lkml.org 
[lkml]   [2013]   [Nov]   [21]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
Patch in this message
/
Date
From
SubjectRe: [PATCH]KGTP (Linux Kernel debugger and tracer) lite patch for review
Hi Andi,

Thanks for your help.
Sorry for late so much time.

On Thu, May 24, 2012 at 11:07 PM, Andi Kleen <andi@firstfloor.org> wrote:
>> I remove them from asm files, and add:
>> #ifndef ULONGEST
>> #define ULONGEST uint64_t
>> #endif
>> #ifndef CORE_ADDR
>> #define CORE_ADDR unsigned long
>> #endif
>> in gtp.c
>> Then if not need, the arch didn't define ULONGEST and CORE_ADDR for itself.
>
> Which architecture needs it? Linux prefers to use "native" types.

I removed all of ULONGEST and CORE_ADDR.

>
>> For example ARM and MIPS have a lot of special reg that cannot be converted
>> by a for loop.
>>
>> After check the code the kgdb, I thought that good ways is use dbg_reg_def
>> of kgdb to convert the reg to gdb rsp format. But use it directly will
>> make kgtp depend on kgdb.
>
> That's fine. Code reuse is good. Code duplication is bad.
>
>> What I thought is move this part of code out from kgdb, when kgdb or kgtp
>> need, select it too. But I am not sure Jason is OK with that.
>
> Just send a patch.

I removed the GTP_REG_ASCII_SIZE and gtp_regs2ascii.
Now, to convert pt_reg to gdb format, KGTP use:
pt_regs_to_gdb_regs(gdb_regs, &fr->regs);
kgdb_mem2hex((char *)gdb_regs, gtp_rw_bufp, NUMREGBYTES);

>
>> >
>> >>+ memcpy(&freg->regs, regs, sizeof(struct pt_regs));
>> >>+#ifdef CONFIG_X86_32
>> >>+ freg->regs.sp = (unsigned long)&regs->sp;
>> >>+#endif /* CONFIG_X86_32 */
>> >>+#ifdef CONFIG_X86
>> >>+ freg->regs.ip -= 1;
>> >>+#endif /* CONFIG_X86 */
>> >
>> >What is that for? - 1?
>>
>> That is because when kprobe, the ip of X86 point will have a offset with
>> current ip.
>
> But a kprobe is not necessarily one byte. e.g. a jumper probe is longer.
>
> Anyways if that is really needed there should be some macros provided
> by kprobes to adjust IP. If it's not there it needs to be added.

I changed this part to a function gtp_copy_and_adjuest_regs.

>> >>+
>> >>+ if (gtp_start)
>> >>+ return -EBUSY;
>> >
>> >This is in a lot of places. Can you put it somewhere more central?
>>
>> Sorry I don't understand this part. Do you want I change all "struct
>> gtp_entry *tpe;" to "struct gtp_entry *tpe;"?
>
> I mean the if (gtp_start) return -EBUSY check.
>
>> >
>> >>+ pr_devel("gtp_gdbrsp_QT: %s\n", pkg);
>> >>+
>> >>+ if (strcmp("init", pkg) == 0)
>> >>+ ret = gtp_gdbrsp_qtinit();
>> >
>> >This if cascade should be probably a table walk
>>
>> I cannot find the examle about it in the Kernel, could you give me a
>> example?
>
>
> struct cmd {
> char *name;
> int (*init)(void);
> };
>
> struct cmd cmds[] = {
> { "init", gtp_xyz_init }
> ...
> {}
> };
>
> int i;
> for (i = 0; cmds[i].name; i++)
> if (!strcmp(cmds[i].name, pkg))
> ret = cmds->init();
>

OK. I change gtp_gdbrsp_QT to this format and merge "return -EBUSY" to it together.

>
>> >Ok so what lock protects this buffer?
>>
>> No. The gtp_frame_lock protects the vars that follow it:
>> static int gtp_frame_num;
>> static char *gtp_frame;
>> static char *gtp_frame_r_start;
>> static char *gtp_frame_w_start;
>> static char *gtp_frame_w_end;
>> static char *gtp_frame_r_cache;
>> static int gtp_frame_is_circular;
>> It protects them all.
>>
>> gtp_m_buffer is protected by gtp_rw_lock that I just add in new patch.
>
> Then your comment was wrong/unclear?

This comment is not OK. So I removed it.

>
>>
>>
>> OK. Add some introduce. checkpatch is OK with it.
>
> You must be using an old version?
>
> # check for Kconfig help text having a real description
> # Only applies when adding the entry originally, after that we do not have
> # sufficient context to determine whether it is indeed long enough.
> ...
> WARN("CONFIG_DESCRIPTION",
> "please write a paragraph that describes the config symbol fully\n" . $herecurr) if ($is_start && $is_end && $length < 4);
>
> I wonder how you avoided that.


