This Pull-Request addresses gem5 Issue #550. The code that dumps the
Dmesg buffer is now templated on the two variants of the `Metadata`
structure, and the correct one is chosen based on the detected Kernel
version.
To support this functionality, the pull request also adds Symbol Size
data to the loader Symbol Table, and adds a method to query the Kernel
Version from the image in guest memory. The new attributes in the Symbol
class are de-serialized speculatively, so no checkpoint upgrader is
required to support this change.
This patch reworks the Linux Kernel panic and oops events. The code has
been re-factored to provide re-usable events that can be applied to all
ISAs from the base `KernelWorkload` `SimObject`. At the moment they are
installed for the Arm workloads.
This update also provides more configuration options that can be
specified using the new `KernelPanicOopsBehaviour` enum. The options are
applied to the Kernel Workload parameters `on_panic` and `on_oops` which
are available to all subclasses of `KernelWorkload`.
The main rationale for this reworking is to add the option to cleanly
exit the simulation after dumping the Dmesg buffer. Without this option,
the simulation would continue running after a Kernel panic. If system
components (e.g. a system timer) keep the event queue alive, this causes
the simulation to run slowly to the maximum allowed tick.
Linux v5.18+ changed the format of one of the data structures used to
implement the printk ring buffer. This caused the gem5 feature to dump
the printk messages on Kernel panic to fail for Kernels 5.18.0 and
later.
This patch updates the printk messages dump feature to support the new
printk ring buffer format when Kernels 5.18 and later are detected.
This patch addresses gem5 Issue #550:
https://github.com/gem5/gem5/issues/550
Change-Id: I533d539eafb83c44eeb4b9fbbcdd9c172fd398e6
Reported-by: Hoa Nguyen <hn@hnpl.org>
Reviewed-by: Andreas Sandberg <andreas.sandberg@arm.com>
This function, `extract_kernel_version`, attempts to find the Kernel
version by searching the `uts_namespace` struct at the exported symbol
`init_uts_ns`. This structure contains the Kernel version as a string,
and is referenced by `procfs` to return the Kernel version in a
running system.
Different versions of the Kernel use different layouts for this
structure, and the top level structure is marked as
`__randomize_layout`, so the exact layout in memory cannot be relied
on. Because of this, `extract_kernel_version` takes the approach of
searching the memory holding the structure for printable strings, and
parsing the version from those strings.
Change-Id: If8b2e81a041af891fd6e56a87346a341df3c9728
Reviewed-by: Andreas Sandberg <andreas.sandberg@arm.com>
This commit converts `gem5::loader::Symbol` to a full class with
private members, enforcing encapsulation. Until now client code has
been able to (and does) access members directly.
This change will enable class invariants to be enforced via accessor
methods.
Change-Id: Ia0b5b080d4f656637a211808e13dce1ddca74541
Reviewed-by: Andreas Sandberg <andreas.sandberg@arm.com>
This patch fixes the buggy special path comparisons in
src/kern/linux/linux.cc Linux::openSpecialFile(), which only checked
for equality of path prefixes, but not equality of the paths
themselves. This patch replaces those buggy comparisons with
regular std::string::operator== string equality comparisons.
GitHub issue: https://github.com/gem5/gem5/issues/269
Change-Id: I216ff8019b9a6a3e87e364c2e197d9b991959ec1
The Linux Kernel's printk mechanism and data structures were
overhauled in v5.10. This patch updates gem5's facility to dump the
kernel Dmesg buffer on kernel panic to account for these changes.
The new mechanism splits the Demsg ringbuffer into three separate
ringbuffers, one containing the message data, one containing
descriptors used for lock-free synchronisation, and one containing the
message infos. For a detailed description please see the header of
`kernel/printk/printk_ringbuffer.c` in the Linux source code.
The new gem5 implementation tests for the correct version to
run (pre-v5.10 or post-v5.10) by testing for the presence of symbols
in the kernel. The new, post-v5.10 dump code is templated on types
compatible with the kernel's atomic_long_t to account for differences
between the 64-bit and 32-bit Linux kernels.
