* [PATCH]: __crc_* symbols in System.map
@ 2004-08-12 3:55 David S. Miller
2004-08-12 5:01 ` Sam Ravnborg
0 siblings, 1 reply; 6+ messages in thread
From: David S. Miller @ 2004-08-12 3:55 UTC (permalink / raw)
To: torvalds; +Cc: akpm, linux-kernel
Shouldn't we be grepping these things out of the System.map file?
For one thing, these can confuse readprofile. It's algorithm is
to start at _stext, then stop when it sees a line in the System.map
which is not text (mode is one of 'T' 't' 'W' or 'w')
It will exit early if there are some intermixed __crc_* things in
there (since they are are mode 'A').
For example, in my current sparc64 kernel I have this:
00000000004cef80 t do_split
00000000004cf2a0 t add_dirent_to_buf
00000000004cf5a7 A __crc_init_special_inode
00000000004cf640 t make_indexed_dir
00000000004cf900 t ext3_add_entry
So no symbols after add_dirent_to_buf will be shown in the profiling
output of readprofile.
So we should grep them out, right? If so, here is a patch which
implements that.
===== Makefile 1.511 vs edited =====
--- 1.511/Makefile 2004-08-09 19:12:34 -07:00
+++ edited/Makefile 2004-08-11 20:21:36 -07:00
@@ -538,7 +538,7 @@
echo 'cmd_$@ := $(cmd_vmlinux__)' > $(@D)/.$(@F).cmd
endef
-do_system_map = $(NM) $(1) | grep -v '\(compiled\)\|\(\.o$$\)\|\( [aUw] \)\|\(\.\.ng$$\)\|\(LASH[RL]DI\)' | sort > $(2)
+do_system_map = $(NM) $(1) | grep -v '\(compiled\)\|\(\.o$$\)\|\( [aUw] \)\|\(\.\.ng$$\)\|\(LASH[RL]DI\)\|\(__crc_\)' | sort > $(2)
LDFLAGS_vmlinux += -T arch/$(ARCH)/kernel/vmlinux.lds.s
^ permalink raw reply [flat|nested] 6+ messages in thread
* Re: [PATCH]: __crc_* symbols in System.map
2004-08-12 3:55 [PATCH]: __crc_* symbols in System.map David S. Miller
@ 2004-08-12 5:01 ` Sam Ravnborg
2004-08-12 7:05 ` David S. Miller
0 siblings, 1 reply; 6+ messages in thread
From: Sam Ravnborg @ 2004-08-12 5:01 UTC (permalink / raw)
To: David S. Miller; +Cc: torvalds, akpm, linux-kernel
On Wed, Aug 11, 2004 at 08:55:29PM -0700, David S. Miller wrote:
>
> Shouldn't we be grepping these things out of the System.map file?
>
> For one thing, these can confuse readprofile. It's algorithm is
> to start at _stext, then stop when it sees a line in the System.map
> which is not text (mode is one of 'T' 't' 'W' or 'w')
>
> It will exit early if there are some intermixed __crc_* things in
> there (since they are are mode 'A').
>
> For example, in my current sparc64 kernel I have this:
>
> 00000000004cef80 t do_split
> 00000000004cf2a0 t add_dirent_to_buf
> 00000000004cf5a7 A __crc_init_special_inode
> 00000000004cf640 t make_indexed_dir
> 00000000004cf900 t ext3_add_entry
>
> So no symbols after add_dirent_to_buf will be shown in the profiling
> output of readprofile.
>
> So we should grep them out, right? If so, here is a patch which
> implements that.
I have a patch in this area pending, it moves System.map generation
out of the top-level makefile. And btw simplifies the expression a bit.
iMy patches are only at linux-sam.bkbits.net/kbuild for now,
will post patches later this week.
Would it be an option to skip all 'A' symbols?
Sam
^ permalink raw reply [flat|nested] 6+ messages in thread
* Re: [PATCH]: __crc_* symbols in System.map
2004-08-12 5:01 ` Sam Ravnborg
@ 2004-08-12 7:05 ` David S. Miller
2004-08-13 18:02 ` Sam Ravnborg
0 siblings, 1 reply; 6+ messages in thread
From: David S. Miller @ 2004-08-12 7:05 UTC (permalink / raw)
To: Sam Ravnborg; +Cc: torvalds, akpm, linux-kernel
On Thu, 12 Aug 2004 07:01:36 +0200
Sam Ravnborg <sam@ravnborg.org> wrote:
> Would it be an option to skip all 'A' symbols?
