644569 - SIGBUS on various things using @font-face on sparc

Status: RESOLVED DUPLICATE of bug 643137

(Core :: Graphics, defect)

Description

[Mike Hommey [:glandium]]

Program received signal SIGBUS, Bus error.
ots::OTSStream::Write (this=0xff8c7068, data=0x753ed400, length=254) at ../../../dist/include/ots/opentype-sanitiser.h:68
warning: Source file is more recent than executable.
68                reinterpret_cast<const uint8_t*>(data) + offset));

This is due to a misaligned 32-bits access. I would have expected it to create problems on arm as well, but apparently, it doesn't appear to be a problem on Android.

I noticed this on 3.5, but the ots code hasn't changed in the meanwhile so I don't expect anything to have changed since then. 4.0 doesn't even start yet on sparc, so I can't check, and I don't have 3.6 builds for sparc.

Comment 1

[Mike Hommey [:glandium]]

Attachment: Avoid misaligned 32-bit read in opentype-sanitiser

It looks like this is the only place where this matters. (At least now, all crashtests passes)

Comment 2

[Mike Hommey [:glandium]]

Please note that this doesn't change the generated assembly on x86 and x86-64 with gcc.

Comment 3

[Jonathan Kew [:jfkthame]]

Looks like this was also reported in bug 631636. I notice that the suggested patch there addresses two places in the code, not just one. But the first instance (at line 66) looks to me like it shouldn't be necessary, unless the compiler does something _really_ bizarre with struct member alignment.

Comment 5

[Jonathan Kew [:jfkthame]]

Hmm, this was also filed as bug 643137, apparently.

Comment 6

[Mike Hommey [:glandium]]

Comment on attachment 521500 [details] [diff] [review]
Avoid misaligned 32-bit read in opentype-sanitiser

Clearing review flag