• Douglas Anderson's avatar
    kgdboc: disable the console lock when in kgdb · 81eaadca
    Douglas Anderson authored
    After commit ddde3c18 ("vt: More locking checks") kdb / kgdb has
    become useless because my console is filled with spews of:
    
    WARNING: CPU: 0 PID: 0 at .../drivers/tty/vt/vt.c:3846 con_is_visible+0x50/0x74
    CPU: 0 PID: 0 Comm: swapper/0 Not tainted 5.3.0-rc1+ #48
    Hardware name: Rockchip (Device Tree)
    Backtrace:
    [<c020ce9c>] (dump_backtrace) from [<c020d188>] (show_stack+0x20/0x24)
    [<c020d168>] (show_stack) from [<c0a8fc14>] (dump_stack+0xb0/0xd0)
    [<c0a8fb64>] (dump_stack) from [<c0232c58>] (__warn+0xec/0x11c)
    [<c0232b6c>] (__warn) from [<c0232dc4>] (warn_slowpath_null+0x4c/0x58)
    [<c0232d78>] (warn_slowpath_null) from [<c06338a0>] (con_is_visible+0x50/0x74)
    [<c0633850>] (con_is_visible) from [<c0634078>] (con_scroll+0x108/0x1ac)
    [<c0633f70>] (con_scroll) from [<c0634160>] (lf+0x44/0x88)
    [<c063411c>] (lf) from [<c06363ec>] (vt_console_print+0x1a4/0x2bc)
    [<c0636248>] (vt_console_print) from [<c02f628c>] (vkdb_printf+0x420/0x8a4)
    [<c02f5e6c>] (vkdb_printf) from [<c02f6754>] (kdb_printf+0x44/0x60)
    [<c02f6714>] (kdb_printf) from [<c02fa6f4>] (kdb_main_loop+0xf4/0x6e0)
    [<c02fa600>] (kdb_main_loop) from [<c02fd5f0>] (kdb_stub+0x268/0x398)
    [<c02fd388>] (kdb_stub) from [<c02f3ba0>] (kgdb_cpu_enter+0x1f8/0x674)
    [<c02f39a8>] (kgdb_cpu_enter) from [<c02f4330>] (kgdb_handle_exception+0x1c4/0x1fc)
    [<c02f416c>] (kgdb_handle_exception) from [<c0210fe0>] (kgdb_compiled_brk_fn+0x30/0x3c)
    [<c0210fb0>] (kgdb_compiled_brk_fn) from [<c020d7ac>] (do_undefinstr+0x180/0x1a0)
    [<c020d62c>] (do_undefinstr) from [<c0201b44>] (__und_svc_finish+0x0/0x3c)
    ...
    [<c02f3224>] (kgdb_breakpoint) from [<c02f3310>] (sysrq_handle_dbg+0x58/0x6c)
    [<c02f32b8>] (sysrq_handle_dbg) from [<c062abf0>] (__handle_sysrq+0xac/0x154)
    
    Let's disable this warning when we're in kgdb to avoid the spew.  The
    whole system is stopped when we're in kgdb so we can't exactly wait
    for someone else to drop the lock.  Presumably the best we can do is
    to disable the warning and hope for the best.
    
    Fixes: ddde3c18 ("vt: More locking checks")
    Cc: Daniel Vetter <daniel.vetter@intel.com>
    Signed-off-by: 's avatarDouglas Anderson <dianders@chromium.org>
    Link: https://lore.kernel.org/r/20190725183551.169208-1-dianders@chromium.orgSigned-off-by: 's avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
    81eaadca
Name
Last commit
Last update
..
hvc Loading commit data...
ipwireless Loading commit data...
serdev Loading commit data...
serial Loading commit data...
vt Loading commit data...
Kconfig Loading commit data...
Makefile Loading commit data...
amiserial.c Loading commit data...
cyclades.c Loading commit data...
ehv_bytechan.c Loading commit data...
goldfish.c Loading commit data...
isicom.c Loading commit data...
mips_ejtag_fdc.c Loading commit data...
moxa.c Loading commit data...
moxa.h Loading commit data...
mxser.c Loading commit data...
mxser.h Loading commit data...
n_gsm.c Loading commit data...
n_hdlc.c Loading commit data...
n_null.c Loading commit data...
n_r3964.c Loading commit data...
n_tracerouter.c Loading commit data...
n_tracesink.c Loading commit data...
n_tracesink.h Loading commit data...
n_tty.c Loading commit data...
nozomi.c Loading commit data...
pty.c Loading commit data...
rocket.c Loading commit data...
rocket.h Loading commit data...
rocket_int.h Loading commit data...
synclink.c Loading commit data...
synclink_gt.c Loading commit data...
synclinkmp.c Loading commit data...
sysrq.c Loading commit data...
tty_audit.c Loading commit data...
tty_baudrate.c Loading commit data...
tty_buffer.c Loading commit data...
tty_io.c Loading commit data...
tty_ioctl.c Loading commit data...
tty_jobctrl.c Loading commit data...
tty_ldisc.c Loading commit data...
tty_ldsem.c Loading commit data...
tty_mutex.c Loading commit data...
tty_port.c Loading commit data...
ttynull.c Loading commit data...
vcc.c Loading commit data...