[OpenAFS-devel] Pointers on getting lwp ported?

[Nathan Neulinger]

Been working on the parisc_linux24 port, and trying to get LWP
functional so that tools would work.

I found the LWP_SP definition, and the corresponding value from setjmp.h
(or at least what looked to be the corresponding value based on the
other architectures), and set that in process.c, but am still not having
much luck.

Starting program: /products/openafs/build/src/volser/vos e users

Program received signal SIGBUS, Bus error.
0x400af338 in vfprintf () from /lib/libc.so.6
(gdb) bt
#0  0x400af338 in vfprintf () from /lib/libc.so.6
#1  0x400b7490 in printf () from /lib/libc.so.6
#2  0x0004c624 in Dispatcher () at ../../../openafs/src/lwp/lwp.c:844
#3  0x0004ccb0 in savecontext (ep=0xcccccccd, savearea=0x8fad8, sp=0x0)
    at ../../../openafs/src/lwp/process.c:176
#4  0x0004c4e0 in Create_Process_Part2 () at
../../../openafs/src/lwp/lwp.c:739
#5  0x0004cc80 in savecontext (ep=0xcccccccd, savearea=0x94959697, 
    sp=0x90919293 <Address 0x90919293 out of bounds>)
    at ../../../openafs/src/lwp/process.c:189
Cannot access memory at address 0xa8a9aaa8


Looks like savecontext is being passed a bogus stack pointer?

When I build lwp with -DDEBUG I get:

inst2:/products/openafs/build/src/volser# ./vos e users
savecontext
(0) 0x90870   (1) 0x0   (2) 0x62800   (3) 0x78980   (4) 0x2   
(5) 0x81180   (6) 0xfaf00bc8   (7) 0x78980   (8) 0xfaf001f4   (9) 0x3f  
Returning to 
(0) 0x90870   (1) 0x0   (2) 0x62800   (3) 0x78980   (4) 0x2   
(5) 0x81180   (6) 0xfaf00bc8   (7) 0x78980   (8) 0xfaf001f4   (9) 0x3f  
savecontext
(0) 0x90870   (1) 0x0   (2) 0x62800   (3) 0x78980   (4) 0x2   
(5) 0x81180   (6) 0xfaf00bc8   (7) 0x78980   (8) 0xfaf001f4   (9) 0x3f  
savecontext
(0) 0x90870   (1) 0x0   (2) 0x62800   (3) 0x78980   (4) 0x2   
(5) 0x81180   (6) 0xfaf00bc8   (7) 0x78980   (8) 0xfaf001f4   (9) 0x3f  
Returning to 
(0) 0x90870   (1) 0x0   (2) 0x62800   (3) 0x78980   (4) 0x2   
(5) 0x81180   (6) 0xfaf00bc8   (7) 0x78980   (8) 0xfaf001f4   (9) 0x3f  
savecontext
(0) 0x90870   (1) 0x0   (2) 0x62800   (3) 0x78980   (4) 0x2   
(5) 0x81180   (6) 0xfaf00bc8   (7) 0x78980   (8) 0xfaf001f4   (9) 0x3f  
savecontext
(0) 0x401aa008   (1) 0x0   (2) 0x30000   (3) 0x90a80   (4) 0x90870   
(5) 0x81180   (6) 0x78980   (7) 0x0   (8) 0xfaf001f4   (9) 0x3f   
savecontext
Bus error

I noticed that lwp/process.c seems to have some code that is looking for
HAVE_UCONTEXT_H, but the check for that was not present in configure...
I'm going to look into enabling that check and see if I get anywhere
with that.

-- Nathan

------------------------------------------------------------
Nathan Neulinger                       EMail:  nneul@umr.edu
University of Missouri - Rolla         Phone: (573) 341-4841
Computing Services                       Fax: (573) 341-4216