Support /proc/kcore for MIPS

I wanted to do live debugging on an ornery task_struct this morning, so I hooked up /proc/kcore for MIPS. I'm pretty sure that the CKSEG0 bits are wrong, but I did need to cover that region - because the SB-1 kernel links at 0xffffffff80100000 or so, disassembly and printing static variables don't work unless the debugger can read that region.

Signed-off-by Daniel Jacobowitz <[email protected]>

Index: linux/arch/mips/mm/init.c
===================================================================

arch/mips/mm/init.c +16 -0

@@ -24,6 +24,7 @@
 #include <linux/bootmem.h>
 #include <linux/highmem.h>
 #include <linux/swap.h>
+#include <linux/proc_fs.h>
 
 #include <asm/bootinfo.h>
 #include <asm/cachectl.h>

@@ -197,6 +198,11 @@
 	return 0;
 }
 
+static struct kcore_list kcore_mem, kcore_vmalloc;
+#ifdef CONFIG_MIPS64
+static struct kcore_list kcore_kseg0;
+#endif
+
 void __init mem_init(void)
 {
 	unsigned long codesize, reservedpages, datasize, initsize;

@@ -247,6 +253,16 @@
 	datasize =  (unsigned long) &_edata - (unsigned long) &_etext;
 	initsize =  (unsigned long) &__init_end - (unsigned long) &__init_begin;
 
+#ifdef CONFIG_MIPS64
+	if ((unsigned long) &_text > (unsigned long) CKSEG0)
+		/* The -4 is a hack so that user tools don't have to handle
+		   the overflow.  */
+		kclist_add(&kcore_kseg0, (void *) CKSEG0, 0x80000000 - 4);
+#endif
+	kclist_add(&kcore_mem, __va(0), max_low_pfn << PAGE_SHIFT);
+	kclist_add(&kcore_vmalloc, (void *)VMALLOC_START,
+		   VMALLOC_END-VMALLOC_START);
+
 	printk(KERN_INFO "Memory: %luk/%luk available (%ldk kernel code, "
 	       "%ldk reserved, %ldk data, %ldk init, %ldk highmem)\n",
 	       (unsigned long) nr_free_pages() << (PAGE_SHIFT-10),

Signature · 2 lines

-- 
Daniel Jacobowitz

Ping. I've now tested this patch in both 32-bit and 64-bit kernels.

Quoted 49 lines

I wanted to do live debugging on an ornery task_struct this morning, so I hooked up /proc/kcore for MIPS. I'm pretty sure that the CKSEG0 bits are wrong, but I did need to cover that region - because the SB-1 kernel links at 0xffffffff80100000 or so, disassembly and printing static variables don't work unless the debugger can read that region.

Signed-off-by Daniel Jacobowitz <[email protected]>

Index: linux/arch/mips/mm/init.c
===================================================================

arch/mips/mm/init.c +16 -0

@@ -24,6 +24,7 @@
 #include <linux/bootmem.h>
 #include <linux/highmem.h>
 #include <linux/swap.h>
+#include <linux/proc_fs.h>
 
 #include <asm/bootinfo.h>
 #include <asm/cachectl.h>

@@ -197,6 +198,11 @@
 	return 0;
 }
 
+static struct kcore_list kcore_mem, kcore_vmalloc;
+#ifdef CONFIG_MIPS64
+static struct kcore_list kcore_kseg0;
+#endif
+
 void __init mem_init(void)
 {
 	unsigned long codesize, reservedpages, datasize, initsize;

@@ -247,6 +253,16 @@
 	datasize =  (unsigned long) &_edata - (unsigned long) &_etext;
 	initsize =  (unsigned long) &__init_end - (unsigned long) &__init_begin;
 
+#ifdef CONFIG_MIPS64
+	if ((unsigned long) &_text > (unsigned long) CKSEG0)
+		/* The -4 is a hack so that user tools don't have to handle
+		   the overflow.  */
+		kclist_add(&kcore_kseg0, (void *) CKSEG0, 0x80000000 - 4);
+#endif
+	kclist_add(&kcore_mem, __va(0), max_low_pfn << PAGE_SHIFT);
+	kclist_add(&kcore_vmalloc, (void *)VMALLOC_START,
+		   VMALLOC_END-VMALLOC_START);
+
 	printk(KERN_INFO "Memory: %luk/%luk available (%ldk kernel code, "
 	       "%ldk reserved, %ldk data, %ldk init, %ldk highmem)\n",
 	       (unsigned long) nr_free_pages() << (PAGE_SHIFT-10),

CONFIG_MIPS64 was replaced by CONFIG_64BIT a while ago.