As a followup to r328101, ignore relocation tables for ELF object
sections that are not memory resident. For modules loaded by the
loader, ignore relocation tables whose associated section was not
loaded by the loader (sh_addr is zero). For modules loaded at runtime
via kldload(2), ignore relocation tables whose associated section is
not marked with SHF_ALLOC.
Reported by: Mori Hiroki <yamori813@yahoo.co.jp>, adrian
Tested on: mips, mips64
MFC after: 1 month
Sponsored by: DARPA / AFRL
PowerPC Apple hardware, and likely all Open Firmware systems.
The loader would allocate memory for its heap at whatever address Open
Firmware gave it, which would in general be the lowest unallocated address,
usually starting a page or two above 0. As the kernel is linked at 1 MB,
and loader insists on running the kernel at its link address, any heap
larger than 1 MB would overlap the kernel, causing loader memory allocations
to corrupt the kernel and vice versa.
Although r328806 made this problem much worse by increasing the heap size
to 8 MB, causing 88% of the loader heap to overlap with the kernel, the
problem has always existed. The old heap size was 1 MB and, unless that
started exactly at zero, which would cause other problems, some number of
pages of the loader heap still overlapped with the kernel.
This patch solves the issue in two ways and cleans up some related code:
- Moves the loader heap inside of the loader. This guarantees that the
heap will be contiguous with the loader and simplifies the heap
allocation code at no cost, since the heap lives in BSS.
- Moves the loader, previously at 28 MB and dangerously close to the kernel
it loads, a bit higher to 44 MB. This has the effect of breaking loader
on non-embedded PPC machines with < 48 MB of RAM, but we did not support
those anyway.
The fundamental problem is that the way loader loads ELF files is
incredibly fragile, but that can't be fixed without fundamental
architectural changes.
MFC after: 10 days
The cross-endian loader change in r328536 (review D12422) broke symbol
loading on (at least) amd64 kernels. Temporarily paper over the issue
by restricting the cross-endian support to only powerpc, until a proper
fix arrives.
Submitted by: royger
preference to LIBFICL{,32}. LIBFICL{,32} are now always defined, but
LDR_INTERP{,32} is defined empty when building w/o forth (aka the
simple interpreter) and defined to LIBFICL{,32} when we are building
forth.
I had thought that this would be useful. However it was committed too
late, and wound up being unused. It's in the way of future work now,
so retire it rather than bring it forward.
loader scripts. However, that path won't be taken after all it
seems. Remove this code before it decays into uselessness. Also remove
build dependencies on forth no longer needed.
This has never been installed. It was added to the tree disconnected
to the build in FreeBSD 5 (17 years ago) and has never been used as
far as I can tell. The desired improvements never really happened
(despite a couple minor cleanups along the way). It's relevance is
long past, so better to retire it.
MK_CTF, MK_SSP, MK_PROFILE, NO_PIC, and INTERNALLIB are always the
same, so set them in defs.mk. MAN= is common, so set it here too.
This removes a lot of boring repetition from the Makefiles that added
almost no value.
Whether we should be overwriting the loaded FDT module with the 'fixed up'
version or not was questionable when this was added, and now that overlays
are possible this is downright wrong.
Overlays can increase the size of the blob, so writing it back to the
original VA will generally write past the end of the block and start
clobbering other things in memory.
Rip it out- it was questionable to begin with, it's doing bad things now,
and it serves no purpose since the modified blob will be copied into place
rather than relying on this to reflect the changes.
Reviewed by: gonzo
MFC after: 1 week
Differential Revision: https://reviews.freebsd.org/D14130
akin to what Pedro Souza and Wojciech Koszek did in the lua GSoC with
interp.h, interp_simple.c and changes to interp.c and interp_forth.c,
but completely redone from scratch.
This effectively restores the spirit of r326712 (my first attempt to
bring in Pedro's and Wojciech's work) updated for new requirements
that had silently broke their original work. This change also differs
by using fixed function names instead of function pointers to simply
things. Only one interpreter at a time may be compiled in.
