Two important changes to note:
The kexec_calculate_store_digests() changed to specifically EXCLUDE
the elfcorehdr segment from its list of segments to check.
This is an important change as it allows, in a hotplug environment,
for the elfcorehdr segment (which contains the list of CPUs and
memory regions) to change dynamically without the need to update
purgatory (with the hash/digests of the segments it checks) as well.
The crash_prepare_elf64_headers() changed to look for the offline'd
CPU and exclude it. This due to the fact that the offline'd CPU is
still in the for_each_present_cpu() list at this point in time on
the cpu hotplug handler path.
Signed-off-by: Eric DeVolder <eric.devolder@xxxxxxxxxx>
---
kernel/kexec_file.c | 15 +++++++++++++--
1 file changed, 13 insertions(+), 2 deletions(-)
diff --git a/kernel/kexec_file.c b/kernel/kexec_file.c
index 8347fc158d2b..339995d42169 100644
--- a/kernel/kexec_file.c
+++ b/kernel/kexec_file.c
@@ -765,6 +765,12 @@ static int kexec_calculate_store_digests(struct kimage *image)
for (j = i = 0; i < image->nr_segments; i++) {
struct kexec_segment *ksegment;
+#ifdef CONFIG_CRASH_HOTPLUG
+ /* This segment excluded to allow future changes via hotplug */
+ if (image->elf_index_valid && (j == image->elf_index))
+ continue;
+#endif
+
ksegment = &image->segment[i];
/*
* Skip purgatory as it will be modified once we put digest
@@ -1260,8 +1266,8 @@ int crash_exclude_mem_range(struct crash_mem *mem,
return 0;
}
-int crash_prepare_elf64_headers(struct crash_mem *mem, int kernel_map,
- void **addr, unsigned long *sz)
+int crash_prepare_elf64_headers(struct kimage *image, struct crash_mem *mem,
+ int kernel_map, void **addr, unsigned long *sz)
{
Elf64_Ehdr *ehdr;
Elf64_Phdr *phdr;
@@ -1308,6 +1314,11 @@ int crash_prepare_elf64_headers(struct crash_mem *mem, int kernel_map,
/* Prepare one phdr of type PT_NOTE for each present CPU */
for_each_present_cpu(cpu) {
+#ifdef CONFIG_CRASH_HOTPLUG
+ /* Skip the soon-to-be offlined cpu */
+ if (image->hotplug_event && (cpu == image->offlinecpu))
+ continue;
+#endif
phdr->p_type = PT_NOTE;
notes_addr = per_cpu_ptr_to_phys(per_cpu_ptr(crash_notes, cpu));
phdr->p_offset = phdr->p_paddr = notes_addr;
--
2.27.0
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