On 11/8/20 11:11 PM, Lukas Bulwahn wrote: > make clang-analyzer caught my attention with: > > kernel/sysctl.c:1511:4: warning: Value stored to 'first' is never read \ > [clang-analyzer-deadcode.DeadStores] > first = 0; > ^ > > Commit 9f977fb7ae9d ("sysctl: add proc_do_large_bitmap") introduced > proc_do_large_bitmap(), where the variable first is only effectively used > when write is false; when write is true, the variable first is only used in > a dead assignment. > > So, simply remove this dead assignment and put the variable in local scope. > > As compilers will detect this unneeded assignment and optimize this anyway, > the resulting object code is identical before and after this change. > > No functional change. No change to object code. > > Signed-off-by: Lukas Bulwahn <lukas.bulw...@gmail.com> > --- > applies cleanly on v5.10-rc3 and next-20201106 > > Luis, Kees, Iurii, please pick this minor non-urgent clean-up patch. > > kernel/sysctl.c | 3 +-- > 1 file changed, 1 insertion(+), 2 deletions(-) > > diff --git a/kernel/sysctl.c b/kernel/sysctl.c > index ce75c67572b9..cc274a431d91 100644 > --- a/kernel/sysctl.c > +++ b/kernel/sysctl.c > @@ -1423,7 +1423,6 @@ int proc_do_large_bitmap(struct ctl_table *table, int > write, > void *buffer, size_t *lenp, loff_t *ppos) > { > int err = 0; > - bool first = 1; > size_t left = *lenp; > unsigned long bitmap_len = table->maxlen; > unsigned long *bitmap = *(unsigned long **) table->data; > @@ -1508,12 +1507,12 @@ int proc_do_large_bitmap(struct ctl_table *table, int > write, > } > > bitmap_set(tmp_bitmap, val_a, val_b - val_a + 1); > - first = 0; > proc_skip_char(&p, &left, '\n'); > } > left += skipped; > } else { > unsigned long bit_a, bit_b = 0; > + bool first = 1;
This looks fine, but while you are here how about setting, to match the type first = true And then only clearing first once if (!first) proc_put_char(&buffer, &left, ','); else first = false Instead of at every loop iteraction Tom > > while (left) { > bit_a = find_next_bit(bitmap, bitmap_len, bit_b);