Messages in this thread | | | Date | Tue, 28 Feb 2012 16:24:42 -0800 | From | Randy Dunlap <> | Subject | Re: Build regressions/improvements in v3.3-rc5 (C lang questions) |
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On 02/28/2012 04:08 PM, Linus Torvalds wrote:
> On Tue, Feb 28, 2012 at 3:41 PM, Randy Dunlap <rdunlap@xenotime.net> wrote: >> >>> + src/drivers/usb/misc/sisusbvga/sisusb.c: warning: format '%zd' expects type 'signed size_t', but argument 3 has type 'ssize_t': => 982 >>> + src/fs/ecryptfs/miscdev.c: warning: format '%zd' expects type 'signed size_t', but argument 3 has type 'ssize_t': => 448, 488 >> >> Do the (2) above mean that some platform's gcc is borked? >> (I don't see these on i386 or x86_64.) > > Hmm. We had something similar long ago on i386, where the kernel > "size_t" was "unsigned long", but user-mode size_t was "unsigned int" > (or maybe it was the other way around). Anyway, it's obviously > physically the same type, but it would make gcc unhappy because gcc > felt that somebody was doing something bad. > >>> + src/fs/ecryptfs/miscdev.c: warning: format '%lu' expects type 'long unsigned int', but argument 4 has type 'unsigned int': => 433, 433:60 >> >> I can see that warning on 32-bit i386 (X86_32), but if I change the >> "%lu" to "%u", it causes this warning on 64-bit x86_64: >> >> fs/ecryptfs/miscdev.c:433:38: warning: format '%u' expects type 'unsigned int', but argument 4 has type 'long unsigned int' >> >> so how is this supposed to be handled? > > I suspect that one should be "%zu", because we have > > /* 4 + ECRYPTFS_MAX_ENCRYPTED_KEY_BYTES comes from tag 65 packet format */ > #define MAX_MSG_PKT_SIZE (PKT_TYPE_SIZE + PKT_CTR_SIZE \ > + ECRYPTFS_MAX_PKT_LEN_SIZE \ > + sizeof(struct ecryptfs_message) \ > + 4 + ECRYPTFS_MAX_ENCRYPTED_KEY_BYTES) > > so it's the "sizeof(struct ecryptfs_message)" that makes it a size_t > (everything else is int, if I look at it right, and int+size_t is > going to be size_t) > > Of course, if the platform then has the compiler and the kernel > disagreeing about size_t like above, that isn't going to help > anything. But does it fix the x86-32/64 warnings?
Yes, it does fix both cases (and I should have tried that). Thanks.
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