Messages in this thread | | | Date | Tue, 5 Jun 2012 22:57:29 +0200 | Subject | Re: [PATCH] m68k: Use generic strncpy_from_user(), strlen_user(), and strnlen_user() | From | Geert Uytterhoeven <> |
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On Wed, May 30, 2012 at 4:04 PM, Philippe De Muyter <phdm@macqel.be> wrote: > On Wed, May 30, 2012 at 01:20:02PM +0200, Geert Uytterhoeven wrote: >> On Wed, May 30, 2012 at 12:22 PM, Philippe De Muyter <phdm@macqel.be> wrote: >> > On Tue, May 29, 2012 at 11:33:36PM +0200, Geert Uytterhoeven wrote: >> >> Signed-off-by: Geert Uytterhoeven <geert@linux-m68k.org> >> >> --- >> >> Do we also want >> >> >> >> select HAVE_EFFICIENT_UNALIGNED_ACCESS if (!COLDFIRE && !M68000) >> > >> > Sorry, I did not follow what happened to unaligned accesses, but >> > CPU32 family (at least 68340) crashes on unaligned accesses. >> >> We don't seem to have CONFIG_M68340 in arch/m68k/Kconfig.cpu? > > I have a local port here (but based on an ancient linux kernel, 2.6.2 IIRC) > >> But Freescale's website confirms both 68340 and 68360 are CPU32. >> >> arch/m68k/include/asm/unaligned.h assumes CPU32 (CONFIG_MCPU32) >> can do unaligned accesses: > > That's not true. Accessing a 16- or 32-bit word at an odd address > with a 68340 generates an Address Error Exception. I remember > discovering a bug in the ppp kernel code because of that. > >> >> #if defined(CONFIG_COLDFIRE) || defined(CONFIG_M68000) >> #include <linux/unaligned/be_struct.h> >> #include <linux/unaligned/le_byteshift.h> >> #include <linux/unaligned/generic.h> >> >> #define get_unaligned __get_unaligned_be >> #define put_unaligned __put_unaligned_be >> >> #else >> /* >> * The m68k can do unaligned accesses itself. >> */ >> #include <linux/unaligned/access_ok.h> >> #include <linux/unaligned/generic.h> >> >> #define get_unaligned __get_unaligned_be >> #define put_unaligned __put_unaligned_be >> >> #endif >> >> Is this wrong? > > I can't tell from reading just the lines above, but I think one should add > "|| defined(CONFIG_MCPU32)" at the end of the if condition.
Greg?
If more CPUs cannot handle unaligned accesses, I propose to add CONFIG_CPU_HAS_NO_UNALIGNED.
> I also think that the Coldfire 5272 can do unaligned accesses, but I > cannot test that at the moment.
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 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
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