| Message ID | 20211216173511.10390-3-beaub@linux.microsoft.com (mailing list archive) |
|---|---|
| State | Superseded |
| Headers | show |
| Series | user_events: Enable user processes to create and write to trace events | expand |
On Thu, 16 Dec 2021 09:35:01 -0800 Beau Belgrave <beaub@linux.microsoft.com> wrote: > Addes print_fmt format generation for basic types that are supported for > user processes. Only supports sizes that are the same on 32 and 64 bit. Is the last sentence for user_events itself, or only limiting the print_fmt but user_events supports it? The code looks good to me. Acked-by: Masami Hiramatsu <mhiramat@kernel.org> Thank you, > > Signed-off-by: Beau Belgrave <beaub@linux.microsoft.com> > --- > kernel/trace/trace_events_user.c | 115 ++++++++++++++++++++++++++++++- > 1 file changed, 113 insertions(+), 2 deletions(-) > > diff --git a/kernel/trace/trace_events_user.c b/kernel/trace/trace_events_user.c > index 0a1b6496b9c3..67a92fe04ee4 100644 > --- a/kernel/trace/trace_events_user.c > +++ b/kernel/trace/trace_events_user.c > @@ -358,6 +358,114 @@ static int user_event_parse_fields(struct user_event *user, char *args) > > static struct trace_event_fields user_event_fields_array[1]; > > +static const char *user_field_format(const char *type) > +{ > + if (strcmp(type, "s64") == 0) > + return "%lld"; > + if (strcmp(type, "u64") == 0) > + return "%llu"; > + if (strcmp(type, "s32") == 0) > + return "%d"; > + if (strcmp(type, "u32") == 0) > + return "%u"; > + if (strcmp(type, "int") == 0) > + return "%d"; > + if (strcmp(type, "unsigned int") == 0) > + return "%u"; > + if (strcmp(type, "s16") == 0) > + return "%d"; > + if (strcmp(type, "u16") == 0) > + return "%u"; > + if (strcmp(type, "short") == 0) > + return "%d"; > + if (strcmp(type, "unsigned short") == 0) > + return "%u"; > + if (strcmp(type, "s8") == 0) > + return "%d"; > + if (strcmp(type, "u8") == 0) > + return "%u"; > + if (strcmp(type, "char") == 0) > + return "%d"; > + if (strcmp(type, "unsigned char") == 0) > + return "%u"; > + if (strstr(type, "char[") != 0) > + return "%s"; > + > + /* Unknown, likely struct, allowed treat as 64-bit */ > + return "%llu"; > +} > + > +static bool user_field_is_dyn_string(const char *type, const char **str_func) > +{ > + if (str_has_prefix(type, "__data_loc ")) { > + *str_func = "__get_str"; > + goto check; > + } > + > + if (str_has_prefix(type, "__rel_loc ")) { > + *str_func = "__get_rel_str"; > + goto check; > + } > + > + return false; > +check: > + return strstr(type, "char") != 0; > +} > + > +#define LEN_OR_ZERO (len ? len - pos : 0) > +static int user_event_set_print_fmt(struct user_event *user, char *buf, int len) > +{ > + struct ftrace_event_field *field, *next; > + struct list_head *head = &user->fields; > + int pos = 0, depth = 0; > + const char *str_func; > + > + pos += snprintf(buf + pos, LEN_OR_ZERO, "\""); > + > + list_for_each_entry_safe_reverse(field, next, head, link) { > + if (depth != 0) > + pos += snprintf(buf + pos, LEN_OR_ZERO, " "); > + > + pos += snprintf(buf + pos, LEN_OR_ZERO, "%s=%s", > + field->name, user_field_format(field->type)); > + > + depth++; > + } > + > + pos += snprintf(buf + pos, LEN_OR_ZERO, "\""); > + > + list_for_each_entry_safe_reverse(field, next, head, link) { > + if (user_field_is_dyn_string(field->type, &str_func)) > + pos += snprintf(buf + pos, LEN_OR_ZERO, > + ", %s(%s)", str_func, field->name); > + else > + pos += snprintf(buf + pos, LEN_OR_ZERO, > + ", REC->%s", field->name); > + } > + > + return pos + 1; > +} > +#undef LEN_OR_ZERO > + > +static int user_event_create_print_fmt(struct user_event *user) > +{ > + char *print_fmt; > + int len; > + > + len = user_event_set_print_fmt(user, NULL, 0); > + > + print_fmt = kmalloc(len, GFP_KERNEL); > + > + if (!print_fmt) > + return -ENOMEM; > + > + user_event_set_print_fmt(user, print_fmt, len); > + > + user->call.print_fmt = print_fmt; > + > + return 0; > +} > + > static enum print_line_t user_event_print_trace(struct trace_iterator *iter, > int flags, > struct trace_event *event) > @@ -391,6 +499,7 @@ static int destroy_user_event(struct user_event *user) > clear_bit(user->index, page_bitmap); > hash_del(&user->node); > > + kfree(user->call.print_fmt); > kfree(EVENT_NAME(user)); > kfree(user); > > @@ -663,8 +772,10 @@ static int user_event_parse(char *name, char *args, char *flags, > if (ret) > goto put_user; > > - /* Minimal print format */ > - user->call.print_fmt = "\"\""; > + ret = user_event_create_print_fmt(user); > + > + if (ret) > + goto put_user; > > user->call.data = user; > user->call.class = &user->class; > -- > 2.17.1 >
