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authorLinus Torvalds <torvalds@linux-foundation.org>2014-12-10 19:58:13 -0800
committerLinus Torvalds <torvalds@linux-foundation.org>2014-12-10 19:58:13 -0800
commit1dd7dcb6eaa677b034e7ef63df8320277507ae70 (patch)
tree3f1592b634d7bdde94e00570925be2dade8433d4 /arch
parentb6da0076bab5a12afb19312ffee41c95490af2a0 (diff)
parent3558a5ac50dbb2419cc649d5e154af161d661037 (diff)
Merge tag 'trace-3.19' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace
Pull tracing updates from Steven Rostedt: "There was a lot of clean ups and minor fixes. One of those clean ups was to the trace_seq code. It also removed the return values to the trace_seq_*() functions and use trace_seq_has_overflowed() to see if the buffer filled up or not. This is similar to work being done to the seq_file code as well in another tree. Some of the other goodies include: - Added some "!" (NOT) logic to the tracing filter. - Fixed the frame pointer logic to the x86_64 mcount trampolines - Added the logic for dynamic trampolines on !CONFIG_PREEMPT systems. That is, the ftrace trampoline can be dynamically allocated and be called directly by functions that only have a single hook to them" * tag 'trace-3.19' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace: (55 commits) tracing: Truncated output is better than nothing tracing: Add additional marks to signal very large time deltas Documentation: describe trace_buf_size parameter more accurately tracing: Allow NOT to filter AND and OR clauses tracing: Add NOT to filtering logic ftrace/fgraph/x86: Have prepare_ftrace_return() take ip as first parameter ftrace/x86: Get rid of ftrace_caller_setup ftrace/x86: Have save_mcount_regs macro also save stack frames if needed ftrace/x86: Add macro MCOUNT_REG_SIZE for amount of stack used to save mcount regs ftrace/x86: Simplify save_mcount_regs on getting RIP ftrace/x86: Have save_mcount_regs store RIP in %rdi for first parameter ftrace/x86: Rename MCOUNT_SAVE_FRAME and add more detailed comments ftrace/x86: Move MCOUNT_SAVE_FRAME out of header file ftrace/x86: Have static tracing also use ftrace_caller_setup ftrace/x86: Have static function tracing always test for function graph kprobes: Add IPMODIFY flag to kprobe_ftrace_ops ftrace, kprobes: Support IPMODIFY flag to find IP modify conflict kprobes/ftrace: Recover original IP if pre_handler doesn't change it tracing/trivial: Fix typos and make an int into a bool tracing: Deletion of an unnecessary check before iput() ...
Diffstat (limited to 'arch')
-rw-r--r--arch/powerpc/kernel/ftrace.c2
-rw-r--r--arch/x86/include/asm/ftrace.h33
-rw-r--r--arch/x86/kernel/ftrace.c288
-rw-r--r--arch/x86/kernel/kprobes/ftrace.c9
-rw-r--r--arch/x86/kernel/mcount_64.S224
-rw-r--r--arch/x86/kvm/mmutrace.h4
6 files changed, 460 insertions, 100 deletions
diff --git a/arch/powerpc/kernel/ftrace.c b/arch/powerpc/kernel/ftrace.c
index 390311c0f03d..e66af6d265e8 100644
--- a/arch/powerpc/kernel/ftrace.c
+++ b/arch/powerpc/kernel/ftrace.c
@@ -449,7 +449,7 @@ void ftrace_replace_code(int enable)
rec = ftrace_rec_iter_record(iter);
ret = __ftrace_replace_code(rec, enable);
if (ret) {
- ftrace_bug(ret, rec->ip);
+ ftrace_bug(ret, rec);
return;
}
}
diff --git a/arch/x86/include/asm/ftrace.h b/arch/x86/include/asm/ftrace.h
index e1f7fecaa7d6..f45acad3c4b6 100644
--- a/arch/x86/include/asm/ftrace.h
+++ b/arch/x86/include/asm/ftrace.h
@@ -1,39 +1,6 @@
#ifndef _ASM_X86_FTRACE_H
#define _ASM_X86_FTRACE_H
-#ifdef __ASSEMBLY__
-
- /* skip is set if the stack was already partially adjusted */
- .macro MCOUNT_SAVE_FRAME skip=0
- /*
- * We add enough stack to save all regs.
