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Diffstat (limited to 'arch/sh/kernel/ftrace.c')
-rw-r--r--arch/sh/kernel/ftrace.c265
1 files changed, 235 insertions, 30 deletions
diff --git a/arch/sh/kernel/ftrace.c b/arch/sh/kernel/ftrace.c
index 4c3247477aa3..2c48e267256e 100644
--- a/arch/sh/kernel/ftrace.c
+++ b/arch/sh/kernel/ftrace.c
@@ -1,5 +1,5 @@
/*
- * Copyright (C) 2008 Matt Fleming <mjf@gentoo.org>
+ * Copyright (C) 2008 Matt Fleming <matt@console-pimps.org>
* Copyright (C) 2008 Paul Mundt <lethal@linux-sh.org>
*
* Code for replacing ftrace calls with jumps.
@@ -16,33 +16,44 @@
#include <linux/string.h>
#include <linux/init.h>
#include <linux/io.h>
+#include <linux/kernel.h>
#include <asm/ftrace.h>
#include <asm/cacheflush.h>
+#include <asm/unistd.h>
+#include <trace/syscall.h>
-static unsigned char ftrace_nop[] = {
- 0x09, 0x00, /* nop */
- 0x09, 0x00, /* nop */
-};
-
+#ifdef CONFIG_DYNAMIC_FTRACE
static unsigned char ftrace_replaced_code[MCOUNT_INSN_SIZE];
-unsigned char *ftrace_nop_replace(void)
+static unsigned char ftrace_nop[4];
+/*
+ * If we're trying to nop out a call to a function, we instead
+ * place a call to the address after the memory table.
+ *
+ * 8c011060 <a>:
+ * 8c011060: 02 d1 mov.l 8c01106c <a+0xc>,r1
+ * 8c011062: 22 4f sts.l pr,@-r15
+ * 8c011064: 02 c7 mova 8c011070 <a+0x10>,r0
+ * 8c011066: 2b 41 jmp @r1
+ * 8c011068: 2a 40 lds r0,pr
+ * 8c01106a: 09 00 nop
+ * 8c01106c: 68 24 .word 0x2468 <--- ip
+ * 8c01106e: 1d 8c .word 0x8c1d
+ * 8c011070: 26 4f lds.l @r15+,pr <--- ip + MCOUNT_INSN_SIZE
+ *
+ * We write 0x8c011070 to 0x8c01106c so that on entry to a() we branch
+ * past the _mcount call and continue executing code like normal.
+ */
+static unsigned char *ftrace_nop_replace(unsigned long ip)
{
+ __raw_writel(ip + MCOUNT_INSN_SIZE, ftrace_nop);
return ftrace_nop;
}
-static int is_sh_nop(unsigned char *ip)
-{
- return strncmp(ip, ftrace_nop, sizeof(ftrace_nop));
-}
-
-unsigned char *ftrace_call_replace(unsigned long ip, unsigned long addr)
+static unsigned char *ftrace_call_replace(unsigned long ip, unsigned long addr)
{
/* Place the address in the memory table. */
- if (addr == CALLER_ADDR)
- __raw_writel(addr + MCOUNT_INSN_OFFSET, ftrace_replaced_code);
- else
- __raw_writel(addr, ftrace_replaced_code);
+ __raw_writel(addr, ftrace_replaced_code);
/*
* No locking needed, this must be called via kstop_machine
@@ -51,7 +62,7 @@ unsigned char *ftrace_call_replace(unsigned long ip, unsigned long addr)
return ftrace_replaced_code;
}
-int ftrace_modify_code(unsigned long ip, unsigned char *old_code,
+static int ftrace_modify_code(unsigned long ip, unsigned char *old_code,
unsigned char *new_code)
{
unsigned char replaced[MCOUNT_INSN_SIZE];
@@ -66,13 +77,6 @@ int ftrace_modify_code(unsigned long ip, unsigned char *old_code,
* kstop_machine, or before SMP starts.
*/
- /*
- * If we're trying to nop out a call to a function, we instead
- * place a call to the address after the memory table.
