RISC-V and Arm Linux Kernel Hacks

Why I added new features to crash tool?

Sometimes, some linux kernel in another platform are missing struct task_struct.sched_info.last_arrival element. For this matter, it is hard to know how the processes are executed at the time of order.

The "ps -e" command allows for listing the process at the time of order based on execution launching time.

crash> ps -e

ps: exec_start - task_struct.se.exec_start will be displayed at the time of order

2123 1 4 e2d8ca40 IN 0.2 33324 7556 Aat_key_press

36 2 4 eb5d9440 IN 0.0 0 0 [ksoftirqd/4]

2118 1 4 e203c380 UN 0.2 33324 7556 func_keypress

904 1 4 d0f04380 IN 0.1 57988 3148 thermal-engine

1783 1 4 e59e9b00 UN 0.3 50144 13760 wireless_cmdmgr

1250 1 4 e6eaaf40 UN 0.0 14724 1668 mtsd

347 2 4 c4f9e540 UN 0.0 0 0 [mmc-cmdqd/0]

713 2 4 ccdee540 IN 0.0 0 0 [kworker/u16:9]

1701 1677 4 e58f86c0 UN 0.0 3944 1672 kernel_logger

342 2 4 c4f98000 IN 0.0 0 0 [cfinteractive]

> 545 1 7 e91bc380 RU 0.4 127608 15532 Binder:482_2

1793 1 5 e58fbcc0 IN 0.1 19544 2832 MSensorControl

> 1901 1 5 e4bf6540 RU 0.1 64628 5348 TouchLocation

544 1 5 e91baf40 IN 0.4 127608 15532 DispSync

616 1 5 e92d2880 IN 0.4 127608 15532 EventThread

1878 1 5 e4ba3cc0 IN 0.1 82996 5608 SensorEventAckR

As sanity-test, it proves that output of "ps -e" command is the same as that of "ps -l" command.

crash> ps -l

[303201734830] [IN] PID: 2123 TASK: e2d8ca40 CPU: 4 COMMAND: "Aat_key_press"

[303200690976] [IN] PID: 36 TASK: eb5d9440 CPU: 4 COMMAND: "ksoftirqd/4"

[303163325351] [UN] PID: 2118 TASK: e203c380 CPU: 4 COMMAND: "func_keypress"

[303160294830] [IN] PID: 904 TASK: d0f04380 CPU: 4 COMMAND: "thermal-engine"

[303113625611] [UN] PID: 1783 TASK: e59e9b00 CPU: 4 COMMAND: "wireless_cmdmgr"

[303113595247] [UN] PID: 1250 TASK: e6eaaf40 CPU: 4 COMMAND: "mtsd"

[303113557955] [UN] PID: 347 TASK: c4f9e540 CPU: 4 COMMAND: "mmc-cmdqd/0"

[303113325299] [IN] PID: 713 TASK: ccdee540 CPU: 4 COMMAND: "kworker/u16:9"

[303112047955] [UN] PID: 1701 TASK: e58f86c0 CPU: 4 COMMAND: "kernel_logger"

[303111794049] [IN] PID: 342 TASK: c4f98000 CPU: 4 COMMAND: "cfinteractive"

[303090714882] [RU] PID: 1901 TASK: e4bf6540 CPU: 5 COMMAND: "TouchLocation"

[303090673424] [IN] PID: 1793 TASK: e58fbcc0 CPU: 5 COMMAND: "MSensorControl"

[303084315090] [IN] PID: 544 TASK: e91baf40 CPU: 5 COMMAND: "DispSync"

[303084262278] [IN] PID: 616 TASK: e92d2880 CPU: 5 COMMAND: "EventThread"

[303083165715] [IN] PID: 1878 TASK: e4ba3cc0 CPU: 5 COMMAND: "SensorEventAckR"

As for this project, "ps -l" does not work as below.

crash> ps -l

ps: last-run timestamps do not exist in this kernel

Usage:

ps [-k|-u|-G] [-s] [-p|-c|-t|-[l|m][-C cpu]|-a|-g|-r|-S]

[pid | task | command] ...

