[PATCH v2 4/5] arm64: kexec_file: Simplify load_other_segments()

[Jinjie Ruan]

Use `kbuf` fields directly in crash_prepare_headers() to eliminate
the local variables "headers" and "headers_sz"..

Advance the assignment to image->elf_headers before
calling kexec_add_buffer(). If kexec_add_buffer() fails, the explicit
vfree() in the error path can be removed, as the global infrastructure
in arch_kimage_file_post_load_cleanup() will handle the cleanup.

Cc: Catalin Marinas <catalin.marinas@xxxxxxx>
Cc: Will Deacon <will@xxxxxxxxxx>
Cc: Baoquan He <bhe@xxxxxxxxxx>
Cc: Breno Leitao <leitao@xxxxxxxxxx>
Signed-off-by: Jinjie Ruan <ruanjinjie@xxxxxxxxxx>
---
 arch/arm64/kernel/machine_kexec_file.c | 24 +++++++++---------------
 1 file changed, 9 insertions(+), 15 deletions(-)

diff --git a/arch/arm64/kernel/machine_kexec_file.c b/arch/arm64/kernel/machine_kexec_file.c
index 2f750e5f4fcc..3d907f8ee594 100644
--- a/arch/arm64/kernel/machine_kexec_file.c
+++ b/arch/arm64/kernel/machine_kexec_file.c
@@ -89,36 +89,30 @@ int load_other_segments(struct kimage *image,
 	kbuf.buf_min = kernel_load_addr + kernel_size;
 
 #ifdef CONFIG_CRASH_DUMP
-	/* load elf core header */
-	void *headers;
-	unsigned long headers_sz;
 	if (image->type == KEXEC_TYPE_CRASH) {
-		ret = crash_prepare_headers(true, &headers, &headers_sz, NULL);
+		ret = crash_prepare_headers(true, &kbuf.buffer, &kbuf.bufsz, NULL);
 		if (ret) {
 			pr_err("Preparing elf core header failed\n");
 			goto out_err;
 		}
 
-		kbuf.buffer = headers;
-		kbuf.bufsz = headers_sz;
+		if (unlikely(image->elf_headers))
+			vfree(image->elf_headers);
+
+		image->elf_headers = kbuf.buffer;
+		image->elf_headers_sz = kbuf.bufsz;
+
 		kbuf.mem = KEXEC_BUF_MEM_UNKNOWN;
-		kbuf.memsz = headers_sz;
+		kbuf.memsz = kbuf.bufsz;
 		kbuf.buf_align = SZ_64K; /* largest supported page size */
 		kbuf.buf_max = ULONG_MAX;
 		kbuf.top_down = true;
 
 		ret = kexec_add_buffer(&kbuf);
-		if (ret) {
-			vfree(headers);
+		if (ret)
 			goto out_err;
-		}
-
-		if (unlikely(image->elf_headers))
-			vfree(image->elf_headers);
 
-		image->elf_headers = headers;
 		image->elf_load_addr = kbuf.mem;
-		image->elf_headers_sz = headers_sz;
 
 		kexec_dprintk("Loaded elf core header at 0x%lx bufsz=0x%lx memsz=0x%lx\n",
 			      image->elf_load_addr, kbuf.bufsz, kbuf.memsz);
-- 
2.34.1