Compiling with arm-linux-gnueabihf-gcc (Debian 14.2.0-19) 14.2.0
generates a few more relocation types than the module loader currently
supports.

Import support for them from Linux, so we can start automatically
testing this feature.

Signed-off-by: Ahmad Fatoum <[email protected]>
---
 arch/arm/include/asm/elf.h |  2 ++
 arch/arm/lib32/module.c    | 20 ++++++++++++++++++++
 2 files changed, 22 insertions(+)

diff --git a/arch/arm/include/asm/elf.h b/arch/arm/include/asm/elf.h
index 0b4704a4a561..f3b6e0dd37c3 100644
--- a/arch/arm/include/asm/elf.h
+++ b/arch/arm/include/asm/elf.h
@@ -29,9 +29,11 @@ typedef struct user_fp elf_fpregset_t;
 
 #define R_ARM_NONE     0
 #define R_ARM_PC24     1
+#define R_ARM_REL32    3
 #define R_ARM_ABS32    2
 #define R_ARM_CALL     28
 #define R_ARM_JUMP24   29
+#define R_ARM_PREL31   42
 
 #define R_ARM_THM_CALL         10
 #define R_ARM_THM_JUMP24       30
diff --git a/arch/arm/lib32/module.c b/arch/arm/lib32/module.c
index 7214e3c73c3d..0cf04ea9faba 100644
--- a/arch/arm/lib32/module.c
+++ b/arch/arm/lib32/module.c
@@ -49,6 +49,9 @@ apply_relocate(Elf32_Shdr *sechdrs, const char *strtab, 
unsigned int symindex,
                loc = dstsec->sh_addr + rel->r_offset;
 
                switch (ELF32_R_TYPE(rel->r_info)) {
+               case R_ARM_NONE:
+                       /* ignore */
+                       break;
                case R_ARM_ABS32:
                        *(u32 *)loc += sym->st_value;
                        break;
@@ -90,6 +93,23 @@ apply_relocate(Elf32_Shdr *sechdrs, const char *strtab, 
unsigned int symindex,
                        *(u32 *)loc |= offset & 0x00ffffff;
                        break;
 
+               case R_ARM_PREL31:
+                       offset = (*(s32 *)loc << 1) >> 1; /* sign extend */
+                       offset += sym->st_value - loc;
+                       if (offset >= 0x40000000 || offset < -0x40000000) {
+                               pr_err("%s: section %u reloc %u sym '%s': 
relocation %u out of range (%#lx -> %#x)\n",
+                                      module->name, relindex, i, strtab + 
sym->st_name,
+                                      ELF32_R_TYPE(rel->r_info), loc,
+                                      sym->st_value);
+                               return -ENOEXEC;
+                       }
+                       *(u32 *)loc &= 0x80000000;
+                       *(u32 *)loc |= offset & 0x7fffffff;
+                       break;
+
+               case R_ARM_REL32:
+                       *(u32 *)loc += sym->st_value - loc;
+                       break;
                default:
                        printf("%s: unknown relocation: %u\n",
                               module->name, ELF32_R_TYPE(rel->r_info));
-- 
2.47.3


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