sys: Remove $FreeBSD$: two-line .h pattern

Remove /^\s*\*\n \*\s+\$FreeBSD\$$\n/

kstack_contains(): account for struct pcb on stack

for arm64, arm, powerpc, and riscv

Reviewed by: jhb
Sponsored by: The FreeBSD Foundation
MFC after: 1 week
Differential revision: https://reviews.

kstack_contains(): account for struct pcb on stack

for arm64, arm, powerpc, and riscv

Reviewed by: jhb
Sponsored by: The FreeBSD Foundation
MFC after: 1 week
Differential revision: https://reviews.freebsd.org/D38320

show more ...

Move kstack_contains() and GET_STACK_USAGE() to MD machine/stack.h

Reviewed by: jhb
Sponsored by: The FreeBSD Foundation
MFC after: 1 week
Differential revision: https://reviews.freebsd.org/D38320

Rewrite arm kernel stack unwind code to work when unwinding through modules.

The arm kernel stack unwinder has apparently never been able to unwind when
the path of execution leads through a kernel

Rewrite arm kernel stack unwind code to work when unwinding through modules.

The arm kernel stack unwinder has apparently never been able to unwind when
the path of execution leads through a kernel module. There was code that
tried to handle modules by looking for the unwind data in them, but it did
so by trying to find symbols which have never existed in arm kernel
modules. That caused the unwind code to panic, and because part of panic
handling calls into the unwind code, that just created a recursion loop.

Locating the unwind data in a loaded module requires accessing the Elf
section headers to find the SHT_ARM_EXIDX section. For preloaded modules
those headers are present in a metadata blob. For dynamically loaded
modules, the headers are present only while the loading is in progress; the
memory is freed once the module is ready to use. For that reason, there is
new code in kern/link_elf.c, wrapped in #ifdef __arm__, to extract the
unwind info while the headers are loaded. The values are saved into new
fields in the linker_file structure which are also conditional on __arm__.

In arm/unwind.c there is new code to locally cache the per-module info
needed to find the unwind tables. The local cache is crafted for lockless
read access, because the unwind code often needs to run in context where
sleeping is not allowed. A large comment block describes the local cache
list, so I won't repeat it all here.

show more ...

sys: Remove $FreeBSD$: two-line .h pattern

Remove /^\s*\*\n \*\s+\$FreeBSD\$$\n/

kstack_contains(): account for struct pcb on stack

for arm64, arm, powerpc, and riscv

Reviewed by: jhb
Sponsored by: The FreeBSD Foundation
MFC after: 1 week
Differential revision: https://reviews.

kstack_contains(): account for struct pcb on stack

for arm64, arm, powerpc, and riscv

Reviewed by: jhb
Sponsored by: The FreeBSD Foundation
MFC after: 1 week
Differential revision: https://reviews.freebsd.org/D38320

show more ...

Move kstack_contains() and GET_STACK_USAGE() to MD machine/stack.h

Reviewed by: jhb
Sponsored by: The FreeBSD Foundation
MFC after: 1 week
Differential revision: https://reviews.freebsd.org/D38320

Rewrite arm kernel stack unwind code to work when unwinding through modules.

The arm kernel stack unwinder has apparently never been able to unwind when
the path of execution leads through a kernel

Rewrite arm kernel stack unwind code to work when unwinding through modules.

The arm kernel stack unwinder has apparently never been able to unwind when
the path of execution leads through a kernel module. There was code that
tried to handle modules by looking for the unwind data in them, but it did
so by trying to find symbols which have never existed in arm kernel
modules. That caused the unwind code to panic, and because part of panic
handling calls into the unwind code, that just created a recursion loop.

Locating the unwind data in a loaded module requires accessing the Elf
section headers to find the SHT_ARM_EXIDX section. For preloaded modules
those headers are present in a metadata blob. For dynamically loaded
modules, the headers are present only while the loading is in progress; the
memory is freed once the module is ready to use. For that reason, there is
new code in kern/link_elf.c, wrapped in #ifdef __arm__, to extract the
unwind info while the headers are loaded. The values are saved into new
fields in the linker_file structure which are also conditional on __arm__.

In arm/unwind.c there is new code to locally cache the per-module info
needed to find the unwind tables. The local cache is crafted for lockless
read access, because the unwind code often needs to run in context where
sleeping is not allowed. A large comment block describes the local cache
list, so I won't repeat it all here.

show more ...

Merge sync of head

MFH: r278968-r280640

Sponsored by: The FreeBSD Foundation

Merge from head

Merge r278538 through r279514.

Merging ^/head r278916 through r279022.

Allow the ARM unwinder to work through modules. This will be used to add
support for unwinding from dtrace.

Tested by: gnn (with dtrace)
Sponsored by: ABT Systems Ltd

MFH: r278593-r278966

Sponsored by: The FreeBSD Foundation

Merge ^/head r278756 through r278915.

Pull the ARM ddb unwind code out to a new file. This will allow it to be
used by other places that expect to unwind the stack, e.g. dtrace and
stack(9).

As I have written most of this code I'm chang

Pull the ARM ddb unwind code out to a new file. This will allow it to be
used by other places that expect to unwind the stack, e.g. dtrace and
stack(9).

As I have written most of this code I'm changing the license to the
standard FreeBSD license. I have received approval from the other
developers who have changed any of the affected code.

Approved by: ian, imp, rpaulo, eadler (all license change)

show more ...

Sync from head

Merge head r236710 through r238467.

IFC @238412.

IFC @ r238370

Merge sync of head

MFH: r278968-r280640

Sponsored by: The FreeBSD Foundation

Merge from head

Merge r278538 through r279514.