Commit Graph

20 Commits

Author SHA1 Message Date
Lai Jiangshan b478b782e1 kallsyms, tracing: output more proper symbol name
Impact: bugfix, output more reliable symbol lookup result

Debug tools(dump_stack(), ftrace...) are like to print out symbols.
But it is always print out the first aliased symbol.(Aliased symbols
are symbols with the same address), and the first aliased symbol is
sometime not proper.

 # echo function_graph > current_tracer
 # cat trace
......
 1)   1.923 us    |    select_nohz_load_balancer();
 1) + 76.692 us   |  }
 1)               |  default_idle() {
 1)   ==========> |    __irqentry_text_start() {
 1)   0.000 us    |      native_apic_mem_write();
 1)               |      irq_enter() {
 1)   0.000 us    |        idle_cpu();
 1)               |        tick_check_idle() {
 1)   0.000 us    |          tick_check_oneshot_broadcast();
 1)               |          tick_nohz_stop_idle() {
......

It's very embarrassing, it ouputs "__irqentry_text_start()",
actually, it should output "smp_apic_timer_interrupt()".
(these two symbol are the same address, but "__irqentry_text_start"
is deemed to the first aliased symbol by scripts/kallsyms)

This patch puts symbols like "__irqentry_text_start" to the second
aliased symbols. And a more proper symbol name becomes the first.

Aliased symbols mostly come from linker script. The solution is
guessing "is this symbol defined in linker script", the symbols
defined in linker script will not become the first aliased symbol.

And if symbols are found to be equal in this "linker script provided"
criteria, symbols are sorted by the number of prefix underscores.

Signed-off-by: Lai Jiangshan <laijs@cn.fujitsu.com>
Acked-by: Sam Ravnborg <sam@ravnborg.org>
Reviewed-by: Paulo Marques <pmarques@grupopie.com>
LKML-Reference: <49BA06E2.7080807@cn.fujitsu.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-03-14 09:55:04 +01:00
Sam Ravnborg 2ea038917b Revert "kbuild: strip generated symbols from *.ko"
This reverts commit ad7a953c52.

And commit: ("allow stripping of generated symbols under CONFIG_KALLSYMS_ALL")
            9bb482476c

These stripping patches has caused a set of issues:

1) People have reported compatibility issues with binutils due to
   lack of support for `--strip-unneeded-symbols' with objcopy 2.15.92.0.2
   Reported by: Wenji
2) ccache and distcc no longer works as expeced
   Reported by: Ted, Roland, + others
3) The installed modules increased a lot in size
   Reported by: Ted, Davej + others

Reported-by: Wenji Huang <wenji.huang@oracle.com>
Reported-by: "Theodore Ts'o" <tytso@mit.edu>
Reported-by: Dave Jones <davej@redhat.com>
Reported-by: Roland McGrath <roland@redhat.com>
Signed-off-by: Sam Ravnborg <sam@ravnborg.org>
2009-01-14 21:38:20 +01:00
Jan Beulich 9bb482476c allow stripping of generated symbols under CONFIG_KALLSYMS_ALL
Building upon parts of the module stripping patch, this patch
introduces similar stripping for vmlinux when CONFIG_KALLSYMS_ALL=y.
Using CONFIG_KALLSYMS_STRIP_GENERATED reduces the overhead of
CONFIG_KALLSYMS_ALL from 245k/310k to 65k/80k for the (i386/x86-64)
kernels I tested with.

The patch also does away with the need to special case the kallsyms-
internal symbols by making them available even in the first linking
stage.

While it is a generated file, the patch includes the changes to
scripts/genksyms/keywords.c_shipped, as I'm unsure what the procedure
here is.

Signed-off-by: Jan Beulich <jbeulich@novell.com>
Signed-off-by: Sam Ravnborg <sam@ravnborg.org>
2008-12-19 22:47:10 +01:00
Sam Ravnborg aab34ac858 kbuild: filter away debug symbols from kernel symbols
Andi Kleen <andi@firstfloor.org>
reported that he saw a lot of symbols like this:

0000000000000b24 N DW.aio.h.903a6d92.2
0000000000000bce N DW.task_io_accounting.h.8d8de327.0
0000000000000bec N DW.hrtimer.h.c23659c6.0

in his System.map / kallsyms output.

Simple solution is to skip all debugging
symbols (they are marked 'N').

