kernel.git/arch/x86/kernel/ftrace.c, branch linux-3.17.y

ftrace/x86: Add call to ftrace_graph_is_dead() in function graph code

2014-07-17T13:45:08Z

ftrace_stop() is going away as it disables parts of function tracing that affects users that should not be affected. But ftrace_graph_stop() is built on ftrace_stop(). Here's another example of killing all of function tracing because something went wrong with function graph tracing. Instead of disabling all users of function tracing on function graph error, disable only function graph tracing. To do this, the arch code must call ftrace_graph_is_dead() before it implements function graph. Link: http://lkml.kernel.org/r/53C54D18.3020602@zytor.com Acked-by: H. Peter Anvin Reviewed-by: Masami Hiramatsu Signed-off-by: Steven Rostedt

ftrace/x86: Call text_ip_addr() instead of the duplicated code

2014-06-03T23:44:37Z

I just went over this when looking at some Xen-related ftrace initialization problems. They were related to Xen code that is not upstream but this clean up would make sense here. I think that this was already the intention when text_ip_addr() was introduced in the commit 87fbb2ac6073a703930 (ftrace/x86: Use breakpoints for converting function graph caller). Anyway, better do it now before it shots people into their leg ;-) Link: http://lkml.kernel.org/p/1401812601-2359-1-git-send-email-pmladek@suse.cz Signed-off-by: Petr Mladek Signed-off-by: Steven Rostedt

ftrace: Remove FTRACE_UPDATE_MODIFY_CALL_REGS flag

2014-05-14T15:37:30Z

As the decision to what needs to be done (converting a call to the ftrace_caller to ftrace_caller_regs or to convert from ftrace_caller_regs to ftrace_caller) can easily be determined from the rec->flags of FTRACE_FL_REGS and FTRACE_FL_REGS_EN, there's no need to have the ftrace_check_record() return either a UPDATE_MODIFY_CALL_REGS or a UPDATE_MODIFY_CALL. Just he latter is enough. This added flag causes more complexity than is required. Remove it. Signed-off-by: Steven Rostedt

ftrace: Make get_ftrace_addr() and get_ftrace_addr_old() global

2014-05-14T15:37:29Z

Move and rename get_ftrace_addr() and get_ftrace_addr_old() to ftrace_get_addr_new() and ftrace_get_addr_curr() respectively. This moves these two helper functions in the generic code out from the arch specific code, and renames them to have a better generic name. This will allow other archs to use them as well as makes it a bit easier to work on getting separate trampolines for different functions. ftrace_get_addr_new() returns the trampoline address that the mcount call address will be converted to. ftrace_get_addr_curr() returns the trampoline address of what the mcount call address currently jumps to. Signed-off-by: Steven Rostedt

ftrace/x86: Get the current mcount addr for add_breakpoint()

2014-05-14T15:37:28Z

The add_breakpoint() code in the ftrace updating gets the address of what the call will become, but if the mcount address is changing from regs to non-regs ftrace_caller or vice versa, it will use what the record currently is. This is rather silly as the code should always use what is currently there regardless of if it's changing the regs function or just converting to a nop. Signed-off-by: Steven Rostedt

ftrace/x86: Fix order of warning messages when ftrace modifies code

2014-04-21T18:00:35Z

The colon at the end of the printk message suggests that it should get printed before the details printed by ftrace_bug(). When touching the line, let's use the preferred pr_warn() macro as suggested by checkpatch.pl. Link: http://lkml.kernel.org/r/1392650573-3390-5-git-send-email-pmladek@suse.cz Signed-off-by: Petr Mladek Signed-off-by: Steven Rostedt

ftrace/x86: BUG when ftrace recovery fails

2014-03-07T15:06:16Z

Ftrace modifies function calls using Int3 breakpoints on x86. The breakpoints are handled only when the patching is in progress. If something goes wrong, there is a recovery code that removes the breakpoints. If this fails, the system might get silently rebooted when a remaining break is not handled or an invalid instruction is proceed. We should BUG() when the breakpoint could not be removed. Otherwise, the system silently crashes when the function finishes the Int3 handler is disabled. Note that we need to modify remove_breakpoint() to return non-zero value only when there is an error. The return value was ignored before, so it does not cause any troubles. Link: http://lkml.kernel.org/r/1393258342-29978-4-git-send-email-pmladek@suse.cz Signed-off-by: Petr Mladek Signed-off-by: Steven Rostedt

ftrace: Do not pass data to ftrace_dyn_arch_init

2014-03-07T15:06:14Z

As the data parameter is not really used by any ftrace_dyn_arch_init, remove that from ftrace_dyn_arch_init. This also removes the addr local variable from ftrace_init which is now unused. Note the documentation was imprecise as it did not suggest to set (*data) to 0. Link: http://lkml.kernel.org/r/1393268401-24379-4-git-send-email-jslaby@suse.cz Cc: Frederic Weisbecker Cc: Ingo Molnar Cc: linux-arch@vger.kernel.org Signed-off-by: Jiri Slaby Signed-off-by: Steven Rostedt

ftrace: Pass retval through return in ftrace_dyn_arch_init()

2014-03-07T15:06:13Z

No architecture uses the "data" parameter in ftrace_dyn_arch_init() in any way, it just sets the value to 0. And this is used as a return value in the caller -- ftrace_init, which just checks the retval against zero. Note there is also "return 0" in every ftrace_dyn_arch_init. So it is enough to check the retval and remove all the indirect sets of data on all archs. Link: http://lkml.kernel.org/r/1393268401-24379-3-git-send-email-jslaby@suse.cz Cc: linux-arch@vger.kernel.org Signed-off-by: Jiri Slaby Signed-off-by: Steven Rostedt

ftrace/x86: Have ftrace_write() return -EPERM and clean up callers

2014-03-07T15:05:50Z

Having ftrace_write() return -EPERM on failure, as that's what the callers return, then we can clean up the code a bit. That is, instead of: if (ftrace_write(...)) return -EPERM; return 0; or if (ftrace_write(...)) { ret = -EPERM; goto_out; } We can instead have: return ftrace_write(...); or ret = ftrace_write(...); if (ret) goto out; Signed-off-by: Steven Rostedt