Messages in this thread | | | From | Michael Ellerman <> | Subject | Re: [PATCH] powerpc/vdso32: mark __kernel_datapage_offset as STV_PROTECTED | Date | Mon, 10 Feb 2020 22:01:37 +1100 |
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Fangrui Song <maskray@google.com> writes: > A PC-relative relocation (R_PPC_REL16_LO in this case) referencing a > preemptible symbol in a -shared link is not allowed. GNU ld's powerpc > port is permissive and allows it [1], but lld will report an error after > https://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux.git/commit/?id=ec0895f08f99515194e9fcfe1338becf6f759d38 > > Make the symbol protected so that it is non-preemptible but still > exported.
"preemptible" means something different to me, and I assume we're not using it to mean the same thing.
Can you explain it using small words that a kernel developer can understand? :)
cheers
> [1]: https://sourceware.org/bugzilla/show_bug.cgi?id=25500 > > Link: https://github.com/ClangBuiltLinux/linux/issues/851 > Signed-off-by: Fangrui Song <maskray@google.com>
> --- > arch/powerpc/kernel/vdso32/datapage.S | 3 ++- > 1 file changed, 2 insertions(+), 1 deletion(-) > > diff --git a/arch/powerpc/kernel/vdso32/datapage.S b/arch/powerpc/kernel/vdso32/datapage.S > index 217bb630f8f9..2831a8676365 100644 > --- a/arch/powerpc/kernel/vdso32/datapage.S > +++ b/arch/powerpc/kernel/vdso32/datapage.S > @@ -13,7 +13,8 @@ > #include <asm/vdso_datapage.h> > > .text > - .global __kernel_datapage_offset; > + .global __kernel_datapage_offset > + .protected __kernel_datapage_offset > __kernel_datapage_offset: > .long 0 > > -- > 2.25.0.341.g760bfbb309-goog
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