- */
- subq $(SS+8-\skip), %rsp
- movq %rax, RAX(%rsp)
- movq %rcx, RCX(%rsp)
- movq %rdx, RDX(%rsp)
- movq %rsi, RSI(%rsp)
- movq %rdi, RDI(%rsp)
- movq %r8, R8(%rsp)
- movq %r9, R9(%rsp)
- /* Move RIP to its proper location */
- movq SS+8(%rsp), %rdx
- movq %rdx, RIP(%rsp)
- .endm
-
- .macro MCOUNT_RESTORE_FRAME skip=0
- movq R9(%rsp), %r9
- movq R8(%rsp), %r8
- movq RDI(%rsp), %rdi
- movq RSI(%rsp), %rsi
- movq RDX(%rsp), %rdx
- movq RCX(%rsp), %rcx
- movq RAX(%rsp), %rax
- addq $(SS+8-\skip), %rsp
- .endm
-
-#endif
-
#ifdef CONFIG_FUNCTION_TRACER
#ifdef CC_USING_FENTRY
# define MCOUNT_ADDR ((long)(__fentry__))
diff --git a/arch/x86/kernel/ftrace.c b/arch/x86/kernel/ftrace.c
index 3386dc9aa333..2142376dc8c6 100644
--- a/arch/x86/kernel/ftrace.c
+++ b/arch/x86/kernel/ftrace.c
@@ -17,6 +17,7 @@
#include <linux/ftrace.h>
#include <linux/percpu.h>
#include <linux/sched.h>
+#include <linux/slab.h>
#include <linux/init.h>
#include <linux/list.h>
#include <linux/module.h>
@@ -47,7 +48,7 @@ int ftrace_arch_code_modify_post_process(void)
union ftrace_code_union {
char code[MCOUNT_INSN_SIZE];
struct {
- char e8;
+ unsigned char e8;
int offset;
} __attribute__((packed));
};
@@ -582,7 +583,7 @@ void ftrace_replace_code(int enable)
remove_breakpoints:
pr_warn("Failed on %s (%d):\n", report, count);
- ftrace_bug(ret, rec ? rec->ip : 0);
+ ftrace_bug(ret, rec);
for_ftrace_rec_iter(iter) {
rec = ftrace_rec_iter_record(iter);
/*
@@ -644,13 +645,8 @@ int __init ftrace_dyn_arch_init(void)
{
return 0;
}
-#endif
-
-#ifdef CONFIG_FUNCTION_GRAPH_TRACER
-
-#ifdef CONFIG_DYNAMIC_FTRACE
-extern void ftrace_graph_call(void);
+#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;
@@ -664,6 +660,280 @@ static unsigned char *ftrace_jmp_replace(unsigned long ip, unsigned long addr)
*/
return calc.code;
}
+#endif
+
+/* Currently only x86_64 supports dynamic trampolines */
+#ifdef CONFIG_X86_64
+
+#ifdef CONFIG_MODULES
+#include <linux/moduleloader.h>
+/* Module allocation simplifies allocating memory for code */
+static inline void *alloc_tramp(unsigned long size)
+{
+ return module_alloc(size);
+}
+static inline void tramp_free(void *tramp)
+{
+ module_free(NULL, tramp);
+}
+#else
+/* Trampolines can only be created if modules are supported */
+static inline void *alloc_tramp(unsigned long size)
+{
+ return NULL;
+}
+static inline void tramp_free(void *tramp) { }
+#endif
+
+/* Defined as markers to the end of the ftrace default trampolines */
+extern void ftrace_caller_end(void);
+extern void ftrace_regs_caller_end(void);
+extern void ftrace_return(void);
+extern void ftrace_caller_op_ptr(void);
+extern void ftrace_regs_caller_op_ptr(void);
+
+/* movq function_trace_op(%rip), %rdx */
+/* 0x48 0x8b 0x15 <offset-to-ftrace_trace_op (4 bytes)> */
+#define OP_REF_SIZE 7
+
+/*
+ * The ftrace_ops is passed to the function callback. Since the
+ * trampoline only services a single ftrace_ops, we can pass in
+ * that ops directly.
