* [PATCH 1/3 v5] ftrace: Have the callbacks receive a struct ftrace_regs instead of pt_regs
2020-11-12 1:15 [PATCH 0/3 v5] ftrace: Add access to function arguments for all callbacks Steven Rostedt
@ 2020-11-12 1:15 ` Steven Rostedt
2020-11-12 17:08 ` Naveen N. Rao
2020-11-12 1:15 ` [PATCH 2/3 v5] ftrace/x86: Allow for arguments to be passed in to ftrace_regs by default Steven Rostedt
2020-11-12 1:15 ` [PATCH 3/3 v5] livepatch: Use the default ftrace_ops instead of REGS when ARGS is available Steven Rostedt
2 siblings, 1 reply; 9+ messages in thread
From: Steven Rostedt @ 2020-11-12 1:15 UTC (permalink / raw)
To: linux-kernel
Cc: Ingo Molnar, Andrew Morton, Miroslav Benes, Peter Zijlstra,
Thomas Gleixner, Masami Hiramatsu
From: "Steven Rostedt (VMware)" <rostedt@goodmis.org>
In preparation to have arguments of a function passed to callbacks attached
to functions as default, change the default callback prototype to receive a
struct ftrace_regs as the forth parameter instead of a pt_regs.
For callbacks that set the FL_SAVE_REGS flag in their ftrace_ops flags, they
will now need to get the pt_regs via a ftrace_get_regs() helper call. If
this is called by a callback that their ftrace_ops did not have a
FL_SAVE_REGS flag set, it that helper function will return NULL.
This will allow the ftrace_regs to hold enough just to get the parameters
and stack pointer, but without the worry that callbacks may have a pt_regs
that is not completely filled.
Reviewed-by: Masami Hiramatsu <mhiramat@kernel.org>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
---
arch/x86/kernel/kprobes/ftrace.c | 3 ++-
fs/pstore/ftrace.c | 2 +-
include/linux/ftrace.h | 16 ++++++++++++++--
include/linux/kprobes.h | 2 +-
kernel/livepatch/patch.c | 3 ++-
kernel/trace/ftrace.c | 27 +++++++++++++++------------
kernel/trace/trace_event_perf.c | 2 +-
kernel/trace/trace_events.c | 2 +-
kernel/trace/trace_functions.c | 9 ++++-----
kernel/trace/trace_irqsoff.c | 2 +-
kernel/trace/trace_sched_wakeup.c | 2 +-
kernel/trace/trace_selftest.c | 20 +++++++++++---------
kernel/trace/trace_stack.c | 2 +-
13 files changed, 55 insertions(+), 37 deletions(-)
diff --git a/arch/x86/kernel/kprobes/ftrace.c b/arch/x86/kernel/kprobes/ftrace.c
index 954d930a7127..373e5fa3ce1f 100644
--- a/arch/x86/kernel/kprobes/ftrace.c
+++ b/arch/x86/kernel/kprobes/ftrace.c
@@ -14,8 +14,9 @@
/* Ftrace callback handler for kprobes -- called under preepmt disabed */
void kprobe_ftrace_handler(unsigned long ip, unsigned long parent_ip,
- struct ftrace_ops *ops, struct pt_regs *regs)
+ struct ftrace_ops *ops, struct ftrace_regs *fregs)
{
+ struct pt_regs *regs = ftrace_get_regs(fregs);
struct kprobe *p;
struct kprobe_ctlblk *kcb;
int bit;
diff --git a/fs/pstore/ftrace.c b/fs/pstore/ftrace.c
index adb0935eb062..5939595f0115 100644
--- a/fs/pstore/ftrace.c
+++ b/fs/pstore/ftrace.c
@@ -26,7 +26,7 @@ static u64 pstore_ftrace_stamp;
static void notrace pstore_ftrace_call(unsigned long ip,
unsigned long parent_ip,
struct ftrace_ops *op,
- struct pt_regs *regs)
+ struct ftrace_regs *fregs)
{
int bit;
unsigned long flags;
diff --git a/include/linux/ftrace.h b/include/linux/ftrace.h
index 8dde9c17aaa5..24e1fa52337d 100644
--- a/include/linux/ftrace.h
+++ b/include/linux/ftrace.h
@@ -90,8 +90,20 @@ ftrace_enable_sysctl(struct ctl_table *table, int write,
struct ftrace_ops;
+struct ftrace_regs {
+ struct pt_regs regs;
+};
+
