[PATCH] linux-2.4.23-pre2_proc-interrupts-fix_A1

* [PATCH] linux-2.4.23-pre2_proc-interrupts-fix_A1
@ 2003-08-30 19:20 john stultz
  2003-09-01  7:55 ` Mark Goodwin
  0 siblings, 1 reply; 2+ messages in thread
From: john stultz @ 2003-08-30 19:20 UTC (permalink / raw)
  To: marcelo; +Cc: lkml, Randy.Dunlap

Marcelo, All,

	This patch converts /proc/interrupts to use the seq_file interface on
i386 (thanks to Randy for adding the seq "single" code). This prevents
memory corruption caused by /proc/interrupts overflowing its page sized
buffer on systems with high cpu and interrupt counts. 

Please consider for inclusion.

thanks
-john


diff -Nru a/arch/i386/kernel/irq.c b/arch/i386/kernel/irq.c

--- a/arch/i386/kernel/irq.c	Sat Aug 30 12:02:26 2003
+++ b/arch/i386/kernel/irq.c	Sat Aug 30 12:02:26 2003
@@ -32,6 +32,7 @@
 #include <linux/kernel_stat.h>
 #include <linux/irq.h>
 #include <linux/proc_fs.h>
+#include <linux/seq_file.h>
 
 #include <asm/atomic.h>
 #include <asm/io.h>
@@ -131,55 +132,55 @@
  * Generic, controller-independent functions:
  */
 
-int get_irq_list(char *buf)
+int show_interrupts(struct seq_file *p, void *v)
 {
 	int i, j;
 	struct irqaction * action;
-	char *p = buf;
 
-	p += sprintf(p, "           ");
+	seq_printf(p, "           ");
 	for (j=0; j<smp_num_cpus; j++)
-		p += sprintf(p, "CPU%d       ",j);
-	*p++ = '\n';
+		seq_printf(p, "CPU%d       ",j);
+	seq_putc(p,'\n');
 
 	for (i = 0 ; i < NR_IRQS ; i++) {
 		action = irq_desc[i].action;
 		if (!action) 
 			continue;
-		p += sprintf(p, "%3d: ",i);
+		seq_printf(p, "%3d: ",i);
 #ifndef CONFIG_SMP
-		p += sprintf(p, "%10u ", kstat_irqs(i));
+		seq_printf(p, "%10u ", kstat_irqs(i));
 #else
 		for (j = 0; j < smp_num_cpus; j++)
-			p += sprintf(p, "%10u ",
+			seq_printf(p, "%10u ",
 				kstat.irqs[cpu_logical_map(j)][i]);
 #endif
-		p += sprintf(p, " %14s", irq_desc[i].handler->typename);
-		p += sprintf(p, "  %s", action->name);
+		seq_printf(p, " %14s", irq_desc[i].handler->typename);
+		seq_printf(p, "  %s", action->name);
 
 		for (action=action->next; action; action = action->next)
-			p += sprintf(p, ", %s", action->name);
-		*p++ = '\n';
+			seq_printf(p, ", %s", action->name);
+		seq_putc(p,'\n');
 	}
-	p += sprintf(p, "NMI: ");
+	seq_printf(p, "NMI: ");
 	for (j = 0; j < smp_num_cpus; j++)
-		p += sprintf(p, "%10u ",
+		seq_printf(p, "%10u ",
 			nmi_count(cpu_logical_map(j)));
-	p += sprintf(p, "\n");
+	seq_printf(p, "\n");
 #if CONFIG_X86_LOCAL_APIC
-	p += sprintf(p, "LOC: ");
+	seq_printf(p, "LOC: ");
 	for (j = 0; j < smp_num_cpus; j++)
-		p += sprintf(p, "%10u ",
+		seq_printf(p, "%10u ",
 			apic_timer_irqs[cpu_logical_map(j)]);
-	p += sprintf(p, "\n");
+	seq_printf(p, "\n");
 #endif
-	p += sprintf(p, "ERR: %10u\n", atomic_read(&irq_err_count));
+	seq_printf(p, "ERR: %10u\n", atomic_read(&irq_err_count));
 #ifdef CONFIG_X86_IO_APIC
 #ifdef APIC_MISMATCH_DEBUG
-	p += sprintf(p, "MIS: %10u\n", atomic_read(&irq_mis_count));
+	seq_printf(p, "MIS: %10u\n", atomic_read(&irq_mis_count));
 #endif
 #endif
-	return p - buf;
+
+	return 0;
 }
 
 
diff -Nru a/fs/proc/proc_misc.c b/fs/proc/proc_misc.c
--- a/fs/proc/proc_misc.c	Sat Aug 30 12:02:26 2003
+++ b/fs/proc/proc_misc.c	Sat Aug 30 12:02:26 2003
@@ -58,7 +58,9 @@
 extern int get_device_list(char *);
 extern int get_filesystem_list(char *);
 extern int get_exec_domain_list(char *);
+#ifndef CONFIG_X86
 extern int get_irq_list(char *);
+#endif
 extern int get_dma_list(char *);
 extern int get_locks_status (char *, char **, off_t, int);
 extern int get_swaparea_info (char *);
@@ -389,6 +391,7 @@
 	return proc_calc_metrics(page, start, off, count, eof, len);
 }
 
+#ifndef CONFIG_X86
 #if !defined(CONFIG_ARCH_S390)
 static int interrupts_read_proc(char *page, char **start, off_t off,
 				 int count, int *eof, void *data)
@@ -398,6 +401,35 @@
 }
 #endif
 
+#else /* !CONFIG_X86 */
+
+extern int show_interrupts(struct seq_file *p, void *v);
+static int interrupts_open(struct inode *inode, struct file *file)
+{
+	unsigned size = PAGE_SIZE * (1 + smp_num_cpus / 8);
+	char *buf = kmalloc(size, GFP_KERNEL);
+	struct seq_file *m;
+	int res;
+
+	if (!buf)
+		return -ENOMEM;
+	res = single_open(file, show_interrupts, NULL);
+	if (!res) {
+		m = file->private_data;
+		m->buf = buf;
+		m->size = size;
+	} else
+		kfree(buf);
+	return res;
+}
+static struct file_operations proc_interrupts_operations = {
+	.open		= interrupts_open,
+	.read		= seq_read,
+	.llseek		= seq_lseek,
+	.release	= single_release,
+};
+#endif /* !CONFIG_X86 */
+
 static int filesystems_read_proc(char *page, char **start, off_t off,
 				 int count, int *eof, void *data)
 {
@@ -588,7 +620,7 @@
 #endif
 		{"stat",	kstat_read_proc},
 		{"devices",	devices_read_proc},
-#if !defined(CONFIG_ARCH_S390)
+#if !defined(CONFIG_ARCH_S390) && !defined(CONFIG_X86)
 		{"interrupts",	interrupts_read_proc},
 #endif
 		{"filesystems",	filesystems_read_proc},
@@ -614,6 +646,9 @@
 	if (entry)
 		entry->proc_fops = &proc_kmsg_operations;
 	create_seq_entry("cpuinfo", 0, &proc_cpuinfo_operations);
+#if defined(CONFIG_X86)
+	create_seq_entry("interrupts", 0, &proc_interrupts_operations);
+#endif
 	create_seq_entry("partitions", 0, &proc_partitions_operations);
 	create_seq_entry("slabinfo",S_IWUSR|S_IRUGO,&proc_slabinfo_operations);
 #ifdef CONFIG_MODULES




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