linker: Fix the ifunc symbol value calculation for ET_REL files

Reported by: cy
Fixes: aefae931820f ("linker: Improve handling of ifuncs when fetching symbol metadata")

linker: Improve handling of ifuncs when fetching symbol metadata

When looking up symbol values, we map ifunc symbols to the value
returned by the resolver. However, the returned symbol size is stil

linker: Improve handling of ifuncs when fetching symbol metadata

When looking up symbol values, we map ifunc symbols to the value
returned by the resolver. However, the returned symbol size is still
that of the resolver. Be consistent and provide the size of the
implementation symbol as well.

This fixes an inconsistency in dtrace's FBT provider, which enumerates
all function symbols and disassembles their values, using the symbol
size as the bound for the disassembly loop. In particular, for ifuncs,
we were not creating return probes.

Reviewed by: kib
MFC after: 2 weeks
Sponsored by: Innovate UK
Differential Revision: https://reviews.freebsd.org/D50683

show more ...

sys: use globals for the ELF kernel and module type strings

Initialize the globals with macros so we can use the same values in the
loader.

Also remove unnecessary "elfN module" checks.

Reviewed b

sys: use globals for the ELF kernel and module type strings

Initialize the globals with macros so we can use the same values in the
loader.

Also remove unnecessary "elfN module" checks.

Reviewed by: imp, kib
Pull Request: https://github.com/freebsd/freebsd-src/pull/1394

show more ...

kern linker: Don't invoke dtors without having invoked ctors

I have a kernel module which fails to load because of an unrecognized
relocation type. link_elf_load_file() fails before the module's ct

kern linker: Don't invoke dtors without having invoked ctors

I have a kernel module which fails to load because of an unrecognized
relocation type. link_elf_load_file() fails before the module's ctors
are invoked and it calls linker_file_unload(), which causes the module's
dtors to be executed, resulting in a kernel panic.

Add a flag to the linker file to ensure that dtors are not invoked if
unloading due to an error prior to ctors being invoked.

At the moment I only implemented this for link_elf_obj.c since
link_elf.c doesn't invoke dtors, but I refactored link_elf.c to make
them more similar.

Fixes: 9e575fadf491 ("link_elf_obj: Invoke fini callbacks")
Reviewed by: zlei, kib
MFC after: 2 weeks
Differential Revision: https://reviews.freebsd.org/D44559

show more ...

ddb: Add CTF-based pretty printing

Add basic CTF support and a CTF-powered pretty-printer to ddb.

The db_ctf.* files expose a basic interface for fetching type
data for ELF symbols, interacting wit

ddb: Add CTF-based pretty printing

Add basic CTF support and a CTF-powered pretty-printer to ddb.

The db_ctf.* files expose a basic interface for fetching type
data for ELF symbols, interacting with the CTF string table,
and translating type identifiers to type data.

The db_pprint.c file uses those interfaces to implement
a pretty-printer for all kernel ELF symbols.
The pretty-printer works with symbol names and arbitrary addresses:
pprint struct thread 0xffffffff8194ad90

Pretty-printing currently only works after the root filesystem
gets mounted because the CTF info is not available during
early boot.

Differential Revision: https://reviews.freebsd.org/D37899
Approved by: markj (mentor)

show more ...

sys/kern: Remove a few sys/cdefs.h around some elf things

These sys/cdefs.h are no longer needed. Remove them in advance of
other work in this area.

Sponsored by: Netflix

sysctl: Update 'master' copy of vnet SYSCTLs on kernel environment variables change

Complete phase three of 3da1cf1e88f8.

With commit 110113bc086f, vnet sysctl variables can be loader tunable
but t

sysctl: Update 'master' copy of vnet SYSCTLs on kernel environment variables change

Complete phase three of 3da1cf1e88f8.

With commit 110113bc086f, vnet sysctl variables can be loader tunable
but the feature is limited. When the kernel modules have been initialized,
any changes (e.g. via kenv) to kernel environment variable will not affect
subsequently created VNETs.

This change relexes the limitation by listening on kernel environment
variable's set / unset events, and then update the 'master' copy of vnet
SYSCTL or restore it to its initial value.

With this change, TUNABLE_XXX_FETCH can be greately eliminated for vnet
loader tunables.

Reviewed by: glebius
Fixes: 110113bc086f sysctl(9): Enable vnet sysctl variables to be loader tunable
MFC after: 2 weeks
Differential Revision: https://reviews.freebsd.org/D41825

show more ...

kernel linker: Eliminate unneeded vnet propagation

The module preload happens before vnet0 creation, at this moment the vnet
list is empty thus invoking vnet_data_copy() during preload is a noop.

W

kernel linker: Eliminate unneeded vnet propagation

The module preload happens before vnet0 creation, at this moment the vnet
list is empty thus invoking vnet_data_copy() during preload is a noop.

With recent change 110113bc086f, for dynamic module load, aka via kldload,
linker will do vnet propagation right after registering sysctls which
happens after module load, then previous propagation (during module load)
is redundant.

