genode/repos/os/src/app/cli_monitor/gdb_command.h

554 lines
18 KiB
C++

/*
* \brief Gdb command
* \author Norman Feske
* \author Christian Prochaska
* \date 2013-03-18
*/
/*
* Copyright (C) 2013 Genode Labs GmbH
*
* This file is part of the Genode OS framework, which is distributed
* under the terms of the GNU General Public License version 2.
*/
#ifndef _GDB_COMMAND_H_
#define _GDB_COMMAND_H_
/* Genode includes */
#include <base/elf.h>
#include <os/attached_rom_dataspace.h>
#include <rom_session/connection.h>
#include <util/arg_string.h>
#include <util/xml_node.h>
/* public CLI-monitor includes */
#include <cli_monitor/ram.h>
/* local includes */
#include <child_registry.h>
#include <gdb_prefix.h>
#include <format_util.h>
#include <subsystem_config_registry.h>
class Gdb_command_child : public Child
{
private:
Genode::Signal_context_capability _kill_gdb_sig_cap;
Genode::Signal_context_capability _exit_sig_cap;
Terminal::Session &_terminal;
bool _kill_requested;
void _kill_gdb()
{
_kill_requested = true;
Genode::Signal_transmitter(_kill_gdb_sig_cap).submit();
}
public:
Gdb_command_child(Ram &ram,
char const *label,
char const *binary,
Genode::Cap_session &cap_session,
Genode::size_t ram_quota,
Genode::size_t ram_limit,
Genode::Signal_context_capability yield_response_sig_cap,
Genode::Signal_context_capability kill_gdb_sig_cap,
Genode::Signal_context_capability exit_sig_cap,
Terminal::Session &terminal)
: Child(ram, label, binary, cap_session, ram_quota, ram_limit,
yield_response_sig_cap, exit_sig_cap),
_kill_gdb_sig_cap(kill_gdb_sig_cap),
_exit_sig_cap(exit_sig_cap),
_terminal(terminal),
_kill_requested(false)
{ }
bool kill_requested() const { return _kill_requested; }
/*
* Check if GDB-related (Noux) session-requests will be successful.
* If not, terminate the subsystem and tell the user about it.
*/
Genode::Service *resolve_session_request(const char *service_name,
const char *args)
{
if (_kill_requested)
return 0;
Genode::Service *service =
Child::resolve_session_request(service_name, args);
if (!service) {
tprintf(_terminal, "Error: GDB subsystem session request for service '%s' failed\n",
service_name);
PDBG("session request failed: service_name = %s, args = %s", service_name, args);
_kill_gdb();
return 0;
}
/* Find out if the session request comes from Noux */
const char *noux_label_suffix = " -> noux";
/* Arg::string() needs two extra bytes */
size_t label_size = strlen(name()) + strlen(noux_label_suffix) + 2;
char noux_label_buf[label_size];
snprintf(noux_label_buf, sizeof(noux_label_buf),
"%s%s", name(), noux_label_suffix);
char label_buf[label_size];
Genode::Arg_string::find_arg(args, "label").string(label_buf,
sizeof(label_buf),
"");
if (strcmp(label_buf, noux_label_buf, label_size) == 0) {
/* Try to create and close the session */
try {
Genode::Session_capability s = service->session(args, Genode::Affinity());
service->close(s);
} catch (...) {
tprintf(_terminal, "Error: GDB subsystem session request for service '%s' failed\n",
service_name);
PDBG("session request failed: service_name = %s, args = %s", service_name, args);
_kill_gdb();
return 0;
}
}
return service;
}
};
class Gdb_command : public Command
{
private:
typedef Genode::Xml_node Xml_node;
typedef Genode::Signal_context_capability Signal_context_capability;
struct Child_configuration_failed {}; /* exception */
Ram &_ram;
Child_registry &_children;
Genode::Cap_session &_cap;
Subsystem_config_registry &_subsystem_configs;
Signal_context_capability _yield_response_sigh_cap;
Signal_context_capability _kill_gdb_sig_cap;
Signal_context_capability _exit_sig_cap;
/**
* Generate the config node for the GDB subsystem
*/
Xml_node _gdb_config_node(const char *binary_name,
const char *target_config_addr,
const size_t target_config_size,
Genode::Number_of_bytes gdb_ram_preserve,
