[PATCH v6 11/14] crash: Factor out crash_find_elfcorehdr() helper
From: Jinjie Ruan <hidden>
Date: 2026-09-21 09:04:24
Also in:
driver-core, kexec, lkml, loongarch
Subsystem:
kdump, the rest · Maintainers:
Andrew Morton, Baoquan He, Mike Rapoport, Pasha Tatashin, Pratyush Yadav, Linus Torvalds
The elfcorehdr segment is located by scanning the segments for the ELF magic. Factor that scan out into a new helper function, crash_find_elfcorehdr(), to clean up crash_handle_hotplug_event() and prepare for its reuse in crash hotplug code. Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Baoquan He <baoquan.he@linux.dev> Cc: Mike Rapoport <rppt@kernel.org> Cc: Pasha Tatashin <pasha.tatashin@soleen.com> Cc: Pratyush Yadav <pratyush@kernel.org> Cc: Dave Young <ruirui.yang@linux.dev> Cc: Breno Leitao <leitao@debian.org> Signed-off-by: Jinjie Ruan <redacted> --- kernel/crash_core.c | 39 +++++++++++++++++++++++---------------- 1 file changed, 23 insertions(+), 16 deletions(-)
diff --git a/kernel/crash_core.c b/kernel/crash_core.c
index 406b68d2adfd..4a990b17b66c 100644
--- a/kernel/crash_core.c
+++ b/kernel/crash_core.c@@ -647,6 +647,28 @@ int crash_check_hotplug_support(void) return rc; } +static void crash_find_elfcorehdr(struct kimage *image) +{ + unsigned char *ptr; + unsigned long mem; + unsigned int n; + + if (image->elfcorehdr_index >= 0) + return; + + for (n = 0; n < image->nr_segments; n++) { + mem = image->segment[n].mem; + ptr = kmap_local_page(pfn_to_page(mem >> PAGE_SHIFT)); + if (!ptr) + continue; + + /* The segment containing elfcorehdr */ + if (memcmp(ptr, ELFMAG, SELFMAG) == 0) + image->elfcorehdr_index = (int)n; + kunmap_local(ptr); + } +} + /* * To accurately reflect hot un/plug changes of CPU and Memory resources * (including onling and offlining of those resources), the relevant
@@ -702,22 +724,7 @@ static void crash_handle_hotplug_event(unsigned int hp_action, unsigned int cpu, * is allocated. Find the segment containing the elfcorehdr, * if not already found. */ - if (image->elfcorehdr_index < 0) { - unsigned long mem; - unsigned char *ptr; - unsigned int n; - - for (n = 0; n < image->nr_segments; n++) { - mem = image->segment[n].mem; - ptr = kmap_local_page(pfn_to_page(mem >> PAGE_SHIFT)); - if (ptr) { - /* The segment containing elfcorehdr */ - if (memcmp(ptr, ELFMAG, SELFMAG) == 0) - image->elfcorehdr_index = (int)n; - kunmap_local(ptr); - } - } - } + crash_find_elfcorehdr(image); if (image->elfcorehdr_index < 0) { pr_err("unable to locate elfcorehdr segment");
--
2.34.1