No functional change intended.

MFC after: 2 weeks
Differential Revision: https://reviews.freebsd.org/D39852

show more ...

sysctl(9): Enable vnet sysctl variables to be loader tunable

Complete phase two of 3da1cf1e88f8.

In 3da1cf1e88f8, the meaning of the flag CTLFLAG_TUN is extended to
automatically check if there is

sysctl(9): Enable vnet sysctl variables to be loader tunable

Complete phase two of 3da1cf1e88f8.

In 3da1cf1e88f8, the meaning of the flag CTLFLAG_TUN is extended to
automatically check if there is a kernel environment variable which
shall initialize the SYSCTL during early boot. It works for all SYSCTL
types both statically and dynamically created ones, except for the
SYSCTLs which belong to VNETs.

This change extends the meaning further, to allow it also works for
the SYSCTLs which belong to VNETs. A typical usage is
```
VNET_DEFINE_STATIC(int, foo) = 0;
SYSCTL_INT(_net, OID_AUTO, foo, CTLFLAG_RWTUN | CTLFLAG_VNET,
&VNET_NAME(foo), 0, "Description of the foo loader tunable");
```

Note that the implementation has a limitation. It behaves the same way
as that of non-vnet loader tunables. That is, after the kernel or modules
being initialized, any changes (e.g. via kenv) to kernel environment
variable will not affect the corresponding vnet variable of subsequently
created VNETs. To overcome it, we can use TUNABLE_XXX_FETCH to fetch
the kernel environment variable into those vnet variables during vnet
constructing.

This change will fix the following SYSCTLs those belong to VNETs and
have CTLFLAG_TUN flag:
```
net.add_addr_allfibs
net.bpf.optimize_writers
net.inet.tcp.fastopen.ccache_buckets
net.link.bridge.inherit_mac
net.link.bridge.ipfw_arp
net.link.bridge.log_stp
net.link.bridge.pfil_bridge
net.link.bridge.pfil_local_phys
net.link.bridge.pfil_member
net.link.bridge.pfil_onlyip
net.link.lagg.default_use_flowid
net.link.lagg.default_use_numa
net.link.lagg.default_flowid_shift
net.link.lagg.lacp.debug
net.link.lagg.lacp.default_strict_mode
```

Although the following vnet SYSCTLs have CTLFLAG_TUN flag, theirs
values are re-fetched via TUNABLE_XXX_FETCH, thus are not affected
by this change.
```
net.inet.ip.reass_hashsize
net.inet.tcp.hostcache.cachelimit
net.inet.tcp.hostcache.hashsize
net.inet.tcp.hostcache.bucketlimit
net.inet.tcp.syncache.bucketlimit
net.inet.tcp.syncache.cachelimit
net.inet.tcp.syncache.hashsize
net.key.spdcache.maxentries
net.key.spdcache.threshold
```

In memoriam: hselasky
Discussed with: hselasky, glebius
Fixes: 3da1cf1e88f8 Extend the meaning of the CTLFLAG_TUN flag ...
MFC after: 2 weeks
Relnotes: yes
Differential Revision: https://reviews.freebsd.org/D39638

show more ...

sys: Remove $FreeBSD$: one-line .c pattern

Remove /^[\s*]*__FBSDID\("\$FreeBSD\$"\);?\s*\n/

spdx: The BSD-2-Clause-FreeBSD identifier is obsolete, drop -FreeBSD

The SPDX folks have obsoleted the BSD-2-Clause-FreeBSD identifier. Catch
up to that fact and revert to their recommended match of

spdx: The BSD-2-Clause-FreeBSD identifier is obsolete, drop -FreeBSD

The SPDX folks have obsoleted the BSD-2-Clause-FreeBSD identifier. Catch
up to that fact and revert to their recommended match of BSD-2-Clause.

Discussed with: pfg
MFC After: 3 days
Sponsored by: Netflix

show more ...

vfs: NDFREE(&nd, NDF_ONLY_PNBUF) -> NDFREE_PNBUF(&nd)

Kernel linkers: add emergency sysctl to restore old behavior

allowing linking to static symbols from other files. Default the new
settings to true, delaying the change of the kernel linker behavior

Kernel linkers: add emergency sysctl to restore old behavior

allowing linking to static symbols from other files. Default the new
settings to true, delaying the change of the kernel linker behavior
for other day.

Suggested by: emaste
PR: 207898
Reviewed by: emaste, markj
Sponsored by: The FreeBSD Foundation
MFC after: 1 week
Differential revision: https://reviews.freebsd.org/D32878

show more ...

kernel linker: do not read debug symbol tables for non-debug symbols

In particular, this prevents resolving locals from other files.
To access debug symbol tables, add LINKER_LOOKUP_DEBUG_SYMBOL and

kernel linker: do not read debug symbol tables for non-debug symbols

In particular, this prevents resolving locals from other files.
To access debug symbol tables, add LINKER_LOOKUP_DEBUG_SYMBOL and
LINKER_DEBUG_SYMBOL_VALUES kobj methods, which are allowed to use
any types of present symbols in all tables.

