From: Douglas Anderson dianders@chromium.org
[ Upstream commit 202164fbfa2b2ffa3e66b504e0f126ba9a745006 ]
In commit 81eaadcae81b ("kgdboc: disable the console lock when in kgdb") we avoided the WARN_CONSOLE_UNLOCKED() yell when we were in kgdboc. That still works fine, but it turns out that we get a similar yell when using other I/O drivers. One example is the "I/O driver" for the kgdb test suite (kgdbts). When I enabled that I again got the same yells.
Even though "kgdbts" doesn't actually interact with the user over the console, using it still causes kgdb to print to the consoles. That trips the same warning: con_is_visible+0x60/0x68 con_scroll+0x110/0x1b8 lf+0x4c/0xc8 vt_console_print+0x1b8/0x348 vkdb_printf+0x320/0x89c kdb_printf+0x68/0x90 kdb_main_loop+0x190/0x860 kdb_stub+0x2cc/0x3ec kgdb_cpu_enter+0x268/0x744 kgdb_handle_exception+0x1a4/0x200 kgdb_compiled_brk_fn+0x34/0x44 brk_handler+0x7c/0xb8 do_debug_exception+0x1b4/0x228
Let's increment/decrement the "ignore_console_lock_warning" variable all the time when we enter the debugger.
This will allow us to later revert commit 81eaadcae81b ("kgdboc: disable the console lock when in kgdb").
Signed-off-by: Douglas Anderson dianders@chromium.org Reviewed-by: Greg Kroah-Hartman gregkh@linuxfoundation.org Reviewed-by: Daniel Thompson daniel.thompson@linaro.org Link: https://lore.kernel.org/r/20200507130644.v4.1.Ied2b058357152ebcc8bf68edd6f20... Signed-off-by: Daniel Thompson daniel.thompson@linaro.org Signed-off-by: Sasha Levin sashal@kernel.org --- kernel/debug/debug_core.c | 4 ++++ 1 file changed, 4 insertions(+)
diff --git a/kernel/debug/debug_core.c b/kernel/debug/debug_core.c index 2b7c9b67931d..950dc667c823 100644 --- a/kernel/debug/debug_core.c +++ b/kernel/debug/debug_core.c @@ -668,6 +668,8 @@ return_normal: if (kgdb_skipexception(ks->ex_vector, ks->linux_regs)) goto kgdb_restore;
+ atomic_inc(&ignore_console_lock_warning); + /* Call the I/O driver's pre_exception routine */ if (dbg_io_ops->pre_exception) dbg_io_ops->pre_exception(); @@ -740,6 +742,8 @@ cpu_master_loop: if (dbg_io_ops->post_exception) dbg_io_ops->post_exception();
+ atomic_dec(&ignore_console_lock_warning); + if (!kgdb_single_step) { raw_spin_unlock(&dbg_slave_lock); /* Wait till all the CPUs have quit from the debugger. */