+static __always_inline struct pt_regs *ftrace_get_regs(struct ftrace_regs *fregs)
+{
+ if (!fregs)
+ return NULL;
+
+ return &fregs->regs;
+}
+
typedef void (*ftrace_func_t)(unsigned long ip, unsigned long parent_ip,
- struct ftrace_ops *op, struct pt_regs *regs);
+ struct ftrace_ops *op, struct ftrace_regs *fregs);
ftrace_func_t ftrace_ops_get_func(struct ftrace_ops *ops);
@@ -259,7 +271,7 @@ int register_ftrace_function(struct ftrace_ops *ops);
int unregister_ftrace_function(struct ftrace_ops *ops);
extern void ftrace_stub(unsigned long a0, unsigned long a1,
- struct ftrace_ops *op, struct pt_regs *regs);
+ struct ftrace_ops *op, struct ftrace_regs *fregs);
#else /* !CONFIG_FUNCTION_TRACER */
/*
diff --git a/include/linux/kprobes.h b/include/linux/kprobes.h
index 629abaf25681..be73350955e4 100644
--- a/include/linux/kprobes.h
+++ b/include/linux/kprobes.h
@@ -345,7 +345,7 @@ static inline void wait_for_kprobe_optimizer(void) { }
#endif /* CONFIG_OPTPROBES */
#ifdef CONFIG_KPROBES_ON_FTRACE
extern void kprobe_ftrace_handler(unsigned long ip, unsigned long parent_ip,
- struct ftrace_ops *ops, struct pt_regs *regs);
+ struct ftrace_ops *ops, struct ftrace_regs *fregs);
extern int arch_prepare_kprobe_ftrace(struct kprobe *p);
#endif
diff --git a/kernel/livepatch/patch.c b/kernel/livepatch/patch.c
index 875c5dbbdd33..f89f9e7e9b07 100644
--- a/kernel/livepatch/patch.c
+++ b/kernel/livepatch/patch.c
@@ -40,8 +40,9 @@ struct klp_ops *klp_find_ops(void *old_func)
static void notrace klp_ftrace_handler(unsigned long ip,
unsigned long parent_ip,
struct ftrace_ops *fops,
- struct pt_regs *regs)
+ struct ftrace_regs *fregs)
{
+ struct pt_regs *regs = ftrace_get_regs(fregs);
struct klp_ops *ops;
struct klp_func *func;
int patch_state;
diff --git a/kernel/trace/ftrace.c b/kernel/trace/ftrace.c
index 3db64fb0cce8..67888311784e 100644
--- a/kernel/trace/ftrace.c
+++ b/kernel/trace/ftrace.c
@@ -121,7 +121,7 @@ struct ftrace_ops global_ops;
#if ARCH_SUPPORTS_FTRACE_OPS
static void ftrace_ops_list_func(unsigned long ip, unsigned long parent_ip,
- struct ftrace_ops *op, struct pt_regs *regs);
+ struct ftrace_ops *op, struct ftrace_regs *fregs);
#else
/* See comment below, where ftrace_ops_list_func is defined */
static void ftrace_ops_no_ops(unsigned long ip, unsigned long parent_ip);
@@ -140,7 +140,7 @@ static inline void ftrace_ops_init(struct ftrace_ops *ops)
}
static void ftrace_pid_func(unsigned long ip, unsigned long parent_ip,
- struct ftrace_ops *op, struct pt_regs *regs)
+ struct ftrace_ops *op, struct ftrace_regs *fregs)
{
struct trace_array *tr = op->private;
int pid;
@@ -154,7 +154,7 @@ static void ftrace_pid_func(unsigned long ip, unsigned long parent_ip,
return;
}
- op->saved_func(ip, parent_ip, op, regs);
+ op->saved_func(ip, parent_ip, op, fregs);
}
static void ftrace_sync_ipi(void *data)
@@ -754,7 +754,7 @@ ftrace_profile_alloc(struct ftrace_profile_stat *stat, unsigned long ip)
static void
function_profile_call(unsigned long ip, unsigned long parent_ip,
- struct ftrace_ops *ops, struct pt_regs *regs)
+ struct ftrace_ops *ops, struct ftrace_regs *fregs)
{
struct ftrace_profile_stat *stat;
struct ftrace_profile *rec;
@@ -2143,6 +2143,7 @@ static int ftrace_check_record(struct dyn_ftrace *rec, bool enable, bool update)
else
rec->flags &= ~FTRACE_FL_TRAMP_EN;
}
+
if (flag & FTRACE_FL_DIRECT) {
/*
* If there's only one user (direct_ops helper)
