This patch introduces several new flags to collect kdb commands into
groups (later allowing them to be optionally disabled).
This follows similar prior art to enable/disable magic sysrq
commands.
The commands have been categorized as follows:
Always on: go (w/o args), env, set, help, ?, cpu (w/o args), sr,
dmesg, disable_nmi, defcmd, summary, grephelp
Mem read: md, mdr, mdp, mds, ef, bt (with args), per_cpu
Mem write: mm
Reg read: rd
Reg write: go (with args), rm
Inspect: bt (w/o args), btp, bta, btc, btt, ps, pid, lsmod
Flow ctrl: bp, bl, bph, bc, be, bd, ss
Signal: kill
Reboot: reboot
All: cpu, kgdb, (and all of the above), nmi_console
Signed-off-by: Daniel Thompson <daniel.thomp...@linaro.org>
---
include/linux/kdb.h | 52 ++++++++++++++++++++++-
kernel/debug/kdb/kdb_bp.c | 21 ++++++----
kernel/debug/kdb/kdb_main.c | 100 +++++++++++++++++++++++++++++---------------
kernel/trace/trace_kdb.c | 2 +-
4 files changed, 132 insertions(+), 43 deletions(-)
diff --git a/include/linux/kdb.h b/include/linux/kdb.h
index 4b656d6..2f65c7a 100644
--- a/include/linux/kdb.h
+++ b/include/linux/kdb.h
@@ -14,10 +14,58 @@
*/
typedef enum {
- KDB_REPEAT_NO_ARGS = 0x1, /* Repeat the command w/o arguments */
- KDB_REPEAT_WITH_ARGS = 0x2, /* Repeat the command w/ its arguments */
+ KDB_ENABLE_ALL = 0x00000001, /* Enable everything */
+ KDB_ENABLE_MEM_READ = 0x00000002,
+ KDB_ENABLE_MEM_WRITE = 0x00000004,
+ KDB_ENABLE_REG_READ = 0x00000008,
+ KDB_ENABLE_REG_WRITE = 0x00000010,
+ KDB_ENABLE_INSPECT = 0x00000020,
+ KDB_ENABLE_FLOW_CTRL = 0x00000040,
+ KDB_ENABLE_SIGNAL = 0x00000080,
+ KDB_ENABLE_REBOOT = 0x00000100,
+ /* User exposed values stop here, all remaining flags are
+ * exclusively used to describe a commands behaviour.
+ */
+
+ KDB_ENABLE_ALWAYS_SAFE = 0x00000200,
+ KDB_ENABLE_MASK = 0x000003ff,
+
+ KDB_ENABLE_ALL_NO_ARGS = KDB_ENABLE_ALL << 16,
+ KDB_ENABLE_MEM_READ_NO_ARGS = KDB_ENABLE_MEM_READ << 16,
+ KDB_ENABLE_MEM_WRITE_NO_ARGS = KDB_ENABLE_MEM_WRITE << 16,
+ KDB_ENABLE_REG_READ_NO_ARGS = KDB_ENABLE_REG_READ << 16,
+ KDB_ENABLE_REG_WRITE_NO_ARGS = KDB_ENABLE_REG_WRITE << 16,
+ KDB_ENABLE_INSPECT_NO_ARGS = KDB_ENABLE_INSPECT << 16,
+ KDB_ENABLE_FLOW_CTRL_NO_ARGS = KDB_ENABLE_FLOW_CTRL << 16,
+ KDB_ENABLE_SIGNAL_NO_ARGS = KDB_ENABLE_SIGNAL << 16,
+ KDB_ENABLE_REBOOT_NO_ARGS = KDB_ENABLE_REBOOT << 16,
+ KDB_ENABLE_ALWAYS_SAFE_NO_ARGS = KDB_ENABLE_ALWAYS_SAFE << 16,
+ KDB_ENABLE_MASK_NO_ARGS = KDB_ENABLE_MASK << 16,
+
+ KDB_REPEAT_NO_ARGS = 0x40000000, /* Repeat the command w/o arguments */
+ KDB_REPEAT_WITH_ARGS = 0x80000000, /* Repeat the command with args */
} kdb_cmdflags_t;
+/*
+ * Check whether the flags of the current command and the permissions
+ * of the kdb console has allow a command to be run.
