* New bcache compiler warning (was: Re: bcache: Minor fixes from kbuild robot) @ 2014-02-17 21:00 Geert Uytterhoeven 2014-02-17 21:06 ` Randy Dunlap 0 siblings, 1 reply; 7+ messages in thread From: Geert Uytterhoeven @ 2014-02-17 21:00 UTC (permalink / raw) To: Kent Overstreet; +Cc: Linux Kernel Mailing List, linux-bcache On Fri, Feb 14, 2014 at 8:04 PM, Linux Kernel Mailing List <linux-kernel@vger.kernel.org> wrote: > bcache: Minor fixes from kbuild robot > diff --git a/drivers/md/bcache/bset.c b/drivers/md/bcache/bset.c > index 4f6b594..3f74b4b 100644 > --- a/drivers/md/bcache/bset.c > +++ b/drivers/md/bcache/bset.c > @@ -23,7 +23,7 @@ void bch_dump_bset(struct btree_keys *b, struct bset *i, unsigned set) > for (k = i->start; k < bset_bkey_last(i); k = next) { > next = bkey_next(k); > > - printk(KERN_ERR "block %u key %zi/%u: ", set, > + printk(KERN_ERR "block %u key %li/%u: ", set, > (uint64_t *) k - i->d, i->keys); > > if (b->ops->key_dump) On 32-bit (m68k): drivers/md/bcache/bset.c: In function ‘bch_dump_bset’: drivers/md/bcache/bset.c:27: warning: format ‘%li’ expects type ‘long int’, but argument 3 has type ‘int’ What are you trying to print here? It looks a bit strange to me. Technically, the difference between two pointers is of type ptrdiff_. The kernel had typedef __kernel_ptrdiff_t ptrdiff_t; and #if __BITS_PER_LONG != 64 typedef unsigned int __kernel_size_t; typedef int __kernel_ssize_t; typedef int __kernel_ptrdiff_t; #else typedef __kernel_ulong_t __kernel_size_t; typedef __kernel_long_t __kernel_ssize_t; typedef __kernel_long_t __kernel_ptrdiff_t; #endif So I'd expect "%zi" to be the right way, and a quick test compile on 32-bit (m68k) and 64-bit (amd64) comfirms that. What was wrong with it? Gr{oetje,eeting}s, Geert -- Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- geert@linux-m68k.org In personal conversations with technical people, I call myself a hacker. But when I'm talking to journalists I just say "programmer" or something like that. -- Linus Torvalds ^ permalink raw reply [flat|nested] 7+ messages in thread
* Re: New bcache compiler warning (was: Re: bcache: Minor fixes from kbuild robot) 2014-02-17 21:00 New bcache compiler warning (was: Re: bcache: Minor fixes from kbuild robot) Geert Uytterhoeven @ 2014-02-17 21:06 ` Randy Dunlap 2014-02-17 21:11 ` Geert Uytterhoeven 0 siblings, 1 reply; 7+ messages in thread From: Randy Dunlap @ 2014-02-17 21:06 UTC (permalink / raw) To: Geert Uytterhoeven, Kent Overstreet Cc: Linux Kernel Mailing List, linux-bcache On 02/17/2014 01:00 PM, Geert Uytterhoeven wrote: > On Fri, Feb 14, 2014 at 8:04 PM, Linux Kernel Mailing List > <linux-kernel@vger.kernel.org> wrote: >> bcache: Minor fixes from kbuild robot > >> diff --git a/drivers/md/bcache/bset.c b/drivers/md/bcache/bset.c >> index 4f6b594..3f74b4b 100644 >> --- a/drivers/md/bcache/bset.c >> +++ b/drivers/md/bcache/bset.c >> @@ -23,7 +23,7 @@ void bch_dump_bset(struct btree_keys *b, struct bset *i, unsigned set) >> for (k = i->start; k < bset_bkey_last(i); k = next) { >> next = bkey_next(k); >> >> - printk(KERN_ERR "block %u key %zi/%u: ", set, >> + printk(KERN_ERR "block %u key %li/%u: ", set, >> (uint64_t *) k - i->d, i->keys); >> >> if (b->ops->key_dump) > > On 32-bit (m68k): > drivers/md/bcache/bset.c: In function ‘bch_dump_bset’: > drivers/md/bcache/bset.c:27: warning: format ‘%li’ expects type ‘long > int’, but argument 3 has type ‘int’ > > What are you trying