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| author | Wu Zhangjin <wuzhangjin@gmail.com> | 2010-05-14 19:08:30 +0800 |
|---|---|---|
| committer | Ralf Baechle <ralf@linux-mips.org> | 2010-07-05 17:17:28 +0100 |
| commit | 3a2af2dc1bcbfe86b1f39e9e5f9c2c5447943f16 (patch) | |
| tree | 3c94d93dadcf93ffea7881a7ba0e5a84bda355a3 /arch/mips/kernel/ftrace.c | |
| parent | 56b49cd35fd56e29adb8f97ba051a1670d24d133 (diff) | |
| download | lwn-3a2af2dc1bcbfe86b1f39e9e5f9c2c5447943f16.tar.gz lwn-3a2af2dc1bcbfe86b1f39e9e5f9c2c5447943f16.zip | |
MIPS: Tracing: Fix 32-bit support with -mmcount-ra-address
For 32-bit kernel the -mmcount-ra-address option of gcc 4.5 emits one
extra instruction before calling to _mcount so we need to use a different
"b 1f" for it.
Signed-off-by: Wu Zhangjin <wuzhangjin@gmail.com>
Cc: linux-mips <linux-mips@linux-mips.org>
Cc: David Daney <david.s.daney@gmail.com>
Patchwork: http://patchwork.linux-mips.org/patch/1228/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
Diffstat (limited to 'arch/mips/kernel/ftrace.c')
| -rw-r--r-- | arch/mips/kernel/ftrace.c | 16 |
1 files changed, 14 insertions, 2 deletions
diff --git a/arch/mips/kernel/ftrace.c b/arch/mips/kernel/ftrace.c index e9e64e0ff7aa..37aa7677e76d 100644 --- a/arch/mips/kernel/ftrace.c +++ b/arch/mips/kernel/ftrace.c @@ -62,14 +62,26 @@ int ftrace_make_nop(struct module *mod, return -EFAULT; } +#if defined(KBUILD_MCOUNT_RA_ADDRESS) && defined(CONFIG_32BIT) + /* lui v1, hi_16bit_of_mcount --> b 1f (0x10000005) + * addiu v1, v1, low_16bit_of_mcount + * move at, ra + * move $12, ra_address + * jalr v1 + * sub sp, sp, 8 + * 1: offset = 5 instructions + */ + new = 0x10000005; +#else /* lui v1, hi_16bit_of_mcount --> b 1f (0x10000004) * addiu v1, v1, low_16bit_of_mcount * move at, ra * jalr v1 - * nop - * 1f: (ip + 12) + * nop | move $12, ra_address | sub sp, sp, 8 + * 1: offset = 4 instructions */ new = 0x10000004; +#endif } else { /* record/calculate it for ftrace_make_call */ if (jal_mcount == 0) { |