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linux/arch/s390/kernel/mcount.S

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[S390] ftrace: function tracer backend for s390 This implements just the basic function tracer (_mcount) backend for s390. The dynamic variant will come later. Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2008-12-25 12:38:56 +00:00
/*
s390/comments: unify copyright messages and remove file names Remove the file name from the comment at top of many files. In most cases the file name was wrong anyway, so it's rather pointless. Also unify the IBM copyright statement. We did have a lot of sightly different statements and wanted to change them one after another whenever a file gets touched. However that never happened. Instead people start to take the old/"wrong" statements to use as a template for new files. So unify all of them in one go. Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
2012-07-20 09:15:04 +00:00
* Copyright IBM Corp. 2008, 2009
[S390] ftrace: function tracer backend for s390 This implements just the basic function tracer (_mcount) backend for s390. The dynamic variant will come later. Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2008-12-25 12:38:56 +00:00
*
* Author(s): Heiko Carstens <heiko.carstens@de.ibm.com>,
*
*/
[S390] fix s390 assembler code alignments The alignment is missing for various global symbols in s390 assembly code. With a recent gcc and an instruction like stgrl this can lead to a specification exception if the instruction uses such a mis-aligned address. Specify the alignment explicitely and while add it define __ALIGN for s390 and use the ENTRY define to save some lines of code. Signed-off-by: Jan Glauber <jang@linux.vnet.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2011-07-24 08:48:19 +00:00
#include <linux/linkage.h>
[S390] ftrace/mcount: fix kernel stack backchain With packed stack the backchain is at a different location. Just use __SF_BACKCHAIN as an offset to store the backchain. Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2009-03-18 12:27:34 +00:00
#include <asm/asm-offsets.h>
s390/ftrace: fix mcount adjustment Tony Jones reported that the ftrace self tests on s390 do not work: <6>Testing dynamic ftrace ops #1: (0 0 0 0 0) FAILED! <6>Testing tracer irqsoff: <3>failed to start irqsoff tracer <4>.. no entries found ..FAILED! <6>Testing tracer wakeup: <3>failed to start wakeup tracer <4>.. no entries found ..FAILED! <6>Testing tracer function_graph: <4>Failed to init function_graph tracer, init returned -19 <4>FAILED! This happens because we forgot to adjust the instruction pointer that gets passed to the ftrace trace function by MCOUNT_INSN_SIZE. In addition change MCOUNT_INSN_SIZE to the correct value on 31 bit. It only worked so far because the to be patched instruction was identical. Reported-by: Tony Jones <tonyj@suse.com> Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2013-05-13 12:48:52 +00:00
#include <asm/ftrace.h>
s390/ftrace: remove 31 bit ftrace support 31 bit and 64 bit diverge more and more and it is rather painful to keep both parts running. To make things simpler just remove the 31 bit support which nobody uses anyway. Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2014-10-07 13:45:10 +00:00
#include <asm/ptrace.h>
[S390] ftrace/mcount: fix kernel stack backchain With packed stack the backchain is at a different location. Just use __SF_BACKCHAIN as an offset to store the backchain. Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2009-03-18 12:27:34 +00:00
[S390] add kprobes annotations Add kprobes annotations to get the massive 'probe kernel.function("*") {}' stress test working. Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2011-01-05 11:47:25 +00:00
.section .kprobes.text, "ax"
[S390] fix s390 assembler code alignments The alignment is missing for various global symbols in s390 assembly code. With a recent gcc and an instruction like stgrl this can lead to a specification exception if the instruction uses such a mis-aligned address. Specify the alignment explicitely and while add it define __ALIGN for s390 and use the ENTRY define to save some lines of code. Signed-off-by: Jan Glauber <jang@linux.vnet.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2011-07-24 08:48:19 +00:00
ENTRY(ftrace_stub)
[S390] ftrace: add dynamic ftrace support Dynamic ftrace support for s390. Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2009-06-12 08:26:44 +00:00
br %r14
s390/ftrace: remove 31 bit ftrace support 31 bit and 64 bit diverge more and more and it is rather painful to keep both parts running. To make things simpler just remove the 31 bit support which nobody uses anyway. Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2014-10-07 13:45:10 +00:00
#define STACK_FRAME_SIZE (STACK_FRAME_OVERHEAD + __PT_SIZE)
#define STACK_PTREGS (STACK_FRAME_OVERHEAD)
#define STACK_PTREGS_GPRS (STACK_PTREGS + __PT_GPRS)
#define STACK_PTREGS_PSW (STACK_PTREGS + __PT_PSW)
[S390] fix s390 assembler code alignments The alignment is missing for various global symbols in s390 assembly code. With a recent gcc and an instruction like stgrl this can lead to a specification exception if the instruction uses such a mis-aligned address. Specify the alignment explicitely and while add it define __ALIGN for s390 and use the ENTRY define to save some lines of code. Signed-off-by: Jan Glauber <jang@linux.vnet.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2011-07-24 08:48:19 +00:00
