Messages in this thread | | | Date | Tue, 25 Jul 2023 21:45:20 +0700 | From | Ammar Faizi <> | Subject | Re: [PATCH v1 1/8] tools/nolibc: add support for powerpc |
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Hi Zhangjin,
On Tue, Jul 25, 2023 at 07:02:55PM +0800, Zhangjin Wu wrote: > Btw, have checked "=r" instead of "=a" works on i386 too for we already > bind the _ret variable with "RET" register, but still need to check if > "=a" is necessary?
I need to tell you that syscall6() for i386 can't use "r" and "=r" because there was a historical bug that made GCC stuck in a loop forever when compiling the nolibc code. It's already fixed in the latest version of GCC, but we should still support older compilers.
Ref: https://gcc.gnu.org/bugzilla/show_bug.cgi?id=105032
I discovered that bug in 2022 in the latest version of GCC at that time, so it's pretty new, and those buggy versions are very likely still in the wild today.
-- Ammar Faizi
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