From 71e308a239c098673570d0b417d42262bb535909 Mon Sep 17 00:00:00 2001 From: Steven Rostedt Date: Thu, 18 Jun 2009 12:45:08 -0400 Subject: 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 Cc: Paul Mackerras Cc: Heiko Carstens Cc: Martin Schwidefsky Cc: Frederic Weisbecker Cc: Helge Deller Cc: Kyle McMartin Signed-off-by: Steven Rostedt --- arch/s390/kernel/ftrace.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'arch/s390/kernel/ftrace.c') diff --git a/arch/s390/kernel/ftrace.c b/arch/s390/kernel/ftrace.c index 82ddfd3a75af..3e298e64f0db 100644 --- a/arch/s390/kernel/ftrace.c +++ b/arch/s390/kernel/ftrace.c @@ -190,7 +190,7 @@ unsigned long prepare_ftrace_return(unsigned long ip, unsigned long parent) goto out; if (unlikely(atomic_read(¤t->tracing_graph_pause))) goto out; - if (ftrace_push_return_trace(parent, ip, &trace.depth) == -EBUSY) + if (ftrace_push_return_trace(parent, ip, &trace.depth, 0) == -EBUSY) goto out; trace.func = ftrace_mcount_call_adjust(ip) & PSW_ADDR_INSN; /* Only trace if the calling function expects to. */ -- cgit v1.2.3 From 7515bf59f87f19b2a17972b74230d2f91756fe3c Mon Sep 17 00:00:00 2001 From: Hendrik Brueckner Date: Tue, 25 Aug 2009 14:31:11 +0200 Subject: tracing: Add syscall tracepoints - s390 arch update This patch includes s390 arch updates to synchronize with latest core changes in the syscalls tracing area. - tracing: Map syscall name to number (syscall_name_to_nr()) - tracing: Call arch_init_ftrace_syscalls at boot - tracing: add support tracepoint ids (set_syscall_{enter,exit}_id()) Signed-off-by: Hendrik Brueckner Cc: Jason Baron Cc: Frederic Weisbecker Cc: Ingo Molnar Cc: Lai Jiangshan Cc: Steven Rostedt Cc: Peter Zijlstra Cc: Mathieu Desnoyers Cc: Jiaying Zhang Cc: Martin Bligh Cc: Li Zefan Cc: Martin Schwidefsky Cc: Paul Mundt LKML-Reference: <20090825123111.GD4639@cetus.boeblingen.de.ibm.com> Signed-off-by: Frederic Weisbecker --- arch/s390/kernel/ftrace.c | 36 +++++++++++++++++++++++++++--------- 1 file changed, 27 insertions(+), 9 deletions(-) (limited to 'arch/s390/kernel/ftrace.c') diff --git a/arch/s390/kernel/ftrace.c b/arch/s390/kernel/ftrace.c index 3e298e64f0db..57bdcb1e3cdf 100644 --- a/arch/s390/kernel/ftrace.c +++ b/arch/s390/kernel/ftrace.c @@ -220,6 +220,29 @@ struct syscall_metadata *syscall_nr_to_meta(int nr) return syscalls_metadata[nr]; } +int syscall_name_to_nr(char *name) +{ + int i; + + if (!syscalls_metadata) + return -1; + for (i = 0; i < NR_syscalls; i++) + if (syscalls_metadata[i]) + if (!strcmp(syscalls_metadata[i]->name, name)) + return i; + return -1; +} + +void set_syscall_enter_id(int num, int id) +{ + syscalls_metadata[num]->enter_id = id; +} + +void set_syscall_exit_id(int num, int id) +{ + syscalls_metadata[num]->exit_id = id; +} + static struct syscall_metadata *find_syscall_meta(unsigned long syscall) { struct syscall_metadata *start; @@ -237,24 +260,19 @@ static struct syscall_metadata *find_syscall_meta(unsigned long syscall) return NULL; } -void arch_init_ftrace_syscalls(void) +static int __init arch_init_ftrace_syscalls(void) { struct syscall_metadata *meta; int i; - static atomic_t refs; - - if (atomic_inc_return(&refs) != 1) - goto out; syscalls_metadata = kzalloc(sizeof(*syscalls_metadata) * NR_syscalls, GFP_KERNEL); if (!syscalls_metadata) - goto out; + return -ENOMEM; for (i = 0; i < NR_syscalls; i++) { meta = find_syscall_meta((unsigned long)sys_call_table[i]); syscalls_metadata[i] = meta; } - return; -out: - atomic_dec(&refs); + return 0; } +arch_initcall(arch_init_ftrace_syscalls); #endif -- cgit v1.2.3