[PATCH 04/11] RISC-V: Support CALL relocation type in kernel module

From: Zong Li
Date: Tue Mar 13 2018 - 04:51:55 EST


Signed-off-by: Zong Li <zong@xxxxxxxxxxxxx>
---
arch/riscv/kernel/module.c | 22 ++++++++++++++++++++++
1 file changed, 22 insertions(+)

diff --git a/arch/riscv/kernel/module.c b/arch/riscv/kernel/module.c
index 242d3a14c210..7e85e5840b4d 100644
--- a/arch/riscv/kernel/module.c
+++ b/arch/riscv/kernel/module.c
@@ -141,6 +141,27 @@ static int apply_r_riscv_call_plt_rela(struct module *me, u32 *location,
return 0;
}

+static int apply_r_riscv_call_rela(struct module *me, u32 *location,
+ Elf_Addr v)
+{
+ s64 offset = (void *)v - (void *)location;
+ s32 fill_v = offset;
+ u32 hi20, lo12;
+
+ if (offset != fill_v) {
+ 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 = (offset + 0x800) & 0xfffff000;
+ lo12 = (offset - hi20) & 0xfff;
+ *location = (*location & 0xfff) | hi20;
+ *(location + 1) = (*(location + 1) & 0xfffff) | (lo12 << 20);
+ return 0;
+}
+
static int apply_r_riscv_relax_rela(struct module *me, u32 *location,
Elf_Addr v)
{
@@ -157,6 +178,7 @@ static int (*reloc_handlers_rela[]) (struct module *me, u32 *location,
[R_RISCV_PCREL_LO12_S] = apply_r_riscv_pcrel_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,
[R_RISCV_RELAX] = apply_r_riscv_relax_rela,
};

--
2.16.1