gem5::MemState::updateBrkRegion(), which is called during the syscall
emulation of brk, did not unmap deallocated heap pages when the brk
region is receding. Instead, it kept it mapped for simplicity. This
introduced a bug where subequent expansions of the brk region reused
prior heap page mappings that were not zero-filled. This violates
the assumptions of glibc malloc, resulting in heap corruption and
crashes.
This patch fixes the bug by always unmapping pages that are deallocated
during a call to brk() that reduces the heap size. This makes the
gem5::MemState::_endBrkPoint field obsolete, so this patch removes it.
GitHub issue: https://github.com/gem5/gem5/issues/342
Change-Id: Ib2244e1aa4d2a26666ad60d231fdde2c22d2df35
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>
Initialize _stackSize and _stackMin to the maximum stack size values.
The are setup in each arch's Process::initState and may be uninitialized
until then. If a stack fixup occurs before these are setup, addresses
which are not in the stack might be allocated on the stack. This
prevents that until they are initialized in Process::initState. If an
access occurs before that with these initial values, the stack fixup
will simply allocate a page of memory in the stack space. However, it
will not print the typical info messages about growing the stack during
this time.
Change-Id: I9f9316734f4bf1f773fc538922e83b867731c684
JIRA: https://gem5.atlassian.net/browse/GEM5-629
Reviewed-on: https://gem5-review.googlesource.com/c/public/gem5/+/30394
Reviewed-by: Jason Lowe-Power <power.jg@gmail.com>
Reviewed-by: Gabe Black <gabeblack@google.com>
Maintainer: Jason Lowe-Power <power.jg@gmail.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>
Extend the MemState API to handle tracking dynamically sized memory
regions of a Process class which may be added, moved, removed, or
change in size during the course of simulation. This utilizes the
virtual memory areas (VMA) class to track individual regions and
provides a fixup method to handle physical page allocation in case of
a page fault. This allows for lazy allocation of the stack, heap, and
mmap regions of memory.
Change-Id: I3ef10657e5f8e8f0e328bdf0aa15a27b1dde39bf
Reviewed-on: https://gem5-review.googlesource.com/c/public/gem5/+/25483
Tested-by: Gem5 Cloud Project GCB service account <345032938727@cloudbuild.gserviceaccount.com>
Reviewed-by: Jason Lowe-Power <power.jg@gmail.com>
Maintainer: Jason Lowe-Power <power.jg@gmail.com>