to print here? It looks a bit strange to me. > Technically, the difference between two pointers is of type ptrdiff_. > The kernel had > > typedef __kernel_ptrdiff_t ptrdiff_t; > > and > > #if __BITS_PER_LONG != 64 > typedef unsigned int __kernel_size_t; > typedef int __kernel_ssize_t; > typedef int __kernel_ptrdiff_t; > #else > typedef __kernel_ulong_t __kernel_size_t; > typedef __kernel_long_t __kernel_ssize_t; > typedef __kernel_long_t __kernel_ptrdiff_t; > #endif > > So I'd expect "%zi" to be the right way, and a quick test compile on > 32-bit (m68k) > and 64-bit (amd64) comfirms that. What was wrong with it? The kernel supports 't' (%t) for ptrdiff_t (same as glibc), so %ti should work (or %tu). -- ~Randy ^ permalink raw reply [flat|nested] 7+ messages in thread
* Re: New bcache compiler warning (was: Re: bcache: Minor fixes from kbuild robot) 2014-02-17 21:06 ` Randy Dunlap @ 2014-02-17 21:11 ` Geert Uytterhoeven 2014-02-17 21:45 ` Kent Overstreet 0 siblings, 1 reply; 7+ messages in thread From: Geert Uytterhoeven @ 2014-02-17 21:11 UTC (permalink / raw) To: Randy Dunlap; +Cc: Kent Overstreet, Linux Kernel Mailing List, linux-bcache On Mon, Feb 17, 2014 at 10:06 PM, Randy Dunlap <rdunlap@infradead.org> wrote: > On 02/17/2014 01:00 PM, Geert Uytterhoeven wrote: >> On Fri, Feb 14, 2014 at 8:04 PM, Linux Kernel Mailing List >> <linux-kernel@vger.kernel.org> wrote: >>> bcache: Minor fixes from kbuild robot >> >>> diff --git a/drivers/md/bcache/bset.c b/drivers/md/bcache/bset.c >>> index 4f6b594..3f74b4b 100644 >>> --- a/drivers/md/bcache/bset.c >>> +++ b/drivers/md/bcache/bset.c >>> @@ -23,7 +23,7 @@ void bch_dump_bset(struct btree_keys *b, struct bset *i, unsigned set) >>> for (k = i->start; k < bset_bkey_last(i); k = next) { >>> next = bkey_next(k); >>> >>> - printk(KERN_ERR "block %u key %zi/%u: ", set, >>> + printk(KERN_ERR "block %u key %li/%u: ", set, >>> (uint64_t *) k - i->d, i->keys); >>> >>> if (b->ops->key_dump) >> >> On 32-bit (m68k): >> drivers/md/bcache/bset.c: In function ‘bch_dump_bset’: >> drivers/md/bcache/bset.c:27: warning: format ‘%li’ expects type ‘long >> int’, but argument 3 has type ‘int’ >> >> What are you trying to print here? It looks a bit strange to me. >> Technically, the difference between two pointers is of type ptrdiff_. >> The kernel had >> >> typedef __kernel_ptrdiff_t ptrdiff_t; >> >> and >> >> #if __BITS_PER_LONG != 64 >> typedef unsigned int __kernel_size_t; >> typedef int __kernel_ssize_t; >> typedef int __kernel_ptrdiff_t; >> #else >> typedef __kernel_ulong_t __kernel_size_t; >> typedef __kernel_long_t __kernel_ssize_t; >> typedef __kernel_long_t __kernel_ptrdiff_t; >> #endif >> >> So I'd expect "%zi" to be the right way, and a quick test compile on >> 32-bit (m68k) >> and 64-bit (amd64) comfirms that. What was wrong with it? > > The kernel supports 't' (%t) for ptrdiff_t (same as glibc), > so %ti should work (or %tu). Yes, that compiles without warnings, too. And after more decyphering, "(uint64_t *) k - i->d" seems to be positive, so "%tu" should be OK. Gr{oetje,eeting}s, Geert -- Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- geert@linux-m68k.org In personal conversations with technical people, I call myself a hacker. But when I'm talking to journalists I just say "programmer" or something like that. -- Linus Torvalds ^ permalink raw reply [flat|nested] 7+ messages in thread
