Messages in this thread | | | Date | Thu, 14 May 2020 12:15:40 +0200 | From | Christian Brauner <> | Subject | Re: [PATCH] ia64: enable HAVE_COPY_THREAD_TLS, switch to kernel_clone_args |
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On Thu, May 14, 2020 at 12:08:27PM +0200, John Paul Adrian Glaubitz wrote: > On 5/14/20 12:04 PM, Christian Brauner wrote: > > So that's interesting because systemd doesn't support itanium correctly afaict. > > They have a raw_clone() function that they use which is not tailored to > > ia64. __NR_clone should be defined as so to hit clone2() but they don't > > pass a stack size argument down which is invalid on ia64: > Ah, I wasn't aware of this limitation. I'm surprised the systemd testsuite passes > then on ia64. > > On sparc64, Michael Karcher provided the hand-written assembly you quoted to > fix the raw_clone() on this architecture. > > I assume we could do the same on ia64?
I think the following should be correct:
(Probably worth checking that __NR_clone and __NR_clone2 are the same for ia64. Also note, that __NR_clone was _never_ supported by glibc on ia64. They even have this comment:
/* clone is not supported under Linux/ia64, use clone2. */ )
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
if (ret == 0) reset_cached_pid();
return ret; }
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