+ *
+ * The ftrace_op_code_union is used to create a pointer to the
+ * ftrace_ops that will be passed to the callback function.
+ */
+union ftrace_op_code_union {
+ char code[OP_REF_SIZE];
+ struct {
+ char op[3];
+ int offset;
+ } __attribute__((packed));
+};
+
+static unsigned long
+create_trampoline(struct ftrace_ops *ops, unsigned int *tramp_size)
+{
+ unsigned const char *jmp;
+ unsigned long start_offset;
+ unsigned long end_offset;
+ unsigned long op_offset;
+ unsigned long offset;
+ unsigned long size;
+ unsigned long ip;
+ unsigned long *ptr;
+ void *trampoline;
+ /* 48 8b 15 <offset> is movq <offset>(%rip), %rdx */
+ unsigned const char op_ref[] = { 0x48, 0x8b, 0x15 };
+ union ftrace_op_code_union op_ptr;
+ int ret;
+
+ if (ops->flags & FTRACE_OPS_FL_SAVE_REGS) {
+ start_offset = (unsigned long)ftrace_regs_caller;
+ end_offset = (unsigned long)ftrace_regs_caller_end;
+ op_offset = (unsigned long)ftrace_regs_caller_op_ptr;
+ } else {
+ start_offset = (unsigned long)ftrace_caller;
+ end_offset = (unsigned long)ftrace_caller_end;
+ op_offset = (unsigned long)ftrace_caller_op_ptr;
+ }
+
+ size = end_offset - start_offset;
+
+ /*
+ * Allocate enough size to store the ftrace_caller code,
+ * the jmp to ftrace_return, as well as the address of
+ * the ftrace_ops this trampoline is used for.
+ */
+ trampoline = alloc_tramp(size + MCOUNT_INSN_SIZE + sizeof(void *));
+ if (!trampoline)
+ return 0;
+
+ *tramp_size = size + MCOUNT_INSN_SIZE + sizeof(void *);
+
+ /* Copy ftrace_caller onto the trampoline memory */
+ ret = probe_kernel_read(trampoline, (void *)start_offset, size);
+ if (WARN_ON(ret < 0)) {
+ tramp_free(trampoline);
+ return 0;
+ }
+
+ ip = (unsigned long)trampoline + size;
+
+ /* The trampoline ends with a jmp to ftrace_return */
+ jmp = ftrace_jmp_replace(ip, (unsigned long)ftrace_return);
+ memcpy(trampoline + size, jmp, MCOUNT_INSN_SIZE);
+
+ /*
+ * The address of the ftrace_ops that is used for this trampoline
+ * is stored at the end of the trampoline. This will be used to
+ * load the third parameter for the callback. Basically, that
+ * location at the end of the trampoline takes the place of
+ * the global function_trace_op variable.
+ */
+
+ ptr = (unsigned long *)(trampoline + size + MCOUNT_INSN_SIZE);
+ *ptr = (unsigned long)ops;
+
+ op_offset -= start_offset;
+ memcpy(&op_ptr, trampoline + op_offset, OP_REF_SIZE);
+
+ /* Are we pointing to the reference? */
+ if (WARN_ON(memcmp(op_ptr.op, op_ref, 3) != 0)) {
+ tramp_free(trampoline);
+ return 0;
+ }
+
+ /* Load the contents of ptr into the callback parameter */
+ offset = (unsigned long)ptr;
+ offset -= (unsigned long)trampoline + op_offset + OP_REF_SIZE;
+
+ op_ptr.offset = offset;
+
+ /* put in the new offset to the ftrace_ops */
+ memcpy(trampoline + op_offset, &op_ptr, OP_REF_SIZE);
+
+ /* ALLOC_TRAMP flags lets us know we created it */
+ ops->flags |= FTRACE_OPS_FL_ALLOC_TRAMP;
+
+ return (unsigned long)trampoline;
+}
+
+static unsigned long calc_trampoline_call_offset(bool save_regs)
+{
+ unsigned long start_offset;
+ unsigned long call_offset;
+
+ if (save_regs) {
+ start_offset = (unsigned long)ftrace_regs_caller;
+ call_offset = (unsigned long)ftrace_regs_call;
+ } else {
+ start_offset = (unsigned long)ftrace_caller;
+ call_offset = (unsigned long)ftrace_call;
+ }
+
+ return call_offset - start_offset;
+}
+
+void arch_ftrace_update_trampoline(struct ftrace_ops *ops)
+{
+ ftrace_func_t func;
+ unsigned char *new;
+ unsigned long offset;
+ unsigned long ip;
+ unsigned int size;
+ int ret;
+
+ if (ops->trampoline) {
+ /*
+ * The ftrace_ops caller may set up its own trampoline.