I am not sure. I checked my checkpatch.py and it has check for description.
My desciption is:
+config GTP
+ tristate "KGTP"
+ depends on X86
+ select KPROBES
+ select DEBUG_FS
+ select KGDB
+ ---help---
+ KGTP is a flexible, lightweight and realtime Linux (include
+ Android) debugger and tracer.
+ It makes Linux Kernel supply a GDB remote debug interface.
+ Then GDB in current machine or remote machine can debug and
+ trace Linux kernel and user space program through GDB tracepoint
+ and some other functions without stopping the Linux Kernel.
+ http://kgtp.googlecode.com/

I post a new version patch.
Please help me review it.

Thanks,
Hui

Signed-off-by: Hui Zhu <teawater@gmail.com>
---
--- a/arch/arc/kernel/kgdb.c
+++ b/arch/arc/kernel/kgdb.c
@@ -61,6 +61,7 @@ void pt_regs_to_gdb_regs(unsigned long *
to_gdb_regs(gdb_regs, kernel_regs, (struct callee_regs *)
current->thread.callee_reg);
}
+EXPORT_SYMBOL_GPL(pt_regs_to_gdb_regs);

void gdb_regs_to_pt_regs(unsigned long *gdb_regs, struct pt_regs *kernel_regs)
{
--- a/arch/blackfin/kernel/kgdb.c
+++ b/arch/blackfin/kernel/kgdb.c
@@ -73,6 +73,7 @@ void pt_regs_to_gdb_regs(unsigned long *
gdb_regs[BFIN_EXTRA3] = 0;
gdb_regs[BFIN_IPEND] = regs->ipend;
}
+EXPORT_SYMBOL_GPL(pt_regs_to_gdb_regs);

/*
* Extracts ebp, esp and eip values understandable by gdb from the values
--- a/arch/microblaze/kernel/kgdb.c
+++ b/arch/microblaze/kernel/kgdb.c
@@ -64,6 +64,7 @@ void pt_regs_to_gdb_regs(unsigned long *
__asm__ __volatile__ ("mfs %0, rtlbhi;" : "=r"(temp) : );
gdb_regs[GDB_RTLBHI] = temp;
}
+EXPORT_SYMBOL_GPL(pt_regs_to_gdb_regs);

void gdb_regs_to_pt_regs(unsigned long *gdb_regs, struct pt_regs *regs)
{
--- a/arch/mn10300/kernel/kgdb.c
+++ b/arch/mn10300/kernel/kgdb.c
@@ -66,6 +66,7 @@ void pt_regs_to_gdb_regs(unsigned long *
gdb_regs[GDB_FR_DUMMY1] = 0;
gdb_regs[GDB_FR_FS0] = 0;
}
+EXPORT_SYMBOL_GPL(pt_regs_to_gdb_regs);

/*
* Extracts kernel SP/PC values understandable by gdb from the values
--- a/arch/sparc/kernel/kgdb_32.c
+++ b/arch/sparc/kernel/kgdb_32.c
@@ -41,6 +41,7 @@ void pt_regs_to_gdb_regs(unsigned long *
gdb_regs[GDB_FSR] = 0;
gdb_regs[GDB_CSR] = 0;
}
+EXPORT_SYMBOL_GPL(pt_regs_to_gdb_regs);

void sleeping_thread_to_gdb_regs(unsigned long *gdb_regs, struct task_struct *p)
{
--- a/arch/sparc/kernel/kgdb_64.c
+++ b/arch/sparc/kernel/kgdb_64.c
@@ -37,6 +37,7 @@ void pt_regs_to_gdb_regs(unsigned long *
gdb_regs[GDB_FPRS] = 0;
gdb_regs[GDB_Y] = regs->y;
}
+EXPORT_SYMBOL_GPL(pt_regs_to_gdb_regs);

void sleeping_thread_to_gdb_regs(unsigned long *gdb_regs, struct task_struct *p)
{
--- /dev/null
+++ b/arch/x86/include/asm/gtp.h
@@ -0,0 +1,16 @@
+#ifndef _ASM_X86_GTP_H_
+#define _ASM_X86_GTP_H_
+
+static inline void gtp_copy_and_adjuest_regs(struct pt_regs *dest,
+ struct pt_regs *src)
+{
+ memcpy(dest, src, sizeof(struct pt_regs));
+
+#ifdef CONFIG_X86_32
+ dest->sp = (unsigned long)&src->sp;
+#endif /* CONFIG_X86_32 */
+
+ dest->ip -= 1;
+}
+
+#endif
--- a/kernel/Makefile
+++ b/kernel/Makefile
@@ -93,6 +93,8 @@ obj-$(CONFIG_CRASH_DUMP) += crash_dump.o
obj-$(CONFIG_JUMP_LABEL) += jump_label.o
obj-$(CONFIG_CONTEXT_TRACKING) += context_tracking.o