+ */
+static inline bool kdb_check_flags(kdb_cmdflags_t flags, int permissions,
+ bool no_args)
+{
+ /* permissions comes from userspace so needs massaging slightly */
+ permissions &= KDB_ENABLE_MASK;
+ permissions |= KDB_ENABLE_ALWAYS_SAFE;
+
+ /* some commands change group when launched with no arguments */
+ if (no_args)
+ permissions |= permissions << 16;
+
+ flags |= KDB_ENABLE_ALL;
+
+ return permissions & flags;
+}
+
typedef int (*kdb_func_t)(int, const char **);
#ifdef CONFIG_KGDB_KDB
diff --git a/kernel/debug/kdb/kdb_bp.c b/kernel/debug/kdb/kdb_bp.c
index 87343f0..f5b3d89 100644
--- a/kernel/debug/kdb/kdb_bp.c
+++ b/kernel/debug/kdb/kdb_bp.c
@@ -532,21 +532,28 @@ void __init kdb_initbptab(void)
bp->bp_free = 1;
kdb_register_flags("bp", kdb_bp, "[<vaddr>]",
- "Set/Display breakpoints", 0, KDB_REPEAT_NO_ARGS);
+ "Set/Display breakpoints", 0,
+ KDB_ENABLE_FLOW_CTRL | KDB_REPEAT_NO_ARGS);
kdb_register_flags("bl", kdb_bp, "[<vaddr>]",
- "Display breakpoints", 0, KDB_REPEAT_NO_ARGS);
+ "Display breakpoints", 0,
+ KDB_ENABLE_FLOW_CTRL | KDB_REPEAT_NO_ARGS);
if (arch_kgdb_ops.flags & KGDB_HW_BREAKPOINT)
kdb_register_flags("bph", kdb_bp, "[<vaddr>]",
- "[datar [length]|dataw [length]] Set hw brk", 0,
KDB_REPEAT_NO_ARGS);
+ "[datar [length]|dataw [length]] Set hw brk", 0,
+ KDB_ENABLE_FLOW_CTRL | KDB_REPEAT_NO_ARGS);
kdb_register_flags("bc", kdb_bc, "<bpnum>",
- "Clear Breakpoint", 0, 0);
+ "Clear Breakpoint", 0,
+ KDB_ENABLE_FLOW_CTRL);
kdb_register_flags("be", kdb_bc, "<bpnum>",
- "Enable Breakpoint", 0, 0);
+ "Enable Breakpoint", 0,
+ KDB_ENABLE_FLOW_CTRL);
kdb_register_flags("bd", kdb_bc, "<bpnum>",
- "Disable Breakpoint", 0, 0);
+ "Disable Breakpoint", 0,
+ KDB_ENABLE_FLOW_CTRL);
kdb_register_flags("ss", kdb_ss, "",
- "Single Step", 1, KDB_REPEAT_NO_ARGS);
+ "Single Step", 1,
+ KDB_ENABLE_FLOW_CTRL | KDB_REPEAT_NO_ARGS);
/*
* Architecture dependent initialization.
*/
diff --git a/kernel/debug/kdb/kdb_main.c b/kernel/debug/kdb/kdb_main.c
index a40b05b..e88fbb1 100644
--- a/kernel/debug/kdb/kdb_main.c
+++ b/kernel/debug/kdb/kdb_main.c
@@ -641,8 +641,13 @@ static int kdb_defcmd2(const char *cmdstr, const char
*argv0)
if (!s->count)
s->usable = 0;
if (s->usable)
- kdb_register(s->name, kdb_exec_defcmd,
- s->usage, s->help, 0);
+ /* macros are always safe because when executed each
+ * internal command re-enters kdb_parse() and is
+ * safety checked individually.
