Patchwork [10/18] powerpc/boot: add 64bit and little endian support to addnote

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Submitter Cédric Le Goater
Date March 20, 2014, 3:10 p.m.
Message ID <1395328213-19206-11-git-send-email-clg@fr.ibm.com>
Download mbox | patch
Permalink /patch/332234/
State Accepted
Commit 284b52c4c6e32870cacbd16872a7ed9e522cde0d
Headers show

Comments

Cédric Le Goater - March 20, 2014, 3:10 p.m.
It could certainly be improved using Elf macros and byteswapping
routines, but the initial version of the code is organised to be a
single file program with limited dependencies. yaboot is the same.

Please scream if you want a total rewrite.

Signed-off-by: Cédric Le Goater <clg@fr.ibm.com>
---

From the comment in the header :

    "This is needed for OF on RS/6000s to load an image correctly" 

If so, the data written in the ELF note should be in Big Endian as this 
code is doing ?

Changes since RFC:

 - fixed the note creation which was done with the wrong endianess 
 - increased 'buf' as ELF structures are larger in 64bit

 arch/powerpc/boot/addnote.c |  128 ++++++++++++++++++++++++++++---------------
 1 file changed, 85 insertions(+), 43 deletions(-)

Patch

diff --git a/arch/powerpc/boot/addnote.c b/arch/powerpc/boot/addnote.c
index 349b5530d2c4..9d9f6f334d3c 100644
--- a/arch/powerpc/boot/addnote.c
+++ b/arch/powerpc/boot/addnote.c
@@ -6,6 +6,8 @@ 
  *
  * Copyright 2000 Paul Mackerras.
  *
+ * Adapted for 64 bit little endian images by Andrew Tauferner.
+ *
  * This program is free software; you can redistribute it and/or
  * modify it under the terms of the GNU General Public License
  * as published by the Free Software Foundation; either version
@@ -55,36 +57,61 @@  unsigned int rpanote[N_RPA_DESCR] = {
 
 #define ROUNDUP(len)	(((len) + 3) & ~3)
 
-unsigned char buf[512];
+unsigned char buf[1024];
+#define ELFDATA2LSB     1
+#define ELFDATA2MSB     2
+static int e_data = ELFDATA2MSB;
+#define ELFCLASS32      1
+#define ELFCLASS64      2
+static int e_class = ELFCLASS32;
 
 #define GET_16BE(off)	((buf[off] << 8) + (buf[(off)+1]))
-#define GET_32BE(off)	((GET_16BE(off) << 16) + GET_16BE((off)+2))
-
-#define PUT_16BE(off, v)	(buf[off] = ((v) >> 8) & 0xff, \
-				 buf[(off) + 1] = (v) & 0xff)
-#define PUT_32BE(off, v)	(PUT_16BE((off), (v) >> 16), \
-				 PUT_16BE((off) + 2, (v)))
+#define GET_32BE(off)	((GET_16BE(off) << 16U) + GET_16BE((off)+2U))
+#define GET_64BE(off)	((((unsigned long long)GET_32BE(off)) << 32ULL) + \
+			((unsigned long long)GET_32BE((off)+4ULL)))
+#define PUT_16BE(off, v)(buf[off] = ((v) >> 8) & 0xff, \
+			 buf[(off) + 1] = (v) & 0xff)
+#define PUT_32BE(off, v)(PUT_16BE((off), (v) >> 16L), PUT_16BE((off) + 2, (v)))
+#define PUT_64BE(off, v)((PUT_32BE((off), (v) >> 32L), \
+			  PUT_32BE((off) + 4, (v))))
+
+#define GET_16LE(off)	((buf[off]) + (buf[(off)+1] << 8))
+#define GET_32LE(off)	(GET_16LE(off) + (GET_16LE((off)+2U) << 16U))
+#define GET_64LE(off)	((unsigned long long)GET_32LE(off) + \
+			(((unsigned long long)GET_32LE((off)+4ULL)) << 32ULL))
+#define PUT_16LE(off, v) (buf[off] = (v) & 0xff, \
+			  buf[(off) + 1] = ((v) >> 8) & 0xff)
+#define PUT_32LE(off, v) (PUT_16LE((off), (v)), PUT_16LE((off) + 2, (v) >> 16L))
+#define PUT_64LE(off, v) (PUT_32LE((off), (v)), PUT_32LE((off) + 4, (v) >> 32L))
+
+#define GET_16(off)	(e_data == ELFDATA2MSB ? GET_16BE(off) : GET_16LE(off))
+#define GET_32(off)	(e_data == ELFDATA2MSB ? GET_32BE(off) : GET_32LE(off))
+#define GET_64(off)	(e_data == ELFDATA2MSB ? GET_64BE(off) : GET_64LE(off))
+#define PUT_16(off, v)	(e_data == ELFDATA2MSB ? PUT_16BE(off, v) : \
+			 PUT_16LE(off, v))
+#define PUT_32(off, v)  (e_data == ELFDATA2MSB ? PUT_32BE(off, v) : \
+			 PUT_32LE(off, v))
+#define PUT_64(off, v)  (e_data == ELFDATA2MSB ? PUT_64BE(off, v) : \
+			 PUT_64LE(off, v))
 
