remove support for un-needed _extratext section

When passing a zero address to kallsyms_lookup(), the kernel thought it was
a valid kernel address, even if it is not.  This is because is_ksym_addr()
called is_kernel_extratext() and checked against labels that don't exist on
many archs (which default as zero).  Since PPC was the only kernel which
defines _extra_text, (in 2005), and no longer needs it, this patch removes
_extra_text support.

For some history (provided by Jon):
 http://ozlabs.org/pipermail/linuxppc-dev/2005-September/019734.html
 http://ozlabs.org/pipermail/linuxppc-dev/2005-September/019736.html
 http://ozlabs.org/pipermail/linuxppc-dev/2005-September/019751.html

[akpm@linux-foundation.org: coding-style fixes]
Signed-off-by: Robin Getz <rgetz@blackfin.uclinux.org>
Cc: David Woodhouse <dwmw2@infradead.org>
Cc: Jon Loeliger <jdl@freescale.com>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Sam Ravnborg <sam@ravnborg.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

4 files changed, 11 insertions, 31 deletions

diff --git a/arch/ppc/kernel/vmlinux.lds.S b/arch/ppc/kernel/vmlinux.lds.S
index 52b64fcbdfc5..8a24bc47eb6c 100644
--- a/arch/ppc/kernel/vmlinux.lds.S
+++ b/arch/ppc/kernel/vmlinux.lds.S
@@ -143,11 +143,6 @@ SECTIONS
 
   . = ALIGN(4096);
   __init_end = .;
-
-  . = ALIGN(4096);
-  _sextratext = .;
-  _eextratext = .;
-
   __bss_start = .;
   .bss       :
   {
diff --git a/include/asm-generic/sections.h b/include/asm-generic/sections.h
index 962cad7cfbbd..8feeae1f2369 100644
--- a/include/asm-generic/sections.h
+++ b/include/asm-generic/sections.h
@@ -8,8 +8,6 @@ extern char _data[], _sdata[], _edata[];
 extern char __bss_start[], __bss_stop[];
 extern char __init_begin[], __init_end[];
 extern char _sinittext[], _einittext[];
-extern char _sextratext[] __attribute__((weak));
-extern char _eextratext[] __attribute__((weak));
 extern char _end[];
 extern char __per_cpu_start[], __per_cpu_end[];
 extern char __kprobes_text_start[], __kprobes_text_end[];
diff --git a/kernel/kallsyms.c b/kernel/kallsyms.c
index 7dadc71ce516..f091d13def00 100644
--- a/kernel/kallsyms.c
+++ b/kernel/kallsyms.c
@@ -53,14 +53,6 @@ static inline int is_kernel_inittext(unsigned long addr)
         return 0;
 }
 
-static inline int is_kernel_extratext(unsigned long addr)
-{
-        if (addr >= (unsigned long)_sextratext
-            && addr <= (unsigned long)_eextratext)
-                return 1;
-        return 0;
-}
-
 static inline int is_kernel_text(unsigned long addr)
 {
         if (addr >= (unsigned long)_stext && addr <= (unsigned long)_etext)
@@ -80,8 +72,7 @@ static int is_ksym_addr(unsigned long addr)
         if (all_var)
                 return is_kernel(addr);
 
-        return is_kernel_text(addr) || is_kernel_inittext(addr) ||
-                is_kernel_extratext(addr);
+        return is_kernel_text(addr) || is_kernel_inittext(addr);
 }
 
 /* expand a compressed symbol data into the resulting uncompressed string,
diff --git a/scripts/kallsyms.c b/scripts/kallsyms.c
index 1f11d848532a..8fb87003d5d3 100644
--- a/scripts/kallsyms.c
+++ b/scripts/kallsyms.c
@@ -41,7 +41,7 @@ struct sym_entry {
 
 static struct sym_entry *table;
 static unsigned int table_size, table_cnt;
-static unsigned long long _text, _stext, _etext, _sinittext, _einittext, _sextratext, _eextratext;
+static unsigned long long _text, _stext, _etext, _sinittext, _einittext;
 static int all_symbols = 0;
 static char symbol_prefix_char = '\0';
 
@@ -99,10 +99,6 @@ static int read_symbol(FILE *in, struct sym_entry *s)
                 _sinittext = s->addr;
         else if (strcmp(sym, "_einittext") == 0)
                 _einittext = s->addr;
-        else if (strcmp(sym, "_sextratext") == 0)
-                _sextratext = s->addr;
-        else if (strcmp(sym, "_eextratext") == 0)
-                _eextratext = s->addr;
         else if (toupper(stype) == 'A')
         {
                 /* Keep these useful absolute symbols */
@@ -165,18 +161,18 @@ static int symbol_valid(struct sym_entry *s)
          * and inittext sections are discarded */
         if (!all_symbols) {
                 if ((s->addr < _stext || s->addr > _etext)
-                    && (s->addr < _sinittext || s->addr > _einittext)
-                    && (s->addr < _sextratext || s->addr > _eextratext))
+                    && (s->addr < _sinittext || s->addr > _einittext))
                         return 0;
                 /* Corner case.  Discard any symbols with the same value as
-                 * _etext _einittext or _eextratext; they can move between pass
-                 * 1 and 2 when the kallsyms data are added.  If these symbols
-                 * move then they may get dropped in pass 2, which breaks the
-                 * kallsyms rules.
+                 * _etext _einittext; they can move between pass 1 and 2 when
+                 * the kallsyms data are added.  If these symbols move then
+                 * they may get dropped in pass 2, which breaks the kallsyms
+                 * rules.
                  */
-                if ((s->addr == _etext && strcmp((char*)s->sym + offset, "_etext")) ||
-                    (s->addr == _einittext && strcmp((char*)s->sym + offset, "_einittext")) ||
-                    (s->addr == _eextratext && strcmp((char*)s->sym + offset, "_eextratext")))
+                if ((s->addr == _etext &&
+                                strcmp((char *)s->sym + offset, "_etext")) ||
+                    (s->addr == _einittext &&
+                                strcmp((char *)s->sym + offset, "_einittext")))
                         return 0;
         }