Enter "help ps" for details.

crash> ps -e

crash> ps -e

ps: exec_start - task_struct.se.exec_start will be displayed at the time of order

> 31114 2 3 c2385280 RU 0.0 0 0 [kworker/u8:0]

> 21723 2 0 eb33bc80 RU 0.0 0 0 [kworker/u8:3]

20759 1 1 d243b700 IN 0.0 42688 1536 atd

> 29684 1 2 c1c31080 RU 0.0 0 0 thread-pool-0

31741 2 0 c2888580 IN 0.0 0 0 [kworker/0:0]

32030 2 0 cd6c5d80 IN 0.0 0 0 [kworker/u8:2]

757 1 1 dccfb700 IN 0.0 50520 1248 thermal-engine

701 1 1 e4624d00 IN 0.0 10848 904 gbmd

30403 2 3 e6decd00 IN 0.0 0 0 [kworker/3:2]

10 2 0 ee45b180 IN 0.0 0 0 [rcuop/0]

7 2 0 ee45a100 IN 0.0 0 0 [rcu_preempt]

700 1 0 e4623180 IN 0.0 10848 904 gbmd

699 1 0 e4623c80 IN 0.0 10848 904 gbmd

32291 1 0 e6dee300 IN 0.4 70608 14952 cameraserver

446 1 0 e9de3700 IN 0.0 4868 952 servicemanager

23230 2 1 e6e41080 IN 0.0 0 0 [kworker/1:2]

293 2 0 c3e47380 UN 0.0 0 0 [mmc-cmdqd/0]

289 2 0 c3e45d80 IN 0.0 0 0 [irq/148-7824900]

Patches to add new feature listing the process at the time of order based upon "((struct task_struct).se.exec_start"

diff --git a/defs.h b/defs.h

index a1746cc..c5d26ea 100644

--- a/defs.h

+++ b/defs.h

@@ -952,6 +952,9 @@ struct vaddr_range {

#define MAX_MACHDEP_ARGS 5 /* for --machdep/-m machine-specific args */

struct machdep_table {

ulong flags;

ulong kvbase;

@@ -1719,6 +1722,11 @@ struct offset_table { /* stash of commonly-used offsets */

long vcpu_struct_rq;

long task_struct_sched_info;

long sched_info_last_arrival;

+ long task_struct_sched_entity;

+ long se_exec_start;

+

long page_objects;

long kmem_cache_oo;

long char_device_struct_cdev;

@@ -4426,9 +4434,18 @@ extern long _ZOMBIE_;

#define PS_BY_REGEX (0x8000)

#define PS_NO_HEADER (0x10000)

#define PS_MSECS (0x20000)

+#if 1

+#define PS_EXEC_START (0x40000)

+#define PS_SUMMARY (0x80000)

+#else

#define PS_SUMMARY (0x40000)

+#endif

+#if 1

+#else

+#endif

#define MAX_PS_ARGS (100) /* maximum command-line specific requests */

@@ -5102,6 +5119,9 @@ ulong task_state(ulong);

ulong task_mm(ulong, int);

ulong task_tgid(ulong);

ulonglong task_last_run(ulong);

+#if 1

+ulonglong task_exec_start(ulong);

+#endif

ulong vaddr_in_task_struct(ulong);

int comm_exists(char *);

struct task_context *task_to_context(ulong);

diff --git a/filesys.c b/filesys.c

index 9b59998..68452f5 100644

--- a/filesys.c

+++ b/filesys.c

@@ -3671,7 +3671,7 @@ get_live_memory_source(void)

sprintf(modname1, "%s.o", pc->memory_module);

sprintf(modname2, "%s.ko", pc->memory_module);

while (fgets(buf, BUFSIZE, pipe)) {

- if (strstr(buf, "invalid option") &&

+ if (strstr(buf, "invalid option: filesys.c 3674") &&

(uname(&utsname) == 0)) {

sprintf(buf,

"/lib/modules/%s/kernel/drivers/char/%s",

diff --git a/main.c b/main.c

index 821bb4e..3985448 100644

--- a/main.c

+++ b/main.c

@@ -408,7 +408,7 @@ main(int argc, char **argv)

break;

default:

