* Re: [next:akpm 155/157] drivers/char/random.c:827:3: warning: format '%zd' expects argument of type 'signed size_t', but argument 7 has type 'size_t'
[not found] ` <20121024005612.GA4028@localhost>
@ 2012-10-24 1:30 ` Fengguang Wu
0 siblings, 0 replies; only message in thread
From: Fengguang Wu @ 2012-10-24 1:30 UTC (permalink / raw)
To: Andrew Morton
Cc: Jiri Kosina, Yuanhan Liu, LKML, linux-cris-kernel,
linux-am33-list
[add CC to mn10300/cris arch lists]
On Wed, Oct 24, 2012 at 08:56:12AM +0800, Fengguang Wu wrote:
> On Tue, Oct 23, 2012 at 02:53:58PM -0700, Andrew Morton wrote:
> > On Tue, 23 Oct 2012 18:16:58 +0800
> > Fengguang Wu <fengguang.wu@intel.com> wrote:
> >
> > > Hi Jiri,
> > >
> > > FYI, there are new compile warnings show up in
> > >
> > > tree: git://git.kernel.org/pub/scm/linux/kernel/git/next/linux-next.git akpm
> > > head: dbfe0815b4af06cc4ca6cd12b17e2d13ffaaf991
> > > commit: 0b1f5a647784c406ee33a6ddd3bb6382a2278111 [155/157] random: fix debug format strings
> > > config: mn10300-asb2364_defconfig # make ARCH=mn10300 asb2364_defconfig
> > >
> > > All warnings:
> > >
> > > drivers/char/random.c: In function 'xfer_secondary_pool':
> > > drivers/char/random.c:827:3: warning: format '%zd' expects argument of type 'signed size_t', but argument 7 has type 'size_t' [-Wformat]
> > > drivers/char/random.c: In function 'account':
> > > drivers/char/random.c:859:2: warning: format '%zd' expects argument of type 'signed size_t', but argument 5 has type 'size_t' [-Wformat]
> > > drivers/char/random.c:881:2: warning: format '%zd' expects argument of type 'signed size_t', but argument 5 has type 'size_t' [-Wformat]
> > > drivers/char/random.c: In function 'random_read':
> > > drivers/char/random.c:1141:3: warning: format '%zd' expects argument of type 'signed size_t', but argument 5 has type 'int' [-Wformat]
> > > drivers/char/random.c:1145:3: warning: format '%zd' expects argument of type 'signed size_t', but argument 5 has type 'int' [-Wformat]
> > > drivers/char/random.c:1145:3: warning: format '%zd' expects argument of type 'signed size_t', but argument 6 has type 'size_t' [-Wformat]
> > > drivers/char/random.c: In function 'write_pool':
> > > drivers/char/random.c:1213:11: warning: comparison of distinct pointer types lacks a cast [enabled by default]
> > >
> >
> > Ah, I get it. %zd vs %zu. This?
>
> With the patch, there are still errors (below). I think the reason of the
> warnings is, (size_t * 8) makes it an (int) because the constant 8 is (int).
Sorry (size_t * 8) becomes (unsigned int) because (size_t) is (unsigned int).
And the problem is specific to mn10300/cris: (size_t * 8) is no longer (size_t),
which triggers the gcc warnings discussed here.
