• Guo Ren's avatar
    csky: Add support for function error injection · 71e193d7
    Guo Ren authored
    Inspired by the commit 42d038c4 ("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: default avatarGuo Ren <guoren@linux.alibaba.com>
    Cc: Arnd Bergmann <arnd@arndb.de>
    71e193d7
error-inject.c 251 Bytes