- error(INFO, "invalid option: %s\n",

+ error(INFO, "main.c @411, invalid option: %s\n",

argv[optind-1]);

program_usage(SHORT_FORM);

}

diff --git a/memory.c b/memory.c

index 216038d..0b97477 100644

--- a/memory.c

+++ b/memory.c

@@ -1756,9 +1756,11 @@ cmd_wr(void)

long size;

struct syment *sp;

+// Guillermo would like to update memory content. 11/22/2016

+#if 0

if (DUMPFILE())

error(FATAL, "not allowed on dumpfiles\n");

-

+#endif

memtype = 0;

buf = NULL;

addr = 0;

diff --git a/symbols.c b/symbols.c

index a8d3563..6d80834 100644

--- a/symbols.c

+++ b/symbols.c

@@ -8497,6 +8497,11 @@ dump_offset_table(char *spec, ulong makestruct)

OFFSET(sched_rt_entity_run_list));

fprintf(fp, " sched_info_last_arrival: %ld\n",

OFFSET(sched_info_last_arrival));

+ error(INFO, "dump_offset_table: Initializing task_struct.se.exec_start\n");

+ fprintf(fp, " se_exec_start: %ld\n",

+ OFFSET(se_exec_start));

fprintf(fp, " task_struct_thread_info: %ld\n",

OFFSET(task_struct_thread_info));

fprintf(fp, " task_struct_nsproxy: %ld\n",

@@ -12518,7 +12523,7 @@ OFFSET_verify(long offset, char *func, char *file, int line, char *item)

if (offset < 0) {

void *retaddr[NUMBER_STACKFRAMES] = { 0 };

SAVE_RETURN_ADDRESS(retaddr);

- sprintf(errmsg, "invalid structure member offset: %s",

+ sprintf(errmsg, "Guillermo: invalid structure member offset: %s",

item);

datatype_error(retaddr, errmsg, func, file, line);

}

diff --git a/task.c b/task.c

index b857cf6..ee3ac45 100644

--- a/task.c

+++ b/task.c

@@ -268,6 +268,23 @@ task_init(void)

strcpy(buf, "alias last ps -l");

alias_init(buf);

}

+

+ MEMBER_OFFSET_INIT(task_struct_sched_entity, "task_struct", "se");

+ error(INFO, "Guillermo: Initializing task_struct.se.exec_start\n");

+ if (VALID_MEMBER(task_struct_sched_entity)) {

+ STRUCT_SIZE_INIT(sched_entity, "sched_entity");

+ MEMBER_OFFSET_INIT(se_exec_start, "sched_entity", "exec_start");

+ char buf[BUFSIZE];

+ strcpy(buf, "alias last ps -e");

+

+ alias_init(buf);

+ if (VALID_MEMBER(se_exec_start)) {

+ error(INFO, "Guillermo:VALID task_struct.se.exec_start\n");

+ }

+

MEMBER_OFFSET_INIT(pid_link_pid, "pid_link", "pid");

MEMBER_OFFSET_INIT(pid_hash_chain, "pid", "hash_chain");

@@ -2471,6 +2488,35 @@ sort_by_pid(const void *arg1, const void *arg2)

t1->pid == t2->pid ? 0 : 1);

}

+static int

+sort_by_exec_start(const void *arg1, const void *arg2)

+{

+ ulong task_last_run_stamp(ulong);

+ struct task_context *t1, *t2;

+ ulonglong lr1, lr2;

+

+ t1 = (struct task_context *)arg1;

+ t2 = (struct task_context *)arg2;

