| Message ID | 20210324135143.445443-1-tz.stoyanov@gmail.com (mailing list archive) |
|---|---|
| State | Superseded |
| Headers | show |
| Series | [v2] trace-cmd: Remove all die()s from trace-cmd library | expand |
On Wed, 24 Mar 2021 15:51:43 +0200 "Tzvetomir Stoyanov (VMware)" <tz.stoyanov@gmail.com> wrote: > @@ -366,36 +366,32 @@ void __noreturn __vdie(const char *fmt, va_list ap) > vfprintf(stderr, fmt, ap); > > fprintf(stderr, "\n"); > - exit(ret); > + return ret; > } > > -void __noreturn __die(const char *fmt, ...) > +#ifdef LIB_DIE I wonder if it would be more useful not to have it as a compile time define, but instead a global variable: static bool lib_die; void tracecmd_die_on_error(void) { lib_die = true; } Make the "die()" functions into static variables here. void __hidden _lib_fatal(const char *fmt, ...) { va_list ap; va_start(ap, fmt); if (lib_die) __vdie(fmt, ap); else __vwarning(fmt, ap); va_end(ap); } That way if we run trace-cmd with the --debug option, it could then call the tracecmd_die_on_error() function, and it will crash on any "fatal" places. -- Steve > + > +void __noreturn _lib_fatal(const char *fmt, ...) > { > va_list ap; > + int ret; > > va_start(ap, fmt); > - __vdie(fmt, ap); > + ret = __vlib_fatal(fmt, ap); > va_end(ap); > + exit(ret); > } > > -void __weak __noreturn die(const char *fmt, ...) > +#else > +void _lib_fatal(const char *fmt, ...) > { > va_list ap; > > va_start(ap, fmt); > - __vdie(fmt, ap); > + __vlib_fatal(fmt, ap); > va_end(ap); > } > - > -void __weak *malloc_or_die(unsigned int size) > -{ > - void *data; > - > - data = malloc(size); > - if (!data) > - die("malloc"); > - return data; > -} > +#endif >
On Wed, Mar 24, 2021 at 11:53 PM Steven Rostedt <rostedt@goodmis.org> wrote: > > On Wed, 24 Mar 2021 15:51:43 +0200 > "Tzvetomir Stoyanov (VMware)" <tz.stoyanov@gmail.com> wrote: > > > @@ -366,36 +366,32 @@ void __noreturn __vdie(const char *fmt, va_list ap) > > vfprintf(stderr, fmt, ap); > > > > fprintf(stderr, "\n"); > > - exit(ret); > > + return ret; > > } > > > > -void __noreturn __die(const char *fmt, ...) > > +#ifdef LIB_DIE > > I wonder if it would be more useful not to have it as a compile time > define, but instead a global variable: > > static bool lib_die; > > void tracecmd_die_on_error(void) > { > lib_die = true; > } > There is tracecmd_set_debug() API already, It can be used to trigger that die() logic. It makes sense for the library to do a real die() when running in debug mode, if a fatal error is encountered. > Make the "die()" functions into static variables here. > > void __hidden _lib_fatal(const char *fmt, ...) > { > va_list ap; > > va_start(ap, fmt); > if (lib_die) > __vdie(fmt, ap); > else > __vwarning(fmt, ap); > va_end(ap); > } > > That way if we run trace-cmd with the --debug option, it could then call > the tracecmd_die_on_error() function, and it will crash on any "fatal" > places. > > -- Steve > > > > + > > +void __noreturn _lib_fatal(const char *fmt, ...) > > { > > va_list ap; > > + int ret; > > > > va_start(ap, fmt); > > - __vdie(fmt, ap); > > + ret = __vlib_fatal(fmt, ap); > > va_end(ap); > > + exit(ret); > > } > > > > -void __weak __noreturn die(const char *fmt, ...) > > +#else > > +void _lib_fatal(const char *fmt, ...) > > { > > va_list ap; > > > > va_start(ap, fmt); > > - __vdie(fmt, ap); > > + __vlib_fatal(fmt, ap); > > va_end(ap); > > } > > - > > -void __weak *malloc_or_die(unsigned int size) > > -{ > > - void *data; > > - > > - data = malloc(size); > > - if (!data) > > - die("malloc"); > > - return data; > > -} > > +#endif > >
diff --git a/lib/trace-cmd/include/trace-cmd-local.h b/lib/trace-cmd/include/trace-cmd-local.h index d265e4c8..da9d8d58 100644 --- a/lib/trace-cmd/include/trace-cmd-local.h +++ b/lib/trace-cmd/include/trace-cmd-local.h @@ -12,6 +12,8 @@ /* Can be overridden */ void warning(const char *fmt, ...); +void _lib_fatal(const char *fmt, ...); + #define __packed __attribute__((packed)) /* trace.dat file format version */ diff --git a/lib/trace-cmd/trace-input.c b/lib/trace-cmd/trace-input.c index 2093a3dc..3687de09 100644 --- a/lib/trace-cmd/trace-input.c +++ b/lib/trace-cmd/trace-input.c @@ -16,6 +16,7 @@ #include <linux/time64.h> #include "trace-write-local.h" +#include "trace-cmd-local.h" #include "trace-local.h" #include "kbuffer.h" #include "list.h" @@ -1087,8 +1088,10 @@ static void __free_page(struct tracecmd_input *handle, struct page *page) struct page **pages; int index; - if (!page->ref_count) - die("Page ref count is zero!