On Mon, 17 Apr 2006 15:40:05 +0200, Sam Ravnborg <sam@xxxxxxxxxxxx> wrote:
> Maybe we need to do some simple range check also so it becomes:
> if ((sym->st_shndx >= SHN_LORESERVE) || (sym > elf->symtab_stop))
> continue;
>
> Could you try this - and if you still see the SEGVAL then try to print
> out the value of all members in 'r'.
>
> You can also try to add '-g' to HOSTCFLAGS in toplevel makefile.
> Then use make V=1 to see what arguments modpost is caleld with and call
> it from the commandline or from a debugger.
When segfault happened, 'sym' has an invalid value. Here is gdb session log:
$ gdb scripts/mod/modpost
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This GDB was configured as "i386-linux"...Using host libthread_db library "/lib/tls/libthread_db.so.1".
(gdb) run -m -a -o /home/git/build-swarm-le/Module.symvers vmlinux crypto/aes.o crypto/anubis.o crypto/arc4.o crypto/blowfish.o crypto/cast5.o crypto/cast6.o crypto/crc32c.o crypto/crypto_null.o crypto/deflate.o crypto/des.o crypto/khazad.o crypto/md4.o crypto/md5.o crypto/michael_mic.o crypto/serpent.o crypto/sha1.o crypto/sha256.o crypto/sha512.o crypto/tea.o crypto/tgr192.o crypto/twofish.o crypto/wp512.o drivers/base/firmware_class.o drivers/block/aoe/aoe.o drivers/block/pktcdvd.o drivers/connector/cn.o drivers/input/serio/serio_raw.o drivers/net/phy/cicada.o drivers/net/phy/davicom.o drivers/net/phy/libphy.o drivers/net/phy/lxt.o drivers/net/phy/marvell.o drivers/net/phy/qsemi.o fs/fuse/fuse.o lib/crc16.o lib/libcrc32c.o lib/zlib_deflate/zlib_deflate.o lib/zlib_inflate/zlib_inflate.o net/ieee80211/ieee80211.o net/ieee80211/ieee80211_crypt.o net/ieee80211/ieee80211_crypt_ccmp.o net/ieee80211/ieee80211_crypt_wep.o net/xfrm/xfrm_user.o
Starting program: /home/git/build-swarm-le/scripts/mod/modpost -m -a -o /home/git/build-swarm-le/Module.symvers vmlinux crypto/aes.o crypto/anubis.o crypto/arc4.o crypto/blowfish.o crypto/cast5.o crypto/cast6.o crypto/crc32c.o crypto/crypto_null.o crypto/deflate.o crypto/des.o crypto/khazad.o crypto/md4.o crypto/md5.o crypto/michael_mic.o crypto/serpent.o crypto/sha1.o crypto/sha256.o crypto/sha512.o crypto/tea.o crypto/tgr192.o crypto/twofish.o crypto/wp512.o drivers/base/firmware_class.o drivers/block/aoe/aoe.o drivers/block/pktcdvd.o drivers/connector/cn.o drivers/input/serio/serio_raw.o drivers/net/phy/cicada.o drivers/net/phy/davicom.o drivers/net/phy/libphy.o drivers/net/phy/lxt.o drivers/net/phy/marvell.o drivers/net/phy/qsemi.o fs/fuse/fuse.o lib/crc16.o lib/libcrc32c.o lib/zlib_deflate/zlib_deflate.o lib/zlib_inflate/zlib_inflate.o net/ieee80211/ieee80211.o net/ieee80211/ieee80211_crypt.o net/ieee80211/ieee80211_crypt_ccmp.o net/ieee80211/ieee80211_crypt_wep.o net/xfrm/xfrm_user.o
Program received signal SIGSEGV, Segmentation fault.
check_sec_ref (mod=0x806a2d8, modname=0xbffff79a "crypto/aes.o",
elf=0xbffff230, section=0x804a050 <init_section>,
section_ref_ok=0x804a0b0 <init_section_ref_ok>)
at /home/git/linux-mips/scripts/mod/modpost.c:717
717 if (sym->st_shndx >= SHN_LORESERVE)
(gdb) p/x sym
$1 = 0xf8161a58
(gdb) p/x elf->symtab_start
$2 = 0x40161a58
(gdb) p/x r
$3 = {r_offset = 0x1a4, r_info = 0x1d00000000000004, r_addend = 0x2028}
I suppose r_info have is following layout on 64bit mips:
typedef struct
{
Elf32_Word r_sym; /* Symbol index */
unsigned char r_ssym; /* Special symbol for 2nd relocation */
unsigned char r_type3; /* 3rd relocation type */
unsigned char r_type2; /* 2nd relocation type */
unsigned char r_type1; /* 1st relocation type */
} _Elf64_Mips_R_Info;
For 64bit big-endian mips, r_info was byte-swapped by TO_NATIVE, so I
can use standard ELF_R_SYM().
---
Atsushi Nemoto
