55 lines
995 B
C
55 lines
995 B
C
#define S_SIZE (1024 - (sizeof(unsigned int) + 1))
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struct sbuff {
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unsigned int count;
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char buf[S_SIZE + 1];
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};
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static struct sbuff emergency, *emergency_ptr = &emergency;
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static int sb_add(struct sbuff *m, const char *f, ...)
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{
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va_list args;
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int len;
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if (likely(m->count < S_SIZE)) {
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va_start(args, f);
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len = vsnprintf(m->buf + m->count, S_SIZE - m->count, f, args);
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va_end(args);
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if (likely(m->count + len < S_SIZE)) {
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m->count += len;
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return 0;
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}
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}
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m->count = S_SIZE;
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printk_once(KERN_ERR KBUILD_MODNAME " please increase S_SIZE\n");
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return -1;
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}
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static struct sbuff *sb_open(void)
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{
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struct sbuff *m = kmalloc(sizeof(*m), GFP_ATOMIC);
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if (unlikely(!m)) {
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local_bh_disable();
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do {
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m = xchg(&emergency_ptr, NULL);
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} while (!m);
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}
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m->count = 0;
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return m;
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}
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static void sb_close(struct sbuff *m)
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{
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m->buf[m->count] = 0;
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printk("%s\n", m->buf);
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if (likely(m != &emergency))
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kfree(m);
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else {
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xchg(&emergency_ptr, m);
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local_bh_enable();
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}
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}
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