tracing/probes: Implement 'stack' fetch method for uprobes
Use separate method to fetch from stack. Move existing functions to
trace_kprobe.c and make them static. Also add new stack fetch
implementation for uprobes.
Acked-by: Oleg Nesterov <oleg@redhat.com>
Cc: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Cc: Srikar Dronamraju <srikar@linux.vnet.ibm.com>
Cc: zhangwei(Jovi) <jovi.zhangwei@huawei.com>
Cc: Arnaldo Carvalho de Melo <acme@ghostprotocols.net>
Signed-off-by: Namhyung Kim <namhyung@kernel.org>
diff --git a/kernel/trace/trace_uprobe.c b/kernel/trace/trace_uprobe.c
index 2c60925..5395d37 100644
--- a/kernel/trace/trace_uprobe.c
+++ b/kernel/trace/trace_uprobe.c
@@ -74,6 +74,47 @@
static int uretprobe_dispatcher(struct uprobe_consumer *con,
unsigned long func, struct pt_regs *regs);
+#ifdef CONFIG_STACK_GROWSUP
+static unsigned long adjust_stack_addr(unsigned long addr, unsigned int n)
+{
+ return addr - (n * sizeof(long));
+}
+#else
+static unsigned long adjust_stack_addr(unsigned long addr, unsigned int n)
+{
+ return addr + (n * sizeof(long));
+}
+#endif
+
+static unsigned long get_user_stack_nth(struct pt_regs *regs, unsigned int n)
+{
+ unsigned long ret;
+ unsigned long addr = user_stack_pointer(regs);
+
+ addr = adjust_stack_addr(addr, n);
+
+ if (copy_from_user(&ret, (void __force __user *) addr, sizeof(ret)))
+ return 0;
+
+ return ret;
+}
+
+/*
+ * Uprobes-specific fetch functions
+ */
+#define DEFINE_FETCH_stack(type) \
+static __kprobes void FETCH_FUNC_NAME(stack, type)(struct pt_regs *regs,\
+ void *offset, void *dest) \
+{ \
+ *(type *)dest = (type)get_user_stack_nth(regs, \
+ ((unsigned long)offset)); \
+}
+DEFINE_BASIC_FETCH_FUNCS(stack)
+/* No string on the stack entry */
+#define fetch_stack_string NULL
+#define fetch_stack_string_size NULL
+
+
/* Fetch type information table */
const struct fetch_type uprobes_fetch_type_table[] = {
/* Special types */