Patch "riscv/kexec_file: Fix relocation type R_RISCV_ADD16 and R_RISCV_SUB16 unknown" has been added to the 6.6-stable tree

[Sasha Levin <sashal@xxxxxxxxxx>]

This is a note to let you know that I've just added the patch titled

    riscv/kexec_file: Fix relocation type R_RISCV_ADD16 and R_RISCV_SUB16 unknown

to the 6.6-stable tree which can be found at:
    http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary

The filename of the patch is:
     riscv-kexec_file-fix-relocation-type-r_riscv_add16-a.patch
and it can be found in the queue-6.6 subdirectory.

If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.



commit 4185d91f08d91a7f7cedaa07990e3b90113efcce
Author: Ying Sun <sunying@xxxxxxxxxxxxxxxx>
Date:   Thu Jul 11 08:32:36 2024 +0000

    riscv/kexec_file: Fix relocation type R_RISCV_ADD16 and R_RISCV_SUB16 unknown
    
    [ Upstream commit c6ebf2c528470a09be77d0d9df2c6617ea037ac5 ]
    
    Runs on the kernel with CONFIG_RISCV_ALTERNATIVE enabled:
      kexec -sl vmlinux
    
    Error:
      kexec_image: Unknown rela relocation: 34
      kexec_image: Error loading purgatory ret=-8
    and
      kexec_image: Unknown rela relocation: 38
      kexec_image: Error loading purgatory ret=-8
    
    The purgatory code uses the 16-bit addition and subtraction relocation
    type, but not handled, resulting in kexec_file_load failure.
    So add handle to arch_kexec_apply_relocations_add().
    
    Tested on RISC-V64 Qemu-virt, issue fixed.
    
    Co-developed-by: Petr Tesarik <petr@xxxxxxxxxxx>
    Signed-off-by: Petr Tesarik <petr@xxxxxxxxxxx>
    Signed-off-by: Ying Sun <sunying@xxxxxxxxxxxxxxxx>
    Reviewed-by: Andrew Jones <ajones@xxxxxxxxxxxxxxxx>
    Link: https://lore.kernel.org/r/20240711083236.2859632-1-sunying@xxxxxxxxxxxxxxxx
    Signed-off-by: Palmer Dabbelt <palmer@xxxxxxxxxxxx>
    Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>

diff --git a/arch/riscv/kernel/elf_kexec.c b/arch/riscv/kernel/elf_kexec.c
index e60fbd8660c4a..8c32bf1eedda0 100644
--- a/arch/riscv/kernel/elf_kexec.c
+++ b/arch/riscv/kernel/elf_kexec.c
@@ -444,6 +444,12 @@ int arch_kexec_apply_relocations_add(struct purgatory_info *pi,
 			*(u32 *)loc = CLEAN_IMM(CJTYPE, *(u32 *)loc) |
 				 ENCODE_CJTYPE_IMM(val - addr);
 			break;
+		case R_RISCV_ADD16:
+			*(u16 *)loc += val;
+			break;
+		case R_RISCV_SUB16:
+			*(u16 *)loc -= val;
+			break;
 		case R_RISCV_ADD32:
 			*(u32 *)loc += val;
 			break;