* Re: New bcache compiler warning (was: Re: bcache: Minor fixes from kbuild robot) 2014-02-17 21:11 ` Geert Uytterhoeven @ 2014-02-17 21:45 ` Kent Overstreet 2014-02-17 22:44 ` Randy Dunlap 2014-02-18 9:01 ` Geert Uytterhoeven 0 siblings, 2 replies; 7+ messages in thread From: Kent Overstreet @ 2014-02-17 21:45 UTC (permalink / raw) To: Geert Uytterhoeven; +Cc: Randy Dunlap, Linux Kernel Mailing List, linux-bcache On Mon, Feb 17, 2014 at 10:11:51PM +0100, Geert Uytterhoeven wrote: > On Mon, Feb 17, 2014 at 10:06 PM, Randy Dunlap <rdunlap@infradead.org> wrote: > > On 02/17/2014 01:00 PM, Geert Uytterhoeven wrote: > >> On Fri, Feb 14, 2014 at 8:04 PM, Linux Kernel Mailing List > >> <linux-kernel@vger.kernel.org> wrote: > >>> bcache: Minor fixes from kbuild robot > >> > >>> diff --git a/drivers/md/bcache/bset.c b/drivers/md/bcache/bset.c > >>> index 4f6b594..3f74b4b 100644 > >>> --- a/drivers/md/bcache/bset.c > >>> +++ b/drivers/md/bcache/bset.c > >>> @@ -23,7 +23,7 @@ void bch_dump_bset(struct btree_keys *b, struct bset *i, unsigned set) > >>> for (k = i->start; k < bset_bkey_last(i); k = next) { > >>> next = bkey_next(k); > >>> > >>> - printk(KERN_ERR "block %u key %zi/%u: ", set, > >>> + printk(KERN_ERR "block %u key %li/%u: ", set, > >>> (uint64_t *) k - i->d, i->keys); > >>> > >>> if (b->ops->key_dump) > >> > >> On 32-bit (m68k): > >> drivers/md/bcache/bset.c: In function ‘bch_dump_bset’: > >> drivers/md/bcache/bset.c:27: warning: format ‘%li’ expects type ‘long > >> int’, but argument 3 has type ‘int’ > >> > >> What are you trying to print here? It looks a bit strange to me. > >> Technically, the difference between two pointers is of type ptrdiff_. > >> The kernel had > >> > >> typedef __kernel_ptrdiff_t ptrdiff_t; > >> > >> and > >> > >> #if __BITS_PER_LONG != 64 > >> typedef unsigned int __kernel_size_t; > >> typedef int __kernel_ssize_t; > >> typedef int __kernel_ptrdiff_t; > >> #else > >> typedef __kernel_ulong_t __kernel_size_t; > >> typedef __kernel_long_t __kernel_ssize_t; > >> typedef __kernel_long_t __kernel_ptrdiff_t; > >> #endif > >> > >> So I'd expect "%zi" to be the right way, and a quick test compile on > >> 32-bit (m68k) > >> and 64-bit (amd64) comfirms that. What was wrong with it? > > > > The kernel supports 't' (%t) for ptrdiff_t (same as glibc), > > so %ti should work (or %tu). > > Yes, that compiles without warnings, too. > > And after more decyphering, "(uint64_t *) k - i->d" seems to be positive, > so "%tu" should be OK. *swears* Actually, I'm just going to cast this to unsigned (that's definitely safe here): commit 70bc49d421c793f73a772ae1f50622a39c6136d9 Author: Kent Overstreet <kmo@daterainc.com> Date: Mon Feb 17 13:44:06 2014 -0800 bcache: Fix another compiler warning on m68k Use a bigger hammer this time Signed-off-by: Kent Overstreet <kmo@daterainc.com> diff --git a/drivers/md/bcache/bset.c b/drivers/md/bcache/bset.c index 3f74b4b074..5454164153 100644 --- a/drivers/md/bcache/bset.c +++ b/drivers/md/bcache/bset.c @@ -23,8 +23,8 @@ void bch_dump_bset(struct btree_keys *b, struct bset *i, unsigned set) for (k = i->start; k < bset_bkey_last(i); k = next) { next = bkey_next(k); - printk(KERN_ERR "block %u key %li/%u: ", set, - (uint64_t *) k - i->d, i->keys); + printk(KERN_ERR "block %u key %u/%u: ", set, + (unsigned) ((u64 *) k - i->d), i->keys); if (b->ops->key_dump) b->ops->key_dump(b, k); ^ permalink raw reply related [flat|nested] 7+ messages in thread