+obj-$(CONFIG_GTP) += gtp.o
+
$(obj)/configs.o: $(obj)/config_data.h

# config_data.h contains the same information as ikconfig.h but gzipped.
--- a/kernel/debug/gdbstub.c
+++ b/kernel/debug/gdbstub.c
@@ -258,6 +258,7 @@ char *kgdb_mem2hex(char *mem, char *buf,

return buf;
}
+EXPORT_SYMBOL_GPL(kgdb_mem2hex);

/*
* Convert the hex array pointed to by buf into binary to be placed in
@@ -349,6 +350,7 @@ void pt_regs_to_gdb_regs(unsigned long *
idx += dbg_reg_def[i].size;
}
}
+EXPORT_SYMBOL_GPL(pt_regs_to_gdb_regs);

void gdb_regs_to_pt_regs(unsigned long *gdb_regs, struct pt_regs *regs)
{
--- /dev/null
+++ b/kernel/gtp.c
@@ -0,0 +1,876 @@
+/*
+ * KGTP is a realtime and lightweight Linux debugger and tracer.
+ * It makes Linux Kernel supply a GDB remote debug interface.
+ *
+ * Copyright(C) KGTP team (kgtp.googlecode.com), 2010-2013
+ *
+ */
+
+#include <linux/version.h>
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/uaccess.h>
+#include <linux/vmalloc.h>
+#include <linux/poll.h>
+#include <linux/kprobes.h>
+#include <linux/interrupt.h>
+#include <linux/debugfs.h>
+#include <linux/slab.h>
+#include <linux/kgdb.h>
+#include <asm/gtp.h>
+
+#define GTP_RW_MAX 16384
+#define GTP_RW_BUFP_MAX (GTP_RW_MAX - 4 - gtp_rw_size)
+
+#define GTP_FRAME_SIZE 5242880
+#define GTP_FRAME_HEAD_SIZE (1 + sizeof(struct gtp_frame_head))
+#define GTP_FRAME_REG_SIZE (1 + sizeof(struct gtp_frame_reg))
+
+#define TOHEX(h) ((h) > 9 ? (h) + 'a' - 10 : (h) + '0')
+
+struct action {
+ struct list_head node;
+ char type;
+ union {
+ uint64_t reg_mask;
+ } u;
+};
+
+struct gtp_entry {
+ struct list_head node;
+ uint64_t num;
+ uint64_t addr;
+ uint64_t step;
+ uint64_t pass;
+ int nopass;
+ int kpreg;
+ struct kprobe kp;
+ struct list_head action_list;
+};
+
+static LIST_HEAD(gtp_list);
+
+struct gtp_frame_head {
+ int frame_num;
+ uint64_t trace_num;
+ char *next;
+};
+
+struct gtp_frame_reg {
+ struct pt_regs regs;
+ char *next;
+};
+
+static char gtp_read_ack;
+static char *gtp_rw_buf;
+static char *gtp_rw_bufp;
+static size_t gtp_rw_size;
+
+static int gtp_start;
+
+static int gtp_circular;
+
+static DEFINE_SPINLOCK(gtp_frame_lock);
+static int gtp_frame_num;
+static char *gtp_frame;
+static char *gtp_frame_r_start;
+static char *gtp_frame_w_start;
+static char *gtp_frame_w_end;
+static char *gtp_frame_r_cache;
+static int gtp_frame_is_circular;
+static struct gtp_frame_head *gtp_frame_current;
+
+static DEFINE_SEMAPHORE(gtp_rw_lock);
+static int gtp_rw_count;
+
+static char *gtp_frame_alloc(size_t size)
+{
+ char *ret = NULL;
+
+ if (size > GTP_FRAME_SIZE)
+ return NULL;
+
+ spin_lock(&gtp_frame_lock);
+
+ if (gtp_frame_w_start + size > gtp_frame_w_end) {
+ if (gtp_circular) {
+ gtp_frame_is_circular = 1;
+ gtp_frame_w_start = gtp_frame;
+ gtp_frame_r_start = gtp_frame;
+ } else
+ goto out;
+ }
+
+ if (gtp_frame_is_circular) {
+ /* Release some frame entry to get some place.
+ When support new frame type, need add new handler
+ to switch. */
+ while (gtp_frame_w_start + size > gtp_frame_r_start) {
+ switch (gtp_frame_r_start[0]) {
+ case 'h':
+ gtp_frame_r_start += GTP_FRAME_HEAD_SIZE;
+ break;