@@ -2368,8 +2369,9 @@ unsigned long ftrace_find_rec_direct(unsigned long ip)
}
static void call_direct_funcs(unsigned long ip, unsigned long pip,
- struct ftrace_ops *ops, struct pt_regs *regs)
+ struct ftrace_ops *ops, struct ftrace_regs *fregs)
{
+ struct pt_regs *regs = ftrace_get_regs(fregs);
unsigned long addr;
addr = ftrace_find_rec_direct(ip);
@@ -4292,7 +4294,7 @@ static int __init ftrace_mod_cmd_init(void)
core_initcall(ftrace_mod_cmd_init);
static void function_trace_probe_call(unsigned long ip, unsigned long parent_ip,
- struct ftrace_ops *op, struct pt_regs *pt_regs)
+ struct ftrace_ops *op, struct ftrace_regs *fregs)
{
struct ftrace_probe_ops *probe_ops;
struct ftrace_func_probe *probe;
@@ -6911,8 +6913,9 @@ void ftrace_reset_array_ops(struct trace_array *tr)
static nokprobe_inline void
__ftrace_ops_list_func(unsigned long ip, unsigned long parent_ip,
- struct ftrace_ops *ignored, struct pt_regs *regs)
+ struct ftrace_ops *ignored, struct ftrace_regs *fregs)
{
+ struct pt_regs *regs = ftrace_get_regs(fregs);
struct ftrace_ops *op;
int bit;
@@ -6945,7 +6948,7 @@ __ftrace_ops_list_func(unsigned long ip, unsigned long parent_ip,
pr_warn("op=%p %pS\n", op, op);
goto out;
}
- op->func(ip, parent_ip, op, regs);
+ op->func(ip, parent_ip, op, fregs);
}
} while_for_each_ftrace_op(op);
out:
@@ -6968,9 +6971,9 @@ __ftrace_ops_list_func(unsigned long ip, unsigned long parent_ip,
*/
#if ARCH_SUPPORTS_FTRACE_OPS
static void ftrace_ops_list_func(unsigned long ip, unsigned long parent_ip,
- struct ftrace_ops *op, struct pt_regs *regs)
+ struct ftrace_ops *op, struct ftrace_regs *fregs)
{
- __ftrace_ops_list_func(ip, parent_ip, NULL, regs);
+ __ftrace_ops_list_func(ip, parent_ip, NULL, fregs);
}
NOKPROBE_SYMBOL(ftrace_ops_list_func);
#else
@@ -6987,7 +6990,7 @@ NOKPROBE_SYMBOL(ftrace_ops_no_ops);
* this function will be called by the mcount trampoline.
*/
static void ftrace_ops_assist_func(unsigned long ip, unsigned long parent_ip,
- struct ftrace_ops *op, struct pt_regs *regs)
+ struct ftrace_ops *op, struct ftrace_regs *fregs)
{
int bit;
@@ -6998,7 +7001,7 @@ static void ftrace_ops_assist_func(unsigned long ip, unsigned long parent_ip,
preempt_disable_notrace();
if (!(op->flags & FTRACE_OPS_FL_RCU) || rcu_is_watching())
- op->func(ip, parent_ip, op, regs);
+ op->func(ip, parent_ip, op, fregs);
preempt_enable_notrace();
trace_clear_recursion(bit);
diff --git a/kernel/trace/trace_event_perf.c b/kernel/trace/trace_event_perf.c
index 1b202e28dfaa..a71181655958 100644
--- a/kernel/trace/trace_event_perf.c
+++ b/kernel/trace/trace_event_perf.c
@@ -432,7 +432,7 @@ NOKPROBE_SYMBOL(perf_trace_buf_update);
#ifdef CONFIG_FUNCTION_TRACER
static void
perf_ftrace_function_call(unsigned long ip, unsigned long parent_ip,
- struct ftrace_ops *ops, struct pt_regs *pt_regs)
+ struct ftrace_ops *ops, struct ftrace_regs *fregs)
{
struct ftrace_entry *entry;
struct perf_event *event;
diff --git a/kernel/trace/trace_events.c b/kernel/trace/trace_events.c
index f4b459bb6d33..98d194d8460e 100644
--- a/kernel/trace/trace_events.c
+++ b/kernel/trace/trace_events.c
@@ -3673,7 +3673,7 @@ static struct trace_event_file event_trace_file __initdata;
static void __init
function_test_events_call(unsigned long ip, unsigned long parent_ip,
- struct ftrace_ops *op, struct pt_regs *pt_regs)
+ struct ftrace_ops *op, struct ftrace_regs *regs)
{
struct trace_buffer *buffer;
struct ring_buffer_event *event;
