RE: [Linux-ia64] RE: [PATCH] head.S fix for unusual load addrs

["Luck, Tony" <tony.luck@intel.com>]

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Here's what the kcore change looks like if I take the suggestion
that Andi Kleen made on LKML
 http://marc.theaimsgroup.com/?l=linux-kernel&m=103556903730989&w=2
to add the kernel to the vmlist.  Combined with the KCORE_BASE
change (which is 98% included) we avoid the negative addresses
that required a bunch more changes in Andi's patch.

I've juggled the addresses around again, moving the kernel up to
0xA000004000000000 and VMALLOC_START back down to 0xA000000000030000
so that the entry for the kernel goes on the *end* of the vmlist,
so we don't have to uselessly step over it on every call to vmalloc().

I picked that kernel start address as it is half-way between
VMALLOC_START and VMALLOC_END for a PAGE_SIZE=4k kernel.  There
are many alternatives ... choose a different one (between VMALLOC_START
and VMALLOC_END) if you come up with a good reason for a different
address.

This builds and boots on Tiger, and now I can run:

	# gdb vmlinux /proc/kcore
	(gdb) x/s log_buf

and see the contents of kernel memory.

-Tony

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diff -ru l2569-mosberger/arch/ia64/kernel/setup.c l2569-aegl/arch/ia64/kernel/setup.c
--- l2569-mosberger/arch/ia64/kernel/setup.c	Fri May 16 11:46:57 2003
+++ l2569-aegl/arch/ia64/kernel/setup.c	Fri May 16 17:11:18 2003
@@ -32,6 +32,7 @@
 #include <linux/tty.h>
 #include <linux/efi.h>
 #include <linux/initrd.h>
+#include <linux/vmalloc.h>
 
 #include <asm/ia32.h>
 #include <asm/page.h>
@@ -47,7 +48,7 @@
 # error "struct cpuinfo_ia64 too big!"
 #endif
 
-extern char _end;
+extern char _stext, _end;
 
 #ifdef CONFIG_SMP
 unsigned long __per_cpu_offset[NR_CPUS];
@@ -393,6 +394,18 @@
 {
 	extern unsigned long ia64_iobase;
 	unsigned long phys_iobase;
+	static struct vm_struct kern;
+	unsigned long s, e;
+
+	/* Add entry to vmlist for the kernel (round out to how much is mapped) */
+	s = (unsigned long)&_stext;
+	s &= ~(KERNEL_TR_PAGE_SIZE-1);
+	e = (unsigned long)&_end;
+	e = (e + KERNEL_TR_PAGE_SIZE-1) & ~(KERNEL_TR_PAGE_SIZE-1);
+	kern.addr = (void *)s;
+	kern.size = e - s;
+	kern.next = vmlist;
+	vmlist = &kern;
 
 	unw_init();
 
diff -ru l2569-mosberger/fs/proc/kcore.c l2569-aegl/fs/proc/kcore.c
--- l2569-mosberger/fs/proc/kcore.c	Thu May 15 10:12:56 2003
+++ l2569-aegl/fs/proc/kcore.c	Mon May 19 08:57:17 2003
@@ -99,7 +99,9 @@
 }
 #else /* CONFIG_KCORE_AOUT */
 
+#ifndef KCORE_BASE
 #define	KCORE_BASE	PAGE_OFFSET
+#endif
 
 #define roundup(x, y)  ((((x)+((y)-1))/(y))*(y))
 
diff -ru l2569-mosberger/include/asm-ia64/pgtable.h l2569-aegl/include/asm-ia64/pgtable.h
--- l2569-mosberger/include/asm-ia64/pgtable.h	Fri May 16 11:46:57 2003
+++ l2569-aegl/include/asm-ia64/pgtable.h	Mon May 19 09:04:30 2003
@@ -207,7 +207,8 @@
 #define RGN_MAP_LIMIT	((1UL << (4*PAGE_SHIFT - 12)) - PAGE_SIZE)	/* per region addr limit */
 #define RGN_KERNEL	7
 
-#define VMALLOC_START		0xa000000200000000
+#define	KCORE_BASE		0xa000000000000000
+#define VMALLOC_START		(0xa000000000000000 + 3*PERCPU_PAGE_SIZE)
 #define VMALLOC_VMADDR(x)	((unsigned long)(x))
 #ifdef CONFIG_VIRTUAL_MEM_MAP
 # define VMALLOC_END_INIT	(0xa000000000000000 + (1UL << (4*PAGE_SHIFT - 9)))
diff -ru l2569-mosberger/include/asm-ia64/system.h l2569-aegl/include/asm-ia64/system.h
--- l2569-mosberger/include/asm-ia64/system.h	Fri May 16 11:46:57 2003
+++ l2569-aegl/include/asm-ia64/system.h	Mon May 19 09:05:25 2003
@@ -19,7 +19,7 @@
 #include <asm/pal.h>
 #include <asm/percpu.h>
 
-#define KERNEL_START		(0xa000000100000000)
+#define KERNEL_START		(0xa000004000000000)
 
 /* 0xa000000000000000 - 0xa000000000000000+PERCPU_MAX_SIZE remain unmapped */
 #define PERCPU_ADDR		(0xa000000000000000 + PERCPU_PAGE_SIZE)