diff options
| author | Wu Zhangjin <wuzhangjin@gmail.com> | 2010-05-14 19:08:34 +0800 |
|---|---|---|
| committer | Ralf Baechle <ralf@linux-mips.org> | 2010-07-05 17:17:30 +0100 |
| commit | c9f84873c1231621508cd438bb2991ddba770a69 (patch) | |
| tree | 4bf6065b6d184dc54e01bb8445e2de28c42d50fb /arch | |
| parent | 68ccf7521dc89bfcf01432fd1bf8cb4d7d534e4c (diff) | |
MIPS: Tracing: Cleanup of address space checking
This patch adds an inline function in_module() to check which space the
instruction pointer in, kernel space or module space.
Note: This will not work when the kernel space and module space are the
same. If they are the same, we need to modify scripts/recordmcount.pl,
ftrace_make_nop/call() and the other related parts to ensure the
enabling/disabling of the calling site to _mcount is right for both
kernel and module.
[Ralf: It also is still incorrect for some 64-bit kernels.]
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/1232/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
Diffstat (limited to 'arch')
| -rw-r--r-- | arch/mips/kernel/ftrace.c | 22 |
1 files changed, 19 insertions, 3 deletions
diff --git a/arch/mips/kernel/ftrace.c b/arch/mips/kernel/ftrace.c index 628e90b992d1..5a84a1f11231 100644 --- a/arch/mips/kernel/ftrace.c +++ b/arch/mips/kernel/ftrace.c @@ -17,6 +17,22 @@ #include <asm/cacheflush.h> #include <asm/uasm.h> +/* + * If the Instruction Pointer is in module space (0xc0000000), return true; + * otherwise, it is in kernel space (0x80000000), return false. + * + * FIXME: This will not work when the kernel space and module space are the + * same. If they are the same, we need to modify scripts/recordmcount.pl, + * ftrace_make_nop/call() and the other related parts to ensure the + * enabling/disabling of the calling site to _mcount is right for both kernel + * and module. + */ + +static inline int in_module(unsigned long ip) +{ + return ip & 0x40000000; +} + #ifdef CONFIG_DYNAMIC_FTRACE #define JAL 0x0c000000 /* jump & link: ip --> ra, jump to target */ @@ -78,7 +94,7 @@ int ftrace_make_nop(struct module *mod, * We have compiled module with -mlong-calls, but compiled the kernel * without it, we need to cope with them respectively. */ - if (ip & 0x40000000) { + if (in_module(ip)) { #if defined(KBUILD_MCOUNT_RA_ADDRESS) && defined(CONFIG_32BIT) /* * lui v1, hi_16bit_of_mcount --> b 1f (0x10000005) @@ -117,7 +133,7 @@ int ftrace_make_call(struct dyn_ftrace *rec, unsigned long addr) unsigned long ip = rec->ip; /* ip, module: 0xc0000000, kernel: 0x80000000 */ - new = (ip & 0x40000000) ? insn_lui_v1_hi16_mcount : insn_jal_ftrace_caller; + new = in_module(ip) ? insn_lui_v1_hi16_mcount : insn_jal_ftrace_caller; return ftrace_modify_code(ip, new); } @@ -188,7 +204,7 @@ unsigned long ftrace_get_parent_addr(unsigned long self_addr, * instruction "lui v1, hi_16bit_of_mcount"(offset is 20), but for * kernel, move to the instruction "move ra, at"(offset is 12) */ - ip = self_addr - ((self_addr & 0x40000000) ? 20 : 12); + ip = self_addr - (in_module(self_addr) ? 20 : 12); /* * search the text until finding the non-store instruction or "s{d,w} |