diff --git a/kernel/trace/trace_functions.c b/kernel/trace/trace_functions.c
index 646eda6c44a5..c5095dd28e20 100644
--- a/kernel/trace/trace_functions.c
+++ b/kernel/trace/trace_functions.c
@@ -23,10 +23,10 @@ static void tracing_start_function_trace(struct trace_array *tr);
static void tracing_stop_function_trace(struct trace_array *tr);
static void
function_trace_call(unsigned long ip, unsigned long parent_ip,
- struct ftrace_ops *op, struct pt_regs *pt_regs);
+ struct ftrace_ops *op, struct ftrace_regs *fregs);
static void
function_stack_trace_call(unsigned long ip, unsigned long parent_ip,
- struct ftrace_ops *op, struct pt_regs *pt_regs);
+ struct ftrace_ops *op, struct ftrace_regs *fregs);
static struct tracer_flags func_flags;
/* Our option */
@@ -89,7 +89,6 @@ void ftrace_destroy_function_files(struct trace_array *tr)
static int function_trace_init(struct trace_array *tr)
{
ftrace_func_t func;
-
/*
* Instance trace_arrays get their ops allocated
* at instance creation. Unless it failed
@@ -129,7 +128,7 @@ static void function_trace_start(struct trace_array *tr)
static void
function_trace_call(unsigned long ip, unsigned long parent_ip,
- struct ftrace_ops *op, struct pt_regs *pt_regs)
+ struct ftrace_ops *op, struct ftrace_regs *fregs)
{
struct trace_array *tr = op->private;
struct trace_array_cpu *data;
@@ -178,7 +177,7 @@ function_trace_call(unsigned long ip, unsigned long parent_ip,
static void
function_stack_trace_call(unsigned long ip, unsigned long parent_ip,
- struct ftrace_ops *op, struct pt_regs *pt_regs)
+ struct ftrace_ops *op, struct ftrace_regs *fregs)
{
struct trace_array *tr = op->private;
struct trace_array_cpu *data;
diff --git a/kernel/trace/trace_irqsoff.c b/kernel/trace/trace_irqsoff.c
index 10bbb0f381d5..d06aab4dcbb8 100644
--- a/kernel/trace/trace_irqsoff.c
+++ b/kernel/trace/trace_irqsoff.c
@@ -138,7 +138,7 @@ static int func_prolog_dec(struct trace_array *tr,
*/
static void
irqsoff_tracer_call(unsigned long ip, unsigned long parent_ip,
- struct ftrace_ops *op, struct pt_regs *pt_regs)
+ struct ftrace_ops *op, struct ftrace_regs *fregs)
{
struct trace_array *tr = irqsoff_trace;
struct trace_array_cpu *data;
diff --git a/kernel/trace/trace_sched_wakeup.c b/kernel/trace/trace_sched_wakeup.c
index 97b10bb31a1f..c0181066dbe9 100644
--- a/kernel/trace/trace_sched_wakeup.c
+++ b/kernel/trace/trace_sched_wakeup.c
@@ -212,7 +212,7 @@ static void wakeup_print_header(struct seq_file *s)
*/
static void
wakeup_tracer_call(unsigned long ip, unsigned long parent_ip,
- struct ftrace_ops *op, struct pt_regs *pt_regs)
+ struct ftrace_ops *op, struct ftrace_regs *fregs)
{
struct trace_array *tr = wakeup_trace;
struct trace_array_cpu *data;
diff --git a/kernel/trace/trace_selftest.c b/kernel/trace/trace_selftest.c
index 8ee3c0bb5d8a..5ed081c6471c 100644
--- a/kernel/trace/trace_selftest.c
+++ b/kernel/trace/trace_selftest.c
@@ -107,7 +107,7 @@ static int trace_selftest_test_probe1_cnt;
static void trace_selftest_test_probe1_func(unsigned long ip,
unsigned long pip,
struct ftrace_ops *op,
- struct pt_regs *pt_regs)
+ struct ftrace_regs *fregs)
{
trace_selftest_test_probe1_cnt++;
}
@@ -116,7 +116,7 @@ static int trace_selftest_test_probe2_cnt;
static void trace_selftest_test_probe2_func(unsigned long ip,
unsigned long pip,
struct ftrace_ops *op,
- struct pt_regs *pt_regs)
+ struct ftrace_regs *fregs)
{
trace_selftest_test_probe2_cnt++;
