diff options
author | David Brownell <david-b@pacbell.net> | 2007-02-20 21:58:16 (GMT) |
---|---|---|
committer | Linus Torvalds <torvalds@woody.linux-foundation.org> | 2007-02-21 01:10:16 (GMT) |
commit | da68d61f89e275260cc993a0d4a39e63700098fb (patch) | |
tree | 2b54d5e695cc233045cb854d7e1fc7470cd6d3a6 /scripts/mod | |
parent | 3deac046e2883686a732960050ab74fca0db11fa (diff) | |
download | linux-fsl-qoriq-da68d61f89e275260cc993a0d4a39e63700098fb.tar.xz |
[PATCH] remove modpost false warnings on ARM
This patch stops "modpost" from issuing erroneous modpost warnings on ARM
builds, which it's been doing since since maybe last summer. A canonical
example would be driver method table entries:
WARNING: <path> - Section mismatch: reference to .exit.text:<name>_remove
from .data after '$d' (at offset 0x4)
That "$d" symbol is generated by tools conformant with ARM ABI specs; in
this case it's a symbol **in the middle of** a "<name>_driver" struct.
The erroneous warnings appear to be issued because "modpost" whitelists
references from "<name>_driver" data into init and exit sections ... but
doesn't know should also include those "$d" mapping symbols, which are not
otherwise associated with "<name>_driver" symbols.
This patch prevents the modpost symbol lookup code from ever returning
those mapping symbols, so it will return a whitelisted symbol instead.
Then things work as expected.
Now to revert various code-bloating "fixes" that got merged because of this
modpost bug....
Signed-off-by: David Brownell <dbrownell@users.sourceforge.net>
Acked-by: Rusty Russell <rusty@rustcorp.com.au>
Cc: Roman Zippel <zippel@linux-m68k.org>
Acked-by: Sam Ravnborg <sam@ravnborg.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'scripts/mod')
-rw-r--r-- | scripts/mod/modpost.c | 36 |
1 files changed, 28 insertions, 8 deletions
diff --git a/scripts/mod/modpost.c b/scripts/mod/modpost.c index 569e684..c4b5398 100644 --- a/scripts/mod/modpost.c +++ b/scripts/mod/modpost.c @@ -686,6 +686,30 @@ static Elf_Sym *find_elf_symbol(struct elf_info *elf, Elf_Addr addr, return NULL; } +static inline int is_arm_mapping_symbol(const char *str) +{ + return str[0] == '$' && strchr("atd", str[1]) + && (str[2] == '\0' || str[2] == '.'); +} + +/* + * If there's no name there, ignore it; likewise, ignore it if it's + * one of the magic symbols emitted used by current ARM tools. + * + * Otherwise if find_symbols_between() returns those symbols, they'll + * fail the whitelist tests and cause lots of false alarms ... fixable + * only by merging __exit and __init sections into __text, bloating + * the kernel (which is especially evil on embedded platforms). + */ +static inline int is_valid_name(struct elf_info *elf, Elf_Sym *sym) +{ + const char *name = elf->strtab + sym->st_name; + + if (!name || !strlen(name)) + return 0; + return !is_arm_mapping_symbol(name); +} + /* * Find symbols before or equal addr and after addr - in the section sec. * If we find two symbols with equal offset prefer one with a valid name. @@ -714,16 +738,15 @@ static void find_symbols_between(struct elf_info *elf, Elf_Addr addr, symsec = secstrings + elf->sechdrs[sym->st_shndx].sh_name; if (strcmp(symsec, sec) != 0) continue; + if (!is_valid_name(elf, sym)) + continue; if (sym->st_value <= addr) { if ((addr - sym->st_value) < beforediff) { beforediff = addr - sym->st_value; *before = sym; } else if ((addr - sym->st_value) == beforediff) { - /* equal offset, valid name? */ - const char *name = elf->strtab + sym->st_name; - if (name && strlen(name)) - *before = sym; + *before = sym; } } else @@ -733,10 +756,7 @@ static void find_symbols_between(struct elf_info *elf, Elf_Addr addr, *after = sym; } else if ((sym->st_value - addr) == afterdiff) { - /* equal offset, valid name? */ - const char *name = elf->strtab + sym->st_name; - if (name && strlen(name)) - *after = sym; + *after = sym; } } } |