#include <linux/filter.h>
#include <linux/ftrace.h>
#include <linux/kprobes.h>
+#include <linux/build_bug.h>
#include <linux/compiler.h>
+#include <linux/module.h>
+#include <linux/kernel.h>
/*
* These will be re-linked against their real values
get_symbol_pos(addr, symbolsize, offset);
return 1;
}
- return !!module_address_lookup(addr, symbolsize, offset, NULL, namebuf) ||
+ return !!module_address_lookup(addr, symbolsize, offset, NULL, NULL, namebuf) ||
!!__bpf_address_lookup(addr, symbolsize, offset, namebuf);
}
-/*
- * Lookup an address
- * - modname is set to NULL if it's in the kernel.
- * - We guarantee that the returned name is valid until we reschedule even if.
- * It resides in a module.
- * - We also guarantee that modname will be valid until rescheduled.
- */
-const char *kallsyms_lookup(unsigned long addr,
- unsigned long *symbolsize,
- unsigned long *offset,
- char **modname, char *namebuf)
+static const char *kallsyms_lookup_buildid(unsigned long addr,
+ unsigned long *symbolsize,
+ unsigned long *offset, char **modname,
+ const unsigned char **modbuildid, char *namebuf)
{
const char *ret;
namebuf, KSYM_NAME_LEN);
if (modname)
*modname = NULL;
+ if (modbuildid)
+ *modbuildid = NULL;
ret = namebuf;
goto found;
/* See if it's in a module or a BPF JITed image. */
ret = module_address_lookup(addr, symbolsize, offset,
- modname, namebuf);
+ modname, modbuildid, namebuf);
if (!ret)
ret = bpf_address_lookup(addr, symbolsize,
offset, modname, namebuf);
return ret;
}
+/*
+ * Lookup an address
+ * - modname is set to NULL if it's in the kernel.
+ * - We guarantee that the returned name is valid until we reschedule even if.
+ * It resides in a module.
+ * - We also guarantee that modname will be valid until rescheduled.
+ */
+const char *kallsyms_lookup(unsigned long addr,
+ unsigned long *symbolsize,
+ unsigned long *offset,
+ char **modname, char *namebuf)
+{
+ return kallsyms_lookup_buildid(addr, symbolsize, offset, modname,
+ NULL, namebuf);
+}
+
int lookup_symbol_name(unsigned long addr, char *symname)
{
int res;
/* Look up a kernel symbol and return it in a text buffer. */
static int __sprint_symbol(char *buffer, unsigned long address,
- int symbol_offset, int add_offset)
+ int symbol_offset, int add_offset, int add_buildid)
{
char *modname;
+ const unsigned char *buildid;
const char *name;
unsigned long offset, size;
int len;
address += symbol_offset;
- name = kallsyms_lookup(address, &size, &offset, &modname, buffer);
+ name = kallsyms_lookup_buildid(address, &size, &offset, &modname, &buildid,
+ buffer);
if (!name)
return sprintf(buffer, "0x%lx", address - symbol_offset);
if (add_offset)
len += sprintf(buffer + len, "+%#lx/%#lx", offset, size);
- if (modname)
- len += sprintf(buffer + len, " [%s]", modname);
+ if (modname) {
+ len += sprintf(buffer + len, " [%s", modname);
+#if IS_ENABLED(CONFIG_STACKTRACE_BUILD_ID)
+ if (add_buildid && buildid) {
+ /* build ID should match length of sprintf */
+#if IS_ENABLED(CONFIG_MODULES)
+ static_assert(sizeof(typeof_member(struct module, build_id)) == 20);
+#endif
+ len += sprintf(buffer + len, " %20phN", buildid);
+ }
+#endif
+ len += sprintf(buffer + len, "]");
+ }
return len;
}
*/
int sprint_symbol(char *buffer, unsigned long address)
{
- return __sprint_symbol(buffer, address, 0, 1);
+ return __sprint_symbol(buffer, address, 0, 1, 0);
}
EXPORT_SYMBOL_GPL(sprint_symbol);
+/**
+ * sprint_symbol_build_id - Look up a kernel symbol and return it in a text buffer
+ * @buffer: buffer to be stored
+ * @address: address to lookup
+ *
+ * This function looks up a kernel symbol with @address and stores its name,
+ * offset, size, module name and module build ID to @buffer if possible. If no
+ * symbol was found, just saves its @address as is.
+ *
+ * This function returns the number of bytes stored in @buffer.
+ */
+int sprint_symbol_build_id(char *buffer, unsigned long address)
+{
+ return __sprint_symbol(buffer, address, 0, 1, 1);
+}
+EXPORT_SYMBOL_GPL(sprint_symbol_build_id);
+
/**
* sprint_symbol_no_offset - Look up a kernel symbol and return it in a text buffer
* @buffer: buffer to be stored
*/
int sprint_symbol_no_offset(char *buffer, unsigned long address)
{
- return __sprint_symbol(buffer, address, 0, 0);
+ return __sprint_symbol(buffer, address, 0, 0, 0);
}
EXPORT_SYMBOL_GPL(sprint_symbol_no_offset);
*/
int sprint_backtrace(char *buffer, unsigned long address)
{
- return __sprint_symbol(buffer, address, -1, 1);
+ return __sprint_symbol(buffer, address, -1, 1, 0);
+}
+
+/**
+ * sprint_backtrace_build_id - Look up a backtrace symbol and return it in a text buffer
+ * @buffer: buffer to be stored
+ * @address: address to lookup
+ *
+ * This function is for stack backtrace and does the same thing as
+ * sprint_symbol() but with modified/decreased @address. If there is a
+ * tail-call to the function marked "noreturn", gcc optimized out code after
+ * the call so that the stack-saved return address could point outside of the
+ * caller. This function ensures that kallsyms will find the original caller
+ * by decreasing @address. This function also appends the module build ID to
+ * the @buffer if @address is within a kernel module.
+ *
+ * This function returns the number of bytes stored in @buffer.
+ */
+int sprint_backtrace_build_id(char *buffer, unsigned long address)
+{
+ return __sprint_symbol(buffer, address, -1, 1, 1);
}
/* To avoid using get_symbol_offset for every symbol, we carry prefix along. */
projects / linux-2.6-microblaze.git / blobdiff