+ case 'r':
+ gtp_frame_r_start += GTP_FRAME_REG_SIZE;
+ break;
+ default:
+ goto out;
+ }
+ }
+ }
+
+ ret = gtp_frame_w_start;
+ gtp_frame_w_start += size;
+
+out:
+ spin_unlock(&gtp_frame_lock);
+ return ret;
+}
+
+static inline char **gtp_action_r(struct pt_regs *regs, struct action *ae,
+ char **next)
+{
+ struct gtp_frame_reg *freg;
+ char *tmp;
+
+ tmp = gtp_frame_alloc(GTP_FRAME_REG_SIZE);
+ if (!tmp)
+ return NULL;
+
+ *next = tmp;
+ tmp[0] = 'r';
+ freg = (struct gtp_frame_reg *) (tmp + 1);
+ gtp_copy_and_adjuest_regs(&freg->regs, regs);
+ freg->next = NULL;
+
+ return &freg->next;
+}
+
+static int gtp_kp_pre_handler(struct kprobe *p, struct pt_regs *regs)
+{
+ struct gtp_entry *tpe = container_of(p, struct gtp_entry, kp);
+ struct gtp_frame_head *head;
+ char *tmp;
+ struct action *ae;
+ struct list_head *cur;
+ char **next;
+
+ pr_devel("gtp_kp_pre_handler: tracepoint %d\n", (int)tpe->num);
+
+ /* Get the head. */
+ tmp = gtp_frame_alloc(GTP_FRAME_HEAD_SIZE);
+ if (!tmp)
+ goto no_memory;
+ tmp[0] = 'h';
+ head = (struct gtp_frame_head *) (tmp + 1);
+ /* Get a new frame num from gtp_frame_num. */
+ spin_lock(&gtp_frame_lock);
+ if (gtp_frame_num < 0)
+ gtp_frame_num = head->frame_num = 0;
+ else
+ head->frame_num = gtp_frame_num++;
+ spin_unlock(&gtp_frame_lock);
+ head->trace_num = tpe->num;
+ head->next = NULL;
+ next = &head->next;
+
+ /* Handle actions. */
+ list_for_each(cur, &tpe->action_list) {
+ ae = list_entry(cur, struct action, node);
+ switch (ae->type) {
+ case 'r':
+ next = gtp_action_r(regs, ae, next);
+ if (!next)
+ goto no_memory;
+ break;
+ }
+ }
+
+ return 0;
+
+no_memory:
+ pr_devel("gtp_kp_pre_handler: tracepoint %d no memory.\n",
+ (int)tpe->num);
+ return 0;
+}
+
+static struct action *gtp_action_alloc(char type)
+{
+ struct action *ret;
+
+ ret = kzalloc(sizeof(struct action), GFP_KERNEL);
+ if (!ret)
+ goto out;
+
+ ret->type = type;
+
+out:
+ return ret;
+}
+
+static struct gtp_entry *gtp_list_add(uint64_t num, uint64_t addr)
+{
+ struct gtp_entry *ret = kzalloc(sizeof(struct gtp_entry),
+ GFP_KERNEL);
+
+ if (!ret)
+ goto out;
+ ret->num = num;
+ ret->addr = addr;
+ ret->kp.addr = (kprobe_opcode_t *) (unsigned long)addr;
+ ret->kp.pre_handler = gtp_kp_pre_handler;
+ INIT_LIST_HEAD(&ret->action_list);
+
+ list_add(&ret->node, &gtp_list);
+
+out:
+ return ret;
+}
+
+static struct gtp_entry *gtp_list_find(uint64_t num, uint64_t addr)
+{
+ struct gtp_entry *tpe;
+ struct list_head *cur;
+
+ list_for_each(cur, &gtp_list) {
+ tpe = list_entry(cur, struct gtp_entry, node);
+ if (tpe->num == num && tpe->addr == addr)
+ return tpe;
+ }
+
+ return NULL;
+}
+
+static void gtp_list_release(void)
+{
+ struct gtp_entry *tpe;
+ struct list_head *cur, *next;
+
+ list_for_each_safe(cur, next, &gtp_list) {
+ struct action *ae;
+ struct list_head *cur_ae, *next_ae;
+
+ tpe = list_entry(cur, struct gtp_entry, node);
+
+ list_for_each_safe(cur_ae, next_ae, &tpe->action_list) {
+ ae = list_entry(cur_ae, struct action, node);
+ kfree(ae);
+ }
+
+ kfree(tpe);
+ }
+}
+
+static void gtp_frame_reset(void)
+{
+ gtp_frame_num = 0;
+ gtp_frame_r_start = gtp_frame;