+ */
+ kdb_register_flags(s->name, kdb_exec_defcmd, s->usage,
+ s->help, 0,
+ KDB_ENABLE_ALWAYS_SAFE);
return 0;
}
if (!s->usable)
@@ -2757,78 +2762,107 @@ static void __init kdb_inittab(void)
kdb_register_flags("md", kdb_md, "<vaddr>",
"Display Memory Contents, also mdWcN, e.g. md8c1", 1,
- KDB_REPEAT_NO_ARGS);
+ KDB_ENABLE_MEM_READ | KDB_REPEAT_NO_ARGS);
kdb_register_flags("mdr", kdb_md, "<vaddr> <bytes>",
- "Display Raw Memory", 0, KDB_REPEAT_NO_ARGS);
+ "Display Raw Memory", 0,
+ KDB_ENABLE_MEM_READ | KDB_REPEAT_NO_ARGS);
kdb_register_flags("mdp", kdb_md, "<paddr> <bytes>",
- "Display Physical Memory", 0, KDB_REPEAT_NO_ARGS);
+ "Display Physical Memory", 0,
+ KDB_ENABLE_MEM_READ | KDB_REPEAT_NO_ARGS);
kdb_register_flags("mds", kdb_md, "<vaddr>",
- "Display Memory Symbolically", 0, KDB_REPEAT_NO_ARGS);
+ "Display Memory Symbolically", 0,
+ KDB_ENABLE_MEM_READ | KDB_REPEAT_NO_ARGS);
kdb_register_flags("mm", kdb_mm, "<vaddr> <contents>",
- "Modify Memory Contents", 0, KDB_REPEAT_NO_ARGS);
+ "Modify Memory Contents", 0,
+ KDB_ENABLE_MEM_WRITE | KDB_REPEAT_NO_ARGS);
kdb_register_flags("go", kdb_go, "[<vaddr>]",
- "Continue Execution", 1, 0);
+ "Continue Execution", 1,
+ KDB_ENABLE_REG_WRITE | KDB_ENABLE_ALWAYS_SAFE_NO_ARGS);
kdb_register_flags("rd", kdb_rd, "",
- "Display Registers", 0, 0);
+ "Display Registers", 0,
+ KDB_ENABLE_REG_READ);
kdb_register_flags("rm", kdb_rm, "<reg> <contents>",
- "Modify Registers", 0, 0);
+ "Modify Registers", 0,
+ KDB_ENABLE_REG_WRITE);
kdb_register_flags("ef", kdb_ef, "<vaddr>",
- "Display exception frame", 0, 0);
+ "Display exception frame", 0,
+ KDB_ENABLE_MEM_READ);
kdb_register_flags("bt", kdb_bt, "[<vaddr>]",
- "Stack traceback", 1, 0);
+ "Stack traceback", 1,
+ KDB_ENABLE_MEM_READ | KDB_ENABLE_INSPECT_NO_ARGS);
kdb_register_flags("btp", kdb_bt, "<pid>",
- "Display stack for process <pid>", 0, 0);
+ "Display stack for process <pid>", 0,
+ KDB_ENABLE_INSPECT);
kdb_register_flags("bta", kdb_bt, "[D|R|S|T|C|Z|E|U|I|M|A]",
- "Backtrace all processes matching state flag", 0, 0);
+ "Backtrace all processes matching state flag", 0,
+ KDB_ENABLE_INSPECT);
kdb_register_flags("btc", kdb_bt, "",
- "Backtrace current process on each cpu", 0, 0);
+ "Backtrace current process on each cpu", 0,
+ KDB_ENABLE_INSPECT);
kdb_register_flags("btt", kdb_bt, "<vaddr>",
"Backtrace process given its struct task address", 0,
- 0);
+ KDB_ENABLE_MEM_READ | KDB_ENABLE_INSPECT_NO_ARGS);
kdb_register_flags("env", kdb_env, "",
- "Show environment variables", 0, 0);
+ "Show environment variables", 0,
+ KDB_ENABLE_ALWAYS_SAFE);
kdb_register_flags("set", kdb_set, "",
- "Set environment variables", 0, 0);
+ "Set environment variables", 0,
+ KDB_ENABLE_ALWAYS_SAFE);
kdb_register_flags("help", kdb_help, "",
- "Display Help Message", 1, 0);
+ "Display Help Message", 1,
