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fix(dkm): support R_X86_64_PLT32 relocations in ELF loader (DKM-E37)

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Multi-TU drivers produce PLT32 for cross-object calls (lld keeps a
relocation for potentially-interposable global symbols). ath9k.drv
(ath9k.o + wpa2_crypto.o) has 22 such relocations, which tripped
"DKM-E37 UNSUPPORTED RELOCATION" at boot.

PLT32 has the same semantics as PC32 in a static relocatable
(patch = S + A - P), and is a 4-byte write. Added the constant, the
patch computation, and switched the write-width branch to
"not R_X86_64_64 -> u32" so all 4-byte types are handled uniformly.

Verified: all 28 .drv files now use only
{R_X86_64_32S, R_X86_64_64, R_X86_64_PC32, R_X86_64_PLT32}.
This commit is contained in:
Linehu
2026-10-06 21:37:37 +08:00
parent 8e6506721d
commit d95ae091e7
1 changed files with 7 additions and 3 deletions
Download Patch File Download Diff File Expand all files Collapse all files
CODE/UTSM/dkm/boot_modules.c
+7 -3
View File
@@ -1,4 +1,4 @@
#include <utsm/dkm.h> #include <utsm/dkm.h>
#include <utsm/log.h> #include <utsm/log.h>
#include <utsm/types.h> #include <utsm/types.h>
#include <utsm/arena.h> #include <utsm/arena.h>
@@ -29,6 +29,10 @@
#define R_X86_64_32 10 #define R_X86_64_32 10
#define R_X86_64_32S 11 #define R_X86_64_32S 11
#define R_X86_64_PC32 2 #define R_X86_64_PC32 2
/* PLT32：lld 对（可能被覆盖的）全局函数调用生成，静态可重定位场景下
* 语义与 PC32 相同（patch = S + A - P）。多编译单元驱动（如 ath9k +
* wpa2_crypto）跨 TU 调用即为此类型。 */
#define R_X86_64_PLT32 4
void *memset(void *dst, int value, usize len); void *memset(void *dst, int value, usize len);
void *memcpy(void *dst, const void *src, usize len); void *memcpy(void *dst, const void *src, usize len);
@@ -363,7 +367,7 @@ int dkm_load_elf_rel(const void *address, u64 size, const struct dkm_symbol_scan
patch = S + A; patch = S + A;
} else if (reloc_type == R_X86_64_32 || reloc_type == R_X86_64_32S) { } else if (reloc_type == R_X86_64_32 || reloc_type == R_X86_64_32S) {
patch = (u64)((i64)(i32)(S + A)); patch = (u64)((i64)(i32)(S + A));
} else if (reloc_type == R_X86_64_PC32) { } else if (reloc_type == R_X86_64_PC32 || reloc_type == R_X86_64_PLT32) {
patch = (u64)((i64)(i32)(S + A - P)); patch = (u64)((i64)(i32)(S + A - P));
} else { } else {
log_error("[DKM] unsupported relocation type"); log_error("[DKM] unsupported relocation type");
@@ -376,7 +380,7 @@ int dkm_load_elf_rel(const void *address, u64 size, const struct dkm_symbol_scan
/* Bounds check: use the actual write width, not always 8. */ /* Bounds check: use the actual write width, not always 8. */
u32 reloc_width = (reloc_type == R_X86_64_64) ? 8 : 4; u32 reloc_width = (reloc_type == R_X86_64_64) ? 8 : 4;
if (rela->offset + reloc_width <= target->size) { if (rela->offset + reloc_width <= target->size) {
if (reloc_type == R_X86_64_32 || reloc_type == R_X86_64_32S || reloc_type == R_X86_64_PC32) { if (reloc_type != R_X86_64_64) {
*(u32 *)(target_base + rela->offset) = (u32)patch; *(u32 *)(target_base + rela->offset) = (u32)patch;
} else { } else {
*(u64 *)(target_base + rela->offset) = patch; *(u64 *)(target_base + rela->offset) = patch;