For relocatable 32bit kernels, boot/compressed/relocs.c processes
relocation entries in the kernel image and appends it to the kernel
image such that boot/compressed/head_32.S can relocate the kernel.
The kernel image is one statically linked object and only uses two
relocation types - R_386_PC32 and R_386_32, of the two only the latter
needs massaging during kernel relocation and thus handled by relocs.
R_386_PC32 is ignored and all other relocation types are considered
error.
When the target of a relocation resides in a discarded section,
binutils doesn't throw away the relocation record but nullifies it by
changing it to R_386_NONE, which unfortunately makes relocs fail.
The problem was triggered by yet out-of-tree x86 stack unwind patches
but given the binutils behavior, ignoring R_386_NONE is the right
thing to do.
The problem has been tracked down to binutils behavior by Jan Beulich.
[ Impact: fix build with certain binutils by ignoring R_386_NONE ]
Signed-off-by: Tejun Heo <tj@kernel.org>
Cc: Jan Beulich <JBeulich@novell.com>
Cc: Ingo Molnar <mingo@elte.hu>
LKML-Reference: <4A1B8150.40702@kernel.org>
Signed-off-by: H. Peter Anvin <hpa@zytor.com>
Impact: segfault on build of a 32-bit relocatable kernel
When converting arch/x86/boot/compressed/relocs.c to support unlimited
sections, the computation of sym_strtab in walk_relocs() was done
incorrectly. This causes a segfault for some people when building the
relocatable 32-bit kernel.
Pointed out by Anonymous <pageexec@freemail.hu>.
Signed-off-by: H. Peter Anvin <hpa@zytor.com>
Impact: build failure in maximal configurations
The 32-bit x86 relocatable kernel requires an auxilliary host program
to process the relocations. This program had a hard-coded arbitrary
limit of a 100 ELF sections. Instead of a hard-coded limit, allocate
the structures dynamically.
Signed-off-by: H. Peter Anvin <hpa@zytor.com>
Acked-by: Vivek Goyal <vgoyal@redhat.com>
This updates the exceptions for absolute relocs for the new symbol name
convention used for symbols extracted from the vDSO images.
Signed-off-by: Roland McGrath <roland@redhat.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Tejun Heo