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scripts/kallsyms: skip ppc compiler stub *.long_branch.* / *.plt_branch.*

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PowerPC allmodconfig often fails to build as follows:

    LD      .tmp_vmlinux.kallsyms1
    KSYM    .tmp_vmlinux.kallsyms1.o
    LD      .tmp_vmlinux.kallsyms2
    KSYM    .tmp_vmlinux.kallsyms2.o
    LD      .tmp_vmlinux.kallsyms3
    KSYM    .tmp_vmlinux.kallsyms3.o
    LD      vmlinux
    SORTTAB vmlinux
    SYSMAP  System.map
  Inconsistent kallsyms data
  Try make KALLSYMS_EXTRA_PASS=1 as a workaround
  make[2]: *** [../Makefile:1162: vmlinux] Error 1

Setting KALLSYMS_EXTRA_PASS=1 does not help.

This is caused by the compiler inserting stubs such as *.long_branch.*
and *.plt_branch.*

  $ powerpc-linux-nm -n .tmp_vmlinux.kallsyms2
   [ snip ]
  c00000000210c010 t 00000075.plt_branch.da9:19
  c00000000210c020 t 00000075.plt_branch.1677:5
  c00000000210c030 t 00000075.long_branch.memmove
  c00000000210c034 t 00000075.plt_branch.9e0:5
  c00000000210c044 t 00000075.plt_branch.free_initrd_mem
    ...

Actually, the problem mentioned in scripts/link-vmlinux.sh comments;
"In theory it's possible this results in even more stubs, but unlikely"
is happening here, and ends up with another kallsyms step required.

scripts/kallsyms.c already ignores various compiler stubs. Let's do
similar to make kallsysms for PowerPC always succeed in 2 steps.

Reported-by: Guenter Roeck <linux@roeck-us.net>
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
Tested-by: Guenter Roeck <linux@roeck-us.net>
This commit is contained in:
Masahiro Yamada 2020-09-23 02:48:56 +09:00
parent ba4f184e12
commit 516d980f85
1 changed files with 15 additions and 1 deletions
Show stats Download patch file Download diff file Expand all files Collapse all files

16
scripts/kallsyms.c
View file

@ -82,6 +82,7 @@ static char *sym_name(const struct sym_entry *s)
static bool is_ignored_symbol(const char *name, char type)
{
/* Symbol names that exactly match to the following are ignored.*/
static const char * const ignored_symbols[] = {
/*
* Symbols which vary between passes. Passes 1 and 2 must have
@ -104,6 +105,7 @@ static bool is_ignored_symbol(const char *name, char type)
NULL
};
/* Symbol names that begin with the following are ignored.*/
static const char * const ignored_prefixes[] = {
"$", /* local symbols for ARM, MIPS, etc. */
".LASANPC", /* s390 kasan local symbols */
@ -113,6 +115,7 @@ static bool is_ignored_symbol(const char *name, char type)
NULL
};
/* Symbol names that end with the following are ignored.*/
static const char * const ignored_suffixes[] = {
"_from_arm", /* arm */
"_from_thumb", /* arm */
@ -120,9 +123,15 @@ static bool is_ignored_symbol(const char *name, char type)
NULL
};
/* Symbol names that contain the following are ignored.*/
static const char * const ignored_matches[] = {
".long_branch.", /* ppc stub */
".plt_branch.", /* ppc stub */
NULL
};
const char * const *p;
/* Exclude symbols which vary between passes. */
for (p = ignored_symbols; *p; p++)
if (!strcmp(name, *p))
return true;
@ -138,6 +147,11 @@ static bool is_ignored_symbol(const char *name, char type)
return true;
}
for (p = ignored_matches; *p; p++) {
if (strstr(name, *p))
return true;
}
if (type == 'U' || type == 'u')
return true;
/* exclude debugging symbols */