Terminal::Session &terminal)
{
/* local exception types */
struct Config_buffer_overflow { };
struct Binary_elf_check_failed { };
try {
Genode::Attached_rom_dataspace gdb_command_config_ds("gdb_command_config");
enum { CONFIG_BUF_SIZE = 4*1024 };
static char config_buf[CONFIG_BUF_SIZE];
int config_bytes_written = 0;
/*
* Copy the first part of the config file template
*/
Xml_node init_config_node(gdb_command_config_ds.local_addr<const char>(),
gdb_command_config_ds.size());
Xml_node noux_node = init_config_node.sub_node("start");
for (;; noux_node = noux_node.next("start"))
if (noux_node.attribute("name").has_value("noux"))
break;
Xml_node noux_config_node = noux_node.sub_node("config");
/* Genode::strncpy() makes the last character '\0', so we need to add 1 byte */
size_t bytes_to_copy = (Genode::addr_t)noux_config_node.content_addr() -
(Genode::addr_t)init_config_node.addr() + 1;
if ((sizeof(config_buf) - config_bytes_written) < bytes_to_copy)
throw Config_buffer_overflow();
strncpy(&config_buf[config_bytes_written],
init_config_node.addr(),
bytes_to_copy);
/* subtract the byte for '\0' again */
config_bytes_written += bytes_to_copy - 1;
/*
* Create the GDB arguments for breaking in 'main()'
*/
enum { GDB_MAIN_BREAKPOINT_ARGS_BUF_SIZE = 768 };
static char gdb_main_breakpoint_args_buf[GDB_MAIN_BREAKPOINT_ARGS_BUF_SIZE];
try {
Genode::Attached_rom_dataspace binary_rom_ds(binary_name);
Genode::Elf_binary elf_binary((Genode::addr_t)binary_rom_ds.local_addr<void>());
if (elf_binary.is_dynamically_linked()) {
snprintf(gdb_main_breakpoint_args_buf,
sizeof(gdb_main_breakpoint_args_buf),
"<arg value=\"-ex\" /><arg value=\"symbol-file /gdb/ld.lib.so\" />\n \
<arg value=\"-ex\" /><arg value=\"b call_program_main\" />\n \
<arg value=\"-ex\" /><arg value=\"c\" />\n \
<arg value=\"-ex\" /><arg value=\"delete 1\" />\n \
<arg value=\"-ex\" /><arg value=\"symbol-file /gdb/%s\" />\n \
<arg value=\"-ex\" /><arg value=\"b main()\" />\n \
<arg value=\"-ex\" /><arg value=\"set solib-search-path /gdb\" />\n \
<arg value=\"-ex\" /><arg value=\"sharedlibrary\" />\n \
<arg value=\"-ex\" /><arg value=\"c\" />\n \
<arg value=\"-ex\" /><arg value=\"delete 2\" />\n",
binary_name);
} else {
snprintf(gdb_main_breakpoint_args_buf,
sizeof(gdb_main_breakpoint_args_buf),
"<arg value=\"-ex\" /><arg value=\"symbol-file /gdb/%s\" />\n \
<arg value=\"-ex\" /><arg value=\"b main\" />\n \
<arg value=\"-ex\" /><arg value=\"c\" />\n \
<arg value=\"-ex\" /><arg value=\"delete 1\" />\n",
binary_name);
}
} catch (...) {
throw Binary_elf_check_failed();
}
/*
* Insert the '<start>' node for 'noux'
*/
config_bytes_written += snprintf(&config_buf[config_bytes_written],
sizeof(config_buf) - config_bytes_written, "\n \
<start name=\"/bin/%sgdb\">\n \
<arg value=\"/gdb/%s\"/>\n \
<arg value=\"-ex\" /><arg value=\"set interactive-mode off\" />\n \
<arg value=\"-ex\" /><arg value=\"directory /gdb/src\" />\n \
<arg value=\"-ex\" /><arg value=\"target remote /dev/gdb\" />\n \
%s \
<arg value=\"-ex\" /><arg value=\"set interactive-mode auto\" />\n \
</start>",
gdb_prefix,
binary_name,
gdb_main_breakpoint_args_buf);
/*
* Copy the second part of the config file template
*/
Xml_node gdb_monitor_node = noux_node.next("start");
/* Genode::strncpy() makes the last character '\0', so we need to add 1 byte */
bytes_to_copy = (Genode::addr_t)gdb_monitor_node.content_addr() -
(Genode::addr_t)noux_config_node.content_addr() + 1;
if ((sizeof(config_buf) - config_bytes_written) < bytes_to_copy)
throw Config_buffer_overflow();
strncpy(&config_buf[config_bytes_written],
noux_config_node.content_addr(),
bytes_to_copy);
/* subtract the byte for '\0' again */
config_bytes_written += bytes_to_copy - 1;
/*
* Create a zero-terminated string for the GDB target config node
*/
char target_config[target_config_size + 1];
