Hi Mark, On Tue, Oct 29, 2019 at 04:58:24PM +0000, Mark Rutland wrote: > Hi, > > 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. > > Since v1 [3]: > * Add a couple of people to Cc > * Fold in Ard's Reviewed-by tag > * Rename ftrace_code_init_disabled() to ftrace_nop_initialize() > * Move ftrace_init_nop() to <linux/ftrace.h>, with kerneldoc > * Update kerneldoc for rec parameters [..] I tested this series on parisc both with ftracing kernel internal functions and module functions. Both are working fine, so feel free to add my Tested-by: Sven Schnelle <svens@xxxxxxxxxxxxxx> Regards Sven
