Commit 86328b33 authored by Hari Bathini's avatar Hari Bathini Committed by Michael Ellerman
Browse files

vmcore: remove dependency with is_kdump_kernel() for exporting vmcore 

Currently, is_kdump_kernel() returns true when elfcorehdr_addr is set.
While elfcorehdr_addr is set for kexec based kernel dump mechanism,
alternate dump capturing methods like fadump [1] also set it to export
the vmcore. Since, is_kdump_kernel() is used to restrict resources in
crash dump capture kernel and such restrictions may not be desirable
for fadump, allow is_kdump_kernel() to be defined differently for such
scenarios. With this, is_kdump_kernel() could be false while vmcore is
usable. So, remove unnecessary dependency with is_kdump_kernel(), for
exporting vmcore.

[1] https://docs.kernel.org/powerpc/firmware-assisted-dump.html



Suggested-by: default avatarMichael Ellerman <mpe@ellerman.id.au>
Signed-off-by: default avatarHari Bathini <hbathini@linux.ibm.com>
Acked-by: default avatarBaoquan He <bhe@redhat.com>
Signed-off-by: default avatarMichael Ellerman <mpe@ellerman.id.au>
Link: https://msgid.link/20230912082950.856977-1-hbathini@linux.ibm.com
parent 7135b921

include/linux/crash_dump.h

+5 −3
Original line number Diff line number Diff line
@@ -50,6 +50,7 @@ void vmcore_cleanup(void); 
#define vmcore_elf64_check_arch(x) (elf_check_arch(x) || vmcore_elf_check_arch_cross(x))

#endif



#ifndef is_kdump_kernel

/*

 * is_kdump_kernel() checks whether this kernel is booting after a panic of

 * previous kernel or not. This is determined by checking if previous kernel
@@ -64,6 +65,7 @@ static inline bool is_kdump_kernel(void) 
{

	return elfcorehdr_addr != ELFCORE_ADDR_MAX;

}

#endif



/* is_vmcore_usable() checks if the kernel is booting after a panic and

 * the vmcore region is usable.
@@ -75,7 +77,8 @@ static inline bool is_kdump_kernel(void) 


static inline int is_vmcore_usable(void)

{

	return is_kdump_kernel() && elfcorehdr_addr != ELFCORE_ADDR_ERR ? 1 : 0;

	return elfcorehdr_addr != ELFCORE_ADDR_ERR &&

		elfcorehdr_addr != ELFCORE_ADDR_MAX ? 1 : 0;

}



/* vmcore_unusable() marks the vmcore as unusable,
@@ -84,7 +87,6 @@ static inline int is_vmcore_usable(void) 


static inline void vmcore_unusable(void)

{

	if (is_kdump_kernel())

	elfcorehdr_addr = ELFCORE_ADDR_ERR;

}