Le 08/06/2023 à 10:39, Yann a écrit :
June 8, 2023 2:05 AM, "Damien Le Moal" Damien.LeMoal@wdc.com wrote:
Note that to test patches/regressions for risc-v NOMMU builds, you can simply use buildroot and run:
make sipeed_maix_bit_defconfig make
To check that it builds.
Hello Damien,
With buildroot master branch, I can build sipeed_maix_bit_defconfig config with the reverted patch with no build error.
How can I reproduce the issue?
At most I can see those warnings but it still builds fine:
librt/clock_nanosleep.c: In function 'clock_nanosleep': librt/clock_nanosleep.c:43:22: warning: implicit declaration of function 'LIBC_CANCEL_ASYNC'; did you mean 'LIBC_CANCEL_HANDLED'? [-Wimplicit-function-declaration] 43 | int oldstate = LIBC_CANCEL_ASYNC (); | ^~~~~~~~~~~~~~~~~ | LIBC_CANCEL_HANDLED librt/clock_nanosleep.c:48:7: warning: implicit declaration of function 'LIBC_CANCEL_RESET'; did you mean 'LIBC_CANCEL_HANDLED'? [-Wimplicit-function-declaration] 48 | LIBC_CANCEL_RESET (oldstate); | ^~~~~~~~~~~~~~~~~ | LIBC_CANCEL_HANDLED
Also, I tried to build with and without your patch and then I compared the 2 resulting librt/clock_nanosleep.os object files: they show up exactly the same.
I am guessing that now it works because of a newer compiler that does a better job at optimizing because if I build clock_nanosleep.os with -save-temps I can see the output of pre-processor being:
if (1) r = ({ long _sys_result; { register long int _a7 __asm__ ("a7"); register long _a3 __asm__ ("a3"); long _a3tmp; register long _a2 __asm__ ("a2"); long _a2tmp; register long _a1 __asm__ ("a1"); long _a1tmp; long _a0tmp; register long _a0 __asm__ ("a0"); _a0tmp = (long) (clock_id); _a0 = _a0tmp; _a1tmp = (long) (flags); _a1 = _a1tmp; _a2tmp = (long) (req); _a2 = _a2tmp; _a3tmp = (long) (rem); _a3 = _a3tmp; _a7 = (115); __asm__ volatile ( "scall\n\t" : "=r" (_a0) : "r"(_a7) , "r" (_a0), "r" (_a1), "r" (_a2), "r" (_a3) : "memory"); _sys_result = _a0; } _sys_result; }); else { int oldstate = LIBC_CANCEL_ASYNC ();
r = ({ long _sys_result; { register long int _a7 __asm__ ("a7"); register long _a3 __asm__ ("a3"); long _a3tmp; register long _a2 __asm__ ("a2"); long _a2tmp; register long _a1 __asm__ ("a1"); long _a1tmp; long _a0tmp; register long _a0 __asm__ ("a0"); _a0tmp = (long) (clock_id); _a0 = _a0tmp; _a1tmp = (long) (flags); _a1 = _a1tmp; _a2tmp = (long) (req); _a2 = _a2tmp; _a3tmp = (long) (rem); _a3 = _a3tmp; _a7 = (115); __asm__ volatile ( "scall\n\t" : "=r" (_a0) : "r"(_a7) , "r" (_a0), "r" (_a1), "r" (_a2), "r" (_a3) : "memory"); _sys_result = _a0; } _sys_result; }) ;
LIBC_CANCEL_RESET (oldstate); }
So basically if (1) { } else { call to undefined function }.
I guess the `else` part is being optimized out and it silents the issue.
Regards,