And ignore this one too.
On Thu, Jan 20, 2011 at 3:28 AM, Wu Zhangjin <wuzhangjin@xxxxxxxxx> wrote:
> The old in_module() may not work in some situations(e.g. when module &
> kernel are in the same address space when CONFIG_MAPPED_KERNEL=y), The
> in_kernel_space() is more generic and it is also easy to be implemented
> via cloning the existing core_kernel_text(), so, replace the in_module()
> with in_kernel_space().
>
> Signed-off-by: Wu Zhangjin <wuzhangjin@xxxxxxxxx>
> ---
> arch/mips/kernel/ftrace.c | 54 ++++++++++++++++++++++----------------------
> 1 files changed, 27 insertions(+), 27 deletions(-)
>
> diff --git a/arch/mips/kernel/ftrace.c b/arch/mips/kernel/ftrace.c
> index 635c1dc..5970286 100644
> --- a/arch/mips/kernel/ftrace.c
> +++ b/arch/mips/kernel/ftrace.c
> @@ -17,21 +17,7 @@
> #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;
> -}
> +#include <asm-generic/sections.h>
>
> #ifdef CONFIG_DYNAMIC_FTRACE
>
> @@ -69,6 +55,20 @@ static inline void ftrace_dyn_arch_init_insns(void)
> #endif
> }
>
> +/*
> + * Check if the address is in kernel space
> + *
> + * Clone core_kernel_text() from kernel/extable.c, but doesn't call
> + * init_kernel_text() for Ftrace doesn't trace functions in init sections.
> + */
> +static inline int in_kernel_space(unsigned long ip)
> +{
> + if (ip >= (unsigned long)_stext &&
> + ip <= (unsigned long)_etext)
> + return 1;
> + return 0;
> +}
> +
> static int ftrace_modify_code(unsigned long ip, unsigned int new_code)
> {
> int faulted;
> @@ -91,10 +91,16 @@ int ftrace_make_nop(struct module *mod,
> unsigned long ip = rec->ip;
>
> /*
> - * We have compiled module with -mlong-calls, but compiled the kernel
> - * without it, we need to cope with them respectively.
> + * If ip is in kernel space, no long call, otherwise, long call is
> + * needed.
> */
> - if (in_module(ip)) {
> + if (in_kernel_space(ip)) {
> + /*
> + * move at, ra
> + * jal _mcount --> nop
> + */
> + new = INSN_NOP;
> + } else {
> #if defined(KBUILD_MCOUNT_RA_ADDRESS) && defined(CONFIG_32BIT)
> /*
> * lui v1, hi_16bit_of_mcount --> b 1f (0x10000005)
> @@ -117,12 +123,6 @@ int ftrace_make_nop(struct module *mod,
> */
> new = INSN_B_1F_4;
> #endif
> - } else {
> - /*
> - * move at, ra
> - * jal _mcount --> nop
> - */
> - new = INSN_NOP;
> }
> return ftrace_modify_code(ip, new);
> }
> @@ -132,8 +132,8 @@ int ftrace_make_call(struct dyn_ftrace *rec, unsigned long addr)
> unsigned int new;
> unsigned long ip = rec->ip;
>
> - /* ip, module: 0xc0000000, kernel: 0x80000000 */
> - new = in_module(ip) ? insn_lui_v1_hi16_mcount : insn_jal_ftrace_caller;
> + new = in_kernel_space(ip) ? insn_jal_ftrace_caller :
> + insn_lui_v1_hi16_mcount;
>
> return ftrace_modify_code(ip, new);
> }
> @@ -204,7 +204,7 @@ unsigned long ftrace_get_parent_addr(unsigned long self_addr,
> * instruction "lui v1, hi_16bit_of_mcount"(offset is 24), but for
> * kernel, move after the instruction "move ra, at"(offset is 16)
> */
> - ip = self_addr - (in_module(self_addr) ? 24 : 16);
> + ip = self_addr - (in_kernel_space(self_addr) ? 16 : 24);
>
> /*
> * search the text until finding the non-store instruction or "s{d,w}
> --
> 1.7.1
>
>