+ * In such a case, this code must not modify it.
+ */
+ if (!(ops->flags & FTRACE_OPS_FL_ALLOC_TRAMP))
+ return;
+ } else {
+ ops->trampoline = create_trampoline(ops, &size);
+ if (!ops->trampoline)
+ return;
+ ops->trampoline_size = size;
+ }
+
+ offset = calc_trampoline_call_offset(ops->flags & FTRACE_OPS_FL_SAVE_REGS);
+ ip = ops->trampoline + offset;
+
+ func = ftrace_ops_get_func(ops);
+
+ /* Do a safe modify in case the trampoline is executing */
+ new = ftrace_call_replace(ip, (unsigned long)func);
+ ret = update_ftrace_func(ip, new);
+
+ /* The update should never fail */
+ WARN_ON(ret);
+}
+
+/* Return the address of the function the trampoline calls */
+static void *addr_from_call(void *ptr)
+{
+ union ftrace_code_union calc;
+ int ret;
+
+ ret = probe_kernel_read(&calc, ptr, MCOUNT_INSN_SIZE);
+ if (WARN_ON_ONCE(ret < 0))
+ return NULL;
+
+ /* Make sure this is a call */
+ if (WARN_ON_ONCE(calc.e8 != 0xe8)) {
+ pr_warn("Expected e8, got %x\n", calc.e8);
+ return NULL;
+ }
+
+ return ptr + MCOUNT_INSN_SIZE + calc.offset;
+}
+
+void prepare_ftrace_return(unsigned long self_addr, unsigned long *parent,
+ unsigned long frame_pointer);
+
+/*
+ * If the ops->trampoline was not allocated, then it probably
+ * has a static trampoline func, or is the ftrace caller itself.
+ */
+static void *static_tramp_func(struct ftrace_ops *ops, struct dyn_ftrace *rec)
+{
+ unsigned long offset;
+ bool save_regs = rec->flags & FTRACE_FL_REGS_EN;
+ void *ptr;
+
+ if (ops && ops->trampoline) {
+#ifdef CONFIG_FUNCTION_GRAPH_TRACER
+ /*
+ * We only know about function graph tracer setting as static
+ * trampoline.
