| Message ID | 20220302045131.387658-4-tz.stoyanov@gmail.com (mailing list archive) |
|---|---|
| State | Superseded |
| Headers | show |
| Series | trace-cmd: Improvements in compression logic | expand |
On 2022-03-02 06:51:29 [+0200], Tzvetomir Stoyanov (VMware) wrote: > Some zlib APIs set the errno in case of an error and return Z_ERRNO. > In these cases, errno should not be overwritten by the tarce-cmd zlib > wrappers. > > Suggested-by: Sebastian Andrzej Siewior <sebastian@breakpoint.cc> > Signed-off-by: Tzvetomir Stoyanov (VMware) <tz.stoyanov@gmail.com> > --- > lib/trace-cmd/trace-compress-zlib.c | 4 ++++ > 1 file changed, 4 insertions(+) > > diff --git a/lib/trace-cmd/trace-compress-zlib.c b/lib/trace-cmd/trace-compress-zlib.c > index 41342597..0dfd4f15 100644 > --- a/lib/trace-cmd/trace-compress-zlib.c > +++ b/lib/trace-cmd/trace-compress-zlib.c > @@ -33,6 +33,8 @@ static int zlib_compress(const void *in, int in_bytes, void *out, int out_bytes) > case Z_STREAM_ERROR: > errno = -EINVAL; > break; > + case Z_ERRNO: > + break; > default: > errno = -EFAULT; > break; > @@ -61,6 +63,8 @@ static int zlib_decompress(const void *in, int in_bytes, void *out, int out_byte > case Z_DATA_ERROR: > errno = -EINVAL; > break; > + case Z_ERRNO: > + break; > default: > errno = -EFAULT; > break; I was thinking about returning the error for compress/decompress via the return value and not touching errno at all. Sebastian
On Wed, 2 Mar 2022 08:15:30 +0100 Sebastian Andrzej Siewior <sebastian@breakpoint.cc> wrote: > I was thinking about returning the error for compress/decompress via the > return value and not touching errno at all. I know you hate the use of ERRNO in libraries and tooling, but we've decided to go that way for all of trace-cmd and the libraries (libtraceevent and libtracefs). This is just being consistent with all the other callers, and to do it differently will create an inconsistency in the API. -- Steve
On 2022-03-02 10:52:30 [-0500], Steven Rostedt wrote: > On Wed, 2 Mar 2022 08:15:30 +0100 > Sebastian Andrzej Siewior <sebastian@breakpoint.cc> wrote: > > > I was thinking about returning the error for compress/decompress via the > > return value and not touching errno at all. > > I know you hate the use of ERRNO in libraries and tooling, but we've decided > to go that way for all of trace-cmd and the libraries (libtraceevent and > libtracefs). This is just being consistent with all the other callers, and > to do it differently will create an inconsistency in the API. Ah okay then. In that case, the zstd interface does not set errno in the compress or decompress callback. This might need an update to be consistent. Otherwise the return value is < 0 and errno might still be 0. > -- Steve Sebastian
diff --git a/lib/trace-cmd/trace-compress-zlib.c b/lib/trace-cmd/trace-compress-zlib.c index 41342597..0dfd4f15 100644 --- a/lib/trace-cmd/trace-compress-zlib.c +++ b/lib/trace-cmd/trace-compress-zlib.c @@ -33,6 +33,8 @@ static int zlib_compress(const void *in, int in_bytes, void *out, int out_bytes) case Z_STREAM_ERROR: errno = -EINVAL; break; + case Z_ERRNO: + break; default: errno = -EFAULT; break; @@ -61,6 +63,8 @@ static int zlib_decompress(const void *in, int in_bytes, void *out, int out_byte case Z_DATA_ERROR: errno = -EINVAL; break; + case Z_ERRNO: + break; default: errno = -EFAULT; break;
Some zlib APIs set the errno in case of an error and return Z_ERRNO. In these cases, errno should not be overwritten by the tarce-cmd zlib wrappers. Suggested-by: Sebastian Andrzej Siewior <sebastian@breakpoint.cc> Signed-off-by: Tzvetomir Stoyanov (VMware) <tz.stoyanov@gmail.com> --- lib/trace-cmd/trace-compress-zlib.c | 4 ++++ 1 file changed, 4 insertions(+)