Because the new Dmesg buffer dump code in gem5 is intended for
disaster recovery, it intentionally prints the full Dmesg buffer with
minimal checking of the validity of the messages. Partially finished
and/or uncommitted messages will be printed along with the finalised
messages.
Change-Id: I62ac20735e0679f1ba2062ca7bb13692a5ca1eae
Reviewed-on: https://gem5-review.googlesource.com/c/public/gem5/+/59509
Reviewed-by: Bobby Bruce <bbruce@ucdavis.edu>
Reviewed-by: Jason Lowe-Power <power.jg@gmail.com>
Tested-by: kokoro <noreply+kokoro@google.com>
Maintainer: Jason Lowe-Power <power.jg@gmail.com>
This makes what are configuration and what are internal SCons variables
explicit and separate, and makes it unnecessary to call out what
variables to export to C++.
These variables will also be plumbed into and out of kconfiglib in later
changes.
Change-Id: Iaf5e098d7404af06285c421dbdf8ef4171b3f001
Reviewed-on: https://gem5-review.googlesource.com/c/public/gem5/+/56892
Reviewed-by: Andreas Sandberg <andreas.sandberg@arm.com>
Maintainer: Gabe Black <gabe.black@gmail.com>
Tested-by: kokoro <noreply+kokoro@google.com>
The proxies are not used on the critical path, and it's usually implicit
whether they should be the FS or SE version.
Ideally in the future we won't need to worry about which version we need
to use, but the differences haven't quite been abstracted away, and
occasionally we need to decide between the two.
Change-Id: Idb363d6ddc681f7c1ad5e7aba69865f40aa30dc8
Reviewed-on: https://gem5-review.googlesource.com/c/public/gem5/+/45907
Maintainer: Bobby R. Bruce <bbruce@ucdavis.edu>
Tested-by: kokoro <noreply+kokoro@google.com>
Reviewed-by: Giacomo Travaglini <giacomo.travaglini@arm.com>
In C, to refer to a type without a struct or enum tag on the type, you
need to typedef it like this:
typedef struct
{
} Foo;
Foo foo;
In C++, this is unnecessary:
struct Foo
{
};
Foo foo;
Remove all of the first form in C++ files and replace them with the
second form.
Change-Id: I37cc0d63b2777466dc6cc51eb5a3201de2e2cf43
Reviewed-on: https://gem5-review.googlesource.com/c/public/gem5/+/46199
Reviewed-by: Gabe Black <gabe.black@gmail.com>
Maintainer: Gabe Black <gabe.black@gmail.com>
Tested-by: kokoro <noreply+kokoro@google.com>
Apply the gem5 namespace to the codebase.
Some anonymous namespaces could theoretically be removed,
but since this change's main goal was to keep conflicts
at a minimum, it was decided not to modify much the
general shape of the files.
A few missing comments of the form "// namespace X" that
occurred before the newly added "} // namespace gem5"
have been added for consistency.
std out should not be included in the gem5 namespace, so
they weren't.
ProtoMessage has not been included in the gem5 namespace,
since I'm not familiar with how proto works.
Regarding the SystemC files, although they belong to gem5,
they actually perform integration between gem5 and SystemC;
therefore, it deserved its own separate namespace.
Files that are automatically generated have been included
in the gem5 namespace.
The .isa files currently are limited to a single namespace.
This limitation should be later removed to make it easier
to accomodate a better API.
Regarding the files in util, gem5:: was prepended where
suitable. Notice that this patch was tested as much as
possible given that most of these were already not
previously compiling.
Change-Id: Ia53d404ec79c46edaa98f654e23bc3b0e179fe2d
Signed-off-by: Daniel R. Carvalho <odanrc@yahoo.com.br>
Reviewed-on: https://gem5-review.googlesource.com/c/public/gem5/+/46323
Maintainer: Bobby R. Bruce <bbruce@ucdavis.edu>
Reviewed-by: Bobby R. Bruce <bbruce@ucdavis.edu>
Reviewed-by: Matthew Poremba <matthew.poremba@amd.com>
Tested-by: kokoro <noreply+kokoro@google.com>
As part of recent decisions regarding namespace
naming conventions, all namespaces will be changed
to snake case.
sim_clock::Int became sim_clock::as_int.