Thanks,
Fengguang
> CC drivers/char/random.o
> /c/wfg/linux/drivers/char/random.c: In function 'xfer_secondary_pool':
> /c/wfg/linux/drivers/char/random.c:827:3: warning: format '%zu' expects argument of type 'size_t', but argument 7 has type 'unsigned int' [-Wformat]
> /c/wfg/linux/drivers/char/random.c: In function 'account':
> /c/wfg/linux/drivers/char/random.c:859:2: warning: format '%zu' expects argument of type 'size_t', but argument 5 has type 'unsigned int' [-Wformat]
> /c/wfg/linux/drivers/char/random.c:881:2: warning: format '%zu' expects argument of type 'size_t', but argument 5 has type 'unsigned int' [-Wformat]
> /c/wfg/linux/drivers/char/random.c: In function 'random_read':
> /c/wfg/linux/drivers/char/random.c:1141:3: warning: format '%zu' expects argument of type 'size_t', but argument 5 has type 'int' [-Wformat]
> /c/wfg/linux/drivers/char/random.c:1145:3: warning: format '%zu' expects argument of type 'size_t', but argument 5 has type 'int' [-Wformat]
> /c/wfg/linux/drivers/char/random.c:1145:3: warning: format '%zu' expects argument of type 'size_t', but argument 6 has type 'unsigned int' [-Wformat]
>
> And that behavior is depending on arch. Changing %zu to %u will make
> mn10300/parisc/i386 etc. archs compile cleanly, however x86_64 goes
> wrong like this:
>
> /c/wfg/linux/drivers/char/random.c:827:3: warning: format ‘%u’ expects argument of type ‘unsigned int’, but argument 7 has type ‘size_t’ [-Wformat]
>
> So in x86_64, (size_t * 8) is still of type size_t.
>
> Thanks,
> Fengguang
> ---
> >
> > From: Andrew Morton <akpm@linux-foundation.org>
> > Subject: random-fix-debug-format-strings-fix
> >
> > s/%zd/%zu/ for unsigned `size_t'
> >
> > Cc: Jiri Kosina <jkosina@suse.cz>
> > Cc: Theodore Ts'o <tytso@mit.edu>
> > Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
> > ---
> >
> > drivers/char/random.c | 12 ++++++------
> > 1 file changed, 6 insertions(+), 6 deletions(-)
> >
> > diff -puN drivers/char/random.c~random-fix-debug-format-strings-fix drivers/char/random.c
> > --- a/drivers/char/random.c~random-fix-debug-format-strings-fix
> > +++ a/drivers/char/random.c
> > @@ -825,7 +825,7 @@ static void xfer_secondary_pool(struct e
> > bytes = min_t(int, bytes, sizeof(tmp));
> >
> > DEBUG_ENT("going to reseed %s with %d bits "
> > - "(%zd of %d requested)\n",
> > + "(%zu of %d requested)\n",
> > r->name, bytes * 8, nbytes * 8, r->entropy_count);
> >
> > bytes = extract_entropy(r->pull, tmp, bytes,
> > @@ -856,7 +856,7 @@ static size_t account(struct entropy_sto
> > spin_lock_irqsave(&r->lock, flags);
> >
> > BUG_ON(r->entropy_count > r->poolinfo->POOLBITS);
> > - DEBUG_ENT("trying to extract %zd bits from %s\n",
> > + DEBUG_ENT("trying to extract %zu bits from %s\n",
> > nbytes * 8, r->name);
> >
> > /* Can we pull enough? */
> > @@ -878,7 +878,7 @@ static size_t account(struct entropy_sto
> > }
> > }
> >
> > - DEBUG_ENT("debiting %zd entropy credits from %s%s\n",
> > + DEBUG_ENT("debiting %zu entropy credits from %s%s\n",
> > nbytes * 8, r->name, r->limit ? "" : " (unlimited)");
> >
> > spin_unlock_irqrestore(&r->lock, flags);
> > @@ -1138,11 +1138,11 @@ random_read(struct file *file, char __us
> > if (n > SEC_XFER_SIZE)
> > n = SEC_XFER_SIZE;
> >
> > - DEBUG_ENT("reading %zd bits\n", n*8);
> > + DEBUG_ENT("reading %zu bits\n", n*8);
> >
> > n = extract_entropy_user(&blocking_pool, buf, n);
> >
> > - DEBUG_ENT("read got %zd bits (%zd still needed)\n",
> > + DEBUG_ENT("read got %zu bits (%zu still needed)\n",
> > n*8, (nbytes-n)*8);
> >
> > if (n == 0) {
> > @@ -1210,7 +1210,7 @@ write_pool(struct entropy_store *r, cons
> > const char __user *p = buffer;
> >
> > while (count > 0) {
> > - bytes = min(count, sizeof(buf));
> > + bytes = min_t(size_t, count, sizeof(buf));
> > if (copy_from_user(&buf, p, bytes))
> > return -EFAULT;
> >
> > _
^ permalink raw reply [flat|nested] only message in thread