linux-toradex.git/scripts/kallsyms.c, branch v3.0.3

scripts/kallsyms.c: fix potential segfault

2011-05-12T15:23:40+00:00

Description:
This bug hardly appears during real kernel compiling,
 because the vmlinux symbols table is huge.

But we can still catch it under strict condition , as follows.
   $ echo "c101b97b T do_fork" | ./scripts/kallsyms --all-symbols
   #include 
   ......
   ......
   .globl kallsyms_token_table
           ALGN
   kallsyms_token_table:
   Segmentation fault (core dumped)
   $

If symbols table is small, all entries in token_profit[0x10000] may
decrease to 0 after several calls of compress_symbols() in optimize_result().
In that case, find_best_token() always return 0 and
best_table[i] is set to "\0\0" and best_table_len[i] is set to 2.

As a result, expand_symbol(best_table[0]="\0\0", best_table_len[0]=2, buf)
in write_src() will run in infinite recursion until stack overflows,
causing segfault.

This patch checks the find_best_token() return value. If all entries in
token_profit[0x10000] become 0 according to return value, it breaks the loop
in optimize_result().
And expand_symbol() works well when best_table_len[i] is 0.

Signed-off-by: Xiaochen Wang 
Acked-by: Paulo Marques 
Signed-off-by: Michal Marek

scripts/kallsyms: Enable error messages while hush up unnecessary warnings

2010-09-29T14:18:27+00:00

As no error was handled, we wouldn't be able to know when an error does
occur. The fix preserves error messages while it doesn't let unnecessary
compiling warnings show up.

Signed-off-by: Jean Sacren 
Signed-off-by: Michal Marek

scripts/kallsyms: suppress build warning

2010-02-02T13:33:56+00:00

Suppress a warn_unused_result warning.

fgets is called as a part of error handling.  It is called just to drop a
line and return immediately.  read_map is reading the file in a loop and
read_symbol reads line by line.  So I think there is no point in using
return value for useful checking.  Other checks like 3 items were returned
or !EOF have already been done.

Signed-off-by: Himanshu Chauhan 
Cc: WANG Cong 
Cc: Michal Marek 
Signed-off-by: Andrew Morton 
Signed-off-by: Michal Marek

kallsyms: fix segfault in prefix_underscores_count()

2009-09-23T14:39:30+00:00

Commit b478b782e110fdb4135caa3062b6d687e989d994 "kallsyms, tracing: output
more proper symbol name" introduces a "bugfix" that introduces a segfault
in kallsyms in my configurations.

The cause is the introduction of prefix_underscores_count() which attempts
to count underscores, even in symbols that do not have them.  As a result,
it just uselessly runs past the end of the buffer until it crashes:

  CC      init/version.o
  LD      init/built-in.o
  LD      .tmp_vmlinux1
  KSYM    .tmp_kallsyms1.S
/bin/sh: line 1: 16934 Done                    sh-linux-gnu-nm -n .tmp_vmlinux1
     16935 Segmentation fault      | scripts/kallsyms > .tmp_kallsyms1.S
make: *** [.tmp_kallsyms1.S] Error 139

This simplifies the logic and just does a straightforward count.

Signed-off-by: Paul Mundt 
Reviewed-by: Li Zefan 
Cc: Lai Jiangshan 
Cc: Sam Ravnborg 
Cc: Paulo Marques 
Cc: Ingo Molnar 
Cc: 		[2.6.30.x, 2.6.31.x]
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

kallsyms: fix inverted valid symbol checking

2009-06-20T11:33:23+00:00

The previous commit (17b1f0de) introduced a slightly broken consolidation
of the memory text range checking.

Signed-off-by: Mike Frysinger 
Signed-off-by: Sam Ravnborg

kallsyms: generalize text region handling

2009-06-14T20:43:46+00:00

Signed-off-by: Mike Frysinger 
Signed-off-by: Sam Ravnborg

kallsyms: support kernel symbols in Blackfin on-chip memory

2009-06-14T20:43:45+00:00

The Blackfin arch has a discontiguous .text layout due to having on-chip
instruction memory and no virtual memory support.  As such, we need to
add explicit checks for these additional .text regions.

Signed-off-by: Robin Getz 
Signed-off-by: Bryan Wu 
Signed-off-by: Mike Frysinger 
Signed-off-by: Sam Ravnborg

kallsyms, tracing: output more proper symbol name

2009-03-14T08:55:04+00:00

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 
Acked-by: Sam Ravnborg 
Reviewed-by: Paulo Marques 
LKML-Reference: <49BA06E2.7080807@cn.fujitsu.com>
Signed-off-by: Ingo Molnar

Revert "kbuild: strip generated symbols from *.ko"

2009-01-14T20:38:20+00:00

This reverts commit ad7a953c522ceb496611d127e51e278bfe0ff483.

And commit: ("allow stripping of generated symbols under CONFIG_KALLSYMS_ALL")
            9bb482476c6c9d1ae033306440c51ceac93ea80c

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 
Reported-by: "Theodore Ts'o" 
Reported-by: Dave Jones 
Reported-by: Roland McGrath 
Signed-off-by: Sam Ravnborg

allow stripping of generated symbols under CONFIG_KALLSYMS_ALL

2008-12-19T21:47:10+00:00

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 
Signed-off-by: Sam Ravnborg