git: 4d213c595ac3 - main - sys: use globals for the ELF kernel and module type strings

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From: Warner Losh <imp_at_FreeBSD.org>
Date: Fri, 24 Jan 2025 21:37:14 UTC
The branch main has been updated by imp:

URL: https://cgit.FreeBSD.org/src/commit/?id=4d213c595ac3247a85cea5d3ea521db14151a427

commit 4d213c595ac3247a85cea5d3ea521db14151a427
Author:     Ahmad Khalifa <ahmadkhalifa570@gmail.com>
AuthorDate: 2024-08-24 15:12:52 +0000
Commit:     Warner Losh <imp@FreeBSD.org>
CommitDate: 2025-01-24 21:29:39 +0000

    sys: use globals for the ELF kernel and module type strings
    
    Initialize the globals with macros so we can use the same values in the
    loader.
    
    Also remove unnecessary "elfN module" checks.
    
    Reviewed by: imp, kib
    Pull Request: https://github.com/freebsd/freebsd-src/pull/1394
---
 sys/arm/arm/machdep_boot.c     |  8 ++++----
 sys/arm64/arm64/machdep_boot.c |  2 +-
 sys/kern/link_elf.c            |  4 +---
 sys/kern/link_elf_obj.c        |  5 +----
 sys/kern/subr_module.c         |  6 +++++-
 sys/powerpc/powerpc/machdep.c  |  9 ++++-----
 sys/riscv/riscv/machdep.c      |  2 +-
 sys/sys/linker.h               | 11 +++++++++++
 8 files changed, 28 insertions(+), 19 deletions(-)

diff --git a/sys/arm/arm/machdep_boot.c b/sys/arm/arm/machdep_boot.c
index 534d34acabe2..e2416f86ad23 100644
--- a/sys/arm/arm/machdep_boot.c
+++ b/sys/arm/arm/machdep_boot.c
@@ -356,12 +356,12 @@ fake_preload_metadata(struct arm_boot_params *abp __unused, void *dtb_ptr,
 
 	fake_preload[i++] = MODINFO_NAME;
 	fake_preload[i++] = strlen("kernel") + 1;
-	strcpy((char*)&fake_preload[i++], "kernel");
+	strcpy((char *)&fake_preload[i++], "kernel");
 	i += 1;
 	fake_preload[i++] = MODINFO_TYPE;
-	fake_preload[i++] = strlen("elf kernel") + 1;
-	strcpy((char*)&fake_preload[i++], "elf kernel");
-	i += 2;
+	fake_preload[i++] = strlen(preload_kerntype) + 1;
+	strcpy((char *)&fake_preload[i], preload_kerntype);
+	i += howmany(fake_preload[i - 1], sizeof(uint32_t));
 	fake_preload[i++] = MODINFO_ADDR;
 	fake_preload[i++] = sizeof(vm_offset_t);
 	fake_preload[i++] = KERNVIRTADDR;
diff --git a/sys/arm64/arm64/machdep_boot.c b/sys/arm64/arm64/machdep_boot.c
index 029ae23530ff..83bd74ea7317 100644
--- a/sys/arm64/arm64/machdep_boot.c
+++ b/sys/arm64/arm64/machdep_boot.c
@@ -98,7 +98,7 @@ fake_preload_metadata(void *dtb_ptr, size_t dtb_size)
 	PRELOAD_PUSH_STRING("kernel");
 
 	PRELOAD_PUSH_VALUE(uint32_t, MODINFO_TYPE);
-	PRELOAD_PUSH_STRING("elf kernel");
+	PRELOAD_PUSH_STRING(preload_kerntype);
 
 	PRELOAD_PUSH_VALUE(uint32_t, MODINFO_ADDR);
 	PRELOAD_PUSH_VALUE(uint32_t, sizeof(vm_offset_t));
diff --git a/sys/kern/link_elf.c b/sys/kern/link_elf.c
index 23a924636ca2..53af1e164980 100644
--- a/sys/kern/link_elf.c
+++ b/sys/kern/link_elf.c
@@ -895,9 +895,7 @@ link_elf_link_preload(linker_class_t cls, const char *filename,
 	sizeptr = preload_search_info(modptr, MODINFO_SIZE);
 	dynptr = preload_search_info(modptr,
 	    MODINFO_METADATA | MODINFOMD_DYNAMIC);
-	if (type == NULL ||
-	    (strcmp(type, "elf" __XSTRING(__ELF_WORD_SIZE) " module") != 0 &&
-	     strcmp(type, "elf module") != 0))
+	if (type == NULL || strcmp(type, preload_modtype) != 0)
 		return (EFTYPE);
 	if (baseptr == NULL || sizeptr == NULL || dynptr == NULL)
 		return (EINVAL);
diff --git a/sys/kern/link_elf_obj.c b/sys/kern/link_elf_obj.c
index a7c7d4826322..02fd4caffcd9 100644
--- a/sys/kern/link_elf_obj.c
+++ b/sys/kern/link_elf_obj.c
@@ -365,11 +365,8 @@ link_elf_link_preload(linker_class_t cls, const char *filename,
 	    MODINFOMD_ELFHDR);
 	shdr = (Elf_Shdr *)preload_search_info(modptr, MODINFO_METADATA |
 	    MODINFOMD_SHDR);
-	if (type == NULL || (strcmp(type, "elf" __XSTRING(__ELF_WORD_SIZE)
-	    " obj module") != 0 &&
-	    strcmp(type, "elf obj module") != 0)) {
+	if (type == NULL || strcmp(type, preload_modtype_obj) != 0)
 		return (EFTYPE);
-	}
 	if (baseptr == NULL || sizeptr == NULL || hdr == NULL ||
 	    shdr == NULL)
 		return (EINVAL);
diff --git a/sys/kern/subr_module.c b/sys/kern/subr_module.c
index 14272bd913f8..596961606577 100644
--- a/sys/kern/subr_module.c
+++ b/sys/kern/subr_module.c
@@ -46,10 +46,14 @@
 vm_offset_t preload_addr_relocate = 0;
 caddr_t preload_metadata, preload_kmdp;
 
