kernel.git/arch/powerpc/kernel/ftrace.c, branch linux-2.6.37.y

Merge branch 'tracing-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip

2009-06-20T17:56:46Z

* 'tracing-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip: (24 commits) tracing/urgent: warn in case of ftrace_start_up inbalance tracing/urgent: fix unbalanced ftrace_start_up function-graph: add stack frame test function-graph: disable when both x86_32 and optimize for size are configured ring-buffer: have benchmark test print to trace buffer ring-buffer: do not grab locks in nmi ring-buffer: add locks around rb_per_cpu_empty ring-buffer: check for less than two in size allocation ring-buffer: remove useless compile check for buffer_page size ring-buffer: remove useless warn on check ring-buffer: use BUF_PAGE_HDR_SIZE in calculating index tracing: update sample event documentation tracing/filters: fix race between filter setting and module unload tracing/filters: free filter_string in destroy_preds() ring-buffer: use commit counters for commit pointer accounting ring-buffer: remove unused variable ring-buffer: have benchmark test handle discarded events ring-buffer: prevent adding write in discarded area tracing/filters: strloc should be unsigned short tracing/filters: operand can be negative ... Fix up kmemcheck-induced conflict in kernel/trace/ring_buffer.c manually

function-graph: add stack frame test

2009-06-18T22:40:18Z

In case gcc does something funny with the stack frames, or the return from function code, we would like to detect that. An arch may implement passing of a variable that is unique to the function and can be saved on entering a function and can be tested when exiting the function. Usually the frame pointer can be used for this purpose. This patch also implements this for x86. Where it passes in the stack frame of the parent function, and will test that frame on exit. There was a case in x86_32 with optimize for size (-Os) where, for a few functions, gcc would align the stack frame and place a copy of the return address into it. The function graph tracer modified the copy and not the actual return address. On return from the funtion, it did not go to the tracer hook, but returned to the parent. This broke the function graph tracer, because the return of the parent (where gcc did not do this funky manipulation) returned to the location that the child function was suppose to. This caused strange kernel crashes. This test detected the problem and pointed out where the issue was. This modifies the parameters of one of the functions that the arch specific code calls, so it includes changes to arch code to accommodate the new prototype. Note, I notice that the parsic arch implements its own push_return_trace. This is now a generic function and the ftrace_push_return_trace should be used instead. This patch does not touch that code. Cc: Benjamin Herrenschmidt Cc: Paul Mackerras Cc: Heiko Carstens Cc: Martin Schwidefsky Cc: Frederic Weisbecker Cc: Helge Deller Cc: Kyle McMartin Signed-off-by: Steven Rostedt

powerpc/ftrace: Use PPC_INST_NOP directly

2009-06-02T00:36:53Z

There's no need to wrap PPC_INST_NOP in a static inline. Signed-off-by: Michael Ellerman Signed-off-by: Benjamin Herrenschmidt

powerpc/ftrace: Remove unused macros

2009-06-02T00:36:46Z

These macros were used in the original port, but since commit e4486fe316 (ftrace, use probe_kernel API to modify code) they are unused. Signed-off-by: Michael Ellerman Signed-off-by: Benjamin Herrenschmidt

powerpc/ftrace: Use ppc_function_entry() instead of GET_ADDR

2009-06-02T00:36:32Z

Use ppc_function_entry() from code-patching.h. Signed-off-by: Michael Ellerman Signed-off-by: Benjamin Herrenschmidt

powerpc/ftrace: Fix constraint to be early clobber

2009-05-18T05:19:05Z

After upgrading my distcc boxes from gcc 4.2.2 to 4.4.0, the function graph tracer broke. This was discovered on my x86 boxes. The issue is that gcc used the same register for an output as it did for an input in an asm statement. I first thought this was a bug in gcc and reported it. I was notified that gcc was correct and that the output had to be flagged as an "early clobber". I noticed that powerpc had the same issue and this patch fixes it. Signed-off-by: Steven Rostedt Signed-off-by: Benjamin Herrenschmidt

powerpc/ftrace: Use pr_devel() in ftrace.c

2009-05-18T05:19:04Z

pr_debug() can now result in code being generated even when #DEBUG is not defined. That's not really desirable in the ftrace code which we want to be snappy. With CONFIG_DYNAMIC_DEBUG=y: size before: text data bss dec hex filename 3334 672 4 4010 faa arch/powerpc/kernel/ftrace.o size after: text data bss dec hex filename 2616 360 4 2980 ba4 arch/powerpc/kernel/ftrace.o Signed-off-by: Michael Ellerman Acked-by: Steven Rostedt Signed-off-by: Benjamin Herrenschmidt

powerpc/ftrace: Fix printf format warning

2009-04-07T05:19:00Z

'tramp' is an unsigned long, so print it with %lx. Fixes the following build warning: arch/powerpc/kernel/ftrace.c:291: error: format ‘%x’ expects type ‘unsigned int’, but argument 2 has type ‘long unsigned int’ Signed-off-by: Michael Ellerman Acked-by: Steven Rostedt Signed-off-by: Paul Mackerras

powerpc/ftrace: Fix #if that should be #ifdef

2009-04-07T05:19:00Z

Commit bb7253403f7a4670a128e4c080fd8ea1bd4d5029 ("powerpc64, ftrace: save toc only on modules for function graph"), added an #if CONFIG_PPC64. This changes it to #ifdef. Fixes the following warning on 32-bit builds: arch/powerpc/kernel/ftrace.c:562:5: error: "CONFIG_PPC64" is not defined Signed-off-by: Michael Ellerman Acked-by: Steven Rostedt Signed-off-by: Paul Mackerras

tracing, powerpc: fix powerpc tree and tracing tree interaction

2009-04-01T22:50:24Z

Today's linux-next build (powerpc allyesconfig) failed like this: arch/powerpc/kernel/ftrace.c: In function 'prepare_ftrace_return': arch/powerpc/kernel/ftrace.c:612: warning: passing argument 3 of 'ftrace_push_return_trace' makes pointer from integer without a cast arch/powerpc/kernel/ftrace.c:612: error: too many arguments to function 'ftrace_push_return_trace' Caused by commit 5d1a03dc541dc6672e60e57249ed22f40654ca47 ("function-graph: moved the timestamp from arch to generic code") from the tracing tree which (removed an argument from ftrace_push_return_trace()) interacting with commit 6794c78243bfda020ab184d6d578944f8e90d26c ("powerpc64: port of the function graph tracer") from the powerpc tree. Signed-off-by: Stephen Rothwell Cc: Steven Rostedt Cc: Benjamin Herrenschmidt Cc: Paul Mackerras Cc: LKML-Reference: <20090327230834.93d0221d.sfr@canb.auug.org.au> Signed-off-by: Ingo Molnar