summaryrefslogtreecommitdiff
path: root/arch/arm64/kernel/ftrace.c
diff options
context:
space:
mode:
Diffstat (limited to 'arch/arm64/kernel/ftrace.c')
-rw-r--r--arch/arm64/kernel/ftrace.c87
1 files changed, 48 insertions, 39 deletions
diff --git a/arch/arm64/kernel/ftrace.c b/arch/arm64/kernel/ftrace.c
index 8745175f4a75..b30b955a8921 100644
--- a/arch/arm64/kernel/ftrace.c
+++ b/arch/arm64/kernel/ftrace.c
@@ -17,7 +17,49 @@
#include <asm/insn.h>
#include <asm/patching.h>
-#ifdef CONFIG_DYNAMIC_FTRACE
+#ifdef CONFIG_DYNAMIC_FTRACE_WITH_ARGS
+struct fregs_offset {
+ const char *name;
+ int offset;
+};
+
+#define FREGS_OFFSET(n, field) \
+{ \
+ .name = n, \
+ .offset = offsetof(struct ftrace_regs, field), \
+}
+
+static const struct fregs_offset fregs_offsets[] = {
+ FREGS_OFFSET("x0", regs[0]),
+ FREGS_OFFSET("x1", regs[1]),
+ FREGS_OFFSET("x2", regs[2]),
+ FREGS_OFFSET("x3", regs[3]),
+ FREGS_OFFSET("x4", regs[4]),
+ FREGS_OFFSET("x5", regs[5]),
+ FREGS_OFFSET("x6", regs[6]),
+ FREGS_OFFSET("x7", regs[7]),
+ FREGS_OFFSET("x8", regs[8]),
+
+ FREGS_OFFSET("x29", fp),
+ FREGS_OFFSET("x30", lr),
+ FREGS_OFFSET("lr", lr),
+
+ FREGS_OFFSET("sp", sp),
+ FREGS_OFFSET("pc", pc),
+};
+
+int ftrace_regs_query_register_offset(const char *name)
+{
+ for (int i = 0; i < ARRAY_SIZE(fregs_offsets); i++) {
+ const struct fregs_offset *roff = &fregs_offsets[i];
+ if (!strcmp(roff->name, name))
+ return roff->offset;
+ }
+
+ return -EINVAL;
+}
+#endif
+
/*
* Replace a single instruction, which may be a branch or NOP.
* If @validate == true, a replaced instruction is checked against 'old'.
@@ -70,9 +112,6 @@ static struct plt_entry *get_ftrace_plt(struct module *mod, unsigned long addr)
if (addr == FTRACE_ADDR)
return &plt[FTRACE_PLT_IDX];
- if (addr == FTRACE_REGS_ADDR &&
- IS_ENABLED(CONFIG_DYNAMIC_FTRACE_WITH_REGS))
- return &plt[FTRACE_REGS_PLT_IDX];
#endif
return NULL;
}
@@ -154,25 +193,7 @@ int ftrace_make_call(struct dyn_ftrace *rec, unsigned long addr)
return ftrace_modify_code(pc, old, new, true);
}
-#ifdef CONFIG_DYNAMIC_FTRACE_WITH_REGS
-int ftrace_modify_call(struct dyn_ftrace *rec, unsigned long old_addr,
- unsigned long addr)
-{
- unsigned long pc = rec->ip;
- u32 old, new;
-
- if (!ftrace_find_callable_addr(rec, NULL, &old_addr))
- return -EINVAL;
- if (!ftrace_find_callable_addr(rec, NULL, &addr))
- return -EINVAL;
-
- old = aarch64_insn_gen_branch_imm(pc, old_addr,
- AARCH64_INSN_BRANCH_LINK);
- new = aarch64_insn_gen_branch_imm(pc, addr, AARCH64_INSN_BRANCH_LINK);
-
- return ftrace_modify_code(pc, old, new, true);
-}
-
+#ifdef CONFIG_DYNAMIC_FTRACE_WITH_ARGS
/*
* The compiler has inserted two NOPs before the regular function prologue.
* All instrumented functions follow the AAPCS, so x0-x8 and x19-x30 are live,
@@ -228,7 +249,7 @@ int ftrace_make_nop(struct module *mod, struct dyn_ftrace *rec,
*
* Note: 'mod' is only set at module load time.
*/
- if (!IS_ENABLED(CONFIG_DYNAMIC_FTRACE_WITH_REGS) &&
+ if (!IS_ENABLED(CONFIG_DYNAMIC_FTRACE_WITH_ARGS) &&
IS_ENABLED(CONFIG_ARM64_MODULE_PLTS) && mod) {
return aarch64_insn_patch_text_nosync((void *)pc, new);
}
@@ -246,7 +267,6 @@ void arch_ftrace_update_code(int command)
command |= FTRACE_MAY_SLEEP;
ftrace_modify_all_code(command);
}
-#endif /* CONFIG_DYNAMIC_FTRACE */
#ifdef CONFIG_FUNCTION_GRAPH_TRACER
/*
@@ -277,21 +297,11 @@ void prepare_ftrace_return(unsigned long self_addr, unsigned long *parent,
}
}
-#ifdef CONFIG_DYNAMIC_FTRACE
-
-#ifdef CONFIG_DYNAMIC_FTRACE_WITH_REGS
+#ifdef CONFIG_DYNAMIC_FTRACE_WITH_ARGS
void ftrace_graph_func(unsigned long ip, unsigned long parent_ip,
struct ftrace_ops *op, struct ftrace_regs *fregs)
{
- /*
- * When DYNAMIC_FTRACE_WITH_REGS is selected, `fregs` can never be NULL
- * and arch_ftrace_get_regs(fregs) will always give a non-NULL pt_regs
- * in which we can safely modify the LR.
- */
- struct pt_regs *regs = arch_ftrace_get_regs(fregs);
- unsigned long *parent = (unsigned long *)&procedure_link_pointer(regs);
-
- prepare_ftrace_return(ip, parent, frame_pointer(regs));
+ prepare_ftrace_return(ip, &fregs->lr, fregs->fp);
}
#else
/*
@@ -323,6 +333,5 @@ int ftrace_disable_ftrace_graph_caller(void)
{
return ftrace_modify_graph_caller(false);
}
-#endif /* CONFIG_DYNAMIC_FTRACE_WITH_REGS */
-#endif /* CONFIG_DYNAMIC_FTRACE */
+#endif /* CONFIG_DYNAMIC_FTRACE_WITH_ARGS */
#endif /* CONFIG_FUNCTION_GRAPH_TRACER */