+const char preload_modtype[] = MODTYPE;
+const char preload_kerntype[] = KERNTYPE;
+const char preload_modtype_obj[] = MODTYPE_OBJ;
+
 void
 preload_initkmdp(bool fatal)
 {
-	preload_kmdp = preload_search_by_type("elf kernel");
+	preload_kmdp = preload_search_by_type(preload_kerntype);
 
 	if (preload_kmdp == NULL && fatal)
 		panic("unable to find kernel metadata");
diff --git a/sys/powerpc/powerpc/machdep.c b/sys/powerpc/powerpc/machdep.c
index 96f3b292854d..e9979712aa9c 100644
--- a/sys/powerpc/powerpc/machdep.c
+++ b/sys/powerpc/powerpc/machdep.c
@@ -644,15 +644,14 @@ fake_preload_metadata(void) {
 
 	fake_preload[i++] = MODINFO_NAME;
 	fake_preload[i++] = strlen("kernel") + 1;
-	strcpy((char*)&fake_preload[i], "kernel");
+	strcpy((char *)&fake_preload[i], "kernel");
 	/* ['k' 'e' 'r' 'n'] ['e' 'l' '\0' ..] */
 	i += 2;
 
 	fake_preload[i++] = MODINFO_TYPE;
-	fake_preload[i++] = strlen("elf kernel") + 1;
-	strcpy((char*)&fake_preload[i], "elf kernel");
-	/* ['e' 'l' 'f' ' '] ['k' 'e' 'r' 'n'] ['e' 'l' '\0' ..] */
-	i += 3;
+	fake_preload[i++] = strlen(preload_kerntype) + 1;
+	strcpy((char *)&fake_preload[i], preload_kerntype);
+	i += howmany(fake_preload[i - 1], sizeof(uint32_t));
 
 #ifdef __powerpc64__
 	/* Padding -- Fields start on u_long boundaries */
diff --git a/sys/riscv/riscv/machdep.c b/sys/riscv/riscv/machdep.c
index a17cff55f2cc..8d32d348df7d 100644
--- a/sys/riscv/riscv/machdep.c
+++ b/sys/riscv/riscv/machdep.c
@@ -365,7 +365,7 @@ fake_preload_metadata(struct riscv_bootparams *rvbp)
 	PRELOAD_PUSH_VALUE(uint32_t, MODINFO_NAME);
 	PRELOAD_PUSH_STRING("kernel");
 	PRELOAD_PUSH_VALUE(uint32_t, MODINFO_TYPE);
-	PRELOAD_PUSH_STRING("elf kernel");
+	PRELOAD_PUSH_STRING(preload_kerntype);
 
 	PRELOAD_PUSH_VALUE(uint32_t, MODINFO_ADDR);
 	PRELOAD_PUSH_VALUE(uint32_t, sizeof(vm_offset_t));
diff --git a/sys/sys/linker.h b/sys/sys/linker.h
index 77dd437c7ffe..85c50be6c969 100644
--- a/sys/sys/linker.h
+++ b/sys/sys/linker.h
@@ -220,6 +220,14 @@ void linker_kldload_unbusy(int flags);
 
 #endif	/* _KERNEL */
 
+/*
+ * ELF file types
+ */
+#define KERNTYPE_MB	"elf multiboot kernel"
+#define KERNTYPE	"elf kernel"
+#define MODTYPE_OBJ	"elf obj module"
+#define MODTYPE		"elf module"
+
 /*
  * Module information subtypes
  */
@@ -273,6 +281,9 @@ void linker_kldload_unbusy(int flags);
  */
 extern vm_offset_t	preload_addr_relocate;
 extern caddr_t		preload_metadata, preload_kmdp;
+extern const char	preload_modtype[];
+extern const char	preload_kerntype[];
+extern const char	preload_modtype_obj[];
 
 extern void *		preload_fetch_addr(caddr_t _mod);
 extern size_t		preload_fetch_size(caddr_t _mod);