On Fri, Feb 16, 2024 at 12:55:53PM -0700, Nathan Chancellor wrote: > 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. ... > Closes: https://github.com/ClangBuiltLinux/linux/issues/1996 > Link: https://github.com/llvm/llvm-project/commit/3c02cb7492fc78fb678264cebf57ff88e478e14f > Suggested-by: Ulrich Weigand <ulrich.weigand@xxxxxxxxxx> > Signed-off-by: Nathan Chancellor <nathan@xxxxxxxxxx> Thanks a lot, applied! However when building the kernel with "LLVM=1" I can see something else which looks like an llvm-objdump bug to me: $make LLVM=1 bzImage ... SECTCMP .boot.data llvm-objdump: warning: section '.boot.data' mentioned in a -j/--section option, but not found in any input file This works without warning with GNU objcopy, and actually the output is also different: $ objdump -v GNU objdump (GNU Binutils for Ubuntu) 2.41 $ objdump -t -j .boot.data arch/s390/boot/vmlinux arch/s390/boot/vmlinux: file format elf64-s390 SYMBOL TABLE: 0000000000020000 l O .boot.data 0000000000003000 sclp_info_sccb 00000000000240e0 l O .boot.data 0000000000000001 sclp_info_sccb_valid 0000000000023010 g O .boot.data 0000000000000008 ident_map_size 0000000000023018 g O .boot.data 00000000000010c8 physmem_info 00000000000250e2 g .boot.data 0000000000000000 __boot_data_end 0000000000020000 g .boot.data 0000000000000000 __boot_data_start 00000000000240e2 g O .boot.data 0000000000001000 early_command_line 0000000000023008 g O .boot.data 0000000000000008 early_ipl_comp_list_size 0000000000023000 g O .boot.data 0000000000000008 early_ipl_comp_list_addr While with llvm-copy: $ llvm-objdump --version LLVM (http://llvm.org/): LLVM version 19.0.0git $ llvm-objdump -t -j .boot.data arch/s390/boot/vmlinux arch/s390/boot/vmlinux: file format elf64-s390 SYMBOL TABLE: 0000000000000200 l .head.text 0000000000000000 ipl_start 0000000000010020 l .head.text 00000000000000d4 startup_normal 00000000000101b0 l .head.text 00000000000000b2 startup_kdump 0000000000010280 l .head.text 000000000000005a startup_pgm_check_handler 000000000001025c l .head.text 0000000000000000 startup_kdump_relocated 0000000000000000 l df *ABS* 0000000000000000 als.c 000000000001e040 l O .rodata 0000000000000018 als 000000000001f6f0 l O .data 0000000000000050 print_missing_facilities.als_str 0000000000011800 l F .text 00000000000000e2 print_machine_type ... 0000000000020000 l O .boot.data 0000000000003000 sclp_info_sccb 00000000000240e0 l O .boot.data 0000000000000001 sclp_info_sccb_valid ... and so on (everything is dumped) llvm-objdump: warning: section '.boot.data' mentioned in a -j/--section option, but not found in any input file So somehow llvmdump's "-j/--section" option doesn not seem to work.
