_id()))
+ if (unlikely(event->oncpu != cpu))
return -EOPNOTSUPP;
perf_sample_data_init(&sample_data, 0, 0);
- sample_data.raw = &raw;
+ sample_data.raw = raw;
perf_event_output(event, &sample_data, regs);
return 0;
}
+static u64 bpf_perf_event_output(u64 r1, u64 r2, u64 flags, u64 r4, u64 size)
+{
+ struct pt_regs *regs = (struct pt_regs *)(long) r1;
+ struct bpf_map *map = (struct bpf_map *)(long) r2;
+ void *data = (void *)(long) r4;
+ struct perf_raw_record raw = {
+ .frag = {
+ .size = size,
+ .data = data,
+ },
+ };
+
+ if (unlikely(flags & ~(BPF_F_INDEX_MASK)))
+ return -EINVAL;
+
+ return __bpf_perf_event_output(regs, map, flags, &raw);
+}
+
static const struct bpf_func_proto bpf_perf_event_output_proto = {
.func = bpf_perf_event_output,
.gpl_only = true,
@@ -283,31 +341,41 @@ static const struct bpf_func_proto bpf_perf_event_output_proto = {
static DEFINE_PER_CPU(struct pt_regs, bpf_pt_regs);
-static u64 bpf_event_output(u64 r1, u64 r2, u64 flags, u64 r4, u64 size)
+u64 bpf_event_output(struct bpf_map *map, u64 flags, void *meta, u64 meta_size,
+ void *ctx, u64 ctx_size, bpf_ctx_copy_t ctx_copy)
{
struct pt_regs *regs = this_cpu_ptr(&bpf_pt_regs);
+ struct perf_raw_frag frag = {
+ .copy = ctx_copy,
+ .size = ctx_size,
+ .data = ctx,
+ };
+ struct perf_raw_record raw = {
+ .frag = {
+ {
+ .next = ctx_size ? &frag : NULL,
+ },
+ .size = meta_size,
+ .data = meta,
+ },
+ };
perf_fetch_caller_regs(regs);
- return bpf_perf_event_output((long)regs, r2, flags, r4, size);
+ return __bpf_perf_event_output(regs, map, flags, &raw);
+}
+
+static u64 bpf_get_current_task(u64 r1, u64 r2, u64 r3, u64 r4, u64 r5)
+{
+ return (long) current;
}
-static const struct bpf_func_proto bpf_event_output_proto = {
- .func = bpf_event_output,
+static const struct bpf_func_proto bpf_get_current_task_proto = {
+ .func = bpf_get_current_task,
.gpl_only = true,
.ret_type = RET_INTEGER,
- .arg1_type = ARG_PTR_TO_CTX,
- .arg2_type = ARG_CONST_MAP_PTR,
- .arg3_type = ARG_ANYTHING,
- .arg4_type = ARG_PTR_TO_STACK,
- .arg5_type = ARG_CONST_STACK_SIZE,
};
-const struct bpf_func_proto *bpf_get_event_output_proto(void)
-{
- return &bpf_event_output_proto;
-}
-
static const struct bpf_func_proto *tracing_func_proto(enum bpf_func_id func_id)
{
switch (func_id) {
@@ -325,6 +393,8 @@ static const struct bpf_func_proto *tracing_func_proto(enum bpf_func_id func_id)
return &bpf_tail_call_proto;
case BPF_FUNC_get_current_pid_tgid:
return &bpf_get_current_pid_tgid_proto;
+ case BPF_FUNC_get_current_task:
+ return &bpf_get_current_task_proto;
case BPF_FUNC_get_current_uid_gid:
return &bpf_get_current_uid_gid_proto;
case BPF_FUNC_get_current_comm:
@@ -335,6 +405,8 @@ static const struct bpf_func_proto *tracing_func_proto(enum bpf_func_id func_id)
return &bpf_get_smp_processor_id_proto;
case BPF_FUNC_perf_event_read:
return &bpf_perf_event_read_proto;
+ case BPF_FUNC_probe_write_user:
+ return bpf_get_probe_write_proto();
default:
return NULL;
}
@@ -356,18 +428,12 @@ static const struct bpf_func_proto *kprobe_prog_func_proto(enum bpf_func_id func
static bool kprobe_prog_is_valid_access(int off, int size, enum bpf_access_type type,
enum bpf_reg_type *reg_type)
{
- /* check bounds */
if (off < 0 || off >= sizeof(struct pt_regs))
return false;
-
- /* only read is allowed */
if (type != BPF_READ)
return false;
-
- /* disallow misaligned access */
if (off % size != 0)
return false;
-
return true;
}