- */
- if (is_sh_nop(new_code) == 0)
- __raw_writel(ip + MCOUNT_INSN_SIZE, (unsigned long)new_code);
-
/* read the text we want to modify */
if (probe_kernel_read(replaced, (void *)ip, MCOUNT_INSN_SIZE))
return -EFAULT;
@@ -92,13 +96,13 @@ int ftrace_modify_code(unsigned long ip, unsigned char *old_code,
int ftrace_update_ftrace_func(ftrace_func_t func)
{
- unsigned long ip = (unsigned long)(&ftrace_call);
+ unsigned long ip = (unsigned long)(&ftrace_call) + MCOUNT_INSN_OFFSET;
unsigned char old[MCOUNT_INSN_SIZE], *new;
- memcpy(old, (unsigned char *)(ip + MCOUNT_INSN_OFFSET), MCOUNT_INSN_SIZE);
+ memcpy(old, (unsigned char *)ip, MCOUNT_INSN_SIZE);
new = ftrace_call_replace(ip, (unsigned long)func);
- return ftrace_modify_code(ip + MCOUNT_INSN_OFFSET, old, new);
+ return ftrace_modify_code(ip, old, new);
}
int ftrace_make_nop(struct module *mod,
@@ -108,7 +112,7 @@ int ftrace_make_nop(struct module *mod,
unsigned long ip = rec->ip;
old = ftrace_call_replace(ip, addr);
- new = ftrace_nop_replace();
+ new = ftrace_nop_replace(ip);
return ftrace_modify_code(rec->ip, old, new);
}
@@ -118,7 +122,7 @@ int ftrace_make_call(struct dyn_ftrace *rec, unsigned long addr)
unsigned char *new, *old;
unsigned long ip = rec->ip;
- old = ftrace_nop_replace();
+ old = ftrace_nop_replace(ip);
new = ftrace_call_replace(ip, addr);
return ftrace_modify_code(rec->ip, old, new);
@@ -131,3 +135,204 @@ int __init ftrace_dyn_arch_init(void *data)
return 0;
}
+#endif /* CONFIG_DYNAMIC_FTRACE */
+
+#ifdef CONFIG_FUNCTION_GRAPH_TRACER
+#ifdef CONFIG_DYNAMIC_FTRACE
+extern void ftrace_graph_call(void);
+
+static int ftrace_mod(unsigned long ip, unsigned long old_addr,
+ unsigned long new_addr)
+{
+ unsigned char code[MCOUNT_INSN_SIZE];
+
+ if (probe_kernel_read(code, (void *)ip, MCOUNT_INSN_SIZE))
+ return -EFAULT;
+
+ if (old_addr != __raw_readl((unsigned long *)code))
+ return -EINVAL;
+
+ __raw_writel(new_addr, ip);
+ return 0;
+}
+
+int ftrace_enable_ftrace_graph_caller(void)
+{
+ unsigned long ip, old_addr, new_addr;
+
+ ip = (unsigned long)(&ftrace_graph_call) + GRAPH_INSN_OFFSET;
+ old_addr = (unsigned long)(&skip_trace);
+ new_addr = (unsigned long)(&ftrace_graph_caller);
+
+ return ftrace_mod(ip, old_addr, new_addr);
+}
+
+int ftrace_disable_ftrace_graph_caller(void)
+{
+ unsigned long ip, old_addr, new_addr;
+
+ ip = (unsigned long)(&ftrace_graph_call) + GRAPH_INSN_OFFSET;
+ old_addr = (unsigned long)(&ftrace_graph_caller);
+ new_addr = (unsigned long)(&skip_trace);
+
+ return ftrace_mod(ip, old_addr, new_addr);
+}
+#endif /* CONFIG_DYNAMIC_FTRACE */
+
+/*
+ * Hook the return address and push it in the stack of return addrs
+ * in the current thread info.
+ *
+ * This is the main routine for the function graph tracer. The function
+ * graph tracer essentially works like this:
+ *
+ * parent is the stack address containing self_addr's return address.
+ * We pull the real return address out of parent and store it in
+ * current's ret_stack. Then, we replace the return address on the stack
+ * with the address of return_to_handler. self_addr is the function that
+ * called mcount.
+ *
+ * When self_addr returns, it will jump to return_to_handler which calls
+ * ftrace_return_to_handler. ftrace_return_to_handler will pull the real
+ * return address off of current's ret_stack and jump to it.
