From: Baoquan He <bhe@redhat.com>
To: linux-kernel@vger.kernel.org
Cc: yujie.liu@intel.com, Baoquan He <bhe@redhat.com>,
linux-parisc@vger.kernel.org, x86@kernel.org,
kexec@lists.infradead.org, nathan@kernel.org, joe@perches.com,
linux-riscv@lists.infradead.org, linuxppc-dev@lists.ozlabs.org,
akpm@linux-foundation.org, linux-arm-kernel@lists.infradead.org
Subject: [PATCH v2 1/7] kexec_file: add kexec_file flag to control debug printing
Date: Fri, 24 Nov 2023 11:36:36 +0800 [thread overview]
Message-ID: <20231124033642.520686-2-bhe@redhat.com> (raw)
In-Reply-To: <20231124033642.520686-1-bhe@redhat.com>
When specifying 'kexec -c -d', kexec_load interface will print loading
information, e.g the regions where kernel/initrd/purgatory/cmdline
are put, the memmap passed to 2nd kernel taken as system RAM ranges,
and printing all contents of struct kexec_segment, etc. These are
very helpful for analyzing or positioning what's happening when
kexec/kdump itself failed. The debugging printing for kexec_load
interface is made in user space utility kexec-tools.
Whereas, with kexec_file_load interface, 'kexec -s -d' print nothing.
Because kexec_file code is mostly implemented in kernel space, and the
debugging printing functionality is missed. It's not convenient when
debugging kexec/kdump loading and jumping with kexec_file_load
interface.
Now add KEXEC_FILE_DEBUG to kexec_file flag to control the debugging
message printing. And add global variable kexec_file_dbg_print and
macro kexec_dprintk() to facilitate the printing.
This is a preparation, later kexec_dprintk() will be used to replace the
existing pr_debug(). Once 'kexec -s -d' is specified, it will print out
kexec/kdump loading information. If '-d' is not specified, it regresses
to pr_debug().
Signed-off-by: Baoquan He <bhe@redhat.com>
---
include/linux/kexec.h | 10 +++++++++-
include/uapi/linux/kexec.h | 1 +
kernel/kexec_file.c | 5 +++++
3 files changed, 15 insertions(+), 1 deletion(-)
diff --git a/include/linux/kexec.h b/include/linux/kexec.h
index 8227455192b7..66997efe36f1 100644
--- a/include/linux/kexec.h
+++ b/include/linux/kexec.h
@@ -264,6 +264,14 @@ arch_kexec_apply_relocations(struct purgatory_info *pi, Elf_Shdr *section,
return -ENOEXEC;
}
#endif
+
+extern bool kexec_file_dbg_print;
+
+#define kexec_dprintk(fmt, ...) \
+ printk("%s" fmt, \
+ kexec_file_dbg_print ? KERN_INFO : KERN_DEBUG, \
+ ##__VA_ARGS__)
+
#endif /* CONFIG_KEXEC_FILE */
#ifdef CONFIG_KEXEC_ELF
@@ -403,7 +411,7 @@ bool kexec_load_permitted(int kexec_image_type);
/* List of defined/legal kexec file flags */
#define KEXEC_FILE_FLAGS (KEXEC_FILE_UNLOAD | KEXEC_FILE_ON_CRASH | \
- KEXEC_FILE_NO_INITRAMFS)
+ KEXEC_FILE_NO_INITRAMFS | KEXEC_FILE_DEBUG)
/* flag to track if kexec reboot is in progress */
extern bool kexec_in_progress;
diff --git a/include/uapi/linux/kexec.h b/include/uapi/linux/kexec.h
index 01766dd839b0..c17bb096ea68 100644
--- a/include/uapi/linux/kexec.h
+++ b/include/uapi/linux/kexec.h
@@ -25,6 +25,7 @@
#define KEXEC_FILE_UNLOAD 0x00000001
#define KEXEC_FILE_ON_CRASH 0x00000002
#define KEXEC_FILE_NO_INITRAMFS 0x00000004
+#define KEXEC_FILE_DEBUG 0x00000008
/* These values match the ELF architecture values.
* Unless there is a good reason that should continue to be the case.
diff --git a/kernel/kexec_file.c b/kernel/kexec_file.c
index f9a419cd22d4..4c35500ae40a 100644
--- a/kernel/kexec_file.c
+++ b/kernel/kexec_file.c
@@ -38,6 +38,8 @@ void set_kexec_sig_enforced(void)
}
#endif
+bool kexec_file_dbg_print;
+
static int kexec_calculate_store_digests(struct kimage *image);
/* Maximum size in bytes for kernel/initrd files. */
@@ -123,6 +125,8 @@ void kimage_file_post_load_cleanup(struct kimage *image)
*/
kfree(image->image_loader_data);
image->image_loader_data = NULL;
+
+ kexec_file_dbg_print = false;
}
#ifdef CONFIG_KEXEC_SIG
@@ -278,6 +282,7 @@ kimage_file_alloc_init(struct kimage **rimage, int kernel_fd,
if (!image)
return -ENOMEM;
+ kexec_file_dbg_print = !!(flags & KEXEC_FILE_DEBUG);
image->file_mode = 1;
if (kexec_on_panic) {
--
2.41.0
next prev parent reply other threads:[~2023-11-24 3:38 UTC|newest]
Thread overview: 13+ messages / expand[flat|nested] mbox.gz Atom feed top
2023-11-24 3:36 [PATCH v2 0/7] kexec_file: print out debugging message if required Baoquan He
2023-11-24 3:36 ` Baoquan He [this message]
2023-11-24 3:36 ` [PATCH v2 2/7] " Baoquan He
2023-11-24 7:16 ` Joe Perches
2023-11-24 8:40 ` Baoquan He
2023-11-24 3:36 ` [PATCH v2 3/7] kexec_file, x86: " Baoquan He
2023-11-24 3:36 ` [PATCH v2 4/7] kexec_file, arm64: " Baoquan He
2023-11-25 21:26 ` kernel test robot
2023-11-26 11:55 ` Baoquan He
2023-11-24 3:36 ` [PATCH v2 5/7] kexec_file, ricv: " Baoquan He
2023-11-24 3:36 ` [PATCH v2 6/7] kexec_file, power: " Baoquan He
2023-11-24 3:36 ` [PATCH v2 7/7] kexec_file, parisc: " Baoquan He
-- strict thread matches above, loose matches on Subject: below --
2023-11-14 15:32 [PATCH 0/7] kexec_file: " Baoquan He
2023-11-14 15:32 ` [PATCH 1/7] kexec_file: add kexec_file flag to control debug printing Baoquan He
2023-11-15 12:51 ` [PATCH v2 " Baoquan He
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