ENTRY(_mcount)
[S390] ftrace: function tracer backend for s390 This implements just the basic function tracer (_mcount) backend for s390. The dynamic variant will come later. Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2008-12-25 12:38:56 +00:00
br %r14
[S390] fix s390 assembler code alignments The alignment is missing for various global symbols in s390 assembly code. With a recent gcc and an instruction like stgrl this can lead to a specification exception if the instruction uses such a mis-aligned address. Specify the alignment explicitely and while add it define __ALIGN for s390 and use the ENTRY define to save some lines of code. Signed-off-by: Jan Glauber <jang@linux.vnet.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2011-07-24 08:48:19 +00:00
ENTRY(ftrace_caller)
s390/ftrace: remove 31 bit ftrace support 31 bit and 64 bit diverge more and more and it is rather painful to keep both parts running. To make things simpler just remove the 31 bit support which nobody uses anyway. Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2014-10-07 13:45:10 +00:00
.globl ftrace_regs_caller
.set ftrace_regs_caller,ftrace_caller
lgr %r1,%r15
s390/ftrace: hotpatch support for function tracing Make use of gcc's hotpatch support to generate better code for ftrace function tracing. The generated code now contains only a six byte nop in each function prologue instead of a 24 byte code block which will be runtime patched to support function tracing. With the new code generation the runtime overhead for supporting function tracing is close to zero, while the original code did show a significant performance impact. Acked-by: Steven Rostedt <rostedt@goodmis.org> Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2015-01-09 12:08:28 +00:00
#ifndef CC_USING_HOTPATCH
s390/ftrace,kprobes: allow to patch first instruction If the function tracer is enabled, allow to set kprobes on the first instruction of a function (which is the function trace caller): If no kprobe is set handling of enabling and disabling function tracing of a function simply patches the first instruction. Either it is a nop (right now it's an unconditional branch, which skips the mcount block), or it's a branch to the ftrace_caller() function. If a kprobe is being placed on a function tracer calling instruction we encode if we actually have a nop or branch in the remaining bytes after the breakpoint instruction (illegal opcode). This is possible, since the size of the instruction used for the nop and branch is six bytes, while the size of the breakpoint is only two bytes. Therefore the first two bytes contain the illegal opcode and the last four bytes contain either "0" for nop or "1" for branch. The kprobes code will then execute/simulate the correct instruction. Instruction patching for kprobes and function tracer is always done with stop_machine(). Therefore we don't have any races where an instruction is patched concurrently on a different cpu. Besides that also the program check handler which executes the function trace caller instruction won't be executed concurrently to any stop_machine() execution. This allows to keep full fault based kprobes handling which generates correct pt_regs contents automatically. Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2014-10-15 10:17:38 +00:00
aghi %r0,MCOUNT_RETURN_FIXUP
s390/ftrace: hotpatch support for function tracing Make use of gcc's hotpatch support to generate better code for ftrace function tracing. The generated code now contains only a six byte nop in each function prologue instead of a 24 byte code block which will be runtime patched to support function tracing. With the new code generation the runtime overhead for supporting function tracing is close to zero, while the original code did show a significant performance impact. Acked-by: Steven Rostedt <rostedt@goodmis.org> Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2015-01-09 12:08:28 +00:00
#endif
s390/ftrace: remove 31 bit ftrace support 31 bit and 64 bit diverge more and more and it is rather painful to keep both parts running. To make things simpler just remove the 31 bit support which nobody uses anyway. Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2014-10-07 13:45:10 +00:00
aghi %r15,-STACK_FRAME_SIZE
stg %r1,__SF_BACKCHAIN(%r15)
stg %r1,(STACK_PTREGS_GPRS+15*8)(%r15)
stg %r0,(STACK_PTREGS_PSW+8)(%r15)
stmg %r2,%r14,(STACK_PTREGS_GPRS+2*8)(%r15)
#ifdef CONFIG_HAVE_MARCH_Z196_FEATURES
aghik %r2,%r0,-MCOUNT_INSN_SIZE
lgrl %r4,function_trace_op
lgrl %r1,ftrace_trace_function
#else
lgr %r2,%r0
aghi %r2,-MCOUNT_INSN_SIZE
larl %r4,function_trace_op
lg %r4,0(%r4)
larl %r1,ftrace_trace_function
lg %r1,0(%r1)
#endif
lgr %r3,%r14
la %r5,STACK_PTREGS(%r15)
basr %r14,%r1
[S390] ftrace: add function graph tracer support Function graph tracer support for s390. Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2009-06-12 08:26:46 +00:00
#ifdef CONFIG_FUNCTION_GRAPH_TRACER
s390/ftrace: remove 31 bit ftrace support 31 bit and 64 bit diverge more and more and it is rather painful to keep both parts running. To make things simpler just remove the 31 bit support which nobody uses anyway. Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2014-10-07 13:45:10 +00:00