if (target_config_addr)
Genode::strncpy(target_config, target_config_addr, sizeof(target_config));
else
target_config[0] = '\0';
/*
* Insert the '<config>' node for 'gdb_monitor'
*/
config_bytes_written += Genode::snprintf(&config_buf[config_bytes_written],
(sizeof(config_buf) - config_bytes_written), "\n \
<config>\n \
<target name=\"%s\">\n \
%s \
</target>\n \
<preserve name=\"RAM\" quantum=\"%zu\"/>\n \
</config> \
",
binary_name,
target_config,
(size_t)gdb_ram_preserve);
/*
* Copy the third (and final) part of the config file template
*/
/* Genode::strncpy() makes the last character '\0', so we need to add 1 byte */
bytes_to_copy = ((Genode::addr_t)init_config_node.addr() +
init_config_node.size()) -
(Genode::addr_t)gdb_monitor_node.content_addr() + 1;
if ((sizeof(config_buf) - config_bytes_written) < bytes_to_copy)
throw Config_buffer_overflow();
strncpy(&config_buf[config_bytes_written],
gdb_monitor_node.content_addr(),
bytes_to_copy);
/* subtract the byte for '\0' again */
config_bytes_written += bytes_to_copy - 1;
return Xml_node(config_buf, config_bytes_written);
} catch (Config_buffer_overflow) {
tprintf(terminal, "Error: the buffer for the generated GDB "
"subsystem configuration is too small.\n");
throw Child_configuration_failed();
} catch (Binary_elf_check_failed) {
tprintf(terminal, "Error: could not determine link type of the "
"GDB target binary.\n");
throw Child_configuration_failed();
}
}
void _execute_subsystem(char const *name, Command_line &cmd,
Terminal::Session &terminal,
Xml_node subsystem_node)
{
Genode::Number_of_bytes ram = 0;
Genode::Number_of_bytes ram_limit = 0;
Genode::Number_of_bytes gdb_ram_preserve = 10*1024*1024;
/* read default RAM quota from config */
try {
Xml_node rsc = subsystem_node.sub_node("resource");
for (;; rsc = rsc.next("resource")) {
if (rsc.attribute("name").has_value("RAM")) {
rsc.attribute("quantum").value(&ram);
if (rsc.has_attribute("limit"))
rsc.attribute("limit").value(&ram_limit);
break;
}
}
} catch (...) { }
cmd.parameter("--ram", ram);
cmd.parameter("--ram-limit", ram_limit);
cmd.parameter("--gdb-ram-preserve", gdb_ram_preserve);
/* account for cli_monitor local metadata */
size_t preserve_ram = 100*1024;
if ((ram + preserve_ram) > Genode::env()->ram_session()->avail()) {
tprintf(terminal, "Error: RAM quota exceeds available quota\n");
return;
}
bool const verbose = cmd.parameter_exists("--verbose");
/*
* Determine binary name
*
* Use subsystem name by default, override with '<binary>' declaration.
*/
char binary_name[128];
strncpy(binary_name, name, sizeof(binary_name));
try {
Xml_node bin = subsystem_node.sub_node("binary");
bin.attribute("name").value(binary_name, sizeof(binary_name));
} catch (...) { }
/* generate unique child name */
char label[Child_registry::CHILD_NAME_MAX_LEN];
_children.unique_child_name(name, label, sizeof(label));
tprintf(terminal, "starting new subsystem '%s'\n", label);
if (verbose) {
tprintf(terminal, " RAM quota: ");
tprint_bytes(terminal, ram);
tprintf(terminal,"\n");
if (ram_limit) {
tprintf(terminal, " RAM limit: ");
tprint_bytes(terminal, ram_limit);
tprintf(terminal,"\n");
}
tprintf(terminal, " binary: %s\n", binary_name);
}
Child *child = 0;
try {
/* create child configuration */
const char *target_config_addr = 0;
size_t target_config_size = 0;
try {
Xml_node target_config_node = subsystem_node.sub_node("config");
target_config_addr = target_config_node.addr();
target_config_size = target_config_node.size();
} catch (...) { }
Xml_node config_node = _gdb_config_node(binary_name,
target_config_addr,
target_config_size,
gdb_ram_preserve,
terminal);
/* create child */
child = new (Genode::env()->heap())
Gdb_command_child(_ram, label, "init", _cap, ram, ram_limit,
_yield_response_sigh_cap, _kill_gdb_sig_cap,
_exit_sig_cap, terminal);
/* configure child */
