[PATCH] x86, relocs: add percpu fixup for GNU ld 2.23

From: Kees Cook
Date: Wed Oct 16 2013 - 02:43:44 EST


The GNU linker tries to put __per_cpu_load into the percpu area, resulting
in a lack of its relocation. Force this symbol to be relocated. Seen
starting with GNU ld 2.23 and later.

Reported-by: Ingo Molnar <mingo@xxxxxxxxxx>
Signed-off-by: Kees Cook <keescook@xxxxxxxxxxxx>
---
arch/x86/tools/relocs.c | 2 ++
1 file changed, 2 insertions(+)

diff --git a/arch/x86/tools/relocs.c b/arch/x86/tools/relocs.c
index 1fa291f..7a85f29 100644
--- a/arch/x86/tools/relocs.c
+++ b/arch/x86/tools/relocs.c
@@ -729,6 +729,7 @@ static void percpu_init(void)
*
* The GNU linker incorrectly associates:
* __init_begin
+ * __per_cpu_load
*
* The "gold" linker incorrectly associates:
* init_per_cpu__irq_stack_union
@@ -738,6 +739,7 @@ static int is_percpu_sym(ElfW(Sym) *sym, const char *symname)
{
return (sym->st_shndx == per_cpu_shndx) &&
strcmp(symname, "__init_begin") &&
+ strcmp(symname, "__per_cpu_load") &&
strncmp(symname, "init_per_cpu_", 13);
}

--
1.7.9.5


--
Kees Cook
Chrome OS Security
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