 /* Structure of an ELF file */
 #define E_IDENT		0	/* ELF header */
-#define	E_PHOFF		28
-#define E_PHENTSIZE	42
-#define E_PHNUM		44
-#define E_HSIZE		52	/* size of ELF header */
+#define	E_PHOFF		(e_class == ELFCLASS32 ? 28 : 32)
+#define E_PHENTSIZE	(e_class == ELFCLASS32 ? 42 : 54)
+#define E_PHNUM		(e_class == ELFCLASS32 ? 44 : 56)
+#define E_HSIZE		(e_class == ELFCLASS32 ? 52 : 64)
 
 #define EI_MAGIC	0	/* offsets in E_IDENT area */
 #define EI_CLASS	4
 #define EI_DATA		5
 
 #define PH_TYPE		0	/* ELF program header */
-#define PH_OFFSET	4
-#define PH_FILESZ	16
-#define PH_HSIZE	32	/* size of program header */
+#define PH_OFFSET	(e_class == ELFCLASS32 ? 4 : 8)
+#define PH_FILESZ	(e_class == ELFCLASS32 ? 16 : 32)
+#define PH_HSIZE	(e_class == ELFCLASS32 ? 32 : 56)
 
 #define PT_NOTE		4	/* Program header type = note */
 
-#define ELFCLASS32	1
-#define ELFDATA2MSB	2
 
 unsigned char elf_magic[4] = { 0x7f, 'E', 'L', 'F' };
 
@@ -92,8 +119,8 @@  int
 main(int ac, char **av)
 {
 	int fd, n, i;
-	int ph, ps, np;
-	int nnote, nnote2, ns;
+	unsigned long ph, ps, np;
+	long nnote, nnote2, ns;
 
 	if (ac != 2) {
 		fprintf(stderr, "Usage: %s elf-file\n", av[0]);
@@ -114,26 +141,27 @@  main(int ac, char **av)
 		exit(1);
 	}
 
-	if (n < E_HSIZE || memcmp(&buf[E_IDENT+EI_MAGIC], elf_magic, 4) != 0)
+	if (memcmp(&buf[E_IDENT+EI_MAGIC], elf_magic, 4) != 0)
+		goto notelf;
+	e_class = buf[E_IDENT+EI_CLASS];
+	if (e_class != ELFCLASS32 && e_class != ELFCLASS64)
+		goto notelf;
+	e_data = buf[E_IDENT+EI_DATA];
+	if (e_data != ELFDATA2MSB && e_data != ELFDATA2LSB)
+		goto notelf;
+	if (n < E_HSIZE)
 		goto notelf;
 
