On Fri, 2012-11-16 at 13:57 -0800, Alexander Duyck wrote: > 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.
Can I ask what the purpose of this is? I'm a little skeptical of a change that is just "the preferred way". Was there some bug that this fixes? -- Steve > > Cc: Steven Rostedt <rost...@goodmis.org> > Cc: Frederic Weisbecker <fweis...@gmail.com> > Signed-off-by: Alexander Duyck <alexander.h.du...@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); > } -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
