703842 - Binary ends up with a R_SPARC_WDISP22 relocation that ld.so doesn't support

Status: RESOLVED FIXED

(Core :: JavaScript Engine, defect)

Description

[Mike Hommey [:glandium]]

The ld.so message looks like the following:
error while loading shared libraries: libmozjs.so: unexpected reloc type 0x08

Reloc type 0x08 is R_SPARC_WDISP22

This relocation comes from the ba instruction in the following assembly from methodjit/TrampolineSparc.s:

.global JaegerInterpolineScripted
.type   JaegerInterpolineScripted, #function
JaegerInterpolineScripted:
    ld      [%l0 + 0x10], %l0                        /* Load f->prev_ */
    st      %l0, [%fp - 36]                          /* Update f->regs->fp_ */
    ba     JaegerInterpoline
    nop

Replacing ba with call works, but then it goes through the PLT, which is silly.
Another solution that works is to replace JaegerInterpoline with a new label at the same location, but which is not defined as a function.

Comment 1

[Mike Hommey [:glandium]]

Attachment: Avoid R_SPARC_WDISP22 relocation in TrampolineSparc.s

Comment 2

[Mike Hommey [:glandium]]

http://hg.mozilla.org/integration/mozilla-inbound/rev/69791b4d7519

Comment 3

[Ed Morley [:emorley]]

https://hg.mozilla.org/mozilla-central/rev/69791b4d7519