s390/boot: add 'alloc' to info.bin .vmlinux.info section flags
When attempting to boot a kernel compiled with OBJCOPY=llvm-objcopy,
there is a crash right at boot:
Out of memory allocating 6d7800 bytes 8 aligned in range 0:
20000000
Reserved memory ranges:
0000000000000000 a394c3c30d90cdaf DECOMPRESSOR
Usable online memory ranges (info source: sclp read info [3]):
0000000000000000 0000000020000000
Usable online memory total:
20000000 Reserved:
a394c3c30d90cdaf Free: 0
Call Trace:
(sp:
0000000000033e90 [<
0000000000012fbc>] physmem_alloc_top_down+0x5c/0x104)
sp:
0000000000033f00 [<
0000000000011d56>] startup_kernel+0x3a6/0x77c
sp:
0000000000033f60 [<
00000000000100f4>] startup_normal+0xd4/0xd4
GNU objcopy does not have any issues. Looking at differences between the
object files in each build reveals info.bin does not get properly
populated with llvm-objcopy, which results in an empty .vmlinux.info
section.
$ file {gnu,llvm}-objcopy/arch/s390/boot/info.bin
gnu-objcopy/arch/s390/boot/info.bin: data
llvm-objcopy/arch/s390/boot/info.bin: empty
$ llvm-readelf --section-headers {gnu,llvm}-objcopy/arch/s390/boot/vmlinux | rg 'File:|\.vmlinux\.info|\.decompressor\.syms'
File: gnu-objcopy/arch/s390/boot/vmlinux
[12] .vmlinux.info PROGBITS
0000000000034000 035000 000078 00 WA 0 0 1
[13] .decompressor.syms PROGBITS
0000000000034078 035078 000b00 00 WA 0 0 1
File: llvm-objcopy/arch/s390/boot/vmlinux
[12] .vmlinux.info PROGBITS
0000000000034000 035000 000000 00 WA 0 0 1
[13] .decompressor.syms PROGBITS
0000000000034000 035000 000b00 00 WA 0 0 1
Ulrich points out that llvm-objcopy only copies sections marked as alloc
with a binary output target, whereas the .vmlinux.info section is only
marked as load. Add 'alloc' in addition to 'load', so that both objcopy
implementations work properly:
$ file {gnu,llvm}-objcopy/arch/s390/boot/info.bin
gnu-objcopy/arch/s390/boot/info.bin: data
llvm-objcopy/arch/s390/boot/info.bin: data
$ llvm-readelf --section-headers {gnu,llvm}-objcopy/arch/s390/boot/vmlinux | rg 'File:|\.vmlinux\.info|\.decompressor\.syms'
File: gnu-objcopy/arch/s390/boot/vmlinux
[12] .vmlinux.info PROGBITS
0000000000034000 035000 000078 00 WA 0 0 1
[13] .decompressor.syms PROGBITS
0000000000034078 035078 000b00 00 WA 0 0 1
File: llvm-objcopy/arch/s390/boot/vmlinux
[12] .vmlinux.info PROGBITS
0000000000034000 035000 000078 00 WA 0 0 1
[13] .decompressor.syms PROGBITS
0000000000034078 035078 000b00 00 WA 0 0 1
Closes: https://github.com/ClangBuiltLinux/linux/issues/1996
Link: https://github.com/llvm/llvm-project/commit/3c02cb7492fc78fb678264cebf57ff88e478e14f
Suggested-by: Ulrich Weigand <ulrich.weigand@de.ibm.com>
Signed-off-by: Nathan Chancellor <nathan@kernel.org>
Link: https://lore.kernel.org/r/20240216-s390-fix-boot-with-llvm-objcopy-v1-1-0ac623daf42b@kernel.org
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>