Also of note: we take a mutable string, pass it in via a const char *
pointer into intrp_forth's interp_run(). We then cast away the const
to pass into ficlExec since ficl would require extensive changes to
properly const-poison. See Sections 6.5.2.5 and 6.7.3 of C11 standard
noting it's only UB if you modify a const object through a non-const
pointer, but not char [] -> const char * -> char * as here.
Move prototypes to proper section now that we don't have modified
versions of strtol and strtoul in libsa. Add prototypes for new
strtoll and strtoull. Use prototypes copied from stdlib.h instead of
the old hand-rolled ones.
(I forgot to move this file form my lua branch in r328613)
since they suffice. Create xlocale_private.h which provides the most
minimal locale implementation we can get away with. Add strtoll and
strtoull from libc.
On POWER8 with current petitpoot, the loader.kboot might be
run as little-endian application. The FreeBSD kernel is
always big-endian, so the load_elf_* routines must be aware
of proper endianness of all fields.
Submitted by: Wojciech Macek <wma@semihalf.com>
Obtained from: Semihalf
Sponsored by: IBM, QCM Technologies
Differential revision: https://reviews.freebsd.org/D12422
Example overlays seen in other places use a compatible property on root node
of an overlay to specify SOC compatibility. These don't get merged into base
FDT as they're not part of a fragment, but it's expected that consumers of
the overlay may want to check it.
If /compatible on the overlay is missing, just apply it. This is the "I know
what I'm doing" mode for those wanting to whip up a quick overlay and apply
it. An overlay intended for distribution should include /compatible so as
not to break a user's system.
If /compatible on the overlay exists, honor it and cross-check it with
/compatible on the base FDT. If /compatible on the base FDT is missing in
this case, don't apply the overlay rather than risk breaking the system.
Move the COPYOUT of overlay material to before we allocate space for
next_fdtp so that we can avoid the allocation and copy into next_fdtp if we
already know that the overlay can't apply.
This gives way to the possibility of autoloading overlays found in
/boot/overlays, since this provides a means of filtering out overlays not
applicable to the current board.
Reviewed by: gonzo
MFC after: 1 week
Differential Revision: https://reviews.freebsd.org/D13969
This should have been done as part of r327350, but due to lack of foresight
it came later. In the different places we apply overlays, we duplicate the
bits that check for fdt_overlays in the environment and supplement that with
any other places we need to check for overlays to load. These "other places"
will be loader specific and are not candidates for consolidation.
Provide an fdt_load_dtb_overlays to capture the common logic, allow passing
in an additional list of overlays to be loaded. This additional list of
overlays is used in practice for ubldr to pull in any fdt_overlays passed to
it from U-Boot environment, but it can be used for any other source of
overlays.
These additional overlays supplement loader.conf(5) fdt_overlays, rather
than replace, so that we're not restricted to specifying overlays in only
one place. This is a change from previous behavior where loader.conf(5)
supplied fdt_overlays would cause us to ignore U-Boot environment, and this
seems nonsensical- user should have sufficient control over both of these
aspects, or lack of control for good reasons.
A knob could be considered in the future to ignore U-Boot supplied overlays,
but the supplemental treatment seems like a good start.
Reviewed by: imp (earlier version), gonzo (earlier version)
Differential Revision: https://reviews.freebsd.org/D13993
Specifically reading is done if ffs_sbget() and writing is done
in ffs_sbput(). These functions are exported to libufs via the
sbget() and sbput() functions which then used in the various
filesystem utilities. This work is in preparation for adding
subperblock check hashes.
No functional change intended.
Reviewed by: kib
These were found during bring-up on a new arm64 platform and in an
amd64 VM.
