relocating them. The text is allocated as RWX, and then mprotected to RW.
There is a bug that prevents us from doing RW->RX on amd64 and perhaps
sparc64. On x86, the pmap waits for the page to fault before granting it
the X permission. But in the trap handler, such a page is considered as
belonging to kernel_map, while it actually belongs to module_map. The
kernel then finds out the page is not present in kernel_map, and panics.
In all cases, module_map is non pageable, so even if the trap were handled
properly, it still wouldn't work.
Therefore, there is a small window in which the segment is RWX. But that's
fine enough, for now.
up the module segments into one big RWX chunk. Split this chunk into two
different text and data+bss+rodata chunks. The latter is made non-
executable. This also provides some kind of ASLR, since the chunks are
not necessarily contiguous.
- fix the (symstrindex > hdr->e_shnum) check: it should be >=, otherwise there's an
off-by-one
- fix the (symstrindex < 0) check: the value is unsigned, so it can't be <0. However,
we should ensure that symstrindex!=0 (done with SHN_UNDEF)
- set 'error' as appropriate
- ensure that e_shstrndx < hdr->e_shnum, to prevent out-of-bound reads
Fixes several crashes that could occur when loading a kernel module.
Quick glance from martin@
sys/stdarg.h and expect compiler to provide proper builtins, defaulting
to the GCC interface. lint still has a special fallback.
Reduce abuse of _BSD_VA_LIST_ by defining __va_list by default and
derive va_list as required by standards.
When I originally wrote this, I was going for maximum flexibility.
However, after a private discussion with dholland@, I see how this
will cause problems with the future world order of namei whenever
that might be. At the moment, I don't need the extra flexibility,
but if something comes up this may have to be revisited.
these commits move all path handling into module_do_load() from
kobj_load_file(). This way the final path used to load a module
is available for loading <module>.plist, which will store parameters
for a module. The end goal of this project is good support for
MODULAR device drivers.
- Make ksyms MT safe.
- Fix deadlock from an operation like "modload foo.lkm < /dev/ksyms".
- Fix uninitialized structure members.
- Reduce memory footprint for loaded modules.
- Export ksyms structures for kernel grovellers like savecore.
- Some KNF.