-	if (buf[E_IDENT+EI_CLASS] != ELFCLASS32
-	    || buf[E_IDENT+EI_DATA] != ELFDATA2MSB) {
-		fprintf(stderr, "%s is not a big-endian 32-bit ELF image\n",
-			av[1]);
-		exit(1);
-	}
-
-	ph = GET_32BE(E_PHOFF);
-	ps = GET_16BE(E_PHENTSIZE);
-	np = GET_16BE(E_PHNUM);
+	ph = (e_class == ELFCLASS32 ? GET_32(E_PHOFF) : GET_64(E_PHOFF));
+	ps = GET_16(E_PHENTSIZE);
+	np = GET_16(E_PHNUM);
 	if (ph < E_HSIZE || ps < PH_HSIZE || np < 1)
 		goto notelf;
 	if (ph + (np + 2) * ps + nnote + nnote2 > n)
 		goto nospace;
 
 	for (i = 0; i < np; ++i) {
-		if (GET_32BE(ph + PH_TYPE) == PT_NOTE) {
+		if (GET_32(ph + PH_TYPE) == PT_NOTE) {
 			fprintf(stderr, "%s already has a note entry\n",
 				av[1]);
 			exit(0);
@@ -148,15 +176,22 @@  main(int ac, char **av)
 
 	/* fill in the program header entry */
 	ns = ph + 2 * ps;
-	PUT_32BE(ph + PH_TYPE, PT_NOTE);
-	PUT_32BE(ph + PH_OFFSET, ns);
-	PUT_32BE(ph + PH_FILESZ, nnote);
+	PUT_32(ph + PH_TYPE, PT_NOTE);
+	if (e_class == ELFCLASS32)
+		PUT_32(ph + PH_OFFSET, ns);
+	else
+		PUT_64(ph + PH_OFFSET, ns);
+
+	if (e_class == ELFCLASS32)
+		PUT_32(ph + PH_FILESZ, nnote);
+	else
+		PUT_64(ph + PH_FILESZ, nnote);
 
 	/* fill in the note area we point to */
 	/* XXX we should probably make this a proper section */
-	PUT_32BE(ns, strlen(arch) + 1);
-	PUT_32BE(ns + 4, N_DESCR * 4);
-	PUT_32BE(ns + 8, 0x1275);
+	PUT_32(ns, strlen(arch) + 1);
+	PUT_32(ns + 4, N_DESCR * 4);
+	PUT_32(ns + 8, 0x1275);
 	strcpy((char *) &buf[ns + 12], arch);
 	ns += 12 + strlen(arch) + 1;
 	for (i = 0; i < N_DESCR; ++i, ns += 4)
@@ -164,21 +199,28 @@  main(int ac, char **av)
 
 	/* fill in the second program header entry and the RPA note area */
 	ph += ps;
-	PUT_32BE(ph + PH_TYPE, PT_NOTE);
-	PUT_32BE(ph + PH_OFFSET, ns);
-	PUT_32BE(ph + PH_FILESZ, nnote2);
+	PUT_32(ph + PH_TYPE, PT_NOTE);
+	if (e_class == ELFCLASS32)
+		PUT_32(ph + PH_OFFSET, ns);
+	else
+		PUT_64(ph + PH_OFFSET, ns);
+
+	if (e_class == ELFCLASS32)
+		PUT_32(ph + PH_FILESZ, nnote);
+	else
+		PUT_64(ph + PH_FILESZ, nnote2);
 
 	/* fill in the note area we point to */
-	PUT_32BE(ns, strlen(rpaname) + 1);
-	PUT_32BE(ns + 4, sizeof(rpanote));
-	PUT_32BE(ns + 8, 0x12759999);
+	PUT_32(ns, strlen(rpaname) + 1);
+	PUT_32(ns + 4, sizeof(rpanote));
+	PUT_32(ns + 8, 0x12759999);
 	strcpy((char *) &buf[ns + 12], rpaname);
 	ns += 12 + ROUNDUP(strlen(rpaname) + 1);
 	for (i = 0; i < N_RPA_DESCR; ++i, ns += 4)
 		PUT_32BE(ns, rpanote[i]);
 
 	/* Update the number of program headers */
-	PUT_16BE(E_PHNUM, np + 2);
+	PUT_16(E_PHNUM, np + 2);
 
 	/* write back */
 	lseek(fd, (long) 0, SEEK_SET);