# The j instruction gets runtime patched to a nop instruction.
s390/ftrace: simplify enabling/disabling of ftrace_graph_caller We can simply patch the mask field within the branch relative on condition instruction at the beginning of the ftrace_graph_caller code block. This makes the logic even simpler and we get rid of the displacement calculation. Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2014-10-08 08:03:08 +00:00
# See ftrace_enable_ftrace_graph_caller.
s390/ftrace: remove 31 bit ftrace support 31 bit and 64 bit diverge more and more and it is rather painful to keep both parts running. To make things simpler just remove the 31 bit support which nobody uses anyway. Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2014-10-07 13:45:10 +00:00
ENTRY(ftrace_graph_caller)
j ftrace_graph_caller_end
lg %r2,(STACK_PTREGS_GPRS+14*8)(%r15)
lg %r3,(STACK_PTREGS_PSW+8)(%r15)
brasl %r14,prepare_ftrace_return
stg %r2,(STACK_PTREGS_GPRS+14*8)(%r15)
ftrace_graph_caller_end:
.globl ftrace_graph_caller_end
[S390] ftrace: add function graph tracer support Function graph tracer support for s390. Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2009-06-12 08:26:46 +00:00
#endif
s390/ftrace: remove 31 bit ftrace support 31 bit and 64 bit diverge more and more and it is rather painful to keep both parts running. To make things simpler just remove the 31 bit support which nobody uses anyway. Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2014-10-07 13:45:10 +00:00
lg %r1,(STACK_PTREGS_PSW+8)(%r15)
lmg %r2,%r15,(STACK_PTREGS_GPRS+2*8)(%r15)
br %r1
[S390] ftrace: function tracer backend for s390 This implements just the basic function tracer (_mcount) backend for s390. The dynamic variant will come later. Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2008-12-25 12:38:56 +00:00
[S390] ftrace: add function graph tracer support Function graph tracer support for s390. Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2009-06-12 08:26:46 +00:00
#ifdef CONFIG_FUNCTION_GRAPH_TRACER
[S390] fix s390 assembler code alignments The alignment is missing for various global symbols in s390 assembly code. With a recent gcc and an instruction like stgrl this can lead to a specification exception if the instruction uses such a mis-aligned address. Specify the alignment explicitely and while add it define __ALIGN for s390 and use the ENTRY define to save some lines of code. Signed-off-by: Jan Glauber <jang@linux.vnet.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2011-07-24 08:48:19 +00:00
ENTRY(return_to_handler)
s390/ftrace: remove 31 bit ftrace support 31 bit and 64 bit diverge more and more and it is rather painful to keep both parts running. To make things simpler just remove the 31 bit support which nobody uses anyway. Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2014-10-07 13:45:10 +00:00
stmg %r2,%r5,32(%r15)
lgr %r1,%r15
aghi %r15,-STACK_FRAME_OVERHEAD
stg %r1,__SF_BACKCHAIN(%r15)
brasl %r14,ftrace_return_to_handler
aghi %r15,STACK_FRAME_OVERHEAD
lgr %r14,%r2
lmg %r2,%r5,32(%r15)
[S390] ftrace: add function graph tracer support Function graph tracer support for s390. Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2009-06-12 08:26:46 +00:00
br %r14
[S390] improve mcount code Move the 64 bit mount code from mcount.S into mcount64.S and avoid code duplication. Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2009-09-11 08:28:33 +00:00
#endif
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