Two AArch64-related patches

[Andrew Hughes]

----- Original Message -----
> Michal Vyskocil writes:
> 
>  > I'm a maintainer of openjdk for SUSE and recently I've got two
>  > patches
>  > from our AArch64 team for openjdk7. I have no idea if porting of
>  > openjdk7 is important for this group, but it is probably better to
>  > try
>  > it.
> 
> You may be aware that there is an AArch64 porting project.
> 
> Mailing List
>   aarch64-dev at openjdk.java.net
>   http://mail.openjdk.java.net/mailman/listinfo/aarch64-dev
> 
> The actual source code still isn't there, but hopefully will be as
> soon as we get all the legal details sorted out.
> 

Is there an intention to backport the AArch64 port to 7?

> Now for the patch itself:
> 
>  > --- icedtea-2.3.7/openjdk/hotspot/src/os/linux/vm/os_linux.cpp
>  > +++ icedtea-2.3.7/openjdk/hotspot/src/os/linux/vm/os_linux.cpp
>  > @@ -1893,7 +1893,8 @@ void * os::dll_load(const char *filename
>  >      {EM_MIPS,        EM_MIPS,    ELFCLASS32, ELFDATA2MSB,
>  >      (char*)"MIPS"},
>  >      {EM_PARISC,      EM_PARISC,  ELFCLASS32, ELFDATA2MSB,
>  >      (char*)"PARISC"},
>  >      {EM_68K,         EM_68K,     ELFCLASS32, ELFDATA2MSB,
>  >      (char*)"M68k"},
>  > -    {EM_SH,          EM_SH,      ELFCLASS32, ELFDATA2LSB,
>  > (char*)"SH"} /* Support little endian only*/
>  > +    {EM_SH,          EM_SH,      ELFCLASS32, ELFDATA2LSB,
>  > (char*)"SH"}, /* Support little endian only*/
>  > +    {EM_AARCH64,     EM_AARCH64, ELFCLASS64, ELFDATA2LSB,
>  > (char*)"AARCH64"} /* Support little endian only*/
>  >    };
>  >
>  >    #if  (defined IA32)
>  > @@ -1926,6 +1927,8 @@ void * os::dll_load(const char *filename
>  >      static  Elf32_Half running_arch_code=EM_68K;
>  >    #elif  (defined SH)
>  >      static  Elf32_Half running_arch_code=EM_SH;
>  > +  #elif  (defined AARCH64)
>  > +    static  Elf32_Half running_arch_code=EM_AARCH64;
>  >    #else
>  >      #error Method os::dll_load requires that one of following is
>  >      defined:\
>  >           IA32, AMD64, IA64, __sparc, __powerpc__, ARM, S390,
>  >           ALPHA, MIPS, MIPSEL, PARISC, M68K, SH
> 
> This part seems reasonable.

Yes, I'm sure we have similar patches like this for other archs.  I'll
add it to our trees.  Is the little endian comment still applicable
or just a copy-and-paste error?

> 
>  > --- icedtea-2.3.7/openjdk/hotspot/src/os/linux/vm/os_linux.cpp
>  > +++ icedtea-2.3.7/openjdk/hotspot/src/os/linux/vm/os_linux.cpp
>  > @@ -5374,14 +5374,6 @@ void Parker::unpark() {
>  >
>  >  extern char** environ;
>  >
>  > -#ifndef __NR_fork
>  > -#define __NR_fork IA32_ONLY(2) IA64_ONLY(not defined)
>  > AMD64_ONLY(57)
>  > -#endif
>  > -
>  > -#ifndef __NR_execve
>  > -#define __NR_execve IA32_ONLY(11) IA64_ONLY(1033) AMD64_ONLY(59)
>  > -#endif
>  > -
>  >  // Run the specified command in a separate process. Return its
>  >  exit value,
>  >  // or -1 on failure (e.g. can't fork a new process).
>  >  // Unlike system(), this function can be called from signal
>  >  handler. It
>  > @@ -5392,10 +5384,11 @@ int os::fork_and_exec(char* cmd) {
>  >    // fork() in LinuxThreads/NPTL is not async-safe. It needs to
>  >    run
>  >    // pthread_atfork handlers and reset pthread library. All we
>  >    need is a
>  >    // separate process to execve. Make a direct syscall to fork
>  >    process.
>  > -  // On IA64 there's no fork syscall, we have to use fork() and
>  > hope for
>  > -  // the best...
>  > -  pid_t pid = NOT_IA64(syscall(__NR_fork);)
>  > -              IA64_ONLY(fork();)
>  > +#ifdef SYS_fork
>  > +  pid_t pid = syscall(SYS_fork);
>  > +#else
>  > +  pid_t pid = syscall(SYS_clone, SIGCHLD, 0, 0, 0, 0);
>  > +#endif
>  >
>  >    if (pid < 0) {
>  >      // fork failed
>  > @@ -5409,10 +5402,7 @@ int os::fork_and_exec(char* cmd) {
>  >      // not reset by fork() (see notes above), execve() will
>  >      instead kill
>  >      // every thread in the parent process. We know this is the
>  >      only thread
>  >      // in the new process, so make a system call directly.
>  > -    // IA64 should use normal execve() from glibc to match the
>  > glibc fork()
>  > -    // above.
>  > -    NOT_IA64(syscall(__NR_execve, "/bin/sh", argv, environ);)
>  > -    IA64_ONLY(execve("/bin/sh", (char* const*)argv, environ);)
>  > +    syscall(SYS_execve, "/bin/sh", argv, environ);
>  >
>  >      // execve failed
>  >      _exit(-1);
> 
> Why have you deleted the IA-64 code?
> 

This makes no sense to me either.

> Andrew.
> 

-- 
Andrew :)

Free Java Software Engineer
Red Hat, Inc. (http://www.redhat.com)

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