From: Anders Kaseorg Date: Fri, 10 Oct 2008 02:19:08 +0000 (-0400) Subject: ftrace: make ftrace_test_p6nop disassembler-friendly X-Git-Tag: v2.6.28-rc1~78^2~7 X-Git-Url: http://pilppa.com/gitweb/?a=commitdiff_plain;h=8b27386a9ce9c7f0f8702cff7565a46802ad57d1;p=linux-2.6-omap-h63xx.git ftrace: make ftrace_test_p6nop disassembler-friendly Commit 4c3dc21b136f8cb4b72afee16c3ba7e961656c0b in tip introduced the 5-byte NOP ftrace_test_p6nop: jmp . + 5 .byte 0x00, 0x00, 0x00 This is not friendly to disassemblers because an odd number of 0x00s ends in the middle of an instruction boundary. This changes the 0x00s to 1-byte NOPs (0x90). Signed-off-by: Anders Kaseorg Acked-by: Steven Rostedt Signed-off-by: Ingo Molnar --- diff --git a/arch/x86/kernel/ftrace.c b/arch/x86/kernel/ftrace.c index 222507e8157..d073d981a73 100644 --- a/arch/x86/kernel/ftrace.c +++ b/arch/x86/kernel/ftrace.c @@ -132,7 +132,9 @@ int __init ftrace_dyn_arch_init(void *data) ".section .text, \"ax\"\n" "ftrace_test_jmp:" "jmp ftrace_test_p6nop\n" - ".byte 0x00,0x00,0x00\n" /* 2 byte jmp + 3 bytes */ + "nop\n" + "nop\n" + "nop\n" /* 2 byte jmp + 3 bytes */ "ftrace_test_p6nop:" P6_NOP5 "jmp 1f\n" @@ -161,7 +163,7 @@ int __init ftrace_dyn_arch_init(void *data) ftrace_nop = (unsigned long *)ftrace_test_nop5; break; case 2: - pr_info("ftrace: converting mcount calls to jmp 1f\n"); + pr_info("ftrace: converting mcount calls to jmp . + 5\n"); ftrace_nop = (unsigned long *)ftrace_test_jmp; break; }