+ gtp_frame_w_start = gtp_frame;
+ gtp_frame_w_end = gtp_frame + GTP_FRAME_SIZE;
+ gtp_frame_is_circular = 0;
+ gtp_frame_r_cache = NULL;
+ gtp_frame_current = NULL;
+}
+
+static int gtp_gdbrsp_qtinit(char *pkg)
+{
+ gtp_list_release();
+
+ if (gtp_frame)
+ gtp_frame_reset();
+
+ return 0;
+}
+
+static int gtp_gdbrsp_qtdp(char *pkg)
+{
+ int addnew = 1;
+ uint64_t num, addr;
+ struct gtp_entry *tpe;
+
+ pr_devel("gtp_gdbrsp_qtdp: %s\n", pkg);
+
+ if (pkg[0] == '-') {
+ pkg++;
+ addnew = 0;
+ }
+
+ /* Get num and addr. */
+ if (pkg[0] == '\0')
+ return -EINVAL;
+ num = simple_strtoull(pkg, &pkg, 16);
+ if (pkg[0] == '\0')
+ return -EINVAL;
+ pkg++;
+ addr = simple_strtoull(pkg, &pkg, 16);
+ if (pkg[0] == '\0')
+ return -EINVAL;
+ pkg++;
+
+ tpe = gtp_list_find(num, addr);
+ if (addnew) {
+ if (tpe)
+ return -EINVAL;
+ if (pkg[0] == 'D')
+ return 0;
+ if (pkg[0] == '\0')
+ return -EINVAL;
+ pkg++;
+
+ tpe = gtp_list_add(num, addr);
+ if (tpe == NULL)
+ return -ENOMEM;
+
+ /* Get step and pass. */
+ if (pkg[0] == '\0')
+ return -EINVAL;
+ pkg++;
+ tpe->step = simple_strtoull(pkg, &pkg, 16);
+ if (pkg[0] == '\0')
+ return -EINVAL;
+ pkg++;
+ tpe->pass = simple_strtoull(pkg, &pkg, 16);
+ if (tpe->pass == 0)
+ tpe->nopass = 1;
+ } else if (tpe) {
+ /* Add action to tpe. */
+ int step_action = 0;
+
+ if (pkg[0] == 'S') {
+ pkg++;
+ step_action = 1;
+ /* Do not support step now. */
+ return 1;
+ }
+ while (pkg[0]) {
+ struct action *ae;
+
+ switch (pkg[0]) {
+ case 'R':
+ /* reg_mask is ignore because buffer just
+ can record all regs. */
+ ae = gtp_action_alloc(pkg[0]);
+ if (!ae)
+ return -ENOMEM;
+ pkg++;
+ ae->type = 'r';
+ ae->u.reg_mask = simple_strtoull(pkg, &pkg,
+ 16);
+ break;
+ default:
+ return 1;
+ }
+
+ if (ae)
+ list_add(&ae->node, &tpe->action_list);
+ }
+ } else
+ return -EINVAL;
+
+ return 0;
+}
+
+static int gtp_gdbrsp_qtdisconnected(char *pkg)
+{
+ /* Doesn't support disconnected-tracing. */
+
+ return 1;
+}
+
+static int gtp_gdbrsp_qtbuffer(char *pkg)
+{
+ if (strncmp("circular:", pkg, 9) == 0) {
+ uint64_t setting;
+
+ pkg += 9;
+ if (pkg[0] == '\0')
+ return -EINVAL;
+ setting = simple_strtoull(pkg, NULL, 16);
+ gtp_circular = (int)setting;
+
+ return 0;
+ }
+
+ return 1;
+}
+
+static struct gtp_frame_head *gtp_frame_head_find(int num)
+{
+ struct gtp_frame_head *ret = NULL;
+ char *tmp;
+
+ if (gtp_frame_r_cache) {
+ tmp = gtp_frame_r_cache;
+
+ while (tmp < gtp_frame_w_start) {
+ switch (tmp[0]) {
+ case 'h':
+ ret = (struct gtp_frame_head *)(tmp + 1);
+ goto cache_check;
+ break;
+ case 'r':
+ tmp += GTP_FRAME_REG_SIZE;
+ break;
+ default:
+ goto cache_check;
+ break;
+ }
+ }
+
+cache_check:
+ if (ret && ret->frame_num == num)
+ goto out;
+ }
+
+ tmp = gtp_frame_r_start;
+ while (tmp < gtp_frame_w_start) {
+ switch (tmp[0]) {
+ case 'h':
+ ret = (struct gtp_frame_head *) (tmp + 1);
+ if (ret->frame_num == num)
+ goto out;
+ ret = NULL;
+ tmp += GTP_FRAME_HEAD_SIZE;
+ break;
+ case 'r':
+ tmp += GTP_FRAME_REG_SIZE;
+ break;
+ default:
+ goto out;
+ }
+ }
+
+out:
+ return ret;
+}
+
+static int gtp_gdbrsp_qtframe(char *pkg)
+{
+ if (strncmp(pkg, "pc:", 3) == 0) /* Not support. */
