* Andrew John Hughes:
> On 24/06/2019 14:54, Florian Weimer wrote:
>> * Severin Gehwolf:
>>
>>> Could I please get reviews for this 8u only change? The JDK 8u build
>>> logic for launcher files includes linker version script files (a.k.a
>>> mapfiles). The script file for x86 (32bit) marks symbol _IO_stdin_used
>>> as local. When the symbol is not visible to the dynamic loader, glibc
>>> will use a legacy stdio implementation instead. This is a historic, x86
>>> (32bit) only glibc issue, I've been told.
>>
>> It may impact other historic GNU/Linux targets, but I don't think they
>> have OpenJDK ports. POWER and Z are 64-bit only, I assume.
>>
>> Thanks,
>> Florian
>>
>
> OpenJDK is built on s390 (31-bit) and ppc (32-bit) for RHEL 7.
Oh. I did not know this.
I looked at a recent internal s390 build, and found this:
Symbol table [ 6] '.dynsym' contains 8 entries:
1 local symbol String table: [ 7] '.dynstr'
Num: Value Size Type Bind Vis Ndx Name
0: 00000000 0 NOTYPE LOCAL DEFAULT UNDEF
1: 00000000 0 NOTYPE WEAK DEFAULT UNDEF
_ITM_deregisterTMCloneTable
2: 00000000 0 NOTYPE WEAK DEFAULT UNDEF __gmon_start__
3: 00000000 0 NOTYPE WEAK DEFAULT UNDEF _Jv_RegisterClasses
4: 00000000 0 NOTYPE WEAK DEFAULT UNDEF _ITM_registerTMCloneTable
5: 00400474 0 FUNC GLOBAL DEFAULT UNDEF
__libc_start_main@GLIBC_2.0 (2)
6: 00400494 0 FUNC GLOBAL DEFAULT UNDEF
JLI_Launch@SUNWprivate_1.1 (3)
7: 004007b8 4 OBJECT GLOBAL DEFAULT 16 _IO_stdin_used
Same for a ppc build:
Symbol table [ 6] '.dynsym' contains 8 entries:
1 local symbol String table: [ 7] '.dynstr'
Num: Value Size Type Bind Vis Ndx Name
0: 00000000 0 NOTYPE LOCAL DEFAULT UNDEF
1: 00000000 0 NOTYPE WEAK DEFAULT UNDEF
_ITM_deregisterTMCloneTable
2: 00000000 0 NOTYPE WEAK DEFAULT UNDEF __gmon_start__
3: 00000000 0 FUNC GLOBAL DEFAULT UNDEF
__libc_start_main@GLIBC_2.0 (2)
4: 00000000 0 FUNC GLOBAL DEFAULT UNDEF
JLI_Launch@SUNWprivate_1.1 (3)
5: 00000000 0 NOTYPE WEAK DEFAULT UNDEF _Jv_RegisterClasses
6: 00000000 0 NOTYPE WEAK DEFAULT UNDEF _ITM_registerTMCloneTable
7: 100007ac 4 OBJECT GLOBAL DEFAULT 15 _IO_stdin_used
Any binary which references __libc_start_main@GLIBC_2.0 and which does
not export _IO_stdin_used in .dynsym (.symtab does not count) has this
issue, irrespective of the architecture. The key point is support for
the glibc 2.0 ABI level (as indicated by the GLIBC_2.0 symbol version).
Architectures which joined in glibc 2.1 or later do not have this
fallback code (although the _IO_stdin_used marker symbol is sometimes
still there, quite unnecessarily).
So these two builds one does not have the issue. The build is from May,
so it can't have Severin's fix yet
(java-1.8.0-openjdk-1.8.0.222.b04-1.el7, in case you wonder), and the
i686 build does show the issue.
Thanks,
Florian
