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commit aa2e3ac64ace127f403be85aa4d6015b859385f2
parent 323ea40ff6fb1e9d2c481bff50245ee5f559c8af
Author: Linus Torvalds <torvalds@linux-foundation.org>
Date:   Fri, 15 Mar 2019 14:47:02 -0700

Merge tag 'trace-v5.1-2' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace

Pull tracing fixes and cleanups from Steven Rostedt:
 "This contains a series of last minute clean ups, small fixes and error
  checks"

* tag 'trace-v5.1-2' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace:
  tracing/probe: Verify alloc_trace_*probe() result
  tracing/probe: Check event/group naming rule at parsing
  tracing/probe: Check the size of argument name and body
  tracing/probe: Check event name length correctly
  tracing/probe: Check maxactive error cases
  tracing: kdb: Fix ftdump to not sleep
  trace/probes: Remove kernel doc style from non kernel doc comment
  tracing/probes: Make reserved_field_names static

Diffstat:
Minclude/linux/ring_buffer.h | 2+-
Mkernel/trace/ring_buffer.c | 5+++--
Mkernel/trace/trace.c | 6++++--
Mkernel/trace/trace_kdb.c | 6++++--
Mkernel/trace/trace_kprobe.c | 23+++++++++++------------
Mkernel/trace/trace_probe.c | 20++++++++++++++++++--
Mkernel/trace/trace_probe.h | 1+
Mkernel/trace/trace_uprobe.c | 8+++-----
8 files changed, 45 insertions(+), 26 deletions(-)

