5.19-rc1 x86 build failure
From: Joe Damato
Date: Tue Jun 07 2022 - 08:21:16 EST
Greetings:
My apologies if this is the incorrect place to report this, but I got a
build error when trying to compile the net-next 5.19-rc1 tree.
git bisect says that commit a1e2c031ec394 ("x86/mm: Simplify
RESERVE_BRK()") is responsible for the build issue I am hitting.
I am performing this build on an x86_64 system with GNU C11 (Ubuntu
5.4.0-6ubuntu1~16.04.12) version 5.4.0 20160609 (x86_64-linux-gnu).
The assembler outputs a cryptic error message:
/tmp/ccnGOKZ5.s: Assembler messages:
/tmp/ccnGOKZ5.s:98: Error: missing ')'
/tmp/ccnGOKZ5.s:98: Error: missing ')'
/tmp/ccnGOKZ5.s:98: Error: missing ')'
/tmp/ccnGOKZ5.s:98: Error: junk at end of line, first unrecognized
character is `U'
/tmp/ccnGOKZ5.s:99: Error: missing ')'
/tmp/ccnGOKZ5.s:99: Error: missing ')'
/tmp/ccnGOKZ5.s:99: Error: missing ')'
/tmp/ccnGOKZ5.s:99: Error: junk at end of line, first unrecognized
character is `U'
I've asked GCC to generate the assembly and output so I can see more
specifically where this issue is (via "-fverbose-asm -Wa,-adhln=output"):
96 .pushsection .brk_reservation,"aw",@nobits
97 .brk.early_pgt_alloc:
98 ???? 00000000 .skip ((2 * 3) * ((1UL) << 12))
**** Error: missing ')'
**** Error: missing ')'
**** Error: missing ')'
**** Error: junk at end of line, first unrecognized character is `U'
98 0000
100 .popsection
This comes from arch/x86/mm/init.c, which has the following code:
RESERVE_BRK(early_pgt_alloc, INIT_PGT_BUF_SIZE);
wherein INIT_PGT_BUF_SIZE (via PAGE_SIZE) has a "1UL" which makes the
assembler unhappy.
I don't really know what the correct way to fix this is; it seems that the
macro _AC should handle this if ASSEMBLY is defined, IIUC, but that does
not seem to be the case at this point in init.c.
Perhaps I am doing something incorrect during the build process causing
this to happen?
Thanks,
Joe