Messages in this thread | | | From | Andreas Schwab <> | Subject | Re: [PATCH] ia64: enable HAVE_COPY_THREAD_TLS, switch to kernel_clone_args | Date | Thu, 14 May 2020 12:37:03 +0200 |
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On Mai 14 2020, Christian Brauner wrote:
>> static inline pid_t raw_clone(unsigned long flags) { >> pid_t ret; >> >> assert((flags & (CLONE_VM|CLONE_PARENT_SETTID|CLONE_CHILD_SETTID| >> CLONE_CHILD_CLEARTID|CLONE_SETTLS)) == 0); >> #if defined(__s390x__) || defined(__s390__) || defined(__CRIS__) >> /* On s390/s390x and cris the order of the first and second arguments >> * of the raw clone() system call is reversed. */ >> ret = (pid_t) syscall(__NR_clone, NULL, flags); >> #elif defined(__sparc__) >> { >> /** >> * sparc always returns the other process id in %o0, and >> * a boolean flag whether this is the child or the parent in >> * %o1. Inline assembly is needed to get the flag returned >> * in %o1. >> */ >> int in_child, child_pid, error; >> >> asm volatile("mov %3, %%g1\n\t" >> "mov %4, %%o0\n\t" >> "mov 0 , %%o1\n\t" >> #if defined(__arch64__) >> "t 0x6d\n\t" >> #else >> "t 0x10\n\t" >> #endif >> "addx %%g0, 0, %2\n\t" >> "mov %%o1, %0\n\t" >> "mov %%o0, %1" : >> "=r"(in_child), "=r"(child_pid), "=r"(error) : >> "i"(__NR_clone), "r"(flags) : >> "%o1", "%o0", "%g1", "cc" ); >> >> if (error) { >> errno = child_pid; >> ret = -1; >> } else >> ret = in_child ? 0 : child_pid; >> } >> +#elif defined(__ia64__) >> + /* On ia64 the stack and stack size are passed as separate arguments. */ >> + return (pid_t)syscall(__NR_clone, flags, NULL, 0); >> +#else >> + return (pid_t)syscall(__NR_clone, flags, NULL); >> +#endif > > Scratch that. It's even worse. On ia64 it is _invalid_ to pass a NULL > stack.
Only if you want CLONE_VM. But this raw_clone does not allow CLONE_VM, thus it is actually a true fork.
Andreas.
-- Andreas Schwab, schwab@linux-m68k.org GPG Key fingerprint = 7578 EB47 D4E5 4D69 2510 2552 DF73 E780 A9DA AEC1 "And now for something completely different."
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