Try to access RAM with the largest bit width possible, but without
doing unaligned accesses.
A further improvement could be to use multiple read and writes as the
assembly version was trying to do.
Tested on a BeagleV Starlight with a SiFive U74 core, where the
improvement is noticeable.
Signed-off-by: Matteo Croce <mcroce@microsoft.com>
Co-developed-by: Guo Ren <guoren@linux.alibaba.com>
Signed-off-by: Guo Ren <guoren@linux.alibaba.com>
Inspired by the commit 42d038c4fb ("arm64: Add support for function
error injection"), this patch supports function error injection for
csky.
This patch mainly support two functions: one is regs_set_return_value()
which is used to overwrite the return value; the another function is
override_function_with_return() which is to override the probed
function returning and jump to its caller.
Test log:
cd /sys/kernel/debug/fail_function/
echo sys_clone > inject
echo 100 > probability
echo 1 > interval
ls /
[ 108.644163] FAULT_INJECTION: forcing a failure.
[ 108.644163] name fail_function, interval 1, probability 100, space 0, times 1
[ 108.647799] CPU: 0 PID: 104 Comm: sh Not tainted 5.8.0-rc5+ #46
[ 108.648384] Call Trace:
[ 108.649339] [<8005eed4>] walk_stackframe+0x0/0xf0
[ 108.649679] [<8005f16a>] show_stack+0x32/0x5c
[ 108.649927] [<8040f9d2>] dump_stack+0x6e/0x9c
[ 108.650271] [<80406f7e>] should_fail+0x15e/0x1ac
[ 108.650720] [<80118ba8>] fei_kprobe_handler+0x28/0x5c
[ 108.651519] [<80754110>] kprobe_breakpoint_handler+0x144/0x1cc
[ 108.652289] [<8005d6da>] trap_c+0x8e/0x110
[ 108.652816] [<8005ce8c>] csky_trap+0x5c/0x70
-sh: can't fork: Invalid argument
Signed-off-by: Guo Ren <guoren@linux.alibaba.com>
Cc: Arnd Bergmann <arnd@arndb.de>
Add SPDX license identifiers to all Make/Kconfig files which:
- Have no license information of any form
These files fall under the project license, GPL v2 only. The resulting SPDX
license identifier is:
GPL-2.0-only
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Matteo Croce