Iliyan Malchev 2c1417b43a Serial: add input path overriding stdin for --serial ... Allowing the input to be specified for file-based serial ports allows the user of pipes as input/output. That enables kgdb over serial. TEST= Build a kernel with support for gdb ``` make x86_64_defconfig make kvmconfig ./scripts/config --enable GDB_SCRIPTS ./scripts/config --enable KGDB ./scripts/config --enable KGDB_SERIAL_CONSOLE ./scripts/config --enable KGDB_LOW_LEVEL_TRAP ./scripts/config --enable KGDB_KDB ./scripts/config --enable KDB_KEYBOARD ./scripts/config --enable GDB_SCRIPTS ./scripts/config --set-val KDB_CONTINUE_CATASTROPHIC 0 make -j33 ``` Setup devices for PTYs To make sure crosvm doesn't create an ordinary file if socat is started after it, create these named pipes first: ``` mkfifo ~/console_{in,out} ~/kgdb_{in,out} ``` Set up two PTYs: ~/kgdb for the debugger, and ~/serial for the console. PTY ~/kgdb connects to ~/kgdb{in,out}, and ~/serial connects to ~/console{in,out} ``` socat -d -d -d \ 'PIPE:$HOME/console_out,rdonly=1,nonblock=1,ignoreeof=1!!PIPE:$HOME/console_in,wronly=1' \ PTY,link=$HOME/serial,ctty,raw,echo=0 socat -d -d -d \ 'PIPE:$HOME/kgdb_out,rdonly=1,nonblock=1,ignoreeof=1!!PIPE:$HOME/kgdb_in,wronly=1' \ PTY,link=$HOME/kgdb,ctty,raw,echo=0 ``` Start crosvm with serial ports pointed at ~/console{in,out} and ~/kgdb{in,out}. ``` cargo run run -p 'init=/bin/sh panic=0 kgdboc=ttyS1,115200 kgdbwait kgdbcon' \ --serial type=file,path=$HOME/console_out,num=1,console=true,stdin=false,input=$HOME/console_in \ --serial type=file,path=$HOME/kgdb_out,input=$HOME/kgdb_in,num=2,console=false,stdin=false \ -r ~/rootfs.img \ ~/src/linux/arch/x86/boot/bzImage ``` Start GDB ``` gdb vmlinux -ex "target remote /home/dgreid/kgdb" ``` To break into gdb, open up the serial console, mount /proc and send a SysRq ``` minicom -D ~/serial mount -t proc none /proc echo g > /proc/sysrq-trigger ``` Change-Id: I18a9c1087d38301df49de08eeae2f8559b03463a Reviewed-on: https://chromium-review.googlesource.com/c/chromiumos/platform/crosvm/+/2151856 Reviewed-by: Daniel Verkamp <dverkamp@chromium.org> Tested-by: Dylan Reid <dgreid@chromium.org> Commit-Queue: Dylan Reid <dgreid@chromium.org>		2020-04-19 22:22:46 +00:00
..
boot.rs	Serial: add input path overriding stdin for --serial	2020-04-19 22:22:46 +00:00
mini_plugin_template.c	add support for accessing debug registers in the plugin process	2018-02-12 22:42:35 -08:00
plugin.policy	crosvm: pre-cache answers to plugin get calls	2019-10-31 06:18:09 +00:00
plugin_adder.c	allow non-dirty log memory regions from the plugin process	2018-02-12 22:42:37 -08:00
plugin_async_write.c	crosvm: add plugin API for async writes	2019-11-06 23:01:15 +00:00
plugin_dirty_log.c	allow non-dirty log memory regions from the plugin process	2018-02-12 22:42:37 -08:00
plugin_enable_cap.c	crosvm: add handling for hyperv exits	2020-03-05 19:01:24 +00:00
plugin_extensions.c	allow plugin to query for KVM extensions	2018-02-12 22:42:40 -08:00
plugin_hint.c	crosvm: pre-cache answers to plugin get calls	2019-10-31 06:18:09 +00:00
plugin_ioevent.c	allow non-dirty log memory regions from the plugin process	2018-02-12 22:42:37 -08:00
plugin_irqfd.c	allow non-dirty log memory regions from the plugin process	2018-02-12 22:42:37 -08:00
plugin_msr_index_list.c	plugin: allow retrieving list of supported MSRs	2018-07-31 16:37:06 -07:00
plugin_net_config.c	plugin: add missing #include <string.h> in test	2019-10-22 00:09:26 +00:00
plugin_supported_cpuid.c	crosvm: support kvm's hyper-v cpuid ioctl	2020-02-20 02:12:01 +00:00
plugin_vcpu_pause.c	tests: avoid internal error in pause test	2020-02-19 23:05:34 +00:00
plugin_vm_state.c	plugin: allow retrieving and setting VM clock	2019-01-22 21:05:18 -08:00
plugins.rs	crosvm: Apply cargo fix for some clippy errors	2020-04-15 18:01:32 +00:00
vfs_crypto.c	devices: fs: Support fs crypto ioctls	2019-12-10 03:10:57 +00:00