#include <asm/cacheflush.h>
#include <asm/uasm.h>
-/*
- * If the Instruction Pointer is in module space (0xc0000000), return true;
- * otherwise, it is in kernel space (0x80000000), return false.
- *
- * FIXME: This will not work when the kernel space and module space are the
- * same. If they are the same, we need to modify scripts/recordmcount.pl,
- * ftrace_make_nop/call() and the other related parts to ensure the
- * enabling/disabling of the calling site to _mcount is right for both kernel
- * and module.
- */
-
-static inline int in_module(unsigned long ip)
-{
- return ip & 0x40000000;
-}
+#include <asm-generic/sections.h>
#ifdef CONFIG_DYNAMIC_FTRACE
#endif
}
+/*
+ * Check if the address is in kernel space
+ *
+ * Clone core_kernel_text() from kernel/extable.c, but doesn't call
+ * init_kernel_text() for Ftrace doesn't trace functions in init sections.
+ */
+static inline int in_kernel_space(unsigned long ip)
+{
+ if (ip >= (unsigned long)_stext &&
+ ip <= (unsigned long)_etext)
+ return 1;
+ return 0;
+}
+
static int ftrace_modify_code(unsigned long ip, unsigned int new_code)
{
int faulted;
unsigned long ip = rec->ip;
/*
- * We have compiled module with -mlong-calls, but compiled the kernel
- * without it, we need to cope with them respectively.
+ * If ip is in kernel space, no long call, otherwise, long call is
+ * needed.
*/
- if (in_module(ip)) {
+ if (in_kernel_space(ip)) {
+ /*
+ * move at, ra
+ * jal _mcount --> nop
+ */
+ new = INSN_NOP;
+ } else {
#if defined(KBUILD_MCOUNT_RA_ADDRESS) && defined(CONFIG_32BIT)
/*
* lui v1, hi_16bit_of_mcount --> b 1f (0x10000005)
*/
new = INSN_B_1F_4;
#endif
- } else {
- /*
- * move at, ra
- * jal _mcount --> nop
- */
- new = INSN_NOP;
}
return ftrace_modify_code(ip, new);
}
unsigned int new;
unsigned long ip = rec->ip;
- /* ip, module: 0xc0000000, kernel: 0x80000000 */
- new = in_module(ip) ? insn_lui_v1_hi16_mcount : insn_jal_ftrace_caller;
+ new = in_kernel_space(ip) ? insn_jal_ftrace_caller :
+ insn_lui_v1_hi16_mcount;
return ftrace_modify_code(ip, new);
}
int faulted;
/*
- * For module, move the ip from calling site of mcount to the
- * instruction "lui v1, hi_16bit_of_mcount"(offset is 20), but for
- * kernel, move to the instruction "move ra, at"(offset is 12)
+ * For module, move the ip from calling site of mcount after the
+ * instruction "lui v1, hi_16bit_of_mcount"(offset is 24), but for
+ * kernel, move after the instruction "move ra, at"(offset is 16)
*/
- ip = self_addr - (in_module(self_addr) ? 20 : 12);
+ ip = self_addr - (in_kernel_space(self_addr) ? 16 : 24);
/*
* search the text until finding the non-store instruction or "s{d,w}
* ra, offset(sp)" instruction
*/
do {
- ip -= 4;
-
/* get the code at "ip": code = *(unsigned int *)ip; */
safe_load_code(code, ip, faulted);
if ((code & S_R_SP) != S_R_SP)
return parent_addr;
- } while (((code & S_RA_SP) != S_RA_SP));
+ /* Move to the next instruction */
+ ip -= 4;
+ } while ((code & S_RA_SP) != S_RA_SP);
sp = fp + (code & OFFSET_MASK);