}
@@ -125,7 +125,7 @@ static int trace_selftest_test_probe3_cnt;
static void trace_selftest_test_probe3_func(unsigned long ip,
unsigned long pip,
struct ftrace_ops *op,
- struct pt_regs *pt_regs)
+ struct ftrace_regs *fregs)
{
trace_selftest_test_probe3_cnt++;
}
@@ -134,7 +134,7 @@ static int trace_selftest_test_global_cnt;
static void trace_selftest_test_global_func(unsigned long ip,
unsigned long pip,
struct ftrace_ops *op,
- struct pt_regs *pt_regs)
+ struct ftrace_regs *fregs)
{
trace_selftest_test_global_cnt++;
}
@@ -143,7 +143,7 @@ static int trace_selftest_test_dyn_cnt;
static void trace_selftest_test_dyn_func(unsigned long ip,
unsigned long pip,
struct ftrace_ops *op,
- struct pt_regs *pt_regs)
+ struct ftrace_regs *fregs)
{
trace_selftest_test_dyn_cnt++;
}
@@ -414,7 +414,7 @@ static int trace_selftest_recursion_cnt;
static void trace_selftest_test_recursion_func(unsigned long ip,
unsigned long pip,
struct ftrace_ops *op,
- struct pt_regs *pt_regs)
+ struct ftrace_regs *fregs)
{
/*
* This function is registered without the recursion safe flag.
@@ -429,7 +429,7 @@ static void trace_selftest_test_recursion_func(unsigned long ip,
static void trace_selftest_test_recursion_safe_func(unsigned long ip,
unsigned long pip,
struct ftrace_ops *op,
- struct pt_regs *pt_regs)
+ struct ftrace_regs *fregs)
{
/*
* We said we would provide our own recursion. By calling
@@ -548,9 +548,11 @@ static enum {
static void trace_selftest_test_regs_func(unsigned long ip,
unsigned long pip,
struct ftrace_ops *op,
- struct pt_regs *pt_regs)
+ struct ftrace_regs *fregs)
{
- if (pt_regs)
+ struct pt_regs *regs = ftrace_get_regs(fregs);
+
+ if (regs)
trace_selftest_regs_stat = TRACE_SELFTEST_REGS_FOUND;
else
trace_selftest_regs_stat = TRACE_SELFTEST_REGS_NOT_FOUND;
diff --git a/kernel/trace/trace_stack.c b/kernel/trace/trace_stack.c
index 969db526a563..63c285042051 100644
--- a/kernel/trace/trace_stack.c
+++ b/kernel/trace/trace_stack.c
@@ -290,7 +290,7 @@ static void check_stack(unsigned long ip, unsigned long *stack)
static void
stack_trace_call(unsigned long ip, unsigned long parent_ip,
- struct ftrace_ops *op, struct pt_regs *pt_regs)
+ struct ftrace_ops *op, struct ftrace_regs *fregs)
{
unsigned long stack;
--
2.28.0
^ permalink raw reply related [flat|nested] 9+ messages in thread
* [PATCH 3/3 v5] livepatch: Use the default ftrace_ops instead of REGS when ARGS is available
2020-11-12 1:15 [PATCH 0/3 v5] ftrace: Add access to function arguments for all callbacks Steven Rostedt
2020-11-12 1:15 ` [PATCH 1/3 v5] ftrace: Have the callbacks receive a struct ftrace_regs instead of pt_regs Steven Rostedt
2020-11-12 1:15 ` [PATCH 2/3 v5] ftrace/x86: Allow for arguments to be passed in to ftrace_regs by default Steven Rostedt
@ 2020-11-12 1:15 ` Steven Rostedt
2020-11-12 8:21 ` Peter Zijlstra
2 siblings, 1 reply; 9+ messages in thread
From: Steven Rostedt @ 2020-11-12 1:15 UTC (permalink / raw)
To: linux-kernel
Cc: Ingo Molnar, Andrew Morton, Miroslav Benes, Peter Zijlstra,
Thomas Gleixner, Masami Hiramatsu, Josh Poimboeuf, Jiri Kosina,
live-patching
From: "Steven Rostedt (VMware)" <rostedt@goodmis.org>
When CONFIG_HAVE_DYNAMIC_FTRACE_WITH_ARGS is available, the ftrace call
will be able to set the ip of the calling function. This will improve the
performance of live kernel patching where it does not need all the regs to
be stored just to change the instruction pointer.
