Violent cleanup of the code. Lots of effort duplication removed.

Don't look into the headers in read, just build the headers in attach and
ignore them.
mmap should now work (when boot loaders are fixed to align the tables).
Support for ELF.

1 files changed, 118 insertions, 68 deletions

diff --git a/sys/dev/ksyms.c b/sys/dev/ksyms.c
index 31bbf00b092..b04186c325e 100644
--- a/sys/dev/ksyms.c
+++ b/sys/dev/ksyms.c
@@ -1,5 +1,7 @@
+/*	$OpenBSD: ksyms.c,v 1.6 2001/02/03 21:25:26 art Exp $	*/
 /*
  * Copyright (c) 1998 Todd C. Miller <Todd.Miller@courtesan.com>
+ * Copyright (c) 2001 Artur Grabowski <art@openbsd.org>
  * All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
@@ -10,13 +12,13 @@
  * 2. Redistributions in binary form must reproduce the above copyright
  *    notice, this list of conditions and the following disclaimer in the
  *    documentation and/or other materials provided with the distribution.
- * 3. The name of the author may not be used to endorse or promote products
+ * 3. The name of the authors may not be used to endorse or promote products
  *    derived from this software without specific prior written permission.
  *
  * THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES,
  * INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY
  * AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL
- * THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
+ * THE AUTHORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
  * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
  * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS;
  * OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY,
@@ -25,13 +27,6 @@
  * ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  */
 
-/*
- * kernel symbols special file (masquerades as a ZMAGIC a.out file)
- *
- * TODO: get boot loaders to put symbols on a page boundary so we
- *       can mmap them too (also requires minor change to db_aout.c).
- */
-
 #include <sys/param.h>
 #include <sys/buf.h>
 #include <sys/exec.h>
@@ -40,6 +35,10 @@
 #include <sys/malloc.h>
 #include <sys/fcntl.h>
 
+#ifdef _NLIST_DO_ELF
+#include <sys/exec_elf.h>
+#endif
+
 #include <machine/cpu.h>
 
 #include <vm/vm.h>
@@ -47,36 +46,99 @@
 extern char *esym;				/* end of symbol table */
 extern long end;				/* end of kernel */
 
-static struct exec *k1;				/* first page of /dev/ksyms */
-static caddr_t symtab = (caddr_t)(&end + 1);	/* start of symbol table */
+static caddr_t ksym_head;
+static caddr_t ksym_syms;
+static size_t ksym_head_size;
+static size_t ksym_syms_size;
 
 void	ksymsattach __P((int));
 int	ksymsopen __P((dev_t, int, int));
 int	ksymsclose __P((dev_t, int, int));
 int	ksymsread __P((dev_t, struct uio *, int));
 
+/*
+ * We assume __LDPGSZ is a multiple of PAGE_SIZE (it is)
+ */
+
 /*ARGSUSED*/
 void
 ksymsattach(num)
 	int num;
 {
 
-	if (esym > (char *)&end) {
+	if (esym <= (char *)&end) {
+		printf("/dev/ksyms: Symbol table not valid.\n");
+		return;
+	}
+
+#ifdef _NLIST_DO_ELF
+	do {
+		caddr_t symtab = (caddr_t)&end;
+		Elf_Ehdr *elf;
+		Elf_Shdr *shdr;
+		int i;
+
+		elf = (Elf_Ehdr *)symtab;
+		if (memcmp(elf->e_ident, ELFMAG, SELFMAG) != 0 ||
+		    elf->e_ident[EI_CLASS] != ELFCLASS ||
+		    elf->e_machine != ELF_TARG_MACH)
+			break;
+
+		shdr = (Elf_Shdr *)&symtab[elf->e_shoff];
+		for (i = 0; i < elf->e_shnum; i++) {
+			if (shdr[i].sh_type == SHT_SYMTAB) {
+				break;
+  			}
+		}
+
 		/*
-		 * If we have a symbol table, fake up a struct exec.
+		 * No symbol table found.
+		 */
+		if (i == elf->e_shnum)
+			break;
+
+		printf("symbols at: %p\n", symtab);
+		/*
+		 * No additional header.
+		 */
+		ksym_head_size = 0;
+		ksym_syms = symtab;
+		ksym_syms_size = (size_t)(esym - symtab);
+
+		return;
+	} while (0);
+#endif
+
+#ifdef _NLIST_DO_AOUT
+	{
+		/*
+		 * a.out header.
+		 * Fake up a struct exec.
 		 * We only fill in the following non-zero entries:
 		 *	a_text - fake text segment (struct exec only)
 		 *	a_syms - size of symbol table
-		 *
-		 * We assume __LDPGSZ is a multiple of PAGE_SIZE (it is)
 		 */
-		k1 = (struct exec *)malloc(__LDPGSZ, M_TEMP, M_WAITOK);
-		bzero(k1, __LDPGSZ);
+		caddr_t symtab = (char *)(&end + 1);
+		struct exec *k1;
+
+		ksym_head_size = __LDPGSZ;
+		ksym_head = malloc(ksym_head_size, M_DEVBUF, M_NOWAIT);
+		if (ksym_head == NULL) {
+			printf("failed to allocate memory for /dev/ksyms\n");
+			return;
+		}
+		bzero(ksym_head, ksym_head_size);
+
+		k1 = (struct exec *)ksym_head;
+
 		N_SETMAGIC(*k1, ZMAGIC, MID_MACHINE, 0);
 		k1->a_text = __LDPGSZ;
 		k1->a_syms = end;
+
+		ksym_syms = symtab;
+		ksym_syms_size = (size_t)(esym - symtab);
 	}
-	return;
+#endif
 }
 