+ */
+ if (ops->trampoline == FTRACE_GRAPH_ADDR)
+ return (void *)prepare_ftrace_return;
+#endif
+ return NULL;
+ }
+
+ offset = calc_trampoline_call_offset(save_regs);
+
+ if (save_regs)
+ ptr = (void *)FTRACE_REGS_ADDR + offset;
+ else
+ ptr = (void *)FTRACE_ADDR + offset;
+
+ return addr_from_call(ptr);
+}
+
+void *arch_ftrace_trampoline_func(struct ftrace_ops *ops, struct dyn_ftrace *rec)
+{
+ unsigned long offset;
+
+ /* If we didn't allocate this trampoline, consider it static */
+ if (!ops || !(ops->flags & FTRACE_OPS_FL_ALLOC_TRAMP))
+ return static_tramp_func(ops, rec);
+
+ offset = calc_trampoline_call_offset(ops->flags & FTRACE_OPS_FL_SAVE_REGS);
+ return addr_from_call((void *)ops->trampoline + offset);
+}
+
+void arch_ftrace_trampoline_free(struct ftrace_ops *ops)
+{
+ if (!ops || !(ops->flags & FTRACE_OPS_FL_ALLOC_TRAMP))
+ return;
+
+ tramp_free((void *)ops->trampoline);
+ ops->trampoline = 0;
+}
+
+#endif /* CONFIG_X86_64 */
+#endif /* CONFIG_DYNAMIC_FTRACE */
+
+#ifdef CONFIG_FUNCTION_GRAPH_TRACER
+
+#ifdef CONFIG_DYNAMIC_FTRACE
+extern void ftrace_graph_call(void);
static int ftrace_mod_jmp(unsigned long ip, void *func)
{
@@ -694,7 +964,7 @@ int ftrace_disable_ftrace_graph_caller(void)
* Hook the return address and push it in the stack of return addrs
* in current thread info.
*/
-void prepare_ftrace_return(unsigned long *parent, unsigned long self_addr,
+void prepare_ftrace_return(unsigned long self_addr, unsigned long *parent,
unsigned long frame_pointer)
{
unsigned long old;
diff --git a/arch/x86/kernel/kprobes/ftrace.c b/arch/x86/kernel/kprobes/ftrace.c
index 717b02a22e67..5f8f0b3cc674 100644
--- a/arch/x86/kernel/kprobes/ftrace.c
+++ b/arch/x86/kernel/kprobes/ftrace.c
@@ -27,7 +27,7 @@
static nokprobe_inline
int __skip_singlestep(struct kprobe *p, struct pt_regs *regs,
- struct kprobe_ctlblk *kcb)
+ struct kprobe_ctlblk *kcb, unsigned long orig_ip)
{
/*
* Emulate singlestep (and also recover regs->ip)
@@ -39,6 +39,8 @@ int __skip_singlestep(struct kprobe *p, struct pt_regs *regs,
p->post_handler(p, regs, 0);
}
__this_cpu_write(current_kprobe, NULL);
+ if (orig_ip)
+ regs->ip = orig_ip;
return 1;
}
@@ -46,7 +48,7 @@ int skip_singlestep(struct kprobe *p, struct pt_regs *regs,
struct kprobe_ctlblk *kcb)
{
if (kprobe_ftrace(p))
- return __skip_singlestep(p, regs, kcb);
+ return __skip_singlestep(p, regs, kcb, 0);
else
return 0;
}
@@ -71,13 +73,14 @@ void kprobe_ftrace_handler(unsigned long ip, unsigned long parent_ip,
if (kprobe_running()) {
kprobes_inc_nmissed_count(p);
} else {
+ unsigned long orig_ip = regs->ip;
/* Kprobe handler expects regs->ip = ip + 1 as breakpoint hit */
regs->ip = ip + sizeof(kprobe_opcode_t);
__this_cpu_write(current_kprobe, p);
kcb->kprobe_status = KPROBE_HIT_ACTIVE;
if (!p->pre_handler || !p->pre_handler(p, regs))
- __skip_singlestep(p, regs, kcb);
+ __skip_singlestep(p, regs, kcb, orig_ip);
/*
* If pre_handler returns !0, it sets regs->ip and
* resets current kprobe.
diff --git a/arch/x86/kernel/mcount_64.S b/arch/x86/kernel/mcount_64.S
index c73aecf10d34..94ea120fa21f 100644
--- a/arch/x86/kernel/mcount_64.S
+++ b/arch/x86/kernel/mcount_64.S
@@ -21,40 +21,159 @@
# define function_hook mcount
#endif
+/* All cases save the original rbp (8 bytes) */
+#ifdef CONFIG_FRAME_POINTER
+# ifdef CC_USING_FENTRY
+/* Save parent and function stack frames (rip and rbp) */
+# define MCOUNT_FRAME_SIZE (8+16*2)
+# else
+/* Save just function stack frame (rip and rbp) */
+# define MCOUNT_FRAME_SIZE (8+16)
+# endif
+#else
+/* No need to save a stack frame */
+# define MCOUNT_FRAME_SIZE 8
+#endif /* CONFIG_FRAME_POINTER */
+
+/* Size of stack used to save mcount regs in save_mcount_regs */
+#define MCOUNT_REG_SIZE (SS+8 + MCOUNT_FRAME_SIZE)
+
+/*
+ * gcc -pg option adds a call to 'mcount' in most functions.
