Messages in this thread | | | From | Geert Uytterhoeven <> | Date | Tue, 2 Nov 2021 08:56:06 +0100 | Subject | Re: [PATCH] string: uninline memcpy_and_pad |
| |
Hi Günter,
Thanks for your patch!
On Tue, Nov 2, 2021 at 5:30 AM Guenter Roeck <linux@roeck-us.net> wrote: > When building m68k:allmodconfig, recent versions of gcc generate the > following error if the length of UTS_RELEASE is less than 8 bytes. > > In function 'memcpy_and_pad', > inlined from 'nvmet_execute_disc_identify' at > drivers/nvme/target/discovery.c:268:2: > arch/m68k/include/asm/string.h:72:25: error: > '__builtin_memcpy' reading 8 bytes from a region of size 7 > > Discussions around the problem suggest that this only happens if an > architecture does not provide strlen(), if -ffreestanding is provided as > compiler option, and if CONFIG_FORTIFY_SOURCE=n. All of this is the case > for m68k. The exact reasons are unknown, but seem to be related to the > ability of the compiler to evaluate the return value of strlen() and > the resulting execution flow in memcpy_and_pad(). It would be possible > to work around the problem by using sizeof(UTS_RELEASE) instead of > strlen(UTS_RELEASE), but that would only postpone the problem until the > function is called in a similar way. Uninline memcpy_and_pad() instead > to solve the problem for good. > > Suggested-by: Linus Torvalds <torvalds@linux-foundation.org> > Cc: Geert Uytterhoeven <geert@linux-m68k.org> > Signed-off-by: Guenter Roeck <linux@roeck-us.net>
Reviewed-by: Geert Uytterhoeven <geert@linux-m68k.org>
> include/linux/string.h | 19 ++----------------- > lib/string.c | 19 +++++++++++++++++++ > 2 files changed, 21 insertions(+), 17 deletions(-)
Given this now conflicts with commit cfecea6ead5f1588 ("lib/string: Move helper functions out of string.c"). perhaps you should move this to lib/string_helpers.c when respinning?
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
| |