+ return 1;
+ else if (strncmp(pkg, "tdp:", 4) == 0) /* Not support. */
+ return 1;
+ else if (strncmp(pkg, "range:", 6) == 0) /* Not support. */
+ return 1;
+ else if (strncmp(pkg, "outside:", 8) == 0) /* Not support. */
+ return 1;
+ else {
+ uint64_t num;
+ struct gtp_frame_head *ret;
+
+ if (pkg[0] == '\0')
+ return -EINVAL;
+ num = simple_strtoull(pkg, NULL, 16);
+
+ pr_devel("gtp_gdbrsp_qtframe: %d\n", (int) num);
+
+ if (((int) num) < 0) {
+ /* Return to current. */
+ gtp_frame_current = NULL;
+
+ return 0;
+ }
+ ret = gtp_frame_head_find((int) num);
+ if (ret) {
+ gtp_frame_current = ret;
+ gtp_frame_r_cache = (char *)ret;
+ gtp_frame_r_cache += sizeof(struct gtp_frame_head);
+ sprintf(gtp_rw_bufp, "F%xT%x",
+ gtp_frame_current->frame_num,
+ (unsigned int)gtp_frame_current->trace_num);
+ gtp_rw_size += strlen(gtp_rw_bufp);
+ gtp_rw_bufp += strlen(gtp_rw_bufp);
+ } else {
+ strcpy(gtp_rw_bufp, "F-1");
+ gtp_rw_bufp += 3;
+ gtp_rw_size += 3;
+ }
+ }
+
+ return 1;
+}
+
+static int gtp_gdbrsp_qtstop(char *pkg)
+{
+ struct gtp_entry *tpe;
+ struct list_head *cur;
+
+ if (!gtp_start)
+ return -EBUSY;
+
+ list_for_each(cur, &gtp_list) {
+ tpe = list_entry(cur, struct gtp_entry, node);
+ if (tpe->kpreg) {
+ unregister_kprobe(&tpe->kp);
+ tpe->kpreg = 0;
+ }
+ }
+
+ gtp_start = 0;
+
+ return 0;
+}
+
+static int gtp_gdbrsp_qtstart(char *pkg)
+{
+ struct gtp_entry *tpe;
+ struct list_head *cur;
+
+ if (!gtp_frame) {
+ gtp_frame = vmalloc(GTP_FRAME_SIZE);
+ if (!gtp_frame)
+ return -ENOMEM;
+
+ gtp_frame_reset();
+ }
+
+ list_for_each(cur, &gtp_list) {
+ tpe = list_entry(cur, struct gtp_entry, node);
+ if (!list_empty(&tpe->action_list)) {
+ int ret = register_kprobe(&tpe->kp);
+ if (ret < 0) {
+ gtp_gdbrsp_qtstop(NULL);
+ return ret;
+ }
+ tpe->kpreg = 1;
+ }
+ }
+
+ gtp_start = 1;
+
+ return 0;
+}
+
+struct QTpkg_s {
+ const char *header;
+
+ /* If size is bigger than 0, this is the size of package's header.
+ And this package has some data after header need send to fun.
+ If size is 0, this package just has a header. */
+ int size;
+
+ /* If check_start is true, before call fun, need check if gtp_start.
+ If gtp_start, then return -EBUSY. */
+ int check_start;
+
+ int (*fun)(char *pkg);
+};
+
+struct QTpkg_s QTpkgs[] = {
+ {"init", 0, 1, gtp_gdbrsp_qtinit},
+ {"DP:", 3, 1, gtp_gdbrsp_qtdp},
+ {"Disconnected:", 13, 0, gtp_gdbrsp_qtdisconnected},
+ {"Buffer:", 7, 0, gtp_gdbrsp_qtbuffer},
+ {"Frame:", 6, 1, gtp_gdbrsp_qtframe},
+ {"Start", 0, 1, gtp_gdbrsp_qtstart},
+ {"Stop", 0, 0, gtp_gdbrsp_qtstop},
+};
+
+static int gtp_gdbrsp_QT(char *pkg)
+{
+ int ret = 1;
+ int i;
+
+ pr_devel("gtp_gdbrsp_QT: %s\n", pkg);
+
+ for (i = 0; i < sizeof (QTpkgs) / sizeof (struct QTpkg_s); i++) {
+ int not_same;
+
+ if (QTpkgs[i].size == 0)
+ not_same = strcmp(QTpkgs[i].header, pkg);
+ else
+ not_same = strncmp(QTpkgs[i].header, pkg,
+ QTpkgs[i].size);
+ if (not_same)
+ continue;
+ if (QTpkgs[i].check_start && gtp_start)
+ ret = -EBUSY;
+ else
+ ret = QTpkgs[i].fun(pkg + QTpkgs[i].size);
+ }
+
+ return ret;
+}
+
+static unsigned char gtp_m_buffer[0xffff];
+