+ * When -mfentry is used, the call is to 'fentry' and not 'mcount'
+ * and is done before the function's stack frame is set up.
+ * They both require a set of regs to be saved before calling
+ * any C code and restored before returning back to the function.
+ *
+ * On boot up, all these calls are converted into nops. When tracing
+ * is enabled, the call can jump to either ftrace_caller or
+ * ftrace_regs_caller. Callbacks (tracing functions) that require
+ * ftrace_regs_caller (like kprobes) need to have pt_regs passed to
+ * it. For this reason, the size of the pt_regs structure will be
+ * allocated on the stack and the required mcount registers will
+ * be saved in the locations that pt_regs has them in.
+ */
+
+/*
+ * @added: the amount of stack added before calling this
+ *
+ * After this is called, the following registers contain:
+ *
+ * %rdi - holds the address that called the trampoline
+ * %rsi - holds the parent function (traced function's return address)
+ * %rdx - holds the original %rbp
+ */
+.macro save_mcount_regs added=0
+
+ /* Always save the original rbp */
+ pushq %rbp
+
+#ifdef CONFIG_FRAME_POINTER
+ /*
+ * Stack traces will stop at the ftrace trampoline if the frame pointer
+ * is not set up properly. If fentry is used, we need to save a frame
+ * pointer for the parent as well as the function traced, because the
+ * fentry is called before the stack frame is set up, where as mcount
+ * is called afterward.
+ */
+#ifdef CC_USING_FENTRY
+ /* Save the parent pointer (skip orig rbp and our return address) */
+ pushq \added+8*2(%rsp)
+ pushq %rbp
+ movq %rsp, %rbp
+ /* Save the return address (now skip orig rbp, rbp and parent) */
+ pushq \added+8*3(%rsp)
+#else
+ /* Can't assume that rip is before this (unless added was zero) */
+ pushq \added+8(%rsp)
+#endif
+ pushq %rbp
+ movq %rsp, %rbp
+#endif /* CONFIG_FRAME_POINTER */
+
+ /*
+ * We add enough stack to save all regs.
+ */
+ subq $(MCOUNT_REG_SIZE - MCOUNT_FRAME_SIZE), %rsp
+ movq %rax, RAX(%rsp)
+ movq %rcx, RCX(%rsp)
+ movq %rdx, RDX(%rsp)
+ movq %rsi, RSI(%rsp)
+ movq %rdi, RDI(%rsp)
+ movq %r8, R8(%rsp)
+ movq %r9, R9(%rsp)
+ /*
+ * Save the original RBP. Even though the mcount ABI does not
+ * require this, it helps out callers.
+ */
+ movq MCOUNT_REG_SIZE-8(%rsp), %rdx
+ movq %rdx, RBP(%rsp)
+
+ /* Copy the parent address into %rsi (second parameter) */
+#ifdef CC_USING_FENTRY
+ movq MCOUNT_REG_SIZE+8+\added(%rsp), %rsi
+#else
+ /* %rdx contains original %rbp */
+ movq 8(%rdx), %rsi
+#endif
+
+ /* Move RIP to its proper location */
+ movq MCOUNT_REG_SIZE+\added(%rsp), %rdi
+ movq %rdi, RIP(%rsp)
+
+ /*
+ * Now %rdi (the first parameter) has the return address of
+ * where ftrace_call returns. But the callbacks expect the
+ * address of the call itself.