On Wed, Dec 22, 2021 at 09:30:30AM +0900, Masami Hiramatsu wrote: > On Thu, 16 Dec 2021 09:35:01 -0800 > Beau Belgrave <beaub@linux.microsoft.com> wrote: > > > Addes print_fmt format generation for basic types that are supported for > > user processes. Only supports sizes that are the same on 32 and 64 bit. > > Is the last sentence for user_events itself, or only limiting the > print_fmt but user_events supports it? > It's only for print_fmt to prevent incorrect decoding at that level, as we discussed previously. > The code looks good to me. > > Acked-by: Masami Hiramatsu <mhiramat@kernel.org> > > Thank you, > Thanks, -Beau
diff --git a/kernel/trace/trace_events_user.c b/kernel/trace/trace_events_user.c index 0a1b6496b9c3..67a92fe04ee4 100644 --- a/kernel/trace/trace_events_user.c +++ b/kernel/trace/trace_events_user.c @@ -358,6 +358,114 @@ static int user_event_parse_fields(struct user_event *user, char *args) static struct trace_event_fields user_event_fields_array[1]; +static const char *user_field_format(const char *type) +{ + if (strcmp(type, "s64") == 0) + return "%lld"; + if (strcmp(type, "u64") == 0) + return "%llu"; + if (strcmp(type, "s32") == 0) + return "%d"; + if (strcmp(type, "u32") == 0) + return "%u"; + if (strcmp(type, "int") == 0) + return "%d"; + if (strcmp(type, "unsigned int") == 0) + return "%u"; + if (strcmp(type, "s16") == 0) + return "%d"; + if (strcmp(type, "u16") == 0) + return "%u"; + if (strcmp(type, "short") == 0) + return "%d"; + if (strcmp(type, "unsigned short") == 0) + return "%u"; + if (strcmp(type, "s8") == 0) + return "%d"; + if (strcmp(type, "u8") == 0) + return "%u"; + if (strcmp(type, "char") == 0) + return "%d"; + if (strcmp(type, "unsigned char") == 0) + return "%u"; + if (strstr(type, "char[") != 0) + return "%s"; + + /* Unknown, likely struct, allowed treat as 64-bit */ + return "%llu"; +} + +static bool user_field_is_dyn_string(const char *type, const char **str_func) +{ + if (str_has_prefix(type, "__data_loc ")) { + *str_func = "__get_str"; + goto check; + } + + if (str_has_prefix(type, "__rel_loc ")) { + *str_func = "__get_rel_str"; + goto check; + } + + return false; +check: + return strstr(type, "char") != 0; +} + +#define LEN_OR_ZERO (len ? len - pos : 0) +static int user_event_set_print_fmt(struct user_event *user, char *buf, int len) +{ + struct ftrace_event_field *field, *next; + struct list_head *head = &user->fields; + int pos = 0, depth = 0; + const char *str_func; + + pos += snprintf(buf + pos, LEN_OR_ZERO, "\""); + + list_for_each_entry_safe_reverse(field, next, head, link) { + if (depth != 0) + pos += snprintf(buf + pos, LEN_OR_ZERO, " "); + + pos += snprintf(buf + pos, LEN_OR_ZERO, "%s=%s", + field->name, user_field_format(field->type)); + + depth++; + } + + pos += snprintf(buf + pos, LEN_OR_ZERO, "\""); + + list_for_each_entry_safe_reverse(field, next, head, link) { + if (user_field_is_dyn_string(field->type, &str_func)) + pos += snprintf(buf + pos, LEN_OR_ZERO, + ", %s(%s)", str_func, field->name); + else + pos += snprintf(buf + pos, LEN_OR_ZERO, + ", REC->%s", field->name); + } + + return pos + 1; +} +#undef LEN_OR_ZERO + +static int user_event_create_print_fmt(struct user_event *user) +{ + char *print_fmt; + int len; + + len = user_event_set_print_fmt(user, NULL, 0); + + print_fmt = kmalloc(len, GFP_KERNEL); + + if (!print_fmt) + return -ENOMEM; + + user_event_set_print_fmt(user, print_fmt, len); + + user->call.print_fmt = print_fmt; + + return 0; +} + static enum print_line_t user_event_print_trace(struct trace_iterator *iter, int flags, struct trace_event *event) @@ -391,6 +499,7 @@ static int destroy_user_event(struct user_event *user) clear_bit(user->index, page_bitmap); hash_del(&user->node); + kfree(user->call.print_fmt); kfree(EVENT_NAME(user)); kfree(user); @@ -663,8 +772,10 @@ static int user_event_parse(char *name, char *args, char *flags, if (ret) goto put_user; - /* Minimal print format */ - user->call.print_fmt = "\"\""; + ret = user_event_create_print_fmt(user); + + if (ret) + goto put_user; user->call.data = user; user->call.class = &user->class;
Addes print_fmt format generation for basic types that are supported for user processes. Only supports sizes that are the same on 32 and 64 bit. Signed-off-by: Beau Belgrave <beaub@linux.microsoft.com> --- kernel/trace/trace_events_user.c | 115 ++++++++++++++++++++++++++++++- 1 file changed, 113 insertions(+), 2 deletions(-)