+ KDB_ENABLE_ALWAYS_SAFE);
kdb_register_flags("?", kdb_help, "",
- "Display Help Message", 0, 0);
+ "Display Help Message", 0,
+ KDB_ENABLE_ALWAYS_SAFE);
kdb_register_flags("cpu", kdb_cpu, "<cpunum>",
- "Switch to new cpu", 0, 0);
+ "Switch to new cpu", 0,
+ KDB_ENABLE_ALWAYS_SAFE_NO_ARGS);
kdb_register_flags("kgdb", kdb_kgdb, "",
"Enter kgdb mode", 0, 0);
kdb_register_flags("ps", kdb_ps, "[<flags>|A]",
- "Display active task list", 0, 0);
+ "Display active task list", 0,
+ KDB_ENABLE_INSPECT);
kdb_register_flags("pid", kdb_pid, "<pidnum>",
- "Switch to another task", 0, 0);
+ "Switch to another task", 0,
+ KDB_ENABLE_INSPECT);
kdb_register_flags("reboot", kdb_reboot, "",
- "Reboot the machine immediately", 0, 0);
+ "Reboot the machine immediately", 0,
+ KDB_ENABLE_REBOOT);
#if defined(CONFIG_MODULES)
kdb_register_flags("lsmod", kdb_lsmod, "",
- "List loaded kernel modules", 0, 0);
+ "List loaded kernel modules", 0,
+ KDB_ENABLE_INSPECT);
#endif
#if defined(CONFIG_MAGIC_SYSRQ)
kdb_register_flags("sr", kdb_sr, "<key>",
- "Magic SysRq key", 0, 0);
+ "Magic SysRq key", 0,
+ KDB_ENABLE_ALWAYS_SAFE);
#endif
#if defined(CONFIG_PRINTK)
kdb_register_flags("dmesg", kdb_dmesg, "[lines]",
- "Display syslog buffer", 0, 0);
+ "Display syslog buffer", 0,
+ KDB_ENABLE_ALWAYS_SAFE);
#endif
if (arch_kgdb_ops.enable_nmi) {
kdb_register_flags("disable_nmi", kdb_disable_nmi, "",
- "Disable NMI entry to KDB", 0, 0);
+ "Disable NMI entry to KDB", 0,
+ KDB_ENABLE_ALWAYS_SAFE);
}
kdb_register_flags("defcmd", kdb_defcmd, "name \"usage\" \"help\"",
- "Define a set of commands, down to endefcmd", 0, 0);
+ "Define a set of commands, down to endefcmd", 0,
+ KDB_ENABLE_ALWAYS_SAFE);
kdb_register_flags("kill", kdb_kill, "<-signal> <pid>",
- "Send a signal to a process", 0, 0);
+ "Send a signal to a process", 0,
+ KDB_ENABLE_SIGNAL);
kdb_register_flags("summary", kdb_summary, "",
- "Summarize the system", 4, 0);
+ "Summarize the system", 4,
+ KDB_ENABLE_ALWAYS_SAFE);
kdb_register_flags("per_cpu", kdb_per_cpu, "<sym> [<bytes>] [<cpu>]",
- "Display per_cpu variables", 3, 0);
+ "Display per_cpu variables", 3,
+ KDB_ENABLE_MEM_READ);
kdb_register_flags("grephelp", kdb_grep_help, "",
- "Display help on | grep", 0, 0);
+ "Display help on | grep", 0,
+ KDB_ENABLE_ALWAYS_SAFE);
}
/* Execute any commands defined in kdb_cmds. */
diff --git a/kernel/trace/trace_kdb.c b/kernel/trace/trace_kdb.c
index 3da7e30..1058f6b 100644
--- a/kernel/trace/trace_kdb.c
+++ b/kernel/trace/trace_kdb.c
@@ -128,7 +128,7 @@ static int kdb_ftdump(int argc, const char **argv)
static __init int kdb_ftrace_register(void)
{
kdb_register_flags("ftdump", kdb_ftdump, "[skip_#lines] [cpu]",
- "Dump ftrace log", 0, 0);
+ "Dump ftrace log", 0, KDB_ENABLE_ALWAYS_SAFE);
return 0;
}
--
1.9.0
--
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