"as_int" was chosen because "int" is a reserved
keyword, and this namespace acts as a selector of
how to read the internal variables.
Another possibility to resolve this would be to
remove the namespaces "Float" and "Int" and use
unions instead.
Change-Id: I65f47608d2212424bed1731c7f53d242d5a7d89a
Signed-off-by: Daniel R. Carvalho <odanrc@yahoo.com.br>
Reviewed-on: https://gem5-review.googlesource.com/c/public/gem5/+/45436
Tested-by: kokoro <noreply+kokoro@google.com>
Reviewed-by: Hoa Nguyen <hoanguyen@ucdavis.edu>
Maintainer: Gabe Black <gabe.black@gmail.com>
These were not caught by the previous patches because
the grep used ignored:
- anonymous structures
(e.g., "struct {")
- opening braces without leading spaces
(e.g., "struct Name{"),
- weird chars in auto-generation files
(e.g., "struct $name {").
- extra characters after the opening brace.
(e.g., "struct Name { // Comment")
- typedefs (note that this is not caught by the verifier)
(e.g., "typedef struct Name {")
Most of this has been fixed be grepping structures
with the following regex:
grep -nrE --exclude-dir=systemc \
"^ *(typedef)* *(struct|class|enum|union) [^{]*{$" src/
The following makes sure that "struct{" is captured:
grep -nrE --exclude-dir=systemc \
"^ *(struct|class|enum|union){" src/
To find cases that contain a comment after the
opening brace:
grep -nrE --exclude-dir=systemc \
"^ *(struct|class|enum|union)[^{]*{\s*//" src/
Change-Id: I9f822bed628d13b1a09ccd6059373aff63a8d7bd
Signed-off-by: Daniel R. Carvalho <odanrc@yahoo.com.br>
Reviewed-on: https://gem5-review.googlesource.com/c/public/gem5/+/43505
Reviewed-by: Bobby R. Bruce <bbruce@ucdavis.edu>
Maintainer: Bobby R. Bruce <bbruce@ucdavis.edu>
Tested-by: kokoro <noreply+kokoro@google.com>
The systemc dir was not included in this fix.
First it was identified that there were only occurrences
at 0, 1, 2 and 3 levels of indentation (and a single
occurrence of 2 and 3 spaces), using:
grep -nrE --exclude-dir=systemc \
"^ *struct [A-Za-z].* {$" src/
Then the following commands were run to replace:
<indent level>struct X ... {
by:
<indent level>struct X ...
<indent level>{
Level 0:
grep -nrl --exclude-dir=systemc
"^struct [A-Za-z].* {$" src/ | \
xargs sed -Ei \
's/^struct ([A-Za-z].*) \{$/struct \1\n\{/g'
Level 1:
grep -nrl --exclude-dir=systemc \
"^ struct [A-Za-z].* {$" src/ | \
xargs sed -Ei \
's/^ struct ([A-Za-z].*) \{$/ struct \1\n \{/g'
and so on.
Change-Id: I362ef58c86912dabdd272c7debb8d25d587cd455
Signed-off-by: Daniel R. Carvalho <odanrc@yahoo.com.br>
Reviewed-on: https://gem5-review.googlesource.com/c/public/gem5/+/39017
Reviewed-by: Giacomo Travaglini <giacomo.travaglini@arm.com>
Maintainer: Giacomo Travaglini <giacomo.travaglini@arm.com>
Tested-by: kokoro <noreply+kokoro@google.com>
The systemc dir was not included in this fix.
First it was identified that there were only occurrences
at 0, 1, and 2 levels of indentation, using:
grep -nrE --exclude-dir=systemc \
"^ *class [A-Za-z].* {$" src/
Then the following commands were run to replace:
<indent level>class X ... {
by:
<indent level>class X ...
<indent level>{
Level 0:
grep -nrl --exclude-dir=systemc
"^class [A-Za-z].* {$" src/ | \
xargs sed -Ei \
's/^class ([A-Za-z].*) \{$/class \1\n\{/g'
Level 1:
grep -nrl --exclude-dir=systemc \
"^ class [A-Za-z].* {$" src/ | \
xargs sed -Ei \
's/^ class ([A-Za-z].*) \{$/ class \1\n \{/g'
and so on.
