From 151fecfb72a0d602dfe79790602ef64b4e241574 Mon Sep 17 00:00:00 2001
From: hc <hc@nodka.com>
Date: Mon, 19 Feb 2024 01:51:07 +0000
Subject: [PATCH] export RK_PA3
---
kernel/arch/x86/kernel/unwind_orc.c | 118 ++++++++++++++++++++++++++++++++++++++---------------------
1 files changed, 76 insertions(+), 42 deletions(-)
diff --git a/kernel/arch/x86/kernel/unwind_orc.c b/kernel/arch/x86/kernel/unwind_orc.c
index 4f17c1c..d557a54 100644
--- a/kernel/arch/x86/kernel/unwind_orc.c
+++ b/kernel/arch/x86/kernel/unwind_orc.c
@@ -1,3 +1,5 @@
+// SPDX-License-Identifier: GPL-2.0-only
+#include <linux/objtool.h>
#include <linux/module.h>
#include <linux/sort.h>
#include <asm/ptrace.h>
@@ -7,19 +9,21 @@
#include <asm/orc_lookup.h>
#define orc_warn(fmt, ...) \
- printk_deferred_once(KERN_WARNING pr_fmt("WARNING: " fmt), ##__VA_ARGS__)
+ printk_deferred_once(KERN_WARNING "WARNING: " fmt, ##__VA_ARGS__)
+
+#define orc_warn_current(args...) \
+({ \
+ if (state->task == current) \
+ orc_warn(args); \
+})
extern int __start_orc_unwind_ip[];
extern int __stop_orc_unwind_ip[];
extern struct orc_entry __start_orc_unwind[];
extern struct orc_entry __stop_orc_unwind[];
-static DEFINE_MUTEX(sort_mutex);
-int *cur_orc_ip_table = __start_orc_unwind_ip;
-struct orc_entry *cur_orc_table = __start_orc_unwind;
-
-unsigned int lookup_num_blocks;
-bool orc_init;
+static bool orc_init __ro_after_init;
+static unsigned int lookup_num_blocks __ro_after_init;
static inline unsigned long orc_ip(const int *ip)
{
@@ -81,30 +85,35 @@
* But they are copies of the ftrace entries that are static and
* defined in ftrace_*.S, which do have orc entries.
*
- * If the undwinder comes across a ftrace trampoline, then find the
+ * If the unwinder comes across a ftrace trampoline, then find the
* ftrace function that was used to create it, and use that ftrace
- * function's orc entrie, as the placement of the return code in
+ * function's orc entry, as the placement of the return code in
* the stack will be identical.
*/
static struct orc_entry *orc_ftrace_find(unsigned long ip)
{
struct ftrace_ops *ops;
- unsigned long caller;
+ unsigned long tramp_addr, offset;
ops = ftrace_ops_trampoline(ip);
if (!ops)
return NULL;
+ /* Set tramp_addr to the start of the code copied by the trampoline */
if (ops->flags & FTRACE_OPS_FL_SAVE_REGS)
- caller = (unsigned long)ftrace_regs_call;
+ tramp_addr = (unsigned long)ftrace_regs_caller;
else
- caller = (unsigned long)ftrace_call;
+ tramp_addr = (unsigned long)ftrace_caller;
+
+ /* Now place tramp_addr to the location within the trampoline ip is at */
+ offset = ip - ops->trampoline;
+ tramp_addr += offset;
/* Prevent unlikely recursion */
- if (ip == caller)
+ if (ip == tramp_addr)
return NULL;
- return orc_find(caller);
+ return orc_find(tramp_addr);
}
#else
static struct orc_entry *orc_ftrace_find(unsigned long ip)
@@ -124,7 +133,17 @@
.sp_offset = sizeof(long),
.sp_reg = ORC_REG_SP,
.bp_reg = ORC_REG_UNDEFINED,
- .type = ORC_TYPE_CALL
+ .type = UNWIND_HINT_TYPE_CALL
+};
+
+/* Fake frame pointer entry -- used as a fallback for generated code */
+static struct orc_entry orc_fp_entry = {
+ .type = UNWIND_HINT_TYPE_CALL,
+ .sp_reg = ORC_REG_BP,
+ .sp_offset = 16,
+ .bp_reg = ORC_REG_PREV_SP,
+ .bp_offset = -16,
+ .end = 0,
};
static struct orc_entry *orc_find(unsigned long ip)
@@ -173,6 +192,12 @@
return orc_ftrace_find(ip);
}
+#ifdef CONFIG_MODULES
+
+static DEFINE_MUTEX(sort_mutex);
+static int *cur_orc_ip_table = __start_orc_unwind_ip;
+static struct orc_entry *cur_orc_table = __start_orc_unwind;
+
static void orc_sort_swap(void *_a, void *_b, int size)
{
struct orc_entry *orc_a, *orc_b;
@@ -215,7 +240,6 @@
return orc_a->sp_reg == ORC_REG_UNDEFINED && !orc_a->end ? -1 : 1;
}
-#ifdef CONFIG_MODULES
void unwind_module_init(struct module *mod, void *_orc_ip, size_t orc_ip_size,
void *_orc, size_t orc_size)
{
@@ -259,9 +283,11 @@
return;
}
- /* Sort the .orc_unwind and .orc_unwind_ip tables: */
- sort(__start_orc_unwind_ip, num_entries, sizeof(int), orc_sort_cmp,
- orc_sort_swap);
+ /*
+ * Note, the orc_unwind and orc_unwind_ip tables were already
+ * sorted at build time via the 'sorttable' tool.