Signed-off-by: Sam Ravnborg <sam@ravnborg.org>
Cc: Paulo Marques <pmarques@grupopie.com>
2008-05-19 20:07:58 +02:00
Bryan Wu c6495aaabf kallsyms: nuke all ChangeLog, this should be logged by git
Pointed out by Paulo:
  "When I wrote this initially, it was a mistake to add a Changelog in
   the first place, but I didn't know better at the time.

   If you're going to make changes to this file, please remove all the
   Changelog, instead of adding more entries to it.  The 'Changelog'
   should be kept by the version control system, and not the source code
   itself."

Cc: Paulo Marques <pmarques@grupopie.com>
Signed-off-by: Bryan Wu <cooloney@kernel.org>
Acked-by: Paulo Marques <pmarques@grupopie.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-04-30 08:29:31 -07:00
Paulo Marques f2df3f65d0 kallsyms should prefer non weak symbols
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>
2008-02-06 10:41:07 -08:00
Robin Getz a3b81113fb 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>
2008-02-06 10:41:01 -08:00
Linus Torvalds efffbeee5b Merge git://git.kernel.org/pub/scm/linux/kernel/git/sam/kbuild
* git://git.kernel.org/pub/scm/linux/kernel/git/sam/kbuild: (33 commits)
  xtensa: use DATA_DATA in xtensa
  powerpc: add missing DATA_DATA to powerpc
  cris: use DATA_DATA in cris
  kallsyms: remove usage of memmem and _GNU_SOURCE from scripts/kallsyms.c
  kbuild: use -fno-optimize-sibling-calls unconditionally
  kconfig: reset generated values only if Kconfig and .config agree.
  kbuild: fix the warning when running make tags
  kconfig: strip 'CONFIG_' automatically in kernel configuration search
  kbuild: use POSIX BRE in headers install target
  Whitelist references from __dbe_table to .init
  modpost white list pattern adjustment
  kbuild: do section mismatch check on full vmlinux
  kbuild: whitelist references from variables named _timer to .init.text
  kbuild: remove hardcoded _logo names from modpost
  kbuild: remove hardcoded apic_es7000 from modpost
  kbuild: warn about references from .init.text to .exit.text
  kbuild: consolidate section checks
  kbuild: refactor code in modpost to improve maintainability
  kbuild: ignore section mismatch warnings originating from .note section
  kbuild: .paravirtprobe section is obsolete, so modpost doesn't need to handle it
  ...
2007-07-19 14:28:19 -07:00
Tejun Heo 9281acea6a kallsyms: make KSYM_NAME_LEN include space for trailing '\0'
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>
2007-07-17 10:23:03 -07:00
Paulo Marques 7c5d249ad3 kallsyms: remove usage of memmem and _GNU_SOURCE from scripts/kallsyms.c
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>
2007-07-17 14:36:08 +02:00
Jan Beulich aad094701c [PATCH] move kallsyms data to .rodata
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>
2006-12-08 08:28:37 -08:00
Vivek Goyal 2c22d8baa9 [PATCH] relocatable kernel: Fix kallsyms on avr32 after relocatable kernel changes
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>
2006-12-07 02:14:10 +01:00
Eric W. Biederman fd593d1277 [PATCH] relocatable kernel: Kallsyms generate relocatable symbols
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>
2006-12-07 02:14:04 +01:00
Jesper Juhl f1a136e0d0 [PATCH] kallsyms: handle malloc() failure
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>
2006-03-25 08:22:56 -08:00
Ralf Baechle 6f00df24ee [PATCH] Strip local symbols from kallsyms
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>
2005-09-07 16:57:20 -07:00
Paulo Marques b3dbb4ecd4 [PATCH] kallsyms: change compression algorithm
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>
2005-09-07 16:57:18 -07:00
J.A. Magallon 61d9cdf2a9 [PATCH] kbuild: signed char fixes for scripts
This time I did not break anything... and they shut up gcc4 ;)

Signed-off-by: Sam Ravnborg <sam@ravnborg.org>
2005-07-27 22:27:08 +02:00
David Woodhouse 075d6eb16d [PATCH] ppc32: platform-specific functions missing from kallsyms.
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>
2005-05-05 16:36:31 -07:00
Yoshinori Sato 41f11a4fa3 [PATCH] kallsyms C_SYMBOL_PREFIX support
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>
2005-05-01 08:59:06 -07:00
Linus Torvalds 1da177e4c3 Linux-2.6.12-rc2
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!
2005-04-16 15:20:36 -07:00