Many core dumps in pthread_getspecific.

[Konstantin Belousov]

On Wed, Jul 22, 2015 at 11:46:35AM +0200, Andre Meiser wrote:
> On Sun, Jul 19, 2015 at 22:57 +0200, Konstantin Belousov wrote:
> > It seems that besides sigreturn(), ucontext symbols must be pre-resolved
> > as well.  Try this update (it includes the previous change).
> 
> thanks for looking into this, but this patch wasn't funny at all.  Did you tested your patch?  Almost every programme crashed with a core dump.  Here the example for simply starting vim:
> 
> % readelf -d vim | grep NEEDED
>  0x0000000000000001 (NEEDED)             Shared library: [libm.so.5]
>  0x0000000000000001 (NEEDED)             Shared library: [libncurses.so.8]
>  0x0000000000000001 (NEEDED)             Shared library: [libintl.so.8]
>  0x0000000000000001 (NEEDED)             Shared library: [libpython2.7.so.1]
>  0x0000000000000001 (NEEDED)             Shared library: [libthr.so.3]
>  0x0000000000000001 (NEEDED)             Shared library: [libc.so.7]
> 
> 
> (gdb) bt
> #0  0x00000008014a30d4 in _thr_rtld_init () at /usr/src/lib/libthr/thread/thr_rtld.c:239
> #1  0x00000008014a2f03 in _libpthread_init (curthread=<value optimized out>) at /usr/src/lib/libthr/thread/thr_init.c:372
> #2  0x00000008014a5c22 in _thread_printf () from /lib/libthr.so.3
> #3  0x0000000801498d06 in _init () from /lib/libthr.so.3
> #4  0x00007fffffffe000 in ?? ()
> #5  0x000000080083d6bf in r_debug_state () from /libexec/ld-elf.so.1
> #6  0x000000080083cd17 in __tls_get_addr () from /libexec/ld-elf.so.1
> #7  0x000000080083b129 in .text () from /libexec/ld-elf.so.1
> #8  0x0000000000000000 in ?? ()
> 
> 
> (gdb) info locals
> li = {rtli_version = 0, lock_create = 0x8014a30f0 <_thr_rtld_lock_create>, lock_destroy = 0x8014a3160 <_thr_rtld_lock_destroy>,
>   rlock_acquire = 0x8014a31b0 <_thr_rtld_rlock_acquire>, wlock_acquire = 0x8014a3270 <_thr_rtld_wlock_acquire>,
>   lock_release = 0x8014a3300 <_thr_rtld_lock_release>, thread_set_flag = 0x8014a33c0 <_thr_rtld_set_flag>,
>   thread_clr_flag = 0x8014a33d0 <_thr_rtld_clr_flag>, at_fork = 0}
> dummy = -1
> curthread = (struct pthread *) 0x7fffff0f2650
> uc_len = <value optimized out
> 
> 
> (gdb) info registers
> rax            0xf0b470 15774832
> rbx            0x7fffff0f2650   140737472570960
> rcx            0x0  0
> rdx            0xca0000 13238272
> rsi            0x8024064e8  34397512936
> rdi            0x7fffff0f2650   140737472570960
> rbp            0x7fffffffdb20   0x7fffffffdb20
> rsp            0x7fffff0f2650   0x7fffff0f2650
> r8             0x0  0
> r9             0xfffff8000e35f4c0   -8795854605120
> r10            0x0  0
> r11            0x246    582
> r12            0x800a54a28  34370570792
> r13            0x800a545b0  34370569648
> r14            0x1  1
> r15            0x800855420  34368476192
> rip            0x8014a30d4  0x8014a30d4 <_thr_rtld_init+244>
> eflags         0x10206  66054
> cs             0x43 67
> ss             0x3b 59
> ds             0x0  0
> es             0x0  0
> fs             0x0  0
> gs             0x0  0
%rbp-%rsp == 0xf0b4d0 == 15774928

Can you do the following:
1. Compile and run the program at the end of the message and send me
the output.
2. Also send me the first 40 lines of the dmesg for bootverbose boot.
3. (Optional) Install x86info program, compiled from the sources on
github, https://github.com/dankamongmen/x86info, then run, as root
	kldload cpuctl
	x86info -a

#include <stdio.h>
extern int __getcontextx_size(void);
int main(void)
{
	printf("%#x\n", __getcontextx_size());
}