From 2c78a79ec7fc0b3729e9f16214cf8e08e4664a0b Mon Sep 17 00:00:00 2001 From: Heinrich Schuchardt Date: Sat, 13 Oct 2018 20:52:07 -0700 Subject: [PATCH] x86: put global data pointer into the .data section On x86_64 the field global_data_ptr is assigned before relocation. As sections for uninitialized global data (.bss) overlap with the relocation sections (.rela) this destroys the relocation table and leads to spurious errors. Initialization forces the global_data_ptr into a section for initialized global data (.data) which cannot overlap any .rela section. Fixes: a160092a610f ("x86: Support global_data on x86_64") Signed-off-by: Heinrich Schuchardt Reviewed-by: Bin Meng Tested-by: Bin Meng Signed-off-by: Bin Meng --- arch/x86/cpu/x86_64/cpu.c | 10 ++++++++-- 1 file changed, 8 insertions(+), 2 deletions(-) diff --git a/arch/x86/cpu/x86_64/cpu.c b/arch/x86/cpu/x86_64/cpu.c index 18b3e94..ef5e812 100644 --- a/arch/x86/cpu/x86_64/cpu.c +++ b/arch/x86/cpu/x86_64/cpu.c @@ -7,8 +7,14 @@ #include #include -/* Global declaration of gd */ -struct global_data *global_data_ptr; +/* + * Global declaration of gd. + * + * As we write to it before relocation we have to make sure it is not put into + * a .bss section which may overlap a .rela section. Initialization forces it + * into a .data section which cannot overlap any .rela section. + */ +struct global_data *global_data_ptr = (struct global_data *)~0; void arch_setup_gd(gd_t *new_gd) {