Commit 03722454 authored by Gao Chen's avatar Gao Chen Committed by guzitao
Browse files

sw64: trace user task unalignment 

Sunway inclusion
category: feature
bugzilla: https://gitee.com/openeuler/kernel/issues/I73O8X



--------------------------------

It specifies user command to be traced, and records count, address
and PC into debugfs. Note that it can only trace a task with its
command name.

To specify command name and clear old unaligned stat:
	echo something > /sys/kernel/debug/sw64/unaligned

To show unaligned stat:
	cat /sys/kernel/debug/sw64/unaligned

Signed-off-by: default avatarGao Chen <gaochen@wxiat.com>
Reviewed-by: default avatarHe Sheng <hesheng@wxiat.com>
Signed-off-by: default avatarGu Zitao <guzitao@wxiat.com>
parent f92e794d

arch/sw_64/include/asm/debug.h

+11 −0
Original line number Diff line number Diff line
@@ -24,4 +24,15 @@ 
 */

extern struct dentry *sw64_debugfs_dir;



#define UNA_MAX_ENTRIES	64



struct unaligned_stat {

	unsigned long pc;

	unsigned long va;

};



extern char unaligned_task[];

extern unsigned long unaligned_count;

extern struct unaligned_stat unaligned[];



#endif /* _ASM_SW64_DEBUG_H */

arch/sw_64/kernel/Makefile

+1 −1
Original line number Diff line number Diff line
@@ -30,7 +30,7 @@ obj-$(CONFIG_HIBERNATION) += hibernate_asm.o hibernate.o 
obj-$(CONFIG_AUDIT)     += audit.o

obj-$(CONFIG_PCI) += pci_common.o

obj-$(CONFIG_RELOCATABLE)   += relocate.o

obj-$(CONFIG_DEBUG_FS)	+= segvdbg.o

obj-$(CONFIG_DEBUG_FS)	+= segvdbg.o unaligned.o

obj-$(CONFIG_JUMP_LABEL) += jump_label.o



ifeq ($(CONFIG_DEBUG_FS)$(CONFIG_NUMA),yy)

arch/sw_64/kernel/traps.c

+16 −0
Original line number Diff line number Diff line
@@ -28,6 +28,7 @@ 
#include <asm/stacktrace.h>

#include <asm/processor.h>

#include <asm/ptrace.h>

#include <asm/debug.h>

#include <asm/efi.h>



#include "proto.h"
@@ -573,6 +574,21 @@ do_entUnaUser(void __user *va, unsigned long opcode, 
	unsigned long fp[4];

	unsigned long instr, instr_op, value;



#ifdef CONFIG_DEBUG_FS

	/*

	 * If command name is specified, record some information

	 * to debugfs.

	 */

	if (unaligned_task[0] && !strcmp(unaligned_task, current->comm)) {

		int idx;



		idx = unaligned_count % UNA_MAX_ENTRIES;

		unaligned[idx].va = (unsigned long)va;

		unaligned[idx].pc = regs->pc;

		unaligned_count++;

	}

#endif



	/* Check the UAC bits to decide what the user wants us to do

	 * with the unaliged access.

	 */

arch/sw_64/kernel/unaligned.c

0 → 100644
+80 −0
Original line number Diff line number Diff line 
// SPDX-License-Identifier: GPL-2.0

#include <asm/debug.h>



#include <linux/debugfs.h>

#include <linux/slab.h>

#include <linux/uaccess.h>



unsigned long unaligned_count;

char unaligned_task[TASK_COMM_LEN];

struct unaligned_stat unaligned[UNA_MAX_ENTRIES];



static ssize_t unaligned_set(struct file *file, const char __user *user_buf,

			size_t len, loff_t *ppos)

{

	size_t size;



	unaligned_count = 0;

	size = min(sizeof(unaligned_task), len);

	if (copy_from_user(unaligned_task, user_buf, size))

		return -EFAULT;

	unaligned_task[size - 1] = '\0';



	return len;

}



static int unaligned_show(struct seq_file *m, void *v)

{

	int i, idx, nr;



	if (!unaligned_task[0]) {

		seq_puts(m, "No task traced\n");

		return 0;

	}

	seq_printf(m, "Task command:\t\t%s\n", unaligned_task);

	seq_printf(m, "Unaligned count:\t%ld\n", unaligned_count);

	if (!unaligned_count)

		return 0;

	nr = 0;

	idx = unaligned_count % UNA_MAX_ENTRIES;

	seq_printf(m, "Latest %d unaligned stat:\nNo.\tVA\t\tPC\n", UNA_MAX_ENTRIES);

	if (unaligned_count >= UNA_MAX_ENTRIES) {

		for (i = idx; i < UNA_MAX_ENTRIES; i++)

			seq_printf(m, "%d\t%#lx\t%#lx\n",

					nr++, unaligned[i].va, unaligned[i].pc);

	}

	for (i = 0; i < idx; i++)

		seq_printf(m, "%d\t%#lx\t%#lx\n",

				nr++, unaligned[i].va, unaligned[i].pc);

	return 0;

}



static int unaligned_open(struct inode *inode, struct file *file)

{

	return single_open(file, unaligned_show, NULL);

}



static const struct file_operations unaligned_fops = {

	.read		= seq_read,

	.write		= unaligned_set,

	.open		= unaligned_open,

	.llseek		= default_llseek,

};



static int __init unaligned_init(void)

{

	struct dentry *unaligned;



	if (!sw64_debugfs_dir)

		return -ENODEV;



	unaligned = debugfs_create_file("unaligned", 0644,

			sw64_debugfs_dir, NULL,

			&unaligned_fops);

	if (!unaligned)

		return -ENOMEM;



	return 0;

}



late_initcall(unaligned_init);