+

+ lr1 = task_exec_start(t1->task);

+ lr2 = task_exec_start(t2->task);

+

+ return (lr2 < lr1 ? -1 :

+ lr2 == lr1 ? 0 : 1);

+}

+

+static void

+sort_context_array_by_exec_start(void)

+{

+ ulong curtask;

+

+ curtask = CURRENT_TASK();

+ qsort((void *)tt->context_array, (size_t)tt->running_tasks,

+ sizeof(struct task_context), sort_by_exec_start);

+ set_context(curtask, NO_PID);

+}

static int

sort_by_last_run(const void *arg1, const void *arg2)

@@ -2897,8 +2943,11 @@ cmd_ps(void)

BZERO(&psinfo, sizeof(struct psinfo));

cpuspec = NULL;

flag = 0;

-

+#if 1

+ while ((c = getopt(argcnt, args, "SgstcpkuGlemarC:")) != EOF) {

+#else

while ((c = getopt(argcnt, args, "SgstcpkuGlmarC:")) != EOF) {

+#endif

switch(c)

{

case 'k':

@@ -2978,7 +3027,18 @@ cmd_ps(void)

check_ps_exclusive(flag, PS_LAST_RUN);

flag |= PS_LAST_RUN;

break;

-

+ case 'e':

+ if (INVALID_MEMBER(se_exec_start)) {

+ error(INFO,

+ "exec_start timestamps do not exist in this kernel\n");

+ argerrs++;

+ break;

+ }

+ check_ps_exclusive(flag, PS_EXEC_START);

+ flag |= PS_EXEC_START;

+ break;

case 's':

flag |= PS_KSTACKP;

break;

@@ -3010,6 +3070,12 @@ cmd_ps(void)

if (flag & (PS_LAST_RUN|PS_MSECS))

sort_context_array_by_last_run();

+ else if (flag & PS_EXEC_START) {

+ error(INFO, "exec_start - task_struct.se.exec_start will be displayed at the time of order\n");

+ sort_context_array_by_exec_start();

+ }

else if (psinfo.cpus) {

error(INFO, "-C option is only applicable with -l and -m\n");

goto bailout;

@@ -5299,6 +5365,26 @@ task_tgid(ulong task)

return (ulong)tgid;

}

+ulonglong

+task_exec_start(ulong task)

+{

+ ulong exec_start;

+ ulonglong timestamp;

+

+ timestamp = 0;

+ fill_task_struct(task);

+

+ if (VALID_MEMBER(se_exec_start)) {

+ timestamp = tt->last_task_read ? ULONGLONG(tt->task_struct +

+ OFFSET(task_struct_sched_entity) +

+ OFFSET(se_exec_start)) : 0;

+ }

+

+ return timestamp;

+}

+

ulonglong

task_last_run(ulong task)

{

[Linux kernel] Enable CONFIG_DEBUG_INFO by reverting CONFIG_DEBUG_INFO_NONE (0)	2024.08.20
[LinuxKernel] Trace32(T32) How to use offsetof/container_of macro? (0)	2019.03.09

RISC-V and Arm Linux Kernel Hacks

[LinuxKernel] Crash-Utility: add new command "ps -e"

Why I added new features to crash tool?

The "ps -e" command allows for listing the process at the time of order based on execution launching time.

As for this project, "ps -l" does not work as below.

'리눅스 커널의 구조와 원리 > 3. 커널 디버깅과 코드 학습' 카테고리의 다른 글

티스토리툴바

[LinuxKernel] Crash-Utility: add new command "ps -e"

Why I added new features to crash tool?

The "ps -e" command allows for listing the process at the time of order based on execution launching time.

As for this project, "ps -l" does not work as below.

'리눅스 커널의 구조와 원리 > 3. 커널 디버깅과 코드 학습' 카테고리의 다른 글

'리눅스 커널의 구조와 원리/3. 커널 디버깅과 코드 학습' Related Articles

티스토리툴바