[PATCH 2/7] kexec_file: print out debugging message if required

From: Baoquan He
Date: Tue Nov 14 2023 - 10:33:36 EST


Replace pr_debug() with the newly added kexec_dprintk() in kexec_file
loading related codes.

And also print out type/start/head of kimage and flags to help debug.

Signed-off-by: Baoquan He <bhe@xxxxxxxxxx>
---
kernel/crash_core.c | 3 ++-
kernel/kexec_file.c | 7 ++++++-
security/integrity/ima/ima_kexec.c | 2 +-
3 files changed, 9 insertions(+), 3 deletions(-)

diff --git a/kernel/crash_core.c b/kernel/crash_core.c
index efe87d501c8c..41001ffbaa99 100644
--- a/kernel/crash_core.c
+++ b/kernel/crash_core.c
@@ -551,7 +551,8 @@ int crash_prepare_elf64_headers(struct crash_mem *mem, int need_kernel_map,
phdr->p_filesz = phdr->p_memsz = mend - mstart + 1;
phdr->p_align = 0;
ehdr->e_phnum++;
- pr_debug("Crash PT_LOAD ELF header. phdr=%p vaddr=0x%llx, paddr=0x%llx, sz=0x%llx e_phnum=%d p_offset=0x%llx\n",
+ kexec_dprintk("Crash PT_LOAD ELF header. phdr=%p vaddr=0x%llx, paddr=0x%llx, "
+ "sz=0x%llx e_phnum=%d p_offset=0x%llx\n",
phdr, phdr->p_vaddr, phdr->p_paddr, phdr->p_filesz,
ehdr->e_phnum, phdr->p_offset);
phdr++;
diff --git a/kernel/kexec_file.c b/kernel/kexec_file.c
index 4c35500ae40a..7ae1b0901aa4 100644
--- a/kernel/kexec_file.c
+++ b/kernel/kexec_file.c
@@ -206,6 +206,8 @@ kimage_file_prepare_segments(struct kimage *image, int kernel_fd, int initrd_fd,
if (ret < 0)
return ret;
image->kernel_buf_len = ret;
+ kexec_dprintk("kernel: %p kernel_size: %#lx\n",
+ image->kernel_buf, image->kernel_buf_len);

/* Call arch image probe handlers */
ret = arch_kexec_kernel_image_probe(image, image->kernel_buf,
@@ -389,11 +391,12 @@ SYSCALL_DEFINE5(kexec_file_load, int, kernel_fd, int, initrd_fd,
if (ret)
goto out;

+ kexec_dprintk("nr_segments = %lu\n", image->nr_segments);
for (i = 0; i < image->nr_segments; i++) {
struct kexec_segment *ksegment;

ksegment = &image->segment[i];
- pr_debug("Loading segment %d: buf=0x%p bufsz=0x%zx mem=0x%lx memsz=0x%zx\n",
+ kexec_dprintk("segment[%d]: buf=0x%p bufsz=0x%zx mem=0x%lx memsz=0x%zx\n",
i, ksegment->buf, ksegment->bufsz, ksegment->mem,
ksegment->memsz);

@@ -408,6 +411,8 @@ SYSCALL_DEFINE5(kexec_file_load, int, kernel_fd, int, initrd_fd,
if (ret)
goto out;

+ kexec_dprintk("kexec_file_load: type:%u, start:0x%lx head:0x%lx flags:0x%lx\n",
+ image->type, image->start, image->head, flags);
/*
* Free up any temporary buffers allocated which are not needed
* after image has been loaded
diff --git a/security/integrity/ima/ima_kexec.c b/security/integrity/ima/ima_kexec.c
index ad133fe120db..e692624bcab3 100644
--- a/security/integrity/ima/ima_kexec.c
+++ b/security/integrity/ima/ima_kexec.c
@@ -129,7 +129,7 @@ void ima_add_kexec_buffer(struct kimage *image)
image->ima_buffer_size = kexec_segment_size;
image->ima_buffer = kexec_buffer;

- pr_debug("kexec measurement buffer for the loaded kernel at 0x%lx.\n",
+ kexec_dprintk("kexec measurement buffer for the loaded kernel at 0x%lx.\n",
kbuf.mem);
}
#endif /* IMA_KEXEC */
--
2.41.0