Vegard Nossum <vegard.nossum@xxxxxxxxxx> writes:
> In order to give assembly code access to C structs without having to
> hardcore member offsets, the kernel compiles a C source file listing all
> the structs and offsets that are needed in assembly code. Using some
> C preprocessor trickery and a sed script, the compiled assembly code is
> turned back into C preprocessor code that in turn can be used by the
> asssembly code.
>
> This sed script is very hard to read and understand.
>
> Remove the sed script and compile the C source listing structs and
> offsets to an object file (instead of assembly code) that embeds C source
> directly. Then extract the C source using objcopy.
>
I threw some builders at this and hit a few errors:
parisc:
# make -s -j 160 ARCH=parisc64 O=/kisskb/build/mpe_generic-64bit_defconfig_parisc64-gcc13 CROSS_COMPILE=/opt/cross/kisskb/korg/gcc-13.1.0-nolibc/hppa-linux/bin/hppa64-linux-
{standard input}: Assembler messages:
{standard input}: Error: .size expression for main does not evaluate to a constant
make[3]: *** [/kisskb/src/scripts/Makefile.build:244: scripts/mod/devicetable-offsets.o] Error 1
s390:
# make -s -j 32 ARCH=s390 O=/kisskb/build/mpe_defconfig_s390x-gcc13 CROSS_COMPILE=/opt/cross/kisskb/korg/gcc-13.1.0-nolibc/s390-linux/bin/s390-linux-
In file included from /kisskb/src/arch/s390/include/asm/ptrace.h:11,
from /kisskb/src/arch/s390/kernel/vdso64/vdso_user_wrapper.S:7:
/kisskb/src/arch/s390/include/uapi/asm/ptrace.h:167: warning: "STACK_FRAME_OVERHEAD" redefined
167 | #define STACK_FRAME_OVERHEAD 160 /* size of minimum stack frame */
|
In file included from /kisskb/src/include/asm-generic/asm-offsets.h:1,
from ./arch/s390/include/generated/asm/asm-offsets.h:1,
from /kisskb/src/arch/s390/kernel/vdso64/vdso_user_wrapper.S:5:
./include/generated/asm-offsets.h:51: note: this is the location of the previous definition
51 | #define STACK_FRAME_OVERHEAD -96 /* sizeof(struct stack_frame) */
mips:
# make -s -j 32 ARCH=mips O=/kisskb/build/mpe_defconfig_mips-gcc13 CROSS_COMPILE=/opt/cross/kisskb/korg/gcc-13.1.0-nolibc/mips-linux/bin/mips-linux-
{standard input}: Assembler messages:
{standard input}:27: Error: junk at end of line, first unrecognized character is `M'
{standard input}:212: Error: junk at end of line, first unrecognized character is `M'
{standard input}:265: Error: junk at end of line, first unrecognized character is `M'
{standard input}:338: Error: junk at end of line, first unrecognized character is `M'
{standard input}:596: Error: junk at end of line, first unrecognized character is `S'
{standard input}:608: Error: junk at end of line, first unrecognized character is `L'
{standard input}:721: Error: junk at end of line, first unrecognized character is `L'
{standard input}:806: Error: junk at end of line, first unrecognized character is `L'
{standard input}:963: Error: junk at end of line, first unrecognized character is `P'
{standard input}:996: Error: junk at end of line, first unrecognized character is `K'
{standard input}:1161: Error: junk at end of line, first unrecognized character is `M'
make[3]: *** [/kisskb/src/scripts/Makefile.build:244: arch/mips/kernel/asm-offsets.o] Error 1
riscv:
# make -s -j 160 ARCH=riscv O=/kisskb/build/mpe_defconfig_riscv-gcc13 CROSS_COMPILE=/opt/cross/kisskb/korg/gcc-13.1.0-nolibc/riscv64-linux/bin/riscv64-linux-
In file included from /kisskb/src/arch/riscv/kernel/asm-offsets.c:9:
/kisskb/src/arch/riscv/kernel/asm-offsets.c: In function 'asm_offsets':
/kisskb/src/include/linux/kbuild.h:6:9: error: invalid 'asm': invalid use of '%c'
6 | asm volatile( \
| ^~~
/kisskb/src/include/linux/kbuild.h:12:9: note: in expansion of macro '_LINE'
12 | _LINE("#define " #sym " %c0 /* " #val " */", "i" (val))
| ^~~~~
/kisskb/src/include/linux/kbuild.h:15:9: note: in expansion of macro 'DEFINE'
15 | DEFINE(sym, offsetof(struct str, mem))
| ^~~~~~
/kisskb/src/arch/riscv/kernel/asm-offsets.c:25:9: note: in expansion of macro 'OFFSET'
25 | OFFSET(TASK_THREAD_RA, task_struct, thread.ra);
| ^~~~~~
/kisskb/src/include/linux/kbuild.h:6:9: error: invalid 'asm': invalid use of '%c'
6 | asm volatile( \
| ^~~
Full list here, but note there are some unrelated pre-existing failures:
http://kisskb.ellerman.id.au/kisskb/head/259bba3447faaf5e5b12ae41a26a62978d4c1965/
cheers