+static int gtp_gdbrsp_m(char *pkg)
+{
+ int i;
+ uint64_t addr, len;
+
+ /* Get add and len. */
+ if (pkg[0] == '\0')
+ return -EINVAL;
+ addr = simple_strtoull(pkg, &pkg, 16);
+ if (pkg[0] != ',')
+ return -EINVAL;
+ pkg++;
+ len = simple_strtoull(pkg, &pkg, 16);
+ if (len == 0)
+ return -EINVAL;
+ len &= 0xffff;
+ len = (uint64_t) min((int)(GTP_RW_BUFP_MAX / 2),
+ (int)len);
+
+ pr_devel("gtp_gdbrsp_m: addr = 0x%lx len = %d\n",
+ (unsigned long) addr, (int) len);
+
+ if (probe_kernel_read(gtp_m_buffer, (void *)(unsigned long)addr,
+ (size_t)len))
+ return -EFAULT;
+
+ for (i = 0; i < (int)len; i++) {
+ sprintf(gtp_rw_bufp, "%02x", gtp_m_buffer[i]);
+ gtp_rw_bufp += 2;
+ gtp_rw_size += 2;
+ }
+
+ return 1;
+}
+
+static int gtp_gdbrsp_g(void)
+{
+ char *next;
+ struct gtp_frame_reg *fr = NULL;
+
+ if (GTP_RW_BUFP_MAX < NUMREGBYTES * 2)
+ return -E2BIG;
+
+ if (gtp_start || !gtp_frame_current)
+ goto empty_out;
+
+ /* Get the fr. */
+ next = gtp_frame_current->next;
+ if (next[0] == 'r') {
+ unsigned long gdb_regs[(NUMREGBYTES +
+ sizeof(unsigned long) - 1) /
+ sizeof(unsigned long)];
+ fr = (struct gtp_frame_reg *) (next + 1);
+ pt_regs_to_gdb_regs(gdb_regs, &fr->regs);
+ kgdb_mem2hex((char *)gdb_regs, gtp_rw_bufp, NUMREGBYTES);
+ } else {
+empty_out:
+ memset(gtp_rw_bufp, '0', NUMREGBYTES * 2);
+ }
+ gtp_rw_bufp += NUMREGBYTES * 2;
+ gtp_rw_size += NUMREGBYTES * 2;
+ return 1;
+}
+
+static int gtp_open(struct inode *inode, struct file *file)
+{
+ int ret = 0;
+
+ down(&gtp_rw_lock);
+
+ if (gtp_rw_count > 0) {
+ ret = -EBUSY;
+ goto out;
+ }
+
+ gtp_read_ack = 0;
+ gtp_rw_buf = vmalloc(GTP_RW_MAX);
+ if (!gtp_rw_buf) {
+ ret = -ENOMEM;
+ goto out;
+ }
+
+ gtp_rw_count++;
+
+out:
+ up(&gtp_rw_lock);
+ return ret;
+}
+
+static int gtp_release(struct inode *inode, struct file *file)
+{
+ down(&gtp_rw_lock);
+ vfree(gtp_rw_buf);
+
+ gtp_gdbrsp_qtstop(NULL);
+ gtp_gdbrsp_qtinit(NULL);
+ vfree(gtp_frame);
+ gtp_frame = NULL;
+
+ gtp_rw_count--;
+
+ up(&gtp_rw_lock);
+
+ return 0;
+}
+
+static long gtp_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
+{
+ /* This function will make GDB happy. */
+ pr_devel("gtp_ioctl: %x\n", cmd);
+
+ return 0;
+}
+
+static ssize_t gtp_write(struct file *file, const char __user *buf,
+ size_t size, loff_t *ppos)
+{
+ char *rsppkg = NULL;
+ int i, ret;
+ unsigned char csum = 0;
+
+ down(&gtp_rw_lock);
+
+ size = min_t(size_t, size, GTP_RW_MAX);
+ if (copy_from_user(gtp_rw_buf, buf, size)) {
+ size = -EFAULT;
+ goto out;
+ }
+
+ if (gtp_rw_buf[0] == '+' || gtp_rw_buf[0] == '-'
+ || gtp_rw_buf[0] == '\3')
+ goto out;
+
+ /* Check format and crc and get the rsppkg. */
+ for (i = 0; i < size - 2; i++) {
+ if (rsppkg == NULL) {
+ if (gtp_rw_buf[i] == '$')
+ rsppkg = gtp_rw_buf + i + 1;
+ } else {
+ if (gtp_rw_buf[i] == '#')
+ break;
+ else
+ csum += gtp_rw_buf[i];
+ }
+ }
+ if (rsppkg && gtp_rw_buf[i] == '#') {
+ /* Format is OK. Check crc. */
+ unsigned char c1, c2;
+
+ gtp_rw_buf[i] = '\0';
+
+ c1 = gtp_rw_buf[i+1];
+ c2 = gtp_rw_buf[i+2];
+ if (csum == (c1 << 4) + c2) {
+ pr_devel("gtp_write: crc error\n");
+ gtp_read_ack = '-';
+ goto out;
+ }
+ } else {