+ * It's ready for binary search straight away, no need to sort it.
+ */
/* Initialize the fast lookup table: */
lookup_num_blocks = orc_lookup_end - orc_lookup;
@@ -420,8 +446,16 @@
* call instruction itself.
*/
orc = orc_find(state->signal ? state->ip : state->ip - 1);
- if (!orc)
- goto err;
+ if (!orc) {
+ /*
+ * As a fallback, try to assume this code uses a frame pointer.
+ * This is useful for generated code, like BPF, which ORC
+ * doesn't know about. This is just a guess, so the rest of
+ * the unwind is no longer considered reliable.
+ */
+ orc = &orc_fp_entry;
+ state->error = true;
+ }
/* End-of-stack check for kernel threads: */
if (orc->sp_reg == ORC_REG_UNDEFINED) {
@@ -453,38 +487,38 @@
case ORC_REG_R10:
if (!get_reg(state, offsetof(struct pt_regs, r10), &sp)) {
- orc_warn("missing regs for base reg R10 at ip %pB\n",
- (void *)state->ip);
+ orc_warn_current("missing R10 value at %pB\n",
+ (void *)state->ip);
goto err;
}
break;
case ORC_REG_R13:
if (!get_reg(state, offsetof(struct pt_regs, r13), &sp)) {
- orc_warn("missing regs for base reg R13 at ip %pB\n",
- (void *)state->ip);
+ orc_warn_current("missing R13 value at %pB\n",
+ (void *)state->ip);
goto err;
}
break;
case ORC_REG_DI:
if (!get_reg(state, offsetof(struct pt_regs, di), &sp)) {
- orc_warn("missing regs for base reg DI at ip %pB\n",
- (void *)state->ip);
+ orc_warn_current("missing RDI value at %pB\n",
+ (void *)state->ip);
goto err;
}
break;
case ORC_REG_DX:
if (!get_reg(state, offsetof(struct pt_regs, dx), &sp)) {
- orc_warn("missing regs for base reg DX at ip %pB\n",
- (void *)state->ip);
+ orc_warn_current("missing DX value at %pB\n",
+ (void *)state->ip);
goto err;
}
break;
default:
- orc_warn("unknown SP base reg %d for ip %pB\n",
+ orc_warn("unknown SP base reg %d at %pB\n",
orc->sp_reg, (void *)state->ip);
goto err;
}
@@ -496,7 +530,7 @@
/* Find IP, SP and possibly regs: */
switch (orc->type) {
- case ORC_TYPE_CALL:
+ case UNWIND_HINT_TYPE_CALL:
ip_p = sp - sizeof(long);
if (!deref_stack_reg(state, ip_p, &state->ip))
@@ -511,10 +545,10 @@
state->signal = false;
break;
- case ORC_TYPE_REGS:
+ case UNWIND_HINT_TYPE_REGS:
if (!deref_stack_regs(state, sp, &state->ip, &state->sp)) {
- orc_warn("can't dereference registers at %p for ip %pB\n",
- (void *)sp, (void *)orig_ip);
+ orc_warn_current("can't access registers at %pB\n",
+ (void *)orig_ip);
goto err;
}
@@ -524,10 +558,10 @@
state->signal = true;
break;
- case ORC_TYPE_REGS_IRET:
+ case UNWIND_HINT_TYPE_REGS_PARTIAL:
if (!deref_stack_iret_regs(state, sp, &state->ip, &state->sp)) {
- orc_warn("can't dereference iret registers at %p for ip %pB\n",
- (void *)sp, (void *)orig_ip);
+ orc_warn_current("can't access iret registers at %pB\n",
+ (void *)orig_ip);
goto err;
}
@@ -539,7 +573,7 @@
break;
default:
- orc_warn("unknown .orc_unwind entry type %d for ip %pB\n",
+ orc_warn("unknown .orc_unwind entry type %d at %pB\n",
orc->type, (void *)orig_ip);
goto err;
}
@@ -571,8 +605,8 @@
if (state->stack_info.type == prev_type &&
on_stack(&state->stack_info, (void *)state->sp, sizeof(long)) &&
state->sp <= prev_sp) {
- orc_warn("stack going in the wrong direction? ip=%pB\n",
- (void *)orig_ip);
+ orc_warn_current("stack going in the wrong direction? at %pB\n",
+ (void *)orig_ip);
goto err;
}
@@ -611,7 +645,7 @@
goto the_end;
state->ip = regs->ip;
- state->sp = kernel_stack_pointer(regs);
+ state->sp = regs->sp;
state->bp = regs->bp;
state->regs = regs;
state->full_regs = true;
@@ -663,7 +697,7 @@
/* Otherwise, skip ahead to the user-specified starting frame: */
while (!unwind_done(state) &&
(!on_stack(&state->stack_info, first_frame, sizeof(long)) ||
- state->sp < (unsigned long)first_frame))
+ state->sp <= (unsigned long)first_frame))
unwind_next_frame(state);
return;
--
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