Hi,
On 11/4/19 7:34 PM, Mark Rutland wrote:
On Mon, Nov 04, 2019 at 01:03:51PM +0000, Amit Kachhap wrote:
On 11/4/19 6:26 PM, Will Deacon wrote:
On Sat, Nov 02, 2019 at 05:42:25PM +0530, Amit Daniel Kachhap wrote:
On 10/29/19 10:28 PM, Mark Rutland wrote:
This series is a reworked version of Torsten's FTRACE_WITH_REGS series
[1]. I've tried to rework the existing code in preparatory patches so
that the patchable-function-entry bits slot in with fewer surprises.
This version is based on v5.4-rc3, and can be found in my
arm64/ftrace-with-regs branch [2].
Patch 1 adds an (optional) ftrace_init_nop(), which the core code uses
to initialize callsites. This allows us to avoid a synthetic MCOUNT_ADDR
symbol, and more cleanly separates the one-time initialization of the
callsite from dynamic NOP<->CALL modification. Architectures which don't
implement this get the existing ftrace_make_nop() with MCOUNT_ADDR.
Recently parisc gained ftrace support using patchable-function-entry.
Patch 2 makes the handling of module callsite locations common in
kernel/module.c with a new FTRACE_CALLSITE_SECTION definition, and
removed the newly redundant bits from arch/parisc.
Patches 3 and 4 move the module PLT initialization to module load time,
which simplifies runtime callsite modification. This also means that we
don't transitently mark the module text RW, and will allow for the
removal of module_disable_ro().
Patches 5 and 6 add some trivial infrastructure, with patch 7 finally
adding FTRACE_WITH_REGS support. Additional work will be required for
livepatching (e.g. implementing reliable stack trace), which is
commented as part of patch 7.
Patch 8 is a trivial cleanup atop of the rest of the series, making the
code easier to read and less susceptible to config-specific breakage.
I tested the whole series with my latest in-kernel ptrauth patches [1]
and graph_tracer/function_graph_tracer works fine, So for the whole series,
Tested-by: Amit Daniel Kachhap <amit.kachhap@xxxxxxx>
Also I gave few minor comments in the individual patches. With those
comments,
Signed-off-by: Amit Daniel Kachhap <amit.kachhap@xxxxxxx>
Oops sorry I meant,
Reviewed-off-by: Amit Daniel Kachhap <amit.kachhap@xxxxxxx>
Thanks!
I've added the Tested-by for the whole series, and the Reviewed-by for
patches 4 and 7. I haven't added it for patch 1 just yet; please reply
to my comment there if you'd still like to add a Reviewed-by.
Those were minor comments. Please go ahead and add the Reviewed-by's.
Thanks,
Amit
Mark.
