When resolving symbol names from addresses with aliased symbol names,
kallsyms_lookup always returns the first symbol, even if it is a weak
symbol.

This patch changes this by sorting the symbols with the weak symbols last
before feeding them to the kernel.  This way the kernel runtime isn't
changed at all, only the kallsyms build system is changed.

Another side effect is that the symbols get sorted by address, too.  So,
even if future binutils version have some bug in "nm" that makes it fail to
correctly sort symbols by address, the kernel won't be affected by this.

Mathieu says:

  I created a module in LTTng that uses kallsyms to get the symbol
  corresponding to a specific system call address.  Unfortunately, all the
  unimplemented syscalls were all referring to the (same) weak symbol
  identifying an unrelated system call rather that sys_ni (or whatever
  non-weak symbol would be expected).  Kallsyms was dumbly returning the first
  symbol that matched.

  This patch makes sure kallsyms returns the non-weak symbol when there is
  one, which seems to be the expected result.

[akpm@linux-foundation.org: coding-style fixes]
Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@polymtl.ca>
Looks-great-to: Rusty Russell <rusty@rustcorp.com.au>
Cc: Sam Ravnborg <sam@ravnborg.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

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>

KSYM_NAME_LEN is peculiar in that it does not include the space for the
trailing '\0', forcing all users to use KSYM_NAME_LEN + 1 when allocating
buffer.  This is nonsense and error-prone.  Moreover, when the caller
forgets that it's very likely to subtly bite back by corrupting the stack
because the last position of the buffer is always cleared to zero.

This patch increments KSYM_NAME_LEN by one and updates code accordingly.

* off-by-one bug in asm-powerpc/kprobes.h::kprobe_lookup_name() macro
  is fixed.

* Where MODULE_NAME_LEN and KSYM_NAME_LEN were used together,
  MODULE_NAME_LEN was treated as if it didn't include space for the
  trailing '\0'.  Fix it.

Signed-off-by: Tejun Heo <htejun@gmail.com>
Acked-by: Paulo Marques <pmarques@grupopie.com>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Paul Mackerras <paulus@samba.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

The only in-kernel user of "memmem" is scripts/kallsyms.c and it only
uses it to find tokens that are 2 bytes in size. It is trivial to
replace it with a simple function that finds 2-byte tokens.

This should help users from systems that don't have the memmem GNU
extension available.

Signed-off-by: Paulo Marques <pmarques@grupopie.com>
Signed-off-by: Sam Ravnborg <sam@ravnborg.org>

Kallsyms data is never written to, so it can as well benefit from
CONFIG_DEBUG_RODATA.

Signed-off-by: Jan Beulich <jbeulich@novell.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

o On some platforms like avr32, section init comes before .text and
  not necessarily a symbol's relative position w.r.t _text is positive.
  In such cases assembler detects the overflow and emits warning. This
  patch fixes it.

Signed-off-by: Vivek Goyal <vgoyal@in.ibm.com>
Signed-off-by: Andi Kleen <ak@suse.de>
Cc: Andi Kleen <ak@suse.de>
Cc: Haavard Skinnemoen <hskinnemoen@atmel.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>

Print the addresses of non-absolute symbols relative to _text
so that ld will generate relocations.  Allowing a relocatable
kernel to relocate them.  We can't actually use the symbol names
because kallsyms includes static symbols that are not exported
from their object files.

Add the _text symbol definitions to the architectures which don't
define it otherwise linker will fail.

Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>
Signed-off-by: Vivek Goyal <vgoyal@in.ibm.com>
Signed-off-by: Andi Kleen <ak@suse.de>

This fixes coverity bugs #398 and #397

Signed-off-by: Jesper Juhl <jesper.juhl@gmail.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

Local symbols generated by gcc start with a `$'; no point in including them
in the kernel.

Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

This patch changes the way the compression algorithm works.  The base
algorithm is similiar to the previous but we force the compressed token
size to 2.

Having a fixed size compressed token allows for a lot of optimizations, and
that in turn allows this code to run over *all* the symbols faster than it
did before over just a subset.

Having it work over all the symbols will make it behave better when symbols
change positions between passes, and the "inconsistent kallsyms" messages
should become less frequent.

In my tests the compression ratio was degraded by about 0.5%, but the
results will depend greatly on the number of symbols to compress.

Signed-off-by: Paulo Marques <pmarques@grupopie.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

This time I did not break anything... and they shut up gcc4 ;)

Signed-off-by: Sam Ravnborg <sam@ravnborg.org>

The PPC32 kernel puts platform-specific functions into separate sections so
that unneeded parts of it can be freed when we've booted and actually
worked out what we're running on today.

This makes kallsyms ignore those functions, because they're not between
_[se]text or _[se]inittext.  Rather than teaching kallsyms about the
various pmac/chrp/etc sections, this patch adds '_[se]extratext' markers
for kallsyms.

Signed-off-by: David Woodhouse <dwmw2@infradead.org>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

kallsyms does not consider SYMBOL_PREFIX of C.  Consequently it does not
work on architectures using that prefix character (h8300, v850).

Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

Initial git repository build. I'm not bothering with the full history,
even though we have it. We can create a separate "historical" git
archive of that later if we want to, and in the meantime it's about
3.2GB when imported into git - space that would just make the early
git days unnecessarily complicated, when we don't have a lot of good
infrastructure for it.

Let it rip!