riscv: tools: Fix prelink-riscv to work on big endian hosts

All ELF fields whose values are inspected by the code are converted to CPU byteorder first. Values which are copied verbatim (relocation fixups) are not swapped to CPU byteorder and back as it is not needed. Signed-off-by: Marcus Comstedt <[email protected]> Cc: Rick Chen <[email protected]> Reviewed-by: Rick Chen <[email protected]>
pjincz · Aug 15, 2019 · e604410 · e604410
1 parent 88af42d
commit e604410
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Showing 2 changed files with 23 additions and 24 deletions.
diff --git a/tools/prelink-riscv.c b/tools/prelink-riscv.c
@@ -8,10 +8,6 @@
  * without fixup. Both RV32 and RV64 are supported.
  */
 
-#if __BYTE_ORDER__ != __ORDER_LITTLE_ENDIAN__
-#error "Only little-endian host is supported"
-#endif
-
 #include <errno.h>
 #include <stdbool.h>
 #include <stdint.h>
@@ -25,6 +21,7 @@
 #include <sys/stat.h>
 #include <sys/types.h>
 #include <unistd.h>
+#include <compiler.h>
 
 #ifndef EM_RISCV
 #define EM_RISCV 243

diff --git a/tools/prelink-riscv.inc b/tools/prelink-riscv.inc
@@ -23,14 +23,15 @@
 #define Elf_Addr        CONCAT3(Elf, PRELINK_INC_BITS, _Addr)
 #define ELF_R_TYPE      CONCAT3(ELF, PRELINK_INC_BITS, _R_TYPE)
 #define ELF_R_SYM       CONCAT3(ELF, PRELINK_INC_BITS, _R_SYM)
+#define lenn_to_cpu     CONCAT3(le, PRELINK_INC_BITS, _to_cpu)
 
 static void* get_offset_nn (void* data, Elf_Phdr* phdrs, size_t phnum, Elf_Addr addr)
 {
 	Elf_Phdr *p;
 
 	for (p = phdrs; p < phdrs + phnum; ++p)
-		if (p->p_vaddr <= addr && p->p_vaddr + p->p_memsz > addr)
-			return data + p->p_offset + (addr - p->p_vaddr);
+		if (lenn_to_cpu(p->p_vaddr) <= addr && lenn_to_cpu(p->p_vaddr) + lenn_to_cpu(p->p_memsz) > addr)
+			return data + lenn_to_cpu(p->p_offset) + (addr - lenn_to_cpu(p->p_vaddr));
 
 	return NULL;
 }
@@ -42,15 +43,15 @@ static void prelink_nn(void *data)
 	Elf_Dyn *dyn;
 	Elf_Rela *r;
 
-	if (ehdr->e_machine != EM_RISCV)
+	if (le16_to_cpu(ehdr->e_machine) != EM_RISCV)
 		die("Machine type is not RISC-V");
 
-	Elf_Phdr *phdrs = data + ehdr->e_phoff;
+	Elf_Phdr *phdrs = data + lenn_to_cpu(ehdr->e_phoff);
 
 	Elf_Dyn *dyns = NULL;
-	for (p = phdrs; p < phdrs + ehdr->e_phnum; ++p) {
-		if (p->p_type == PT_DYNAMIC) {
-			dyns = data + p->p_offset;
+	for (p = phdrs; p < phdrs + le16_to_cpu(ehdr->e_phnum); ++p) {
+		if (le32_to_cpu(p->p_type) == PT_DYNAMIC) {
+			dyns = data + lenn_to_cpu(p->p_offset);
 			break;
 		}
 	}
@@ -62,14 +63,14 @@ static void prelink_nn(void *data)
 	size_t rela_count = 0;
 	Elf_Sym *dynsym = NULL;
 	for (dyn = dyns;; ++dyn) {
-		if (dyn->d_tag == DT_NULL)
+		if (lenn_to_cpu(dyn->d_tag) == DT_NULL)
 			break;
-		else if (dyn->d_tag == DT_RELA)
-			rela_dyn = get_offset_nn(data, phdrs, ehdr->e_phnum, + dyn->d_un.d_ptr);
-		else if (dyn->d_tag == DT_RELASZ)
-			rela_count = dyn->d_un.d_val / sizeof(Elf_Rela);
-		else if (dyn->d_tag == DT_SYMTAB)
-			dynsym = get_offset_nn(data, phdrs, ehdr->e_phnum, + dyn->d_un.d_ptr);
+		else if (lenn_to_cpu(dyn->d_tag) == DT_RELA)
+			rela_dyn = get_offset_nn(data, phdrs, le16_to_cpu(ehdr->e_phnum), + lenn_to_cpu(dyn->d_un.d_ptr));
+		else if (lenn_to_cpu(dyn->d_tag) == DT_RELASZ)
+		  rela_count = lenn_to_cpu(dyn->d_un.d_val) / sizeof(Elf_Rela);
+		else if (lenn_to_cpu(dyn->d_tag) == DT_SYMTAB)
+			dynsym = get_offset_nn(data, phdrs, le16_to_cpu(ehdr->e_phnum), + lenn_to_cpu(dyn->d_un.d_ptr));
 
 	}
 
@@ -80,17 +81,17 @@ static void prelink_nn(void *data)
 		die("No .dynsym found");
 
 	for (r = rela_dyn; r < rela_dyn + rela_count; ++r) {
-		void* buf = get_offset_nn(data, phdrs, ehdr->e_phnum, r->r_offset);
+		void* buf = get_offset_nn(data, phdrs, le16_to_cpu(ehdr->e_phnum), lenn_to_cpu(r->r_offset));
 
 		if (buf == NULL)
 			continue;
 
-		if (ELF_R_TYPE(r->r_info) == R_RISCV_RELATIVE)
+		if (ELF_R_TYPE(lenn_to_cpu(r->r_info)) == R_RISCV_RELATIVE)
 			*((uintnn_t*) buf) = r->r_addend;
-		else if (ELF_R_TYPE(r->r_info) == R_RISCV_32)
-			*((uint32_t*) buf) = dynsym[ELF_R_SYM(r->r_info)].st_value;
-		else if (ELF_R_TYPE(r->r_info) == R_RISCV_64)
-			*((uint64_t*) buf) = dynsym[ELF_R_SYM(r->r_info)].st_value;
+		else if (ELF_R_TYPE(lenn_to_cpu(r->r_info)) == R_RISCV_32)
+			*((uint32_t*) buf) = dynsym[ELF_R_SYM(lenn_to_cpu(r->r_info))].st_value;
+		else if (ELF_R_TYPE(lenn_to_cpu(r->r_info)) == R_RISCV_64)
+			*((uint64_t*) buf) = dynsym[ELF_R_SYM(lenn_to_cpu(r->r_info))].st_value;
 	}
 }
 
@@ -105,6 +106,7 @@ static void prelink_nn(void *data)
 #undef Elf_Addr
 #undef ELF_R_TYPE
 #undef ELF_R_SYM
+#undef lenn_to_cpu
 
 #undef CONCAT_IMPL
 #undef CONCAT