This patch fixes a GCC-10 compile error. Even though the optimization
was quite effective - I measured a speedup of factor 2 - it is not all
that important for the overall application performance. In the nano3d
case, we are talking about 1 vs. 2 percent of CPU time.
Fixes#4140
The kernel-agnostic 'Trace::timestamp' function for arm_64 executes the
'mrs %0, pmccntr_el0' instruction, which is not permitted for user-level
programs on Linux. This patch shadows the generic timestamp.h header
with dummy that returns zero. This return value prompts the timeout
framework to disable the interpolation of time based on timestamps. This
avoid the illegal-instruction abort but comes with two llimitations:
First, time measurements are effectlively limited to a granulariry of 1
millisecond (deliberately constrained by the timer driver).
The quirk is applied when using the base-linux API. Should a generic
application (that uses the base API only) call 'Trace::timestamp'
directly, the illegal instruction is executed.
Issue #4136
This patch adds support for running Genode/Linux on the AARCH64
architecture.
- The kernel-agnostic startup code (crt0) had to be extended to
capture the initial stack pointer, which the Linux kernel uses
to pass the process environment. This is in line with the
existing startup code for x86_32 and x86_64.
- The link order of the host libraries linked to lx_hybrid
programs had to be adjusted such that libgcc appears at last
because the other libraries depend on symbols provided by
libgcc.
- When using AARCH64 Linux as host, one can execute run scripts
via 'make run/<script> KERNEL=linux BOARD=linux' now.
Issue #4136
When a DHCP packet is printed out, it first tries to determine the most
specific message type from the DHCP options and print its human-readable name
right after the protocol name. If finding the message type fails, the less
specific opcode is printed instead, but also in a human-readable way.
Fixes#4131
By moving core's build-description to a library - a pattern already
employed for the other base platforms - we become able to cleanly split
x86-specific code (I/O-port access) from generic code. This is a
prerequisite for enabling non-x86 architectures such as AARCH64.
Issue #4136
This new runscript demonstrates how a file can be overwritten by vfs
import with the flag overwrite set to false. This is due to a bug
in lx_fs that is not propagating an ernno EEXIST syscall error.
Issue genodelabs#4104
This commit introduces a fix for lx_fs to propagate errno EEXIST error.
This prevents vfs <import overwrite="false"> to overwrite an imported
file, if it already exists, without the overwrite flag set to true.
Issue genodelabs#4104
The former implementation called 'TRACE_AND_STOP' which led to the
'usb_host_drv' to stop whenever such a function was called. Rather
than stopping return '0' and let the contrib code deal with this
situation.
Issue #4116.
This commit backports the Linux upstream commit (d4a6106) [*]
that introduces a check to prevent the sglist from being used
unconditionally.
[*] 'xhci: fix bounce buffer usage for non-sg list case'
Fixes#4116.
Unconditionally setting MAKEFLAGS to just 's' is not nice because other
flags cannot be passed through the run script. What the script desires
is to disable the automatically enabled '--print-directory' for sub-make
instances when calling tool/port/current by declaring
'--no-print-directory'.
Until now, Genode's Linux system call bindings were based on original
Unix system calls that were later superseded by more flexibile variants.
E.g., 'openat' is a modern version of 'open'. Even though Linux upholds
the compatiblity with the original versions for existing architectures
like x86, the legacy syscalls are absent for the recently added AARCH64
architecture. A good overview of the system calls accross the prominent
architectures can be found at
https://chromium.googlesource.com/chromiumos/docs/+/master/constants/syscalls.md
This patch updates Genode's syscall bindings to avoid legacy versions,
thereby easing the support for AARCH64. The used "modern" versions
were introduced back in Linux version 2 days. So we are fine to rely
on them.
The patch slightly changes the signature for lx_stat because this system
call is merely used to check for the existance of a file and its size.
The new name 'lx_stat_size' draws a closer connection to its use case.
That said, the stat syscall has not been updated to the modern statx
since statx is still a fairly recent addition.
Issue #4136
This patch simplifies the use of the clone system call for creating
processes and threads. Until now, the binding used an opaque pointer
argument to pass context information to the newly created process or
thread. However, upon close inspection, this is not a strict
requirement.
A newly created thread accesses its contextual information by
using its stack pointer as key. The pointer argument is not used.
The creation of processes is strictly serialized because the
intermediate stack used in-between clone and execve is a global
variable. Since we rely on the serialization anyway, we can pass the
context information of a new process via a global variable as well.
This change simplifies the syscall binding for the upcoming AARCH64
support, which would otherwise require us to deal with the notion
of TLS on Linux.
Issue #4136
With the update to GCC 10, the compiler stopped with an error when compiling
places where a MAC address is copied from outside into a packed object using
the Net::Netaddress::copy method (e.g. in
Net::Arp_packet::dst_mac(Mac_address)):
! error: writing 6 bytes into a region of size 4 [-Werror=stringop-overflow=]
While trying to find a clean solution for this error, I found posts on
gcc.gnu.org and github that stated that the size calculations that cause these
errors are incorrect. Indeed, I could verify that the actual size of the two
regions was static and exactly the same in places were the error occured.
Furthermore, I couldn't find a way of making it more clear to the compiler
that the sizes are the same. By accident, we found that using the address of
the first element of the array that forms the second region instead of the
array address itself, somehow circumvents the error.
Fixes#4109
With the update to GCC 10 the compiler used to warn when using the internet
checksum functions on packet classes (like in
Net::Ipv4_packet::update_checksum):
warning: converting a packed ‘Net::[PACKET_CLASS]’ pointer
(alignment 1) to a ‘const uint16_t’ {aka ‘const short
unsigned int’} pointer (alignment 2) may result in an
unaligned pointer value
Apparently, the 'packed' attribute normally used on packet classes sets the
alignment of the packet class to 1. However, for the purpose of the
internet-checksum functions, we can assume that the packet data has no
alignment. This is expressed by casting the packet-object pointer to a pointer
of the new packed helper struct 'Packed_uint16' that contains only a single
uint16_t member before handing it over to the checksum function (instead of
casting it to a uint16_t pointer).
Ref #4109