Change-Id: I17615ce16a333d69867b27c7bae0f4fdafd8b2eb
Signed-off-by: Daniel R. Carvalho <odanrc@yahoo.com.br>
Reviewed-on: https://gem5-review.googlesource.com/c/public/gem5/+/39015
Reviewed-by: Giacomo Travaglini <giacomo.travaglini@arm.com>
Maintainer: Giacomo Travaglini <giacomo.travaglini@arm.com>
Tested-by: kokoro <noreply+kokoro@google.com>
This change replaces the __attribute__ syntax with the now standard [[]]
syntax. It also reorganizes compiler.hh so that all special macros have
some explanatory text saying what they do, and each attribute which has a
standard version can use that if available and what version of c++ it's
standard in is put in a comment.
Also, the requirements as far as where you put [[]] style attributes are
a little more strict than the old school __attribute__ style. The use of
the attribute macros was updated to fit these new, more strict
requirements.
Change-Id: Iace44306a534111f1c38b9856dc9e88cd9b49d2a
Reviewed-on: https://gem5-review.googlesource.com/c/public/gem5/+/35219
Reviewed-by: Daniel Carvalho <odanrc@yahoo.com.br>
Maintainer: Gabe Black <gabeblack@google.com>
Tested-by: kokoro <noreply+kokoro@google.com>
isa_traits.hh used to have much more in it, but now it only has
PageShift, PageBytes, and (for now) the guest endianness. These values
should only be retrieved from the System class generally speaking, so
only the system class should include arch/isa_traits.hh.
Some gpu compute related files need PageBytes or PageShift. Even though
those files don't advertise their ISA dependence, they are tied to x86.
In those files, they can include arch/x86/isa_traits.hh.
The only other file which legitimately needs arch/isa_traits.hh is the
decoder cache since it uses PageBytes to size an array.
Change-Id: I12686368715623e3140a68a7027c136bd52567b1
Reviewed-on: https://gem5-review.googlesource.com/c/public/gem5/+/33203
Reviewed-by: Gabe Black <gabeblack@google.com>
Reviewed-by: Daniel Carvalho <odanrc@yahoo.com.br>
Maintainer: Gabe Black <gabeblack@google.com>
Tested-by: kokoro <noreply+kokoro@google.com>
These are the stats in the base class, not in any derived classes. Only
Alpha has an additional stats. These were not really "kernel"
statistics, they were just applicable primarily in FS. They are
potentially applicable to any simulation, but will probably not be
incremented in SE simulations.
Also this merges these stats from being per thread to being per
workload, ie operating system instance. This is probably more relevant
since exactly what thread within a workload runs which particular
instruction is not very important/predictable, but the aggregate
behavior is. If necessary, this could be adjusted in the future to
split things back out again into stats per thread while keeping them
inside the single workload object.
Change-Id: I130e11a9022bdfcadcfb02c7995871503114cd53
Reviewed-on: https://gem5-review.googlesource.com/c/public/gem5/+/25147
Reviewed-by: Andreas Sandberg <andreas.sandberg@arm.com>
Maintainer: Andreas Sandberg <andreas.sandberg@arm.com>
Tested-by: kokoro <noreply+kokoro@google.com>
The System class has a few different arrays of values which each
correspond to a thread of execution based on their position. This
change collects them together into a single class to make managing them
easier and less error prone. It also collects methods for manipulating
those threads as an API for that class.
This class acts as a collection point for thread based state which the
System class can look into to get at all its state. It also acts as an
interface for interacting with threads for other classes. This forces
external consumers to use the API instead of accessing the individual
arrays which improves consistency.
Change-Id: Idc4575c5a0b56fe75f5c497809ad91c22bfe26cc
Reviewed-on: https://gem5-review.googlesource.com/c/public/gem5/+/25144
Reviewed-by: Bobby R. Bruce <bbruce@ucdavis.edu>
Maintainer: Bobby R. Bruce <bbruce@ucdavis.edu>
Tested-by: kokoro <noreply+kokoro@google.com>