+ pr_devel("gtp_write: format error\n");
+ gtp_read_ack = '-';
+ goto out;
+ }
+ gtp_read_ack = '+';
+
+ pr_devel("gtp_write: %s\n", rsppkg);
+
+ /* Handle rsppkg and put return to gtp_rw_buf. */
+ gtp_rw_buf[0] = '$';
+ gtp_rw_bufp = gtp_rw_buf + 1;
+ gtp_rw_size = 0;
+ ret = 1;
+ switch (rsppkg[0]) {
+ case '?':
+ strcpy(gtp_rw_bufp, "S05");
+ gtp_rw_bufp += 3;
+ gtp_rw_size += 3;
+ break;
+ case 'g':
+ ret = gtp_gdbrsp_g();
+ break;
+ case 'm':
+ ret = gtp_gdbrsp_m(rsppkg + 1);
+ break;
+ case 'Q':
+ if (rsppkg[1] == 'T')
+ ret = gtp_gdbrsp_QT(rsppkg + 2);
+ break;
+ }
+ if (ret == 0) {
+ strcpy(gtp_rw_bufp, "OK");
+ gtp_rw_bufp += 2;
+ gtp_rw_size += 2;
+ } else if (ret < 0) {
+ sprintf(gtp_rw_bufp, "E%02x", -ret);
+ gtp_rw_bufp += 3;
+ gtp_rw_size += 3;
+ }
+
+ gtp_rw_bufp[0] = '#';
+ csum = 0;
+ for (i = 1; i < gtp_rw_size + 1; i++)
+ csum += gtp_rw_buf[i];
+ gtp_rw_bufp[1] = TOHEX(csum >> 4);
+ gtp_rw_bufp[2] = TOHEX(csum & 0x0f);
+ gtp_rw_bufp = gtp_rw_buf;
+ gtp_rw_size += 4;
+
+out:
+ up(&gtp_rw_lock);
+ return size;
+}
+
+static ssize_t gtp_read(struct file *file, char __user *buf, size_t size,
+ loff_t *ppos)
+{
+ if (size == 0)
+ return 0;
+
+ down(&gtp_rw_lock);
+
+ if (gtp_read_ack) {
+ int err = put_user(gtp_read_ack, buf);
+ if (err) {
+ size = -err;
+ goto out;
+ }
+ gtp_read_ack = 0;
+ size = 1;
+ goto out;
+ }
+
+ size = min(gtp_rw_size, size);
+
+ if (copy_to_user(buf, gtp_rw_bufp, size)) {
+ size = -EFAULT;
+ goto out;
+ }
+ gtp_rw_bufp += size;
+ gtp_rw_size -= size;
+
+out:
+ up(&gtp_rw_lock);
+ return size;
+}
+
+static const struct file_operations gtp_operations = {
+ .owner = THIS_MODULE,
+ .open = gtp_open,
+ .release = gtp_release,
+ .unlocked_ioctl = gtp_ioctl,
+ .compat_ioctl = gtp_ioctl,
+ .read = gtp_read,
+ .write = gtp_write,
+};
+
+struct dentry *gtp_dir;
+
+static int __init gtp_init(void)
+{
+ gtp_dir = debugfs_create_file("gtp",
+ S_IFREG | S_IRUSR | S_IWUSR,
+ NULL, NULL, &gtp_operations);
+ if (gtp_dir == NULL || gtp_dir == ERR_PTR(-ENODEV))
+ return -ENOMEM;
+
+ return 0;
+}
+
+static void __exit gtp_exit(void)
+{
+ if (gtp_dir)
+ debugfs_remove_recursive(gtp_dir);
+}
+
+module_init(gtp_init)
+module_exit(gtp_exit)
+
+MODULE_AUTHOR("Hui Zhu <teawater@gmail.com>");
+MODULE_LICENSE("GPL");
--- a/lib/Kconfig.debug
+++ b/lib/Kconfig.debug
@@ -1578,6 +1578,21 @@ config DMA_API_DEBUG
This option causes a performance degredation. Use only if you want
to debug device drivers. If unsure, say N.

+config GTP
+ tristate "KGTP"
+ depends on X86
+ select KPROBES
+ select DEBUG_FS
+ select KGDB
+ ---help---
+ KGTP is a flexible, lightweight and realtime Linux (include
+ Android) debugger and tracer.
+ It makes Linux Kernel supply a GDB remote debug interface.
+ Then GDB in current machine or remote machine can debug and
+ trace Linux kernel and user space program through GDB tracepoint
+ and some other functions without stopping the Linux Kernel.
+ http://kgtp.googlecode.com/
+
source "samples/Kconfig"

source "lib/Kconfig.kgdb"

\
 
 \ /
  Last update: 2013-11-21 07:01    [W:0.183 / U:0.428 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site