542401d97a
Add checking for allocated memory. Indents and spaces are added to be familiar with the kernel coding style. Signed-off-by: Cyrill Gorcunov <gorcunov@gmail.com> Acked-by: Mikael Starvik <starvik@axis.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
88 lines
1.8 KiB
C
88 lines
1.8 KiB
C
#include <linux/init.h>
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#include <linux/errno.h>
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#include <linux/kernel.h>
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#include <linux/proc_fs.h>
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#include <linux/types.h>
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#include <asm/ptrace.h>
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#include <asm/uaccess.h>
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#define SAMPLE_BUFFER_SIZE 8192
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static char* sample_buffer;
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static char* sample_buffer_pos;
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static int prof_running = 0;
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void
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cris_profile_sample(struct pt_regs* regs)
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{
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if (!prof_running)
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return;
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if (user_mode(regs))
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*(unsigned int*)sample_buffer_pos = current->pid;
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else
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*(unsigned int*)sample_buffer_pos = 0;
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*(unsigned int*)(sample_buffer_pos + 4) = instruction_pointer(regs);
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sample_buffer_pos += 8;
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if (sample_buffer_pos == sample_buffer + SAMPLE_BUFFER_SIZE)
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sample_buffer_pos = sample_buffer;
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}
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static ssize_t
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read_cris_profile(struct file *file, char __user *buf,
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size_t count, loff_t *ppos)
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{
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unsigned long p = *ppos;
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if (p > SAMPLE_BUFFER_SIZE)
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return 0;
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if (p + count > SAMPLE_BUFFER_SIZE)
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count = SAMPLE_BUFFER_SIZE - p;
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if (copy_to_user(buf, sample_buffer + p,count))
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return -EFAULT;
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memset(sample_buffer + p, 0, count);
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*ppos += count;
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return count;
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}
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static ssize_t
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write_cris_profile(struct file *file, const char __user *buf,
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size_t count, loff_t *ppos)
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{
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sample_buffer_pos = sample_buffer;
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memset(sample_buffer, 0, SAMPLE_BUFFER_SIZE);
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}
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static const struct file_operations cris_proc_profile_operations = {
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.read = read_cris_profile,
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.write = write_cris_profile,
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};
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static int
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__init init_cris_profile(void)
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{
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struct proc_dir_entry *entry;
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sample_buffer = kmalloc(SAMPLE_BUFFER_SIZE, GFP_KERNEL);
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if (!sample_buffer) {
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return -ENOMEM;
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}
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sample_buffer_pos = sample_buffer;
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entry = create_proc_entry("system_profile", S_IWUSR | S_IRUGO, NULL);
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if (entry) {
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entry->proc_fops = &cris_proc_profile_operations;
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entry->size = SAMPLE_BUFFER_SIZE;
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}
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prof_running = 1;
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return 0;
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}
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__initcall(init_cris_profile);
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