Debug build functions use more stack space than normal, such that the
KVM-nosplit function call chain doesn't fit. This patch replaces calls into
unix.RawSyscall* functions with variants that do not grow the stack, and inlines
some functions in ring0/pagetables in order to reduce stack usage. Additionally
seccompMmapHandler is not used during debug builds anymore for making it fit
into the nosplit stack size requirements.
PiperOrigin-RevId: 679774881
It is an idea of running codespell as part of our presubmit checks.
Before enabling it for new changes, let's fix what it has found.
Signed-off-by: Andrei Vagin <avagin@gmail.com>
For all trivial and zero frame-sized functions, we now require an explicit
NOFRAME annotation as the heuristic has changed. See go.dev/cl/466316.
Most of these functions do not *require* NOFRAME, but this change encodes
the existing behavior in order to avoid accidental bugs or regressions.
PiperOrigin-RevId: 513946210
We install seccomp rules so that the SIGSYS signal is generated for
each mmap system call. Then our signal handler executes the real mmap
syscall and if a new regions is created, it maps it to the guest.
Signed-off-by: Andrei Vagin <avagin@google.com>
The root table physical page has to be mapped to not fault in iret or sysret
after switching into a user address space. sysret and iret are in the upper
half that is global and so page tables of lower levels are already mapped.
Fixes#5742
PiperOrigin-RevId: 371458644
Split usermem package to help remove syserror dependency in go_marshal.
New hostarch package contains code not dependent on syserror.
PiperOrigin-RevId: 365651233
This allows the package to serve as a general purpose ring0 support package, as
opposed to being bound to specific sentry platforms.
Updates #5039
PiperOrigin-RevId: 355220044
Jamie LiuandgVisor bot
Konstantin BogomolovandgVisor bot
Jing ChenandgVisor bot
Andrei Vagin
Adin ScannellandgVisor bot
Ayush RanjanandgVisor bot
Howard Zhang
Zach KoopmansandgVisor bot