diff options
author | Steven Rostedt <srostedt@redhat.com> | 2009-06-18 12:45:08 -0400 |
---|---|---|
committer | Steven Rostedt <rostedt@goodmis.org> | 2009-06-18 18:40:18 -0400 |
commit | 71e308a239c098673570d0b417d42262bb535909 (patch) | |
tree | a9e415d0ae6302e820a1f9d4ff55a724b3a12cf6 /arch/x86 | |
parent | eb4a03780d4c4464ef2ad86d80cca3f3284fe81d (diff) |
function-graph: add stack frame test
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 <benh@kernel.crashing.org>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Helge Deller <deller@gmx.de>
Cc: Kyle McMartin <kyle@mcmartin.ca>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
Diffstat (limited to 'arch/x86')
-rw-r--r-- | arch/x86/Kconfig | 1 | ||||
-rw-r--r-- | arch/x86/kernel/entry_32.S | 2 | ||||
-rw-r--r-- | arch/x86/kernel/entry_64.S | 2 | ||||
-rw-r--r-- | arch/x86/kernel/ftrace.c | 6 |
4 files changed, 9 insertions, 2 deletions
diff --git a/arch/x86/Kconfig b/arch/x86/Kconfig index 356d2ec8e2fb..fcf12af07427 100644 --- a/arch/x86/Kconfig +++ b/arch/x86/Kconfig | |||
@@ -33,6 +33,7 @@ config X86 | |||
33 | select HAVE_DYNAMIC_FTRACE | 33 | select HAVE_DYNAMIC_FTRACE |
34 | select HAVE_FUNCTION_TRACER | 34 | select HAVE_FUNCTION_TRACER |
35 | select HAVE_FUNCTION_GRAPH_TRACER | 35 | select HAVE_FUNCTION_GRAPH_TRACER |
36 | select HAVE_FUNCTION_GRAPH_FP_TEST | ||
36 | select HAVE_FUNCTION_TRACE_MCOUNT_TEST | 37 | select HAVE_FUNCTION_TRACE_MCOUNT_TEST |
37 | select HAVE_FTRACE_NMI_ENTER if DYNAMIC_FTRACE | 38 | select HAVE_FTRACE_NMI_ENTER if DYNAMIC_FTRACE |
38 | select HAVE_FTRACE_SYSCALLS | 39 | select HAVE_FTRACE_SYSCALLS |
diff --git a/arch/x86/kernel/entry_32.S b/arch/x86/kernel/entry_32.S index c929add475c9..0d4b28564c14 100644 --- a/arch/x86/kernel/entry_32.S +++ b/arch/x86/kernel/entry_32.S | |||
@@ -1154,6 +1154,7 @@ ENTRY(ftrace_graph_caller) | |||
1154 | pushl %edx | 1154 | pushl %edx |
1155 | movl 0xc(%esp), %edx | 1155 | movl 0xc(%esp), %edx |
1156 | lea 0x4(%ebp), %eax | 1156 | lea 0x4(%ebp), %eax |
1157 | movl (%ebp), %ecx | ||
1157 | subl $MCOUNT_INSN_SIZE, %edx | 1158 | subl $MCOUNT_INSN_SIZE, %edx |
1158 | call prepare_ftrace_return | 1159 | call prepare_ftrace_return |
1159 | popl %edx | 1160 | popl %edx |
@@ -1168,6 +1169,7 @@ return_to_handler: | |||
1168 | pushl %eax | 1169 | pushl %eax |
1169 | pushl %ecx | 1170 | pushl %ecx |
1170 | pushl %edx | 1171 | pushl %edx |
1172 | movl %ebp, %eax | ||
1171 | call ftrace_return_to_handler | 1173 | call ftrace_return_to_handler |
1172 | movl %eax, 0xc(%esp) | 1174 | movl %eax, 0xc(%esp) |
1173 | popl %edx | 1175 | popl %edx |
diff --git a/arch/x86/kernel/entry_64.S b/arch/x86/kernel/entry_64.S index de74f0a3e0ed..c251be745107 100644 --- a/arch/x86/kernel/entry_64.S +++ b/arch/x86/kernel/entry_64.S | |||
@@ -135,6 +135,7 @@ ENTRY(ftrace_graph_caller) | |||
135 | 135 | ||
136 | leaq 8(%rbp), %rdi | 136 | leaq 8(%rbp), %rdi |
137 | movq 0x38(%rsp), %rsi | 137 | movq 0x38(%rsp), %rsi |
138 | movq (%rbp), %rdx | ||
138 | subq $MCOUNT_INSN_SIZE, %rsi | 139 | subq $MCOUNT_INSN_SIZE, %rsi |
139 | 140 | ||
140 | call prepare_ftrace_return | 141 | call prepare_ftrace_return |
@@ -150,6 +151,7 @@ GLOBAL(return_to_handler) | |||
150 | /* Save the return values */ | 151 | /* Save the return values */ |
151 | movq %rax, (%rsp) | 152 | movq %rax, (%rsp) |
152 | movq %rdx, 8(%rsp) | 153 | movq %rdx, 8(%rsp) |
154 | movq %rbp, %rdi | ||
153 | 155 | ||
154 | call ftrace_return_to_handler | 156 | call ftrace_return_to_handler |
155 | 157 | ||
diff --git a/arch/x86/kernel/ftrace.c b/arch/x86/kernel/ftrace.c index b79c5533c421..d94e1ea3b9fe 100644 --- a/arch/x86/kernel/ftrace.c +++ b/arch/x86/kernel/ftrace.c | |||
@@ -408,7 +408,8 @@ int ftrace_disable_ftrace_graph_caller(void) | |||
408 | * Hook the return address and push it in the stack of return addrs | 408 | * Hook the return address and push it in the stack of return addrs |
409 | * in current thread info. | 409 | * in current thread info. |
410 | */ | 410 | */ |
411 | void prepare_ftrace_return(unsigned long *parent, unsigned long self_addr) | 411 | void prepare_ftrace_return(unsigned long *parent, unsigned long self_addr, |
412 | unsigned long frame_pointer) | ||
412 | { | 413 | { |
413 | unsigned long old; | 414 | unsigned long old; |
414 | int faulted; | 415 | int faulted; |
@@ -453,7 +454,8 @@ void prepare_ftrace_return(unsigned long *parent, unsigned long self_addr) | |||
453 | return; | 454 | return; |
454 | } | 455 | } |
455 | 456 | ||
456 | if (ftrace_push_return_trace(old, self_addr, &trace.depth) == -EBUSY) { | 457 | if (ftrace_push_return_trace(old, self_addr, &trace.depth, |
458 | frame_pointer) == -EBUSY) { | ||
457 | *parent = old; | 459 | *parent = old; |
458 | return; | 460 | return; |
459 | } | 461 | } |