 /*ARGSUSED*/
@@ -93,9 +155,9 @@ ksymsopen(dev, flag, mode)
 	/* This device is read-only */
 	if ((flag & FWRITE))
 		return (EPERM);
-		
-	/* Must have symbols at the end of the kernel to work */
-	if (esym <= (char *)&end)
+
+	/* ksym_syms must be initialized */
+	if (ksym_syms == NULL)
 		return (ENXIO);
 
 	return (0);
@@ -118,70 +180,58 @@ ksymsread(dev, uio, flags)
 	struct uio *uio;
 	int flags;
 {
-	register vaddr_t v;
-	register size_t c, len;
-	int error = 0;
-
-#define iov	(uio->uio_iov)
-	while (uio->uio_resid > 0 && error == 0) {
-		/* Done with this iov?  Fill the next one... */
-		if (iov->iov_len == 0) {
-			uio->uio_iov++;
-			uio->uio_iovcnt--;
-			if (uio->uio_iovcnt < 0)
-				panic("ksymread");
-		}
+	int error;
+	size_t len;
+	caddr_t v;
+	size_t off;
 
-		/* Can't read past size of symbol table... */
-		if (uio->uio_offset >= (vaddr_t)(esym - symtab) + k1->a_text)
+	while (uio->uio_resid > 0) {
+		if (uio->uio_offset >= ksym_head_size + ksym_syms_size)
 			break;
 
-		if (uio->uio_offset < k1->a_text) {
-			/*
-			 * If they asked for more that a_text,
-			 * read the part of k1 first, then the
-			 * part of symtab next time throug the loop.
-			 */
-			if (iov->iov_len + (size_t)uio->uio_offset >
-			    k1->a_text)
-				len = k1->a_text;
-			else
-				len = iov->iov_len;
-
-			/* Make offset relative to struct exec */
-			v = uio->uio_offset + (vaddr_t)k1;
-			c = min(len, MAXPHYS);
-			error = uiomove((caddr_t)v, c, uio);
+		if (uio->uio_offset < ksym_head_size) {
+			v = ksym_head + uio->uio_offset;
+			len = ksym_head_size - uio->uio_offset;
 		} else {
-			/* Make offset relative to symtab */
-			v = uio->uio_offset - k1->a_text + (vaddr_t)symtab;
-			c = min(iov->iov_len, MAXPHYS);
-
-			/* Don't read past esym, truncate. */
-			if (v + c > (vaddr_t)esym)
-				c = (vaddr_t)esym - v;
-			error = uiomove((caddr_t)v, c, uio);
+			off = uio->uio_offset - ksym_head_size;
+			v = ksym_syms + off;
+			len = ksym_syms_size - off;
 		}
+
+		if (len > uio->uio_resid)
+			len = uio->uio_resid;
+
+		if ((error = uiomove(v, len, uio)) != 0)
+			return (error);
 	}
-	return (error);
+
+	return (0);
 }
 
-/* XXX - can't do mmap until boot loaders make the symbol table page aligned */
+/* XXX - not yet */
 #if 0
 int
 ksymsmmap(dev, off, prot)
 	dev_t dev;
 	int off, prot;
 {
-#define ksyms_btop(x)	((vaddr_t)(x) >> PGSHIFT
+	vaddr_t va;
+	paddr_t pa;
+
 	if (off < 0)
 		return (-1);
-	if ((unsigned)off >= (unsigned)(esym - symtab) + k1->a_text)
+	if (off >= ksym_head_size + ksym_syms_size)
 		return (-1);
 
-	if ((unsigned)off < k1->a_text)
-		return (ksyms_btop(off + (unsigned)k1));
-	else
-		return (ksyms_btop(off + (unsigned)symtab - k1->a_text));
+	if ((vaddr_t)off < ksym_head_size) {
+		va = (vaddr_t)ksym_head + off;
+	} else {
+		va = (vaddr_t)ksym_syms + off;
+	}
+
+	if ((pa = pmap_extract(pmap_kernel, va)) == 0)
+		panic("ksymsmmap: null pa");
+
+	return atop(pa);
 }
 #endif