try {
child->configure(config_node.addr(), config_node.size());
if (verbose)
tprintf(terminal, " config: inline\n");
} catch (...) {
if (verbose)
tprintf(terminal, " config: none\n");
}
}
catch (Child_configuration_failed) {
return;
}
catch (Genode::Rom_connection::Rom_connection_failed) {
tprintf(terminal, "Error: could not obtain ROM module \"%s\"\n",
binary_name);
return;
}
catch (Child::Quota_exceeded) {
tprintf(terminal, "Error: insufficient memory, need ");
tprint_bytes(terminal, ram + Child::DONATED_RAM_QUOTA);
tprintf(terminal, ", have ");
tprint_bytes(terminal, Genode::env()->ram_session()->avail());
tprintf(terminal, "\n");
return;
}
catch (Genode::Allocator::Out_of_memory) {
tprintf(terminal, "Error: could not allocate meta data, out of memory\n");
return;
}
_children.insert(child);
child->start();
}
public:
Gdb_command(Ram &ram, Genode::Cap_session &cap, Child_registry &children,
Subsystem_config_registry &subsustem_configs,
Signal_context_capability yield_response_sigh_cap,
Signal_context_capability kill_gdb_sig_cap,
Signal_context_capability exit_sig_cap)
:
Command("gdb", "create new subsystem with GDB"),
_ram(ram), _children(children), _cap(cap),
_subsystem_configs(subsustem_configs),
_yield_response_sigh_cap(yield_response_sigh_cap),
_kill_gdb_sig_cap(kill_gdb_sig_cap),
_exit_sig_cap(exit_sig_cap)
{
add_parameter(new Parameter("--ram", Parameter::NUMBER, "initial RAM quota"));
add_parameter(new Parameter("--ram-limit", Parameter::NUMBER, "limit for expanding RAM quota"));
add_parameter(new Parameter("--gdb-ram-preserve", Parameter::NUMBER,
"RAM quota which GDB monitor should preserve for itself (default: 5M)"));
add_parameter(new Parameter("--verbose", Parameter::VOID, "show diagnostics"));
}
void _for_each_argument(Argument_fn const &fn) const override
{
/* functor for processing a subsystem configuration */
auto process_subsystem_config_fn = [&] (Genode::Xml_node node) {
char name[Parameter::Name::size()];
try { node.attribute("name").value(name, sizeof(name)); }
catch (Xml_node::Nonexistent_attribute) {
PWRN("Missing name in '<subsystem>' configuration");
return;
}
char const *prefix = "config: ";
size_t const prefix_len = strlen(prefix);
char help[Parameter::Short_help::size() + prefix_len];
strncpy(help, prefix, ~0);
try { node.attribute("help").value(help + prefix_len,
sizeof(help) - prefix_len); }
catch (Xml_node::Nonexistent_attribute) {
PWRN("Missing help in '<subsystem>' configuration");
return;
}
Argument arg(name, help);
fn(arg);
};
/* scan subsystem config registry for possible subsystem arguments */
_subsystem_configs.for_each_config(process_subsystem_config_fn);
}
void execute(Command_line &cmd, Terminal::Session &terminal)
{
/* check if the GDB-related ROM modules are available */
try {
Genode::Rom_connection gdb_command_config("gdb_command_config");
Genode::Rom_connection terminal_crosslink("terminal_crosslink");
Genode::Rom_connection noux("noux");
Genode::Rom_connection gdb_monitor("gdb_monitor");
} catch (Genode::Rom_connection::Rom_connection_failed) {
tprintf(terminal, "Error: The 'gdb' command needs the following ROM "
"modules (of which some are currently missing): "
"gdb_command_config, terminal_crosslink, noux, ",
"gdb_monitor\n");
return;
}
char name[128];
name[0] = 0;
if (cmd.argument(0, name, sizeof(name)) == false) {
tprintf(terminal, "Error: no configuration name specified\n");
return;
}
char buf[128];
if (cmd.argument(1, buf, sizeof(buf))) {
tprintf(terminal, "Error: unexpected argument \"%s\"\n", buf);
return;
}
try {
_subsystem_configs.for_config(name, [&] (Genode::Xml_node node)
{
_execute_subsystem(name, cmd, terminal, node);
});
} catch (Subsystem_config_registry::Nonexistent_subsystem_config) {
tprintf(terminal, "Error: no configuration for \"%s\"\n", name);
}
}
};
#endif /* _GDB_COMMAND_H_ */