Unverified Commit e7456e69 authored by Zong Li's avatar Zong Li Committed by Palmer Dabbelt
Browse files

RISC-V: Support HI20/LO12_I/LO12_S relocation type in kernel module 



HI20 and LO12_I/LO12_S relocate the absolute address, the range of
offset must in 32-bit.

Signed-off-by: default avatarZong Li <zong@andestech.com>
Signed-off-by: default avatarPalmer Dabbelt <palmer@sifive.com>
parent e1910c72

arch/riscv/kernel/module.c

+42 −0
Original line number Diff line number Diff line
@@ -92,6 +92,45 @@ static int apply_r_riscv_pcrel_lo12_s_rela(struct module *me, u32 *location, 
	return 0;

}



static int apply_r_riscv_hi20_rela(struct module *me, u32 *location,

				   Elf_Addr v)

{

	s32 hi20;



	if (IS_ENABLED(CMODEL_MEDLOW)) {

		pr_err(

		  "%s: target %016llx can not be addressed by the 32-bit offset from PC = %p\n",

		  me->name, v, location);

		return -EINVAL;

	}



	hi20 = ((s32)v + 0x800) & 0xfffff000;

	*location = (*location & 0xfff) | hi20;

	return 0;

}



static int apply_r_riscv_lo12_i_rela(struct module *me, u32 *location,

				     Elf_Addr v)

{

	/* Skip medlow checking because of filtering by HI20 already */

	s32 hi20 = ((s32)v + 0x800) & 0xfffff000;

	s32 lo12 = ((s32)v - hi20);

	*location = (*location & 0xfffff) | ((lo12 & 0xfff) << 20);

	return 0;

}



static int apply_r_riscv_lo12_s_rela(struct module *me, u32 *location,

				     Elf_Addr v)

{

	/* Skip medlow checking because of filtering by HI20 already */

	s32 hi20 = ((s32)v + 0x800) & 0xfffff000;

	s32 lo12 = ((s32)v - hi20);

	u32 imm11_5 = (lo12 & 0xfe0) << (31 - 11);

	u32 imm4_0 = (lo12 & 0x1f) << (11 - 4);

	*location = (*location & 0x1fff07f) | imm11_5 | imm4_0;

	return 0;

}



static int apply_r_riscv_got_hi20_rela(struct module *me, u32 *location,

				       Elf_Addr v)

{
@@ -176,6 +215,9 @@ static int (*reloc_handlers_rela[]) (struct module *me, u32 *location, 
	[R_RISCV_PCREL_HI20]		= apply_r_riscv_pcrel_hi20_rela,

	[R_RISCV_PCREL_LO12_I]		= apply_r_riscv_pcrel_lo12_i_rela,

	[R_RISCV_PCREL_LO12_S]		= apply_r_riscv_pcrel_lo12_s_rela,

	[R_RISCV_HI20]			= apply_r_riscv_hi20_rela,

	[R_RISCV_LO12_I]		= apply_r_riscv_lo12_i_rela,

	[R_RISCV_LO12_S]		= apply_r_riscv_lo12_s_rela,

	[R_RISCV_GOT_HI20]		= apply_r_riscv_got_hi20_rela,

	[R_RISCV_CALL_PLT]		= apply_r_riscv_call_plt_rela,

	[R_RISCV_CALL]			= apply_r_riscv_call_rela,