| Message ID | 20230927041629.43ffbfd9@rorschach.local.home (mailing list archive) |
|---|---|
| State | Superseded |
| Headers | show |
| Series | libtraceeval: Fix comparing unsigned against zero | expand |
On Wed, Sep 27, 2023 at 04:16:29AM -0400, Steven Rostedt wrote: > From: "Steven Rostedt (Google)" <rostedt@goodmis.org> > > nr_key_types and nr_val_types are both size_t which is an unsized number. > A compare against zero is always false: > > if (teval->nr_key_types < 0) > > Typecast it to signed for these comparisons. > > Also change the few places the "size_t i" is used where it does: > > for (; i >= 0; i--) > > as that too needs to be signed to work. > > Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org> > --- > src/histograms.c | 10 +++++----- > 1 file changed, 5 insertions(+), 5 deletions(-) > > diff --git a/src/histograms.c b/src/histograms.c > index 96f0926f062c..42959c154a11 100644 > --- a/src/histograms.c > +++ b/src/histograms.c > @@ -159,7 +159,7 @@ static size_t type_alloc(const struct traceeval_type *defs, > { > struct traceeval_type *new_defs = NULL; > size_t size; > - size_t i; > + ssize_t i; > > *copy = NULL; > > @@ -196,7 +196,7 @@ fail: > else > print_err("traceeval_type list missing a name"); > > - for (; i >=0; i--) > + for (; i >= 0; i--) > free(new_defs[i].name); > free(new_defs); > return -1; > @@ -303,14 +303,14 @@ struct traceeval *traceeval_init(struct traceeval_type *keys, > > /* alloc key types */ > teval->nr_key_types = type_alloc(keys, &teval->key_types); > - if (teval->nr_key_types <= 0) { > + if ((ssize_t)teval->nr_key_types <= 0) { Rather than casting, wouldn't it be better to just change the type of nr_key_types and nr_val_types to ssize_t? I think this should be the return type of type_alloc() as well, since this returns -1 on error. > err_msg = "Failed to allocate user defined keys"; > goto fail_release; > } > > /* alloc val types */ > teval->nr_val_types = type_alloc(vals, &teval->val_types); > - if (teval->nr_val_types < 0) { > + if ((ssize_t)teval->nr_val_types < 0) { > err_msg = "Failed to allocate user defined values"; > goto fail_release; > } > @@ -785,7 +785,7 @@ static int update_entry(struct traceeval *teval, struct entry *entry, > union traceeval_data *copy = entry->vals; > union traceeval_data old[teval->nr_val_types]; > size_t size = teval->nr_val_types; > - size_t i; > + ssize_t i; > > if (!size) > return 0; > -- > 2.40.1 >
On Mon, 2 Oct 2023 12:31:02 -0600 Ross Zwisler <zwisler@google.com> wrote: > > @@ -303,14 +303,14 @@ struct traceeval *traceeval_init(struct traceeval_type *keys, > > > > /* alloc key types */ > > teval->nr_key_types = type_alloc(keys, &teval->key_types); > > - if (teval->nr_key_types <= 0) { > > + if ((ssize_t)teval->nr_key_types <= 0) { > > Rather than casting, wouldn't it be better to just change the type of > nr_key_types and nr_val_types to ssize_t? I think this should be the return > type of type_alloc() as well, since this returns -1 on error. I thought about that, and there was a reason against it. But I forgot what that was :-p -- Steve
On Mon, 2 Oct 2023 14:37:15 -0400 Steven Rostedt <rostedt@goodmis.org> wrote: > On Mon, 2 Oct 2023 12:31:02 -0600 > Ross Zwisler <zwisler@google.com> wrote: > > > > @@ -303,14 +303,14 @@ struct traceeval *traceeval_init(struct traceeval_type *keys, > > > > > > /* alloc key types */ > > > teval->nr_key_types = type_alloc(keys, &teval->key_types); > > > - if (teval->nr_key_types <= 0) { > > > + if ((ssize_t)teval->nr_key_types <= 0) { > > > > Rather than casting, wouldn't it be better to just change the type of > > nr_key_types and nr_val_types to ssize_t? I think this should be the return > > type of type_alloc() as well, since this returns -1 on error. > > I thought about that, and there was a reason against it. But I forgot what > that was :-p I still can't remember why I didn't convert ssize_t, so maybe it was not a real reason. I'll send a v2 changing the type to ssize_t and if there was a reason I didn't do that before, maybe it will show up when I make the change! -- Steve
diff --git a/src/histograms.c b/src/histograms.c index 96f0926f062c..42959c154a11 100644 --- a/src/histograms.c +++ b/src/histograms.c @@ -159,7 +159,7 @@ static size_t type_alloc(const struct traceeval_type *defs, { struct traceeval_type *new_defs = NULL; size_t size; - size_t i; + ssize_t i; *copy = NULL; @@ -196,7 +196,7 @@ fail: else print_err("traceeval_type list missing a name"); - for (; i >=0; i--) + for (; i >= 0; i--) free(new_defs[i].name); free(new_defs); return -1; @@ -303,14 +303,14 @@ struct traceeval *traceeval_init(struct traceeval_type *keys, /* alloc key types */ teval->nr_key_types = type_alloc(keys, &teval->key_types); - if (teval->nr_key_types <= 0) { + if ((ssize_t)teval->nr_key_types <= 0) { err_msg = "Failed to allocate user defined keys"; goto fail_release; } /* alloc val types */ teval->nr_val_types = type_alloc(vals, &teval->val_types); - if (teval->nr_val_types < 0) { + if ((ssize_t)teval->nr_val_types < 0) { err_msg = "Failed to allocate user defined values"; goto fail_release; } @@ -785,7 +785,7 @@ static int update_entry(struct traceeval *teval, struct entry *entry, union traceeval_data *copy = entry->vals; union traceeval_data old[teval->nr_val_types]; size_t size = teval->nr_val_types; - size_t i; + ssize_t i; if (!size) return 0;