Submitted by: Arshan Khanifar <arshankhanifar_gmail.com>
Reviewed by: imp
Sponsored by: The FreeBSD Foundation
Differential Revision: https://reviews.freebsd.org/D14036
This behavior also matches a Linux-ism by allowing fdt_overlays to specify
names of overlays without an extension, e.g. fdt-overlays="sunxi-h3-h5-emac"
If we fail to load the file given by a name in fdt_overlays, try again with
".dtbo" appended to it. This still allows overlays to lack .dtbo extension
if user prefers it and just adds a fallback cushion.
Future work could move this from a hard-coded ".dtbo" to a loader.conf(5)
configuration option.
Reviewed by: gonzo
MFC after: 1 week
Differential Revision: https://reviews.freebsd.org/D13968
Right now, we'll leak memory when we display a help topic because we
don't free t, s, d that we've just used when breaking out of the loop.
NB: coverity just reported t, but s and d also leak.
CID: 1007776
Always free dev and fstyp before strduping new values to assign to
them. Free them at the end of the loop. This keeps them from leaking
for mal-formed /etc/fstab lines.
CID: 1007777, 1007778, 1007779
Sponsored by: Netflix
When building loader bits, lld fails with the following error:
"ld: error: section: .dynamic is not contiguous with other relro sections"
on both ubldr and EFI loader.
Move .dynamic up to make ld.lld happy, adjust .got as necessary for ubldr.
Tested on: OrangePi One (ld.lld, ubldr)
Tested on: Banana Pi-M3 (ld.lld, ubldr)
Tested on: qemu-armv7 (ld.lld, EFI)
Tested on: qemu-armv7 (ld.bfd, EFI)
Tested on: Raspberry Pi 2 (ld.bfd, ubldr) [manu]
Tested on: Banana Pi-M2 (ld.bfd, ubldr) [manu]
Reviewed by: andrew, emaste, imp
Differential Revision: https://reviews.freebsd.org/D13942
This matches directory structure used commonly in Linux-land, and it's
cleaner than mixing overlays into the existing module paths. Overlays are
still mixed in by specifying fdt_overlays in loader.conf(5).
Reviewed by: manu
Differential Revision: https://reviews.freebsd.org/D13922
libfdt highlights since 1.4.3:
- fdt_property_placeholder added to create a property without specifying its
value at creation time
- stringlist helper functions added to libfdt
- Improved overlay support
- Various internal cleanup
Also switch stand/fdt over to using libfdt for overlay support with this
update. Our current overlay implementation works only for limited use cases
with overlays generated only by some specific versions of our dtc(1). Swap
it out for the libfdt implementation, which supports any properly generated
overlay being applied to a properly generated base.
This will be followed up fairly soon with an update to dtc(1) in tree to
properly generate overlays.
MFC note: the <stdlib.h> include this update introduces in libfdt_env.h is
apparently not necessary in the context we use this in. It's not immediately
clear to me the motivation for it being introduced, but it came in with
overlay support. I've left it in for the sake of accuracy and because it's
not harmful here on HEAD, but MFC'ing this to stable/11 will require
wrapping the #include in an `#ifndef _STANDALONE` block or else it will
cause build failures.
Tested on: Banana Pi-M3 (ARMv7)
Tested on: Pine64 (aarch64)
Tested on: PowerPC [nwhitehorn]
Reviewed by: manu, nwhitehorn
MFC after: 1 week
Differential Revision: https://reviews.freebsd.org/D13893
ELF object files can contain program sections which are not supposed
to be loaded into memory (e.g. .comment). Normally the static linker
uses these flags to decide which sections are allocated to loadable
program segments in ELF binaries and shared objects (including kernels
on all architectures and kernel modules on architectures other than
amd64).
Mapping ELF object files (such as amd64 kernel modules) into memory
directly is a bit of a grey area. ELF object files are intended to be
used as inputs to the static linker. As a result, there is not a
standardized definition for what the memory layout of an ELF object
should be (none of the section headers have valid virtual memory
addresses for example).
