Date:   Fri, 10 Mar 2023 19:27:26 +0100
From:   Torsten Duwe <duwe@lst.de>
To:     Li Zhengyu <lizhengyu3@huawei.com>,
        Paul Walmsley <paul.walmsley@sifive.com>,
        Conor Dooley <conor.dooley@microchip.com>,
        Palmer Dabbelt <palmer@dabbelt.com>
Cc:     Albert Ou <aou@eecs.berkeley.edu>,
        Li Huafei <lihuafei1@huawei.com>,
        Liao Chang <liaochang1@huawei.com>,
        linux-riscv@lists.infradead.org, linux-kernel@vger.kernel.org
Subject: [PATCH] riscv: relocate R_RISCV_CALL_PLT in kexec_file
Message-ID: <20230310182726.GA25154@lst.de>
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Depending on the toolchain (here: gcc-12, binutils-2.40) the
relocation entries for function calls are no longer R_RISCV_CALL, but
R_RISCV_CALL_PLT. When trying kexec_load_file on such kernels, it will
fail with

 kexec_image: Unknown rela relocation: 19
 kexec_image: Error loading purgatory ret=-8

The binary code at the call site remains the same, so tell
arch_kexec_apply_relocations_add() to handle _PLT alike.

fixes: 838b3e28488f702 ("Load purgatory in kexec_file")
Signed-off-by: Torsten Duwe <duwe@suse.de>
Cc: stable@vger.kernel.org

---
--- a/arch/riscv/kernel/elf_kexec.c
+++ b/arch/riscv/kernel/elf_kexec.c
@@ -425,6 +425,7 @@ int arch_kexec_apply_relocations_add(struct purgatory_info *pi,
 		 * sym, instead of searching the whole relsec.
 		 */
 		case R_RISCV_PCREL_HI20:
+		case R_RISCV_CALL_PLT:
 		case R_RISCV_CALL:
 			*(u64 *)loc = CLEAN_IMM(UITYPE, *(u64 *)loc) |
 				 ENCODE_UJTYPE_IMM(val - addr);