From: Sasha Levin <sashal@kernel.org>
To: linux-kernel@vger.kernel.org, stable@vger.kernel.org
Cc: "Steven Rostedt (VMware)" <rostedt@goodmis.org>,
Arnd Bergmann <arnd@arndb.de>, Sasha Levin <sashal@kernel.org>
Subject: [PATCH AUTOSEL 4.19 10/29] x86/ftrace: Fix warning and considate ftrace_jmp_replace() and ftrace_call_replace()
Date: Thu, 29 Aug 2019 06:49:50 -0400 [thread overview]
Message-ID: <20190829105009.2265-10-sashal@kernel.org> (raw)
In-Reply-To: <20190829105009.2265-1-sashal@kernel.org>
From: "Steven Rostedt (VMware)" <rostedt@goodmis.org>
[ Upstream commit 745cfeaac09ce359130a5451d90cb0bd4094c290 ]
Arnd reported the following compiler warning:
arch/x86/kernel/ftrace.c:669:23: error: 'ftrace_jmp_replace' defined but not used [-Werror=unused-function]
The ftrace_jmp_replace() function now only has a single user and should be
simply moved by that user. But looking at the code, it shows that
ftrace_jmp_replace() is similar to ftrace_call_replace() except that instead
of using the opcode of 0xe8 it uses 0xe9. It makes more sense to consolidate
that function into one implementation that both ftrace_jmp_replace() and
ftrace_call_replace() use by passing in the op code separate.
The structure in ftrace_code_union is also modified to replace the "e8"
field with the more appropriate name "op".
Cc: stable@vger.kernel.org
Reported-by: Arnd Bergmann <arnd@arndb.de>
Acked-by: Arnd Bergmann <arnd@arndb.de>
Link: http://lkml.kernel.org/r/20190304200748.1418790-1-arnd@arndb.de
Fixes: d2a68c4effd8 ("x86/ftrace: Do not call function graph from dynamic trampolines")
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
arch/x86/kernel/ftrace.c | 42 ++++++++++++++++------------------------
1 file changed, 17 insertions(+), 25 deletions(-)
diff --git a/arch/x86/kernel/ftrace.c b/arch/x86/kernel/ftrace.c
index 50d309662d78c..5790671857e55 100644
--- a/arch/x86/kernel/ftrace.c
+++ b/arch/x86/kernel/ftrace.c
@@ -53,7 +53,7 @@ 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));
};
@@ -63,20 +63,23 @@ 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)
{
@@ -686,22 +689,6 @@ 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
@@ -923,8 +910,8 @@ 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;
}
@@ -995,6 +982,11 @@ 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;
--
2.20.1
next prev parent reply other threads:[~2019-08-29 10:55 UTC|newest]
Thread overview: 33+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-08-29 10:49 [PATCH AUTOSEL 4.19 01/29] hv_sock: Fix hang when a connection is closed Sasha Levin
2019-08-29 10:49 ` [PATCH AUTOSEL 4.19 02/29] Revert "dm bufio: fix deadlock with loop device" Sasha Levin
2019-08-29 10:49 ` [PATCH AUTOSEL 4.19 03/29] kprobes: Fix potential deadlock in kprobe_optimizer() Sasha Levin
2019-08-29 10:49 ` [PATCH AUTOSEL 4.19 04/29] ALSA: line6: Fix memory leak at line6_init_pcm() error path Sasha Levin
2019-08-29 10:49 ` [PATCH AUTOSEL 4.19 05/29] Blk-iolatency: warn on negative inflight IO counter Sasha Levin
2019-08-29 10:49 ` [PATCH AUTOSEL 4.19 06/29] blk-iolatency: fix STS_AGAIN handling Sasha Levin
2019-08-29 10:49 ` [PATCH AUTOSEL 4.19 07/29] {nl,mac}80211: fix interface combinations on crypto controlled devices Sasha Levin
2019-08-29 10:49 ` [PATCH AUTOSEL 4.19 08/29] timekeeping: Use proper ktime_add when adding nsecs in coarse offset Sasha Levin
2019-08-29 10:49 ` [PATCH AUTOSEL 4.19 09/29] selftests: fib_rule_tests: use pre-defined DEV_ADDR Sasha Levin
2019-08-29 10:49 ` Sasha Levin [this message]
2019-08-29 10:49 ` [PATCH AUTOSEL 4.19 11/29] binder: take read mode of mmap_sem in binder_alloc_free_page() Sasha Levin
2019-08-29 15:13 ` Tyler Hicks
2019-08-30 6:29 ` Greg Kroah-Hartman
2019-08-30 7:30 ` Tyler Hicks
2019-09-02 15:54 ` Greg Kroah-Hartman
2019-08-29 10:49 ` [PATCH AUTOSEL 4.19 12/29] powerpc/64: mark start_here_multiplatform as __ref Sasha Levin
2019-08-29 10:49 ` [PATCH AUTOSEL 4.19 13/29] media: stm32-dcmi: fix irq = 0 case Sasha Levin
2019-08-29 10:49 ` [PATCH AUTOSEL 4.19 14/29] HID: input: fix a4tech horizontal wheel custom usage Sasha Levin
2019-08-29 10:49 ` [PATCH AUTOSEL 4.19 15/29] netfilter: nf_tables: use-after-free in failing rule with bound set Sasha Levin
2019-08-29 10:49 ` [PATCH AUTOSEL 4.19 16/29] userfaultfd_release: always remove uffd flags and clear vm_userfaultfd_ctx Sasha Levin
2019-08-29 10:49 ` [PATCH AUTOSEL 4.19 17/29] arm64: dts: rockchip: enable usb-host regulators at boot on rk3328-rock64 Sasha Levin
2019-08-29 10:49 ` [PATCH AUTOSEL 4.19 18/29] mac80211: fix possible sta leak Sasha Levin
2019-08-29 10:49 ` [PATCH AUTOSEL 4.19 19/29] scripts/decode_stacktrace: match basepath using shell prefix operator, not regex Sasha Levin
2019-08-29 10:50 ` [PATCH AUTOSEL 4.19 20/29] KVM: arm/arm64: Only skip MMIO insn once Sasha Levin
2019-08-29 10:50 ` [PATCH AUTOSEL 4.19 21/29] netfilter: ipset: Actually allow destination MAC address for hash:ip,mac sets too Sasha Levin
2019-08-29 10:50 ` [PATCH AUTOSEL 4.19 22/29] netfilter: ipset: Copy the right MAC address in bitmap:ip,mac and hash:ip,mac sets Sasha Levin
2019-08-29 10:50 ` [PATCH AUTOSEL 4.19 23/29] ALSA: usb-audio: Check mixer unit bitmap yet more strictly Sasha Levin
2019-08-29 10:50 ` [PATCH AUTOSEL 4.19 24/29] riscv: remove unused variable in ftrace Sasha Levin
2019-08-29 10:50 ` [PATCH AUTOSEL 4.19 25/29] nvme-fc: use separate work queue to avoid warning Sasha Levin
2019-08-29 10:50 ` [PATCH AUTOSEL 4.19 26/29] clk: s2mps11: Add used attribute to s2mps11_dt_match Sasha Levin
2019-08-29 10:50 ` [PATCH AUTOSEL 4.19 27/29] remoteproc: qcom: q6v5: shore up resource probe handling Sasha Levin
2019-08-29 10:50 ` [PATCH AUTOSEL 4.19 28/29] modules: always page-align module section allocations Sasha Levin
2019-08-29 10:50 ` [PATCH AUTOSEL 4.19 29/29] kernel/module: Fix mem leak in module_add_modinfo_attrs Sasha Levin
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