If all archs that support live kernel patching also support
HAVE_DYNAMIC_FTRACE_WITH_ARGS, then the architecture specific function
klp_arch_set_pc() could be made generic.
It is possible that an arch can support HAVE_DYNAMIC_FTRACE_WITH_ARGS but
not HAVE_DYNAMIC_FTRACE_WITH_REGS and then have access to live patching.
Cc: Josh Poimboeuf <jpoimboe@redhat.com>
Cc: Jiri Kosina <jikos@kernel.org>
Cc: live-patching@vger.kernel.org
Acked-by: Miroslav Benes <mbenes@suse.cz>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
---
arch/powerpc/include/asm/livepatch.h | 4 +++-
arch/s390/include/asm/livepatch.h | 5 ++++-
arch/x86/include/asm/ftrace.h | 3 +++
arch/x86/include/asm/livepatch.h | 4 ++--
arch/x86/kernel/ftrace_64.S | 4 ++++
include/linux/ftrace.h | 7 +++++++
kernel/livepatch/Kconfig | 2 +-
kernel/livepatch/patch.c | 9 +++++----
8 files changed, 29 insertions(+), 9 deletions(-)
diff --git a/arch/powerpc/include/asm/livepatch.h b/arch/powerpc/include/asm/livepatch.h
index 4a3d5d25fed5..ae25e6e72997 100644
--- a/arch/powerpc/include/asm/livepatch.h
+++ b/arch/powerpc/include/asm/livepatch.h
@@ -12,8 +12,10 @@
#include <linux/sched/task_stack.h>
#ifdef CONFIG_LIVEPATCH
-static inline void klp_arch_set_pc(struct pt_regs *regs, unsigned long ip)
+static inline void klp_arch_set_pc(struct ftrace_regs *fregs, unsigned long ip)
{
+ struct pt_regs *regs = ftrace_get_regs(fregs);
+
regs->nip = ip;
}
diff --git a/arch/s390/include/asm/livepatch.h b/arch/s390/include/asm/livepatch.h
index 818612b784cd..d578a8c76676 100644
--- a/arch/s390/include/asm/livepatch.h
+++ b/arch/s390/include/asm/livepatch.h
@@ -11,10 +11,13 @@
#ifndef ASM_LIVEPATCH_H
#define ASM_LIVEPATCH_H
+#include <linux/ftrace.h>
#include <asm/ptrace.h>
-static inline void klp_arch_set_pc(struct pt_regs *regs, unsigned long ip)
+static inline void klp_arch_set_pc(struct ftrace_regs *fregs, unsigned long ip)
{
+ struct pt_regs *regs = ftrace_get_regs(fregs);
+
regs->psw.addr = ip;
}
diff --git a/arch/x86/include/asm/ftrace.h b/arch/x86/include/asm/ftrace.h
index e00fe88146e0..235385a38bd9 100644
--- a/arch/x86/include/asm/ftrace.h
+++ b/arch/x86/include/asm/ftrace.h
@@ -54,6 +54,9 @@ arch_ftrace_get_regs(struct ftrace_regs *fregs)
return NULL;
return &fregs->regs;
}
+
+#define ftrace_regs_set_ip(fregs, _ip) \
+ do { (fregs)->regs.ip = (_ip); } while (0)
#endif
#ifdef CONFIG_DYNAMIC_FTRACE
diff --git a/arch/x86/include/asm/livepatch.h b/arch/x86/include/asm/livepatch.h
index 1fde1ab6559e..59a08d5c6f1d 100644
--- a/arch/x86/include/asm/livepatch.h
+++ b/arch/x86/include/asm/livepatch.h
@@ -12,9 +12,9 @@
#include <asm/setup.h>
#include <linux/ftrace.h>
-static inline void klp_arch_set_pc(struct pt_regs *regs, unsigned long ip)
