[U-Boot] [PATCH v2 1/1] 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 xypron.glpk@gmx.de --- v2 Use .data instead of .text section --- 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 18b3e94e12..a8097bc55d 100644 --- a/arch/x86/cpu/x86_64/cpu.c +++ b/arch/x86/cpu/x86_64/cpu.c @@ -7,8 +7,14 @@ #include <common.h> #include <debug_uart.h>
-/* 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) {

On Sat, Oct 13, 2018 at 3:40 PM Heinrich Schuchardt xypron.glpk@gmx.de wrote:
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 xypron.glpk@gmx.de
v2 Use .data instead of .text section
arch/x86/cpu/x86_64/cpu.c | 10 ++++++++-- 1 file changed, 8 insertions(+), 2 deletions(-)
Reviewed-by: Bin Meng bmeng.cn@gmail.com Tested-by: Bin Meng bmeng.cn@gmail.com
participants (2)
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Bin Meng
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Heinrich Schuchardt