The kernel and loader were not checking the SHF_ALLOC flag but loading
any program sections with certain types such as SHT_PROGBITS. As a
result, the kernel and loader would load into RAM some sections that
weren't marked with SHF_ALLOC such as .comment that are not loaded
into RAM for kernel modules on other architectures (which are
implemented as ELF shared objects). Aside from possibly requiring
slightly more RAM to hold a kernel module this does not affect runtime
correctness as the kernel relocates symbols based on the layout it
uses.
Debuggers such as gdb and lldb do not extract symbol tables from a
running process or kernel. Instead, they replicate the memory layout
of ELF executables and shared objects and use that to construct their
own symbol tables. For executables and shared objects this works
fine. For ELF objects the current logic in kgdb (and probably lldb
based on a simple reading) assumes that only sections with SHF_ALLOC
are memory resident when constructing a memory layout. If the
debugger constructs a different memory layout than the kernel, then it
will compute different addresses for symbols causing symbols in the
debugger to appear to have the wrong values (though the kernel itself
is working fine). The current port of mdb does not check SHF_ALLOC as
it replicates the kernel's logic in its existing kernel support.
The bfd linker sorts the sections in ELF object files such that all of
the allocated sections (sections with SHF_ALLOCATED) are placed first
followed by unallocated sections. As a result, when kgdb composed a
memory layout using only the allocated sections, this layout happened
to match the layout used by the kernel and loader. The lld linker
does not sort the sections in ELF object files and mixed allocated and
unallocated sections. This resulted in kgdb composing a different
memory layout than the kernel and loader.
We could either patch kgdb (and possibly in the future lldb) to use
custom handling when generating memory layouts for kernel modules that
are ELF objects, or we could change the kernel and loader to check
SHF_ALLOCATED. I chose the latter as I feel we shouldn't be loading
things into RAM that the module won't use. This should mostly be a
NOP when linking with bfd but will allow the existing kgdb to work
with amd64 kernel modules linked with lld.
Note that we only require SHF_ALLOC for "program" sections for types
like SHT_PROGBITS and SHT_NOBITS. Other section types such as symbol
tables, string tables, and relocations must also be loaded and are not
marked with SHF_ALLOC.
Reported by: np
Reviewed by: kib, emaste
MFC after: 1 month
Sponsored by: Chelsio Communications
Differential Revision: https://reviews.freebsd.org/D13926
is NULL. That's more correct and doesn't depend on the error behavior
of utf8_to_ucs2. In practice, we'll never see this though since we
pass utf8_to_ucs2 a well formed string.
Sponsored by: Netflix
Differential Revision: https://reviews.freebsd.org/D13918
and utf8_to_ucs2, be sure to NULL out the return pointer too, rather
than return a pointer to free memory.
Sponsored by: Netflix
Differential Revision: https://reviews.freebsd.org/D13917
utf8_to_ucs2 in boot1.efi. We need to initialise the ucs2 output string
so it will allocate space, and use the return value to determine if the
call was successful.
Reviewed by: imp
Sponsored by: DARPA, AFRL
Differential Revision: https://reviews.freebsd.org/D13915
If fdt_overlay_apply fails at some stage to apply the overlay to the base,
both the base and overlay may be in an inconsistent state (some fixups
applied, some phandles adjusted, some symbols merged). These can be bad for
a number of reasons, to include user frustration if some fixups applied and
not others. Fail a little safer by making a clean copy of the base FDT for
every overlay that we can simply discard if things go awry.
This also allows us the luxury of simply discarding overlays if we hit some
kind of memory limit or if they're malformed and extremely large for some
reason. We'll now leave a nice error message indicating that some overlays
could not be applied due to size restrictions and we apply what we can.
I note that our overlay implementation has some flaws that might still leave
your system in an unbootable state even if an overlay applies correctly;
please exercise caution in using overlays until we can swap it out for
libfdt's implementation.
Tested on: BananaPi-M3 (armv7)
Tested on: Pine64 (aarch64)
Differential Revision: https://reviews.freebsd.org/D13709
