Hi Arnd, On Tue, Jan 7, 2014 at 10:12 PM, Arnd Bergmann <a...@arndb.de> wrote: > On Monday 28 October 2013, Ming Lei wrote: >> This patch uses CONFIG_PAGE_OFFSET to filter symbols which >> are not in kernel address space because these symbols are >> generally for generating code purpose and can't be run at >> kernel mode, so we needn't keep them in /proc/kallsyms. >> >> For example, on ARM there are some symbols which are >> linked in relocatable code section, then perf can't parse >> symbols any more from /proc/kallsyms, and this patch fixes >> the problem. >> >> Cc: Russell King <li...@arm.linux.org.uk> >> Cc: linux-arm-ker...@lists.infradead.org >> Cc: Michal Marek <mma...@suse.cz> >> Acked-by: Rusty Russell <ru...@rustcorp.com.au> >> Signed-off-by: Ming Lei <tom.leim...@gmail.com> > > Sorry for the late report, but I seem to have encountered a problem with this > patch, now that it has made it into all stable kernels. > > When linking an ARM nommu kernel, I get the output "No valid symbol." twice, > from scripts/kallsyms. The problem evidently is that PAGE_OFFSET is still > set to 0xC0000000 on ARM NOMMU builds but the kernel is linked to start at > PLAT_PHYS_OFFSET instead, which may be elsehwere. For most platforms, > this is defined in Kconfig these days, so we could get away with > > diff --git a/arch/arm/Kconfig b/arch/arm/Kconfig > index d1e4098..c477a7c 100644 > --- a/arch/arm/Kconfig > +++ b/arch/arm/Kconfig > @@ -1592,6 +1592,7 @@ endchoice > > config PAGE_OFFSET > hex > + default PHYS_OFFSET if !MMU > default 0x40000000 if VMSPLIT_1G > default 0x80000000 if VMSPLIT_2G > default 0xC0000000 > > but there are still a few ARM platforms that define their own PLAT_PHYS_OFFSET > in memory.h, and it wouldn't help on non-ARM systems that might have the same > problem.
We had posted two patches to address the problem, see below link: http://lists.scusting.com/index.php?t=msg&goto=1726509&S=Google Thanks, -- Ming Lei -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