PR: 207898
Reviewed by: emaste, markj
Sponsored by: The FreeBSD Foundation
MFC after: 1 week
Differential revision: https://reviews.freebsd.org/D32878

show more ...

Style

Reviewed by: markj
Sponsored by: The FreeBSD Foundation
MFC after: 1 week
Differential revision: https://reviews.freebsd.org/D32878

vfs: remove the unused thread argument from NDINIT*

See b4a58fbf640409a1 ("vfs: remove cn_thread")

Bump __FreeBSD_version to 1400043.

link_elf_obj: Process global ifunc relocs after other global relocs

This is needed to ensure that resolvers that reference global symbols
return correct results.

Reviewed by: kib
MFC after: 1 week

link_elf_obj: Process global ifunc relocs after other global relocs

This is needed to ensure that resolvers that reference global symbols
return correct results.

Reviewed by: kib
MFC after: 1 week
Sponsored by: The FreeBSD Foundation
Differential Revision: https://reviews.freebsd.org/D33120

show more ...

Kernel linkers: some style

Reviewed by: emaste
Sponsored by: The FreeBSD Foundation
MFC after: 3 days
Differential revision: https://reviews.freebsd.org/D32878

link_elf_obj: Invoke fini callbacks

This is required for KASAN: when a module is unloaded, poisoned regions
(e.g., pad areas between global variables) are left as such, so if they
are reused as KLDs

link_elf_obj: Invoke fini callbacks

This is required for KASAN: when a module is unloaded, poisoned regions
(e.g., pad areas between global variables) are left as such, so if they
are reused as KLDs are loaded, false positives can arise.

Reported by: pho, Jenkins
Reviewed by: kib
MFC after: 2 weeks
Sponsored by: The FreeBSD Foundation
Differential Revision: https://reviews.freebsd.org/D31339

show more ...

link_elf_obj: Add a case missing from 5e6989ba4f26

Fixes: 5e6989ba4f26
MFC after: 3 days
Sponsored by: The FreeBSD Foundation

link_elf_obj: Handle init_array sections in KLDs

Reuse existing handling for .ctors, print a warning if multiple
constructor sections are present. Destructors are not handled as of
yet.

This is r

link_elf_obj: Handle init_array sections in KLDs

Reuse existing handling for .ctors, print a warning if multiple
constructor sections are present. Destructors are not handled as of
yet.

This is required for KASAN.

Reviewed by: kib
MFC after: 2 weeks
Sponsored by: The FreeBSD Foundation
Differential Revision: https://reviews.freebsd.org/D29049

show more ...

vm_map_protect: allow to set prot and max_prot in one go.

This prevents a situation where other thread modifies map entries
permissions between setting max_prot, then relocking, then setting prot,
c

vm_map_protect: allow to set prot and max_prot in one go.

This prevents a situation where other thread modifies map entries
permissions between setting max_prot, then relocking, then setting prot,
confusing the operation outcome. E.g. you can get an error that is not
possible if operation is performed atomic.

Also enable setting rwx for max_prot even if map does not allow to set
effective rwx protection.

Reviewed by: brooks, markj (previous version)
Sponsored by: The FreeBSD Foundation
Differential Revision: https://reviews.freebsd.org/D28117

show more ...

link_elf_obj: Colour VM objects

This will cause the VM to back sufficiently large .text sections, such
as those in zfs.ko or amdgpu.ko on amd64, with superpage mappings when
possible.

Reviewed by:

link_elf_obj: Colour VM objects

This will cause the VM to back sufficiently large .text sections, such
as those in zfs.ko or amdgpu.ko on amd64, with superpage mappings when
possible.

Reviewed by: alc, kib
MFC after: 1 week
Sponsored by: The FreeBSD Foundation
Differential Revision: https://reviews.freebsd.org/D26802

show more ...

Handle kmod local relocation failures gracefully

It is possible for elf_reloc_local() to fail in the unlikely case of
an unsupported relocation type. If this occurs, do not continue to
process the f

Handle kmod local relocation failures gracefully

It is possible for elf_reloc_local() to fail in the unlikely case of
an unsupported relocation type. If this occurs, do not continue to
process the file.

Reviewed by: kib, markj (earlier version)
MFC after: 1 week
Sponsored by: NetApp, Inc.
Sponsored by: Klara, Inc.
Differential Revision: https://reviews.freebsd.org/D26701

show more ...

Convert allocations of the phys pager to vm_pager_allocate().

Future changes would require additional initialization of OBJT_PHYS
objects, and vm_object_allocate() is not suitable for it.

Reviewed

Convert allocations of the phys pager to vm_pager_allocate().

Future changes would require additional initialization of OBJT_PHYS
objects, and vm_object_allocate() is not suitable for it.

Reviewed by: markj
Tested by: pho
Sponsored by: The FreeBSD Foundation
MFC after: 1 week
Differential revision: https://reviews.freebsd.org/D24652

show more ...