\n"); + if (!page->ref_count) { + _lib_fatal("Page ref count is zero!\n"); + return; + } page->ref_count--; if (page->ref_count) @@ -1146,16 +1149,20 @@ void tracecmd_free_record(struct tep_record *record) if (!record) return; - if (!record->ref_count) - die("record ref count is zero!"); + if (!record->ref_count) { + _lib_fatal("record ref count is zero!"); + return; + } record->ref_count--; if (record->ref_count) return; - if (record->locked) - die("freeing record when it is locked!"); + if (record->locked) { + _lib_fatal("freeing record when it is locked!"); + return; + } record->data = NULL; @@ -1318,7 +1325,7 @@ static int get_page(struct tracecmd_input *handle, int cpu, if (offset & (handle->page_size - 1)) { errno = -EINVAL; - die("bad page offset %llx", offset); + _lib_fatal("bad page offset %llx", offset); return -1; } @@ -1326,7 +1333,7 @@ static int get_page(struct tracecmd_input *handle, int cpu, offset > handle->cpu_data[cpu].file_offset + handle->cpu_data[cpu].file_size) { errno = -EINVAL; - die("bad page offset %llx", offset); + _lib_fatal("bad page offset %llx", offset); return -1; } @@ -1891,8 +1898,10 @@ tracecmd_peek_data(struct tracecmd_input *handle, int cpu) if (handle->cpu_data[cpu].next) { record = handle->cpu_data[cpu].next; - if (!record->data) - die("Something freed the record"); + if (!record->data) { + _lib_fatal("Something freed the record"); + return NULL; + } if (handle->cpu_data[cpu].timestamp == record->ts) return record; diff --git a/lib/trace-cmd/trace-util.c b/lib/trace-cmd/trace-util.c index 538adbc2..e8ed22fa 100644 --- a/lib/trace-cmd/trace-util.c +++ b/lib/trace-cmd/trace-util.c @@ -353,12 +353,12 @@ trace_load_plugins(struct tep_handle *tep, int flags) return list; } -void __noreturn __vdie(const char *fmt, va_list ap) +int __vlib_fatal(const char *fmt, va_list ap) { int ret = errno; if (errno) - perror("trace-cmd"); + perror("libtracecmd"); else ret = -1; @@ -366,36 +366,32 @@ void __noreturn __vdie(const char *fmt, va_list ap) vfprintf(stderr, fmt, ap); fprintf(stderr, "\n"); - exit(ret); + return ret; } -void __noreturn __die(const char *fmt, ...) +#ifdef LIB_DIE + +void __noreturn _lib_fatal(const char *fmt, ...) { va_list ap; + int ret; va_start(ap, fmt); - __vdie(fmt, ap); + ret = __vlib_fatal(fmt, ap); va_end(ap); + exit(ret); } -void __weak __noreturn die(const char *fmt, ...) +#else +void _lib_fatal(const char *fmt, ...) { va_list ap; va_start(ap, fmt); - __vdie(fmt, ap); + __vlib_fatal(fmt, ap); va_end(ap); } - -void __weak *malloc_or_die(unsigned int size) -{ - void *data; - - data = malloc(size); - if (!data) - die("malloc"); - return data; -} +#endif #define LOG_BUF_SIZE 1024 static void __plog(const char *prefix, const char *fmt, va_list ap, FILE *fp) @@ -546,8 +542,10 @@ int tracecmd_count_cpus(void) pbuf = buf; fp = fopen("/proc/cpuinfo", "r"); - if (!fp) - die("Can not read cpuinfo"); + if (!fp) { + _lib_fatal("Can not read cpuinfo"); + return 0; + } while ((r = getline(&pbuf, pn, fp)) >= 0) { char *p;
The die() call is used for a fatal error. It terminates the current program with exit(). The program should not be terminated from a library routine, the die() call should not be used in the trace-cmd library context. But as all these logs indicate a fatal error in the library, it is useful to have them. The die() call is replaced with _lib_fatal() library internal function, which prints the error message without terminating the application. If the library is compiled with LIB_DIE defined, the _lib_fatal() call behaves like die() - calls exit() to terminate the application. Signed-off-by: Tzvetomir Stoyanov (VMware) <tz.stoyanov@gmail.com> --- v2 changes: - Replaced die() with _lib_fatal(). lib/trace-cmd/include/trace-cmd-local.h | 2 ++ lib/trace-cmd/trace-input.c | 29 +++++++++++++------- lib/trace-cmd/trace-util.c | 36 ++++++++++++------------- 3 files changed, 38 insertions(+), 29 deletions(-)