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authorLinus Torvalds <torvalds@linux-foundation.org>2019-03-12 00:01:32 (GMT)
committerLinus Torvalds <torvalds@linux-foundation.org>2019-03-12 00:01:32 (GMT)
commit6cdfa54cd22984ae785b0d496b53405d6da9ad1d (patch)
tree6d5d58d21eccdfebf93a5835258d7f333ef21c13 /arch
parenta089e4fed5c5e8717f233d71bb750fbf9e1f38e0 (diff)
parent85f726a35e504418607b77c5e7da165dc1ea63ce (diff)
Merge tag 'trace-v5.1' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace
Pull tracing updates from Steven Rostedt: "The biggest change for this release is in the histogram code: - Add "onchange(var)" histogram handler that executes a action when $var changes. - Add new "snapshot()" action for histogram handlers, that causes a snapshot of the ring buffer when triggered. ie. onchange(var).snapshot() will trigger a snapshot if var changes. - Add alternative for "trace()" action. Currently, to trigger a synthetic event, the name of that event is used as the handler name, which is inconsistent with the other actions. onchange(var).synthetic(param) where it can now be onchange(var).trace(synthetic, param). The older method will still be allowed, as long as the synthetic events do not overlap with other handler names. - The histogram documentation at testcases were updated for the new changes. Outside of the histogram code, we have: - Added a quicker way to enable set_ftrace_filter files, that will make it much quicker to bisect tracing a function that shouldn't be traced and crashes the kernel. (You can echo in numbers to set_ftrace_filter, and it will select the corresponding function that is in available_filter_functions). - Some better displaying of the tracing data (and more information was added). The rest are small fixes and more clean ups to the code" * tag 'trace-v5.1' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace: (37 commits) tracing: Use strncpy instead of memcpy when copying comm in trace.c tracing: Use strncpy instead of memcpy when copying comm for hist triggers tracing: Use strncpy instead of memcpy for string keys in hist triggers tracing: Use str_has_prefix() in synth_event_create() x86/ftrace: Fix warning and considate ftrace_jmp_replace() and ftrace_call_replace() tracing/perf: Use strndup_user() instead of buggy open-coded version doc: trace: Fix documentation for uprobe_profile tracing: Fix spelling mistake: "analagous" -> "analogous" tracing: Comment why cond_snapshot is checked outside of max_lock protection tracing: Add hist trigger action 'expected fail' test case tracing: Add alternative synthetic event trace action test case tracing: Add hist trigger onchange() handler test case tracing: Add hist trigger snapshot() action test case tracing: Add SPDX license GPL-2.0 license identifier to inter-event testcases tracing: Add alternative synthetic event trace action syntax tracing: Add hist trigger onchange() handler Documentation tracing: Add hist trigger onchange() handler tracing: Add hist trigger snapshot() action Documentation tracing: Add hist trigger snapshot() action tracing: Add conditional snapshot ...
Diffstat (limited to 'arch')
-rw-r--r--arch/x86/kernel/ftrace.c42
1 files changed, 17 insertions, 25 deletions
diff --git a/arch/x86/kernel/ftrace.c b/arch/x86/kernel/ftrace.c
index 3e3789c..ef49517 100644
--- a/arch/x86/kernel/ftrace.c
+++ b/arch/x86/kernel/ftrace.c
@@ -49,7 +49,7 @@ int ftrace_arch_code_modify_post_process(void)
union ftrace_code_union {
char code[MCOUNT_INSN_SIZE];
struct {
- unsigned char e8;
+ unsigned char op;
int offset;
} __attribute__((packed));
};
@@ -59,20 +59,23 @@ static int ftrace_calc_offset(long ip, long addr)
return (int)(addr - ip);
}
-static unsigned char *ftrace_call_replace(unsigned long ip, unsigned long addr)
+static unsigned char *
+ftrace_text_replace(unsigned char op, unsigned long ip, unsigned long addr)
{
static union ftrace_code_union calc;
- calc.e8 = 0xe8;
+ calc.op = op;
calc.offset = ftrace_calc_offset(ip + MCOUNT_INSN_SIZE, addr);
- /*
- * No locking needed, this must be called via kstop_machine
- * which in essence is like running on a uniprocessor machine.
- */
return calc.code;
}
+static unsigned char *
+ftrace_call_replace(unsigned long ip, unsigned long addr)
+{
+ return ftrace_text_replace(0xe8, ip, addr);
+}
+
static inline int
within(unsigned long addr, unsigned long start, unsigned long end)
{
@@ -665,22 +668,6 @@ int __init ftrace_dyn_arch_init(void)
return 0;
}
-#if defined(CONFIG_X86_64) || defined(CONFIG_FUNCTION_GRAPH_TRACER)
-static unsigned char *ftrace_jmp_replace(unsigned long ip, unsigned long addr)
-{
- static union ftrace_code_union calc;
-
- /* Jmp not a call (ignore the .e8) */
- calc.e8 = 0xe9;
- calc.offset = ftrace_calc_offset(ip + MCOUNT_INSN_SIZE, addr);
-
- /*
- * ftrace external locks synchronize the access to the static variable.
- */
- return calc.code;
-}
-#endif
-
/* Currently only x86_64 supports dynamic trampolines */
#ifdef CONFIG_X86_64
@@ -892,8 +879,8 @@ static void *addr_from_call(void *ptr)
return NULL;
/* Make sure this is a call */
- if (WARN_ON_ONCE(calc.e8 != 0xe8)) {
- pr_warn("Expected e8, got %x\n", calc.e8);
+ if (WARN_ON_ONCE(calc.op != 0xe8)) {
+ pr_warn("Expected e8, got %x\n", calc.op);
return NULL;
}
@@ -964,6 +951,11 @@ void arch_ftrace_trampoline_free(struct ftrace_ops *ops)
#ifdef CONFIG_DYNAMIC_FTRACE
extern void ftrace_graph_call(void);
+static unsigned char *ftrace_jmp_replace(unsigned long ip, unsigned long addr)
+{
+ return ftrace_text_replace(0xe9, ip, addr);
+}
+
static int ftrace_mod_jmp(unsigned long ip, void *func)
{
unsigned char *new;

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