+ */
+ subq $MCOUNT_INSN_SIZE, %rdi
+ .endm
+
+.macro restore_mcount_regs
+ movq R9(%rsp), %r9
+ movq R8(%rsp), %r8
+ movq RDI(%rsp), %rdi
+ movq RSI(%rsp), %rsi
+ movq RDX(%rsp), %rdx
+ movq RCX(%rsp), %rcx
+ movq RAX(%rsp), %rax
+
+ /* ftrace_regs_caller can modify %rbp */
+ movq RBP(%rsp), %rbp
+
+ addq $MCOUNT_REG_SIZE, %rsp
+
+ .endm
+
#ifdef CONFIG_DYNAMIC_FTRACE
ENTRY(function_hook)
retq
END(function_hook)
-/* skip is set if stack has been adjusted */
-.macro ftrace_caller_setup skip=0
- MCOUNT_SAVE_FRAME \skip
+ENTRY(ftrace_caller)
+ /* save_mcount_regs fills in first two parameters */
+ save_mcount_regs
+GLOBAL(ftrace_caller_op_ptr)
/* Load the ftrace_ops into the 3rd parameter */
movq function_trace_op(%rip), %rdx
- /* Load ip into the first parameter */
- movq RIP(%rsp), %rdi
- subq $MCOUNT_INSN_SIZE, %rdi
- /* Load the parent_ip into the second parameter */
-#ifdef CC_USING_FENTRY
- movq SS+16(%rsp), %rsi
-#else
- movq 8(%rbp), %rsi
-#endif
-.endm
-
-ENTRY(ftrace_caller)
- ftrace_caller_setup
/* regs go into 4th parameter (but make it NULL) */
movq $0, %rcx
GLOBAL(ftrace_call)
call ftrace_stub
- MCOUNT_RESTORE_FRAME
-ftrace_return:
+ restore_mcount_regs
+
+ /*
+ * The copied trampoline must call ftrace_return as it
+ * still may need to call the function graph tracer.
+ */
+GLOBAL(ftrace_caller_end)
+
+GLOBAL(ftrace_return)
#ifdef CONFIG_FUNCTION_GRAPH_TRACER
GLOBAL(ftrace_graph_call)
@@ -66,11 +185,16 @@ GLOBAL(ftrace_stub)
END(ftrace_caller)
ENTRY(ftrace_regs_caller)
- /* Save the current flags before compare (in SS location)*/
+ /* Save the current flags before any operations that can change them */
pushfq
- /* skip=8 to skip flags saved in SS */
- ftrace_caller_setup 8
+ /* added 8 bytes to save flags */
+ save_mcount_regs 8
+ /* save_mcount_regs fills in first two parameters */
+
+GLOBAL(ftrace_regs_caller_op_ptr)
+ /* Load the ftrace_ops into the 3rd parameter */
+ movq function_trace_op(%rip), %rdx
/* Save the rest of pt_regs */
movq %r15, R15(%rsp)
@@ -79,18 +203,17 @@ ENTRY(ftrace_regs_caller)
movq %r12, R12(%rsp)
movq %r11, R11(%rsp)
movq %r10, R10(%rsp)
- movq %rbp, RBP(%rsp)
movq %rbx, RBX(%rsp)
/* Copy saved flags */
- movq SS(%rsp), %rcx
+ movq MCOUNT_REG_SIZE(%rsp), %rcx
movq %rcx, EFLAGS(%rsp)
/* Kernel segments */
movq $__KERNEL_DS, %rcx
movq %rcx, SS(%rsp)
movq $__KERNEL_CS, %rcx
movq %rcx, CS(%rsp)
- /* Stack - skipping return address */
- leaq SS+16(%rsp), %rcx
+ /* Stack - skipping return address and flags */
+ leaq MCOUNT_REG_SIZE+8*2(%rsp), %rcx
movq %rcx, RSP(%rsp)
/* regs go into 4th parameter */
@@ -101,11 +224,11 @@ GLOBAL(ftrace_regs_call)
/* Copy flags back to SS, to restore them */
movq EFLAGS(%rsp), %rax
- movq %rax, SS(%rsp)
+ movq %rax, MCOUNT_REG_SIZE(%rsp)
/* Handlers can change the RIP */
movq RIP(%rsp), %rax
- movq %rax, SS+8(%rsp)
+ movq %rax, MCOUNT_REG_SIZE+8(%rsp)
/* restore the rest of pt_regs */
movq R15(%rsp), %r15
@@ -113,19 +236,22 @@ GLOBAL(ftrace_regs_call)
movq R13(%rsp), %r13
movq R12(%rsp), %r12
movq R10(%rsp), %r10
- movq RBP(%rsp), %rbp
movq RBX(%rsp), %rbx
- /* skip=8 to skip flags saved in SS */
- MCOUNT_RESTORE_FRAME 8
+ restore_mcount_regs
/* Restore flags */
popfq
- jmp ftrace_return
+ /*
+ * As this jmp to ftrace_return can be a short jump
+ * it must not be copied into the trampoline.