+static inline void klp_arch_set_pc(struct ftrace_regs *fregs, unsigned long ip)
{
- regs->ip = ip;
+ ftrace_regs_set_ip(fregs, ip);
}
#endif /* _ASM_X86_LIVEPATCH_H */
diff --git a/arch/x86/kernel/ftrace_64.S b/arch/x86/kernel/ftrace_64.S
index 60e3b64f5ea6..0d54099c2a3a 100644
--- a/arch/x86/kernel/ftrace_64.S
+++ b/arch/x86/kernel/ftrace_64.S
@@ -157,6 +157,10 @@ SYM_INNER_LABEL(ftrace_caller_op_ptr, SYM_L_GLOBAL)
SYM_INNER_LABEL(ftrace_call, SYM_L_GLOBAL)
call ftrace_stub
+ /* Handlers can change the RIP */
+ movq RIP(%rsp), %rax
+ movq %rax, MCOUNT_REG_SIZE(%rsp)
+
restore_mcount_regs
/*
diff --git a/include/linux/ftrace.h b/include/linux/ftrace.h
index 588ea7023a7a..b4eb962e2be9 100644
--- a/include/linux/ftrace.h
+++ b/include/linux/ftrace.h
@@ -97,6 +97,13 @@ struct ftrace_regs {
};
#define arch_ftrace_get_regs(fregs) (&(fregs)->regs)
+/*
+ * ftrace_regs_set_ip() is to be defined by the architecture if
+ * to allow setting of the instruction pointer from the ftrace_regs
+ * when HAVE_DYNAMIC_FTRACE_WITH_ARGS is set and it supports
+ * live kernel patching.
+ */
+#define ftrace_regs_set_ip(fregs, ip) do { } while (0)
#endif /* CONFIG_HAVE_DYNAMIC_FTRACE_WITH_ARGS */
static __always_inline struct pt_regs *ftrace_get_regs(struct ftrace_regs *fregs)
diff --git a/kernel/livepatch/Kconfig b/kernel/livepatch/Kconfig
index 54102deb50ba..53d51ed619a3 100644
--- a/kernel/livepatch/Kconfig
+++ b/kernel/livepatch/Kconfig
@@ -6,7 +6,7 @@ config HAVE_LIVEPATCH
config LIVEPATCH
bool "Kernel Live Patching"
- depends on DYNAMIC_FTRACE_WITH_REGS
+ depends on DYNAMIC_FTRACE_WITH_REGS || DYNAMIC_FTRACE_WITH_ARGS
depends on MODULES
depends on SYSFS
depends on KALLSYMS_ALL
diff --git a/kernel/livepatch/patch.c b/kernel/livepatch/patch.c
index f89f9e7e9b07..e8029aea67f1 100644
--- a/kernel/livepatch/patch.c
+++ b/kernel/livepatch/patch.c
@@ -42,7 +42,6 @@ static void notrace klp_ftrace_handler(unsigned long ip,
struct ftrace_ops *fops,
struct ftrace_regs *fregs)
{
- struct pt_regs *regs = ftrace_get_regs(fregs);
struct klp_ops *ops;
struct klp_func *func;
int patch_state;
@@ -118,7 +117,7 @@ static void notrace klp_ftrace_handler(unsigned long ip,
if (func->nop)
goto unlock;
- klp_arch_set_pc(regs, (unsigned long)func->new_func);
+ klp_arch_set_pc(fregs, (unsigned long)func->new_func);
unlock:
preempt_enable_notrace();
@@ -200,8 +199,10 @@ static int klp_patch_func(struct klp_func *func)
return -ENOMEM;
ops->fops.func = klp_ftrace_handler;
- ops->fops.flags = FTRACE_OPS_FL_SAVE_REGS |
- FTRACE_OPS_FL_DYNAMIC |
+ ops->fops.flags = FTRACE_OPS_FL_DYNAMIC |
+#ifndef CONFIG_HAVE_DYNAMIC_FTRACE_WITH_ARGS
+ FTRACE_OPS_FL_SAVE_REGS |
+#endif
FTRACE_OPS_FL_IPMODIFY |
FTRACE_OPS_FL_PERMANENT;
--
2.28.0
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