* Re: New bcache compiler warning (was: Re: bcache: Minor fixes from kbuild robot) 2014-02-17 21:45 ` Kent Overstreet @ 2014-02-17 22:44 ` Randy Dunlap 2014-02-17 22:46 ` Kent Overstreet 2014-02-18 9:01 ` Geert Uytterhoeven 1 sibling, 1 reply; 7+ messages in thread From: Randy Dunlap @ 2014-02-17 22:44 UTC (permalink / raw) To: Kent Overstreet, Geert Uytterhoeven Cc: Linux Kernel Mailing List, linux-bcache On 02/17/2014 01:45 PM, Kent Overstreet wrote: > On Mon, Feb 17, 2014 at 10:11:51PM +0100, Geert Uytterhoeven wrote: >> On Mon, Feb 17, 2014 at 10:06 PM, Randy Dunlap <rdunlap@infradead.org> wrote: >>> On 02/17/2014 01:00 PM, Geert Uytterhoeven wrote: >>>> On Fri, Feb 14, 2014 at 8:04 PM, Linux Kernel Mailing List >>>> <linux-kernel@vger.kernel.org> wrote: >>>>> bcache: Minor fixes from kbuild robot >>>> >>>>> diff --git a/drivers/md/bcache/bset.c b/drivers/md/bcache/bset.c >>>>> index 4f6b594..3f74b4b 100644 >>>>> --- a/drivers/md/bcache/bset.c >>>>> +++ b/drivers/md/bcache/bset.c >>>>> @@ -23,7 +23,7 @@ void bch_dump_bset(struct btree_keys *b, struct bset *i, unsigned set) >>>>> for (k = i->start; k < bset_bkey_last(i); k = next) { >>>>> next = bkey_next(k); >>>>> >>>>> - printk(KERN_ERR "block %u key %zi/%u: ", set, >>>>> + printk(KERN_ERR "block %u key %li/%u: ", set, >>>>> (uint64_t *) k - i->d, i->keys); >>>>> >>>>> if (b->ops->key_dump) >>>> >>>> On 32-bit (m68k): >>>> drivers/md/bcache/bset.c: In function ‘bch_dump_bset’: >>>> drivers/md/bcache/bset.c:27: warning: format ‘%li’ expects type ‘long >>>> int’, but argument 3 has type ‘int’ >>>> >>>> What are you trying to print here? It looks a bit strange to me. >>>> Technically, the difference between two pointers is of type ptrdiff_. >>>> The kernel had >>>> >>>> typedef __kernel_ptrdiff_t ptrdiff_t; >>>> >>>> and >>>> >>>> #if __BITS_PER_LONG != 64 >>>> typedef unsigned int __kernel_size_t; >>>> typedef int __kernel_ssize_t; >>>> typedef int __kernel_ptrdiff_t; >>>> #else >>>> typedef __kernel_ulong_t __kernel_size_t; >>>> typedef __kernel_long_t __kernel_ssize_t; >>>> typedef __kernel_long_t __kernel_ptrdiff_t; >>>> #endif >>>> >>>> So I'd expect "%zi" to be the right way, and a quick test compile on >>>> 32-bit (m68k) >>>> and 64-bit (amd64) comfirms that. What was wrong with it? >>> >>> The kernel supports 't' (%t) for ptrdiff_t (same as glibc), >>> so %ti should work (or %tu). >> >> Yes, that compiles without warnings, too. >> >> And after more decyphering, "(uint64_t *) k - i->d" seems to be positive, >> so "%tu" should be OK. > > *swears* Actually, I'm just going to cast this to unsigned (that's definitely > safe here): > > > commit 70bc49d421c793f73a772ae1f50622a39c6136d9 > Author: Kent Overstreet <kmo@daterainc.com> > Date: Mon Feb 17 13:44:06 2014 -0800 > > bcache: Fix another compiler warning on m68k > > Use a bigger hammer this time > > Signed-off-by: Kent Overstreet <kmo@daterainc.com> > > diff --git a/drivers/md/bcache/bset.c b/drivers/md/bcache/bset.c > index 3f74b4b074..5454164153 100644 > --- a/drivers/md/bcache/bset.c > +++ b/drivers/md/bcache/bset.c > @@ -23,8 +23,8 @@ void bch_dump_bset(struct btree_keys *b, struct bset *i, unsigned set) > for (k = i->start; k < bset_bkey_last(i); k = next) { > next = bkey_next(k); > > - printk(KERN_ERR "block %u key %li/%u: ", set, > - (uint64_t *) k - i->d, i->keys); > + printk(KERN_ERR "block %u key %u/%u: ", set, > + (unsigned) ((u64 *) k - i->d), i->keys); > > if (b->ops->key_dump) > b->ops->key_dump(b, k); > Could that cause a truncation? unsigned means unsigned int. Can unsigned int be smaller (fewer bits) than the k pointer? If so, is that OK or a problem? -- ~Randy ^ permalink raw reply [flat|nested] 7+ messages in thread