+ */
+void prepare_ftrace_return(unsigned long *parent, unsigned long self_addr)
+{
+ unsigned long old;
+ int faulted, err;
+ struct ftrace_graph_ent trace;
+ unsigned long return_hooker = (unsigned long)&return_to_handler;
+
+ if (unlikely(atomic_read(&current->tracing_graph_pause)))
+ return;
+
+ /*
+ * Protect against fault, even if it shouldn't
+ * happen. This tool is too much intrusive to
+ * ignore such a protection.
+ */
+ __asm__ __volatile__(
+ "1: \n\t"
+ "mov.l @%2, %0 \n\t"
+ "2: \n\t"
+ "mov.l %3, @%2 \n\t"
+ "mov #0, %1 \n\t"
+ "3: \n\t"
+ ".section .fixup, \"ax\" \n\t"
+ "4: \n\t"
+ "mov.l 5f, %0 \n\t"
+ "jmp @%0 \n\t"
+ " mov #1, %1 \n\t"
+ ".balign 4 \n\t"
+ "5: .long 3b \n\t"
+ ".previous \n\t"
+ ".section __ex_table,\"a\" \n\t"
+ ".long 1b, 4b \n\t"
+ ".long 2b, 4b \n\t"
+ ".previous \n\t"
+ : "=&r" (old), "=r" (faulted)
+ : "r" (parent), "r" (return_hooker)
+ );
+
+ if (unlikely(faulted)) {
+ ftrace_graph_stop();
+ WARN_ON(1);
+ return;
+ }
+
+ err = ftrace_push_return_trace(old, self_addr, &trace.depth, 0);
+ if (err == -EBUSY) {
+ __raw_writel(old, parent);
+ return;
+ }
+
+ trace.func = self_addr;
+
+ /* Only trace if the calling function expects to */
+ if (!ftrace_graph_entry(&trace)) {
+ current->curr_ret_stack--;
+ __raw_writel(old, parent);
+ }
+}
+#endif /* CONFIG_FUNCTION_GRAPH_TRACER */
+
+#ifdef CONFIG_FTRACE_SYSCALLS
+
+extern unsigned long __start_syscalls_metadata[];
+extern unsigned long __stop_syscalls_metadata[];
+extern unsigned long *sys_call_table;
+
+static struct syscall_metadata **syscalls_metadata;
+
+static struct syscall_metadata *find_syscall_meta(unsigned long *syscall)
+{
+ struct syscall_metadata *start;
+ struct syscall_metadata *stop;
+ char str[KSYM_SYMBOL_LEN];
+
+
+ start = (struct syscall_metadata *)__start_syscalls_metadata;
+ stop = (struct syscall_metadata *)__stop_syscalls_metadata;
+ kallsyms_lookup((unsigned long) syscall, NULL, NULL, NULL, str);
+
+ for ( ; start < stop; start++) {
+ if (start->name && !strcmp(start->name, str))
+ return start;
+ }
+
+ return NULL;
+}
+
+struct syscall_metadata *syscall_nr_to_meta(int nr)
+{
+ if (!syscalls_metadata || nr >= FTRACE_SYSCALL_MAX || nr < 0)
+ return NULL;
+
+ 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 int __init arch_init_ftrace_syscalls(void)
+{
+ int i;
+ struct syscall_metadata *meta;
+ unsigned long **psys_syscall_table = &sys_call_table;
+
+ syscalls_metadata = kzalloc(sizeof(*syscalls_metadata) *
+ FTRACE_SYSCALL_MAX, GFP_KERNEL);
+ if (!syscalls_metadata) {
+ WARN_ON(1);
+ return -ENOMEM;
+ }
+
+ for (i = 0; i < FTRACE_SYSCALL_MAX; i++) {
+ meta = find_syscall_meta(psys_syscall_table[i]);
+ syscalls_metadata[i] = meta;
+ }
+
+ return 0;
+}
+arch_initcall(arch_init_ftrace_syscalls);
+#endif /* CONFIG_FTRACE_SYSCALLS */
generated by cgit v1.2.3 (git 2.39.0) at 2024-11-27 11:45:03 +0300