[PATCH v4 2/2] riscv: Disable data start offset in flat binaries
Greg Ungerer
gerg at linux-m68k.org
Sat Apr 17 05:56:41 BST 2021
On 17/4/21 11:10 am, Damien Le Moal wrote:
> uclibc/gcc combined with elf2flt riscv linker file fully resolve the
> PC relative __global_pointer$ value at compile time and do not generate
> a relocation entry to set a correct value of the gp register at runtime.
> As a result, if the flatbin loader offsets the start of the data
> section, the relative position change between the text and data sections
> compared to the compile time positions results in an incorrect gp value
> being used. This causes flatbin executables to crash.
>
> Avoid this problem by enabling CONFIG_BINFMT_FLAT_NO_DATA_START_OFFSET
> automatically when CONFIG_RISCV is enabled and CONFIG_MMU is disabled.
>
> Signed-off-by: Damien Le Moal <damien.lemoal at wdc.com>
> Acked-by: Palmer Dabbelt <palmerdabbelt at google.com>
Acked-by: Greg Ungerer <gerg at linux-m68k.org>
Palmer do you want me to take this via my tree with 1/2 in the series,
or are you going to pick it up?
Regards
Greg
> ---
> arch/riscv/Kconfig | 1 +
> 1 file changed, 1 insertion(+)
>
> diff --git a/arch/riscv/Kconfig b/arch/riscv/Kconfig
> index 4515a10c5d22..add528eb9235 100644
> --- a/arch/riscv/Kconfig
> +++ b/arch/riscv/Kconfig
> @@ -33,6 +33,7 @@ config RISCV
> select ARCH_WANT_DEFAULT_TOPDOWN_MMAP_LAYOUT if MMU
> select ARCH_WANT_FRAME_POINTERS
> select ARCH_WANT_HUGE_PMD_SHARE if 64BIT
> + select BINFMT_FLAT_NO_DATA_START_OFFSET if !MMU
> select CLONE_BACKWARDS
> select CLINT_TIMER if !MMU
> select COMMON_CLK
>
More information about the linux-riscv
mailing list