I doubt it. Symbols defined via the linker script will
end up as " A ". On sparc64 this happens for swapper_pmd_dir,
empty_pg_dir, _etext, _edata, and _end for example.
^ permalink raw reply [flat|nested] 6+ messages in thread
* Re: [PATCH]: __crc_* symbols in System.map
2004-08-12 7:05 ` David S. Miller
@ 2004-08-13 18:02 ` Sam Ravnborg
2004-08-13 18:10 ` Sam Ravnborg
0 siblings, 1 reply; 6+ messages in thread
From: Sam Ravnborg @ 2004-08-13 18:02 UTC (permalink / raw)
To: David S. Miller; +Cc: Sam Ravnborg, torvalds, akpm, linux-kernel
On Thu, Aug 12, 2004 at 12:05:58AM -0700, David S. Miller wrote:
> On Thu, 12 Aug 2004 07:01:36 +0200
> Sam Ravnborg <sam@ravnborg.org> wrote:
>
> > Would it be an option to skip all 'A' symbols?
>
> I doubt it. Symbols defined via the linker script will
> end up as " A ". On sparc64 this happens for swapper_pmd_dir,
> empty_pg_dir, _etext, _edata, and _end for example.
Did a:
nm vmlinux | grep ' A ' | grep -v '__crc_' | wc -l
32
So yep.
Modified your patch to match my tree - patched soon to appear at lkml.
Sam
In my tree I now have a script to generate System.map - that now looks like this:
#!/bin/sh -x
# Based on the vmlinux file create the System.map file
# System.map is used by module-init tools and some debugging
# tools to retreive the actual addresses of symbols in the kernel.
#
# Before creating the System.map file as a sideeffect check for
# undefined symbols.
# At least one version of the ARM bin-utils did not error out on
# undefined symbols, so catch them here instead.
# Usage
# mksysmap vmlinux System.map
#####
# Check for undefined symbols.
# Undefined symbols with three leading underscores are ignored since
# they are used by the sparc BTFIXUP logic - and is assumed to be undefined.
if [ "`$NM -u $1 | grep -v ' ___'`" != "" ]; then
echo "$1: error: undefined symbol(s) found:"
$NM -u $1 | grep -v ' ___'
exit 1
fi
#####
# Generate System.map (actual filename passed as second argument)
# $NM produces the following output:
# f0081e80 T alloc_vfsmnt
# The second row specify the type of the symbol:
# A = Absolute
# B = Uninitialised data (.bss)
# C = Comon symbol
# D = Initialised data
# G = Initialised data for small objects
# I = Indirect reference to another symbol
# N = Debugging symbol
# R = Read only
# S = Uninitialised data for small objects
# T = Text code symbol
# U = Undefined symbol
# V = Weak symbol
# W = Weak symbol
# Corresponding small letters are local symbols
# For System.map filter away:
# a - local absolute symbols
# U - undefined global symbols
# w - local weak symbols
# readprofile starts reading symbols when _stext is found, and
# continue until it finds a symbol which is not either of 'T', 't',
# 'W' or 'w'. __crc_ are 'A' and placed in the middle
# so we just ignore them to let readprofile continue to work.
# (At least sparc64 has __crc_ in the middle).
$NM -n $1 | grep '\( [aUw] \)\|\(__crc_\)' > $2
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^ permalink raw reply [flat|nested] 6+ messages in thread
end of thread, other threads:[~2004-08-13 20:27 UTC | newest]
Thread overview: 6+ messages (download: mbox.gz follow: Atom feed
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2004-08-12 3:55 [PATCH]: __crc_* symbols in System.map David S. Miller
2004-08-12 5:01 ` Sam Ravnborg
2004-08-12 7:05 ` David S. Miller
2004-08-13 18:02 ` Sam Ravnborg
2004-08-13 18:10 ` Sam Ravnborg
2004-08-13 20:18 ` David S. Miller
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