+ * The trampoline will add the code to jump
+ * to the return.
+ */
+GLOBAL(ftrace_regs_caller_end)
- popfq
- jmp ftrace_stub
+ jmp ftrace_return
END(ftrace_regs_caller)
@@ -136,6 +262,7 @@ ENTRY(function_hook)
cmpq $ftrace_stub, ftrace_trace_function
jnz trace
+fgraph_trace:
#ifdef CONFIG_FUNCTION_GRAPH_TRACER
cmpq $ftrace_stub, ftrace_graph_return
jnz ftrace_graph_caller
@@ -148,42 +275,35 @@ GLOBAL(ftrace_stub)
retq
trace:
- MCOUNT_SAVE_FRAME
-
- movq RIP(%rsp), %rdi
-#ifdef CC_USING_FENTRY
- movq SS+16(%rsp), %rsi
-#else
- movq 8(%rbp), %rsi
-#endif
- subq $MCOUNT_INSN_SIZE, %rdi
+ /* save_mcount_regs fills in first two parameters */
+ save_mcount_regs
call *ftrace_trace_function
- MCOUNT_RESTORE_FRAME
+ restore_mcount_regs
- jmp ftrace_stub
+ jmp fgraph_trace
END(function_hook)
#endif /* CONFIG_DYNAMIC_FTRACE */
#endif /* CONFIG_FUNCTION_TRACER */
#ifdef CONFIG_FUNCTION_GRAPH_TRACER
ENTRY(ftrace_graph_caller)
- MCOUNT_SAVE_FRAME
+ /* Saves rbp into %rdx and fills first parameter */
+ save_mcount_regs
#ifdef CC_USING_FENTRY
- leaq SS+16(%rsp), %rdi
+ leaq MCOUNT_REG_SIZE+8(%rsp), %rsi
movq $0, %rdx /* No framepointers needed */
#else
- leaq 8(%rbp), %rdi
- movq (%rbp), %rdx
+ /* Save address of the return address of traced function */
+ leaq 8(%rdx), %rsi
+ /* ftrace does sanity checks against frame pointers */
+ movq (%rdx), %rdx
#endif
- movq RIP(%rsp), %rsi
- subq $MCOUNT_INSN_SIZE, %rsi
-
call prepare_ftrace_return
- MCOUNT_RESTORE_FRAME
+ restore_mcount_regs
retq
END(ftrace_graph_caller)
diff --git a/arch/x86/kvm/mmutrace.h b/arch/x86/kvm/mmutrace.h
index 5aaf35641768..ce463a9cc8fb 100644
--- a/arch/x86/kvm/mmutrace.h
+++ b/arch/x86/kvm/mmutrace.h
@@ -22,7 +22,7 @@
__entry->unsync = sp->unsync;
#define KVM_MMU_PAGE_PRINTK() ({ \
- const u32 saved_len = p->len; \
+ const char *saved_ptr = trace_seq_buffer_ptr(p); \
static const char *access_str[] = { \
"---", "--x", "w--", "w-x", "-u-", "-ux", "wu-", "wux" \
}; \
@@ -41,7 +41,7 @@
role.nxe ? "" : "!", \
__entry->root_count, \
__entry->unsync ? "unsync" : "sync", 0); \
- p->buffer + saved_len; \
+ saved_ptr; \
})
#define kvm_mmu_trace_pferr_flags \

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