elf: add PT_RISCV_ATTRIBUTES program header

Attribute is ignored for now.

It is supposed to check ABI compatiblity and reject loading incompatible images.
Haiku currently do not use multiple ABIs for RISC-V so it is safe to ignore attributes.

PT_RISCV_ATTRIBUTES program header is produced by default in GCC 13 and Clang 17.

Change-Id: I4659e9bacbf34a2a0bc16b34c2aaa37232d700fa
Reviewed-on: https://review.haiku-os.org/c/haiku/+/6948
Reviewed-by: David Karoly <[email protected]>
Tested-by: Commit checker robot <[email protected]>
Reviewed-by: Alex von Gluck IV <[email protected]>

headers/build/os/kernel/elf.h

@@ -339,6 +339,7 @@ typedef struct {
 
 #define PT_LOPROC		0x70000000
 #define PT_ARM_UNWIND	0x70000001
+#define PT_RISCV_ATTRIBUTES	0x70000003
 #define PT_HIPROC		0x7fffffff
 
 /* program header segment flags */

headers/os/kernel/elf.h

@@ -350,6 +350,7 @@ typedef struct {
 
 #define PT_LOPROC		0x70000000
 #define PT_ARM_UNWIND	0x70000001
+#define PT_RISCV_ATTRIBUTES	0x70000003
 #define PT_HIPROC		0x7fffffff
 
 /* program header segment flags */

src/system/kernel/elf.cpp

@@ -2279,6 +2279,9 @@ load_kernel_add_on(const char *path)
 				continue;
 			case PT_ARM_UNWIND:
 				continue;
+			case PT_RISCV_ATTRIBUTES:
+				// TODO: check ABI compatibility attributes
+				continue;
 			default:
 				dprintf("%s: unhandled pheader type %#" B_PRIx32 "\n", fileName,
 					programHeaders[i].p_type);

src/system/runtime_loader/elf_load_image.cpp

@@ -88,6 +88,9 @@ count_regions(const char* imagePath, char const* buff, int phnum, int phentsize)
 			case PT_ARM_UNWIND:
 				// will be handled in libgcc_s.so.1
 				break;
+			case PT_RISCV_ATTRIBUTES:
+				// TODO: check ABI compatibility attributes
+				break;
 			default:
 				FATAL("%s: Unhandled pheader type in count 0x%" B_PRIx32 "\n",
 					imagePath, pheaders->p_type);
@@ -219,6 +222,9 @@ parse_program_headers(image_t* image, char* buff, int phnum, int phentsize)
 			case PT_ARM_UNWIND:
 				// will be handled in libgcc_s.so.1
 				break;
+			case PT_RISCV_ATTRIBUTES:
+				// TODO: check ABI compatibility attributes
+				break;
 			default:
 				FATAL("%s: Unhandled pheader type in parse 0x%" B_PRIx32 "\n",
 					image->path, pheader->p_type);