* Re: New bcache compiler warning (was: Re: bcache: Minor fixes from kbuild robot) 2014-02-17 22:44 ` Randy Dunlap @ 2014-02-17 22:46 ` Kent Overstreet 0 siblings, 0 replies; 7+ messages in thread From: Kent Overstreet @ 2014-02-17 22:46 UTC (permalink / raw) To: Randy Dunlap; +Cc: Geert Uytterhoeven, Linux Kernel Mailing List, linux-bcache On Mon, Feb 17, 2014 at 02:44:47PM -0800, Randy Dunlap wrote: > Could that cause a truncation? unsigned means unsigned int. > Can unsigned int be smaller (fewer bits) than the k pointer? > If so, is that OK or a problem? It's just truncating the offset of the pointer within the struct bset, which is part of a btree node - the thing that's being cast is restricted to be no bigger than a btree node, which is at most a few mb. ^ permalink raw reply [flat|nested] 7+ messages in thread
* Re: New bcache compiler warning (was: Re: bcache: Minor fixes from kbuild robot) 2014-02-17 21:45 ` Kent Overstreet 2014-02-17 22:44 ` Randy Dunlap @ 2014-02-18 9:01 ` Geert Uytterhoeven 1 sibling, 0 replies; 7+ messages in thread From: Geert Uytterhoeven @ 2014-02-18 9:01 UTC (permalink / raw) To: Kent Overstreet; +Cc: Randy Dunlap, Linux Kernel Mailing List, linux-bcache On Mon, Feb 17, 2014 at 10:45 PM, Kent Overstreet <kmo@daterainc.com> wrote: > *swears* Actually, I'm just going to cast this to unsigned (that's definitely > safe here): > > > commit 70bc49d421c793f73a772ae1f50622a39c6136d9 > Author: Kent Overstreet <kmo@daterainc.com> > Date: Mon Feb 17 13:44:06 2014 -0800 > > bcache: Fix another compiler warning on m68k JFYI, you also get this warning on other 32-bit platforms (e.g. ARM). > Use a bigger hammer this time Looks like it's big enough, now ;-) > Signed-off-by: Kent Overstreet <kmo@daterainc.com> > > diff --git a/drivers/md/bcache/bset.c b/drivers/md/bcache/bset.c > index 3f74b4b074..5454164153 100644 > --- a/drivers/md/bcache/bset.c > +++ b/drivers/md/bcache/bset.c > @@ -23,8 +23,8 @@ void bch_dump_bset(struct btree_keys *b, struct bset *i, unsigned set) > for (k = i->start; k < bset_bkey_last(i); k = next) { > next = bkey_next(k); > > - printk(KERN_ERR "block %u key %li/%u: ", set, > - (uint64_t *) k - i->d, i->keys); > + printk(KERN_ERR "block %u key %u/%u: ", set, > + (unsigned) ((u64 *) k - i->d), i->keys); > > if (b->ops->key_dump) > b->ops->key_dump(b, k); Gr{oetje,eeting}s, Geert -- Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- geert@linux-m68k.org In personal conversations with technical people, I call myself a hacker. But when I'm talking to journalists I just say "programmer" or something like that. -- Linus Torvalds ^ permalink raw reply [flat|nested] 7+ messages in thread
end of thread, other threads:[~2014-02-18 9:01 UTC | newest] Thread overview: 7+ messages (download: mbox.gz / follow: Atom feed) -- links below jump to the message on this page -- 2014-02-17 21:00 New bcache compiler warning (was: Re: bcache: Minor fixes from kbuild robot) Geert Uytterhoeven 2014-02-17 21:06 ` Randy Dunlap 2014-02-17 21:11 ` Geert Uytterhoeven 2014-02-17 21:45 ` Kent Overstreet 2014-02-17 22:44 ` Randy Dunlap 2014-02-17 22:46 ` Kent Overstreet 2014-02-18 9:01 ` Geert Uytterhoeven
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