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    Subject[PATCH v4 6/8] x86/ftrace: Use __pa_symbol instead of __pa on C visible symbols
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    Instead of using __pa which is meant to be a general function for converting
    virtual addresses to physical addresses we can use __pa_symbol which is the
    preferred way of decoding kernel text virtual addresses to physical addresses.

    In this case we are not directly converting C visible symbols however if we
    know that the instruction pointer is somewhere between _text and _etext we
    know that we are going to be translating an address form the kernel text
    space.

    Cc: Steven Rostedt <rostedt@goodmis.org>
    Cc: Frederic Weisbecker <fweisbec@gmail.com>
    Signed-off-by: Alexander Duyck <alexander.h.duyck@intel.com>
    ---
    arch/x86/kernel/ftrace.c | 4 ++--
    1 files changed, 2 insertions(+), 2 deletions(-)

    diff --git a/arch/x86/kernel/ftrace.c b/arch/x86/kernel/ftrace.c
    index 1d41402..42a392a 100644
    --- a/arch/x86/kernel/ftrace.c
    +++ b/arch/x86/kernel/ftrace.c
    @@ -89,7 +89,7 @@ do_ftrace_mod_code(unsigned long ip, const void *new_code)
    * kernel identity mapping to modify code.
    */
    if (within(ip, (unsigned long)_text, (unsigned long)_etext))
    - ip = (unsigned long)__va(__pa(ip));
    + ip = (unsigned long)__va(__pa_symbol(ip));

    return probe_kernel_write((void *)ip, new_code, MCOUNT_INSN_SIZE);
    }
    @@ -279,7 +279,7 @@ static int ftrace_write(unsigned long ip, const char *val, int size)
    * kernel identity mapping to modify code.
    */
    if (within(ip, (unsigned long)_text, (unsigned long)_etext))
    - ip = (unsigned long)__va(__pa(ip));
    + ip = (unsigned long)__va(__pa_symbol(ip));

    return probe_kernel_write((void *)ip, val, size);
    }


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