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Message-ID: <88259699f98be6eadf574ad01f2bab32c4818b0d.camel@xry111.site>
Subject: [PATCH v4 2/4] LoongArch: Support R_LARCH_SOP_PUSH_GPREL relocation
 type in kernel module
From:   Xi Ruoyao <xry111@xry111.site>
To:     loongarch@lists.linux.dev
Cc:     linux-kernel@vger.kernel.org, WANG Xuerui <kernel@xen0n.name>,
        Huacai Chen <chenhuacai@kernel.org>,
        Youling Tang <tangyouling@loongson.cn>,
        Jinyang He <hejinyang@loongson.cn>
Date:   Fri, 29 Jul 2022 16:40:21 +0800
In-Reply-To: <32a74a218c76611f897fd1df1ad0059068621133.camel@xry111.site>
References: <32a74a218c76611f897fd1df1ad0059068621133.camel@xry111.site>
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This relocation type pushes the offset of the GOT entry for a symbol
from the beginning of GOT into the relocation stack.  Our linker script
has initialized an empty GOT, so we need to create a new GOT entry if
there is no exist one for a symbol.

Signed-off-by: Xi Ruoyao <xry111@xry111.site>
---
 arch/loongarch/kernel/module.c | 11 +++++++++++
 1 file changed, 11 insertions(+)

diff --git a/arch/loongarch/kernel/module.c b/arch/loongarch/kernel/module.=
c
index 638427ff0d51..3ac4fbb5f109 100644
--- a/arch/loongarch/kernel/module.c
+++ b/arch/loongarch/kernel/module.c
@@ -122,6 +122,16 @@ static int apply_r_larch_sop_push_plt_pcrel(struct mod=
ule *mod, u32 *location, E
 	return apply_r_larch_sop_push_pcrel(mod, location, v, rela_stack, rela_st=
ack_top, type);
 }
=20
+static int apply_r_larch_sop_push_gprel(struct module *mod, u32 *location,
+			Elf_Addr v, s64 *rela_stack, size_t *rela_stack_top,
+			unsigned int type)
+{
+	Elf_Addr got =3D module_emit_got_entry(mod, v);
+	ptrdiff_t offset =3D (void *)got - (void *)mod->arch.got.shdr->sh_addr;
+
+	return rela_stack_push(offset, rela_stack, rela_stack_top);
+}
+
 static int apply_r_larch_sop(struct module *mod, u32 *location, Elf_Addr v=
,
 			s64 *rela_stack, size_t *rela_stack_top, unsigned int type)
 {
@@ -306,6 +316,7 @@ static reloc_rela_handler reloc_rela_handlers[] =3D {
 	[R_LARCH_SOP_PUSH_PCREL]			     =3D apply_r_larch_sop_push_pcrel,
 	[R_LARCH_SOP_PUSH_ABSOLUTE]			     =3D apply_r_larch_sop_push_absolute,
 	[R_LARCH_SOP_PUSH_DUP]				     =3D apply_r_larch_sop_push_dup,
+	[R_LARCH_SOP_PUSH_GPREL]			     =3D apply_r_larch_sop_push_gprel,
 	[R_LARCH_SOP_PUSH_PLT_PCREL]			     =3D apply_r_larch_sop_push_plt_pcrel,
 	[R_LARCH_SOP_SUB ... R_LARCH_SOP_IF_ELSE] 	     =3D apply_r_larch_sop,
 	[R_LARCH_SOP_POP_32_S_10_5 ... R_LARCH_SOP_POP_32_U] =3D apply_r_larch_so=
p_imm_field,
--=20
2.37.0