[PATCH] powerpc: add `cur_cpu_spec` symbol to vmcoreinfo

Aditya Gupta adityag at linux.ibm.com
Mon Sep 11 19:14:09 AEST 2023

Presently, while reading a vmcore, makedumpfile uses
`cur_cpu_spec.mmu_features` to decide whether the crashed system had
RADIX MMU or not.

Currently, makedumpfile fails to get the `cur_cpu_spec` symbol (unless
a vmlinux is passed with the `-x` flag to makedumpfile), and hence
assigns offsets and shifts (such as pgd_offset_l4) incorrecly considering
MMU to be hash MMU.

Add `cur_cpu_spec` symbol and offset of `mmu_features` in the
`cpu_spec` struct, to VMCOREINFO, so that the symbol address and offset
is accessible to makedumpfile, without needing the vmlinux file

Signed-off-by: Aditya Gupta <adityag at linux.ibm.com>
 arch/powerpc/kexec/core.c | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/arch/powerpc/kexec/core.c b/arch/powerpc/kexec/core.c
index de64c7962991..369b8334a4f0 100644
--- a/arch/powerpc/kexec/core.c
+++ b/arch/powerpc/kexec/core.c
@@ -63,6 +63,8 @@ void arch_crash_save_vmcoreinfo(void)
 #ifndef CONFIG_NUMA
+	VMCOREINFO_SYMBOL(cur_cpu_spec);
+	VMCOREINFO_OFFSET(cpu_spec, mmu_features);
 #if defined(CONFIG_PPC64) && defined(CONFIG_SPARSEMEM_VMEMMAP)

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