From 3a2af2dc1bcbfe86b1f39e9e5f9c2c5447943f16 Mon Sep 17 00:00:00 2001 From: Wu Zhangjin Date: Fri, 14 May 2010 19:08:30 +0800 Subject: [PATCH] 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 Cc: linux-mips Cc: David Daney Patchwork: http://patchwork.linux-mips.org/patch/1228/ Signed-off-by: Ralf Baechle --- arch/mips/kernel/ftrace.c | 16 ++++++++++++++-- 1 file 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) { -- 2.39.5