diff --git a/include/linux/ring_buffer.h b/include/linux/ring_buffer.h @@ -128,7 +128,7 @@ ring_buffer_consume(struct ring_buffer *buffer, int cpu, u64 *ts, unsigned long *lost_events); struct ring_buffer_iter * -ring_buffer_read_prepare(struct ring_buffer *buffer, int cpu); +ring_buffer_read_prepare(struct ring_buffer *buffer, int cpu, gfp_t flags); void ring_buffer_read_prepare_sync(void); void ring_buffer_read_start(struct ring_buffer_iter *iter); void ring_buffer_read_finish(struct ring_buffer_iter *iter); diff --git a/kernel/trace/ring_buffer.c b/kernel/trace/ring_buffer.c @@ -4191,6 +4191,7 @@ EXPORT_SYMBOL_GPL(ring_buffer_consume); * ring_buffer_read_prepare - Prepare for a non consuming read of the buffer * @buffer: The ring buffer to read from * @cpu: The cpu buffer to iterate over + * @flags: gfp flags to use for memory allocation * * This performs the initial preparations necessary to iterate * through the buffer. Memory is allocated, buffer recording @@ -4208,7 +4209,7 @@ EXPORT_SYMBOL_GPL(ring_buffer_consume); * This overall must be paired with ring_buffer_read_finish. */ struct ring_buffer_iter * -ring_buffer_read_prepare(struct ring_buffer *buffer, int cpu) +ring_buffer_read_prepare(struct ring_buffer *buffer, int cpu, gfp_t flags) { struct ring_buffer_per_cpu *cpu_buffer; struct ring_buffer_iter *iter; @@ -4216,7 +4217,7 @@ ring_buffer_read_prepare(struct ring_buffer *buffer, int cpu) if (!cpumask_test_cpu(cpu, buffer->cpumask)) return NULL; - iter = kmalloc(sizeof(*iter), GFP_KERNEL); + iter = kmalloc(sizeof(*iter), flags); if (!iter) return NULL; diff --git a/kernel/trace/trace.c b/kernel/trace/trace.c @@ -4079,7 +4079,8 @@ __tracing_open(struct inode *inode, struct file *file, bool snapshot) if (iter->cpu_file == RING_BUFFER_ALL_CPUS) { for_each_tracing_cpu(cpu) { iter->buffer_iter[cpu] = - ring_buffer_read_prepare(iter->trace_buffer->buffer, cpu); + ring_buffer_read_prepare(iter->trace_buffer->buffer, + cpu, GFP_KERNEL); } ring_buffer_read_prepare_sync(); for_each_tracing_cpu(cpu) { @@ -4089,7 +4090,8 @@ __tracing_open(struct inode *inode, struct file *file, bool snapshot) } else { cpu = iter->cpu_file; iter->buffer_iter[cpu] = - ring_buffer_read_prepare(iter->trace_buffer->buffer, cpu); + ring_buffer_read_prepare(iter->trace_buffer->buffer, + cpu, GFP_KERNEL); ring_buffer_read_prepare_sync(); ring_buffer_read_start(iter->buffer_iter[cpu]); tracing_iter_reset(iter, cpu); diff --git a/kernel/trace/trace_kdb.c b/kernel/trace/trace_kdb.c @@ -51,14 +51,16 @@ static void ftrace_dump_buf(int skip_lines, long cpu_file) if (cpu_file == RING_BUFFER_ALL_CPUS) { for_each_tracing_cpu(cpu) { iter.buffer_iter[cpu] = - ring_buffer_read_prepare(iter.trace_buffer->buffer, cpu); + ring_buffer_read_prepare(iter.trace_buffer->buffer, + cpu, GFP_ATOMIC); ring_buffer_read_start(iter.buffer_iter[cpu]); tracing_iter_reset(&iter, cpu); } } else { iter.cpu_file = cpu_file; iter.buffer_iter[cpu_file] = - ring_buffer_read_prepare(iter.trace_buffer->buffer, cpu_file); + ring_buffer_read_prepare(iter.trace_buffer->buffer, + cpu_file, GFP_ATOMIC); ring_buffer_read_start(iter.buffer_iter[cpu_file]); tracing_iter_reset(&iter, cpu_file); } diff --git a/kernel/trace/trace_kprobe.c b/kernel/trace/trace_kprobe.c @@ -35,7 +35,7 @@ static struct dyn_event_operations trace_kprobe_ops = { .match = trace_kprobe_match, }; -/** +/* * Kprobe event core functions */ struct trace_kprobe { @@ -221,7 +221,7 @@ static struct trace_kprobe *alloc_trace_kprobe(const char *group, tk->rp.maxactive = maxactive; - if (!event || !is_good_name(event)) { + if (!event || !group) { ret = -EINVAL; goto error; } @@ -231,11 +231,6 @@ static struct trace_kprobe *alloc_trace_kprobe(const char *group, if (!tk->tp.call.name) goto error; - if (!group || !is_good_name(group)) { - ret = -EINVAL; - goto error; - } - tk->tp.class.system = kstrdup(group, GFP_KERNEL); if (!tk->tp.class.system) goto error; @@ -624,7 +619,11 @@ static int trace_kprobe_create(int argc, const char *argv[]) if (event) event++; - if (is_return && isdigit(argv[0][1])) { + if (isdigit(argv[0][1])) { + if (!is_return) { + pr_info("Maxactive is not for kprobe"); + return -EINVAL; + } if (event) len = event - &argv[0][1] - 1; else @@ -634,8 +633,8 @@ static int trace_kprobe_create(int argc, const char *argv[]) memcpy(buf, &argv[0][1], len); buf[len] = '\0'; ret = kstrtouint(buf, 0, &maxactive); - if (ret) { - pr_info("Failed to parse maxactive.\n"); + if (ret || !maxactive) { + pr_info("Invalid maxactive number\n"); return ret; } /* kretprobes instances are iterated over via a list. The @@ -694,9 +693,9 @@ static int trace_kprobe_create(int argc, const char *argv[]) tk = alloc_trace_kprobe(group, event, addr, symbol, offset, maxactive, argc, is_return); if (IS_ERR(tk)) { - pr_info("Failed to allocate trace_probe.(%d)\n", - (int)PTR_ERR(tk)); ret = PTR_ERR(tk); + /* This must return -ENOMEM otherwise there is a bug */ + WARN_ON_ONCE(ret != -ENOMEM); goto out; } diff --git a/kernel/trace/trace_probe.c b/kernel/trace/trace_probe.c @@ -13,7 +13,7 @@ #include "trace_probe.h" -const char *reserved_field_names[] = { +static const char *reserved_field_names[] = { "common_type", "common_flags", "common_preempt_count", @@ -159,6 +159,7 @@ int traceprobe_parse_event_name(const char **pevent, const char **pgroup, char *buf) { const char *slash, *event = *pevent; + int len; slash = strchr(event, '/'); if (slash) { @@ -171,12 +172,25 @@ int traceprobe_parse_event_name(const char **pevent, const char **pgroup, return -E2BIG; } strlcpy(buf, event, slash - event + 1); + if (!is_good_name(buf)) { + pr_info("Group name must follow the same rules as C identifiers\n"); + return -EINVAL; + } *pgroup = buf; *pevent = slash + 1; + event = *pevent; } - if (strlen(event) == 0) { + len = strlen(event); + if (len == 0) { pr_info("Event name is not specified\n"); return -EINVAL; + } else if (len > MAX_EVENT_NAME_LEN) { + pr_info("Event name is too long\n"); + return -E2BIG; + } + if (!is_good_name(event)) { + pr_info("Event name must follow the same rules as C identifiers\n"); + return -EINVAL; } return 0; } @@ -548,6 +562,8 @@ int traceprobe_parse_probe_arg(struct trace_probe *tp, int i, char *arg, body = strchr(arg, '='); if (body) { + if (body - arg > MAX_ARG_NAME_LEN || body == arg) + return -EINVAL; parg->name = kmemdup_nul(arg, body - arg, GFP_KERNEL); body++; } else { diff --git a/kernel/trace/trace_probe.h b/kernel/trace/trace_probe.h @@ -32,6 +32,7 @@ #define MAX_TRACE_ARGS 128 #define MAX_ARGSTR_LEN 63 #define MAX_ARRAY_LEN 64 +#define MAX_ARG_NAME_LEN 32 #define MAX_STRING_SIZE PATH_MAX /* Reserved field names */ diff --git a/kernel/trace/trace_uprobe.c b/kernel/trace/trace_uprobe.c @@ -273,10 +273,7 @@ alloc_trace_uprobe(const char *group, const char *event, int nargs, bool is_ret) { struct trace_uprobe *tu; - if (!event || !is_good_name(event)) - return ERR_PTR(-EINVAL); - - if (!group || !is_good_name(group)) + if (!event || !group) return ERR_PTR(-EINVAL); tu = kzalloc(SIZEOF_TRACE_UPROBE(nargs), GFP_KERNEL); @@ -524,8 +521,9 @@ static int trace_uprobe_create(int argc, const char **argv) tu = alloc_trace_uprobe(group, event, argc, is_return); if (IS_ERR(tu)) { - pr_info("Failed to allocate trace_uprobe.(%d)\n", (int)PTR_ERR(tu)); ret = PTR_ERR(tu); + /* This must return -ENOMEM otherwise there is a bug */ + WARN_ON_ONCE(ret != -ENOMEM); goto fail_address_parse; } tu->offset = offset;