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-rw-r--r--arch/loongarch/kernel/Makefile4
-rw-r--r--arch/loongarch/kernel/entry.S5
-rw-r--r--arch/loongarch/kernel/fpu.S7
-rw-r--r--arch/loongarch/kernel/genex.S6
-rw-r--r--arch/loongarch/kernel/lbt.S3
-rw-r--r--arch/loongarch/kernel/mcount_dyn.S6
-rw-r--r--arch/loongarch/kernel/module.c22
-rw-r--r--arch/loongarch/kernel/relocate_kernel.S7
-rw-r--r--arch/loongarch/kernel/rethook_trampoline.S1
-rw-r--r--arch/loongarch/kernel/setup.c2
-rw-r--r--arch/loongarch/kernel/stacktrace.c41
-rw-r--r--arch/loongarch/kernel/traps.c42
-rw-r--r--arch/loongarch/kernel/unwind_orc.c528
-rw-r--r--arch/loongarch/kernel/vmlinux.lds.S3
14 files changed, 657 insertions, 20 deletions
diff --git a/arch/loongarch/kernel/Makefile b/arch/loongarch/kernel/Makefile
index 3c808c680370..3a7620b66bc6 100644
--- a/arch/loongarch/kernel/Makefile
+++ b/arch/loongarch/kernel/Makefile
@@ -3,6 +3,8 @@
# Makefile for the Linux/LoongArch kernel.
#
+OBJECT_FILES_NON_STANDARD_head.o := y
+
extra-y := vmlinux.lds
obj-y += head.o cpu-probe.o cacheinfo.o env.o setup.o entry.o genex.o \
@@ -21,6 +23,7 @@ obj-$(CONFIG_ARCH_STRICT_ALIGN) += unaligned.o
CFLAGS_module.o += $(call cc-option,-Wno-override-init,)
CFLAGS_syscall.o += $(call cc-option,-Wno-override-init,)
+CFLAGS_traps.o += $(call cc-option,-Wno-override-init,)
CFLAGS_perf_event.o += $(call cc-option,-Wno-override-init,)
ifdef CONFIG_FUNCTION_TRACER
@@ -62,6 +65,7 @@ obj-$(CONFIG_CRASH_DUMP) += crash_dump.o
obj-$(CONFIG_UNWINDER_GUESS) += unwind_guess.o
obj-$(CONFIG_UNWINDER_PROLOGUE) += unwind_prologue.o
+obj-$(CONFIG_UNWINDER_ORC) += unwind_orc.o
obj-$(CONFIG_PERF_EVENTS) += perf_event.o perf_regs.o
obj-$(CONFIG_HAVE_HW_BREAKPOINT) += hw_breakpoint.o
diff --git a/arch/loongarch/kernel/entry.S b/arch/loongarch/kernel/entry.S
index 1ec8e4c4cc2b..48e7e34e355e 100644
--- a/arch/loongarch/kernel/entry.S
+++ b/arch/loongarch/kernel/entry.S
@@ -14,11 +14,13 @@
#include <asm/regdef.h>
#include <asm/stackframe.h>
#include <asm/thread_info.h>
+#include <asm/unwind_hints.h>
.text
.cfi_sections .debug_frame
.align 5
SYM_CODE_START(handle_syscall)
+ UNWIND_HINT_UNDEFINED
csrrd t0, PERCPU_BASE_KS
la.pcrel t1, kernelsp
add.d t1, t1, t0
@@ -57,6 +59,7 @@ SYM_CODE_START(handle_syscall)
cfi_st fp, PT_R22
SAVE_STATIC
+ UNWIND_HINT_REGS
#ifdef CONFIG_KGDB
li.w t1, CSR_CRMD_WE
@@ -75,6 +78,7 @@ SYM_CODE_END(handle_syscall)
_ASM_NOKPROBE(handle_syscall)
SYM_CODE_START(ret_from_fork)
+ UNWIND_HINT_REGS
bl schedule_tail # a0 = struct task_struct *prev
move a0, sp
bl syscall_exit_to_user_mode
@@ -84,6 +88,7 @@ SYM_CODE_START(ret_from_fork)
SYM_CODE_END(ret_from_fork)
SYM_CODE_START(ret_from_kernel_thread)
+ UNWIND_HINT_REGS
bl schedule_tail # a0 = struct task_struct *prev
move a0, s1
jirl ra, s0, 0
diff --git a/arch/loongarch/kernel/fpu.S b/arch/loongarch/kernel/fpu.S
index 4382e36ae3d4..69a85f2479fb 100644
--- a/arch/loongarch/kernel/fpu.S
+++ b/arch/loongarch/kernel/fpu.S
@@ -15,6 +15,7 @@
#include <asm/fpregdef.h>
#include <asm/loongarch.h>
#include <asm/regdef.h>
+#include <asm/unwind_hints.h>
#define FPU_REG_WIDTH 8
#define LSX_REG_WIDTH 16
@@ -526,3 +527,9 @@ SYM_FUNC_END(_restore_lasx_context)
.L_fpu_fault:
li.w a0, -EFAULT # failure
jr ra
+
+#ifdef CONFIG_CPU_HAS_LBT
+STACK_FRAME_NON_STANDARD _restore_fp
+STACK_FRAME_NON_STANDARD _restore_lsx
+STACK_FRAME_NON_STANDARD _restore_lasx
+#endif
diff --git a/arch/loongarch/kernel/genex.S b/arch/loongarch/kernel/genex.S
index 2bb3aa2dcfcb..86d5d90ebefe 100644
--- a/arch/loongarch/kernel/genex.S
+++ b/arch/loongarch/kernel/genex.S
@@ -32,6 +32,7 @@ SYM_FUNC_START(__arch_cpu_idle)
SYM_FUNC_END(__arch_cpu_idle)
SYM_CODE_START(handle_vint)
+ UNWIND_HINT_UNDEFINED
BACKUP_T0T1
SAVE_ALL
la_abs t1, __arch_cpu_idle
@@ -49,6 +50,7 @@ SYM_CODE_START(handle_vint)
SYM_CODE_END(handle_vint)
SYM_CODE_START(except_vec_cex)
+ UNWIND_HINT_UNDEFINED
b cache_parity_error
SYM_CODE_END(except_vec_cex)
@@ -67,6 +69,7 @@ SYM_CODE_END(except_vec_cex)
.macro BUILD_HANDLER exception handler prep
.align 5
SYM_CODE_START(handle_\exception)
+ UNWIND_HINT_UNDEFINED
666:
BACKUP_T0T1
SAVE_ALL
@@ -77,7 +80,9 @@ SYM_CODE_END(except_vec_cex)
668:
RESTORE_ALL_AND_RET
SYM_CODE_END(handle_\exception)
+ .pushsection ".data", "aw", %progbits
SYM_DATA(unwind_hint_\exception, .word 668b - 666b)
+ .popsection
.endm
BUILD_HANDLER ade ade badv
@@ -94,6 +99,7 @@ SYM_CODE_END(except_vec_cex)
BUILD_HANDLER reserved reserved none /* others */
SYM_CODE_START(handle_sys)
+ UNWIND_HINT_UNDEFINED
la_abs t0, handle_syscall
jr t0
SYM_CODE_END(handle_sys)
diff --git a/arch/loongarch/kernel/lbt.S b/arch/loongarch/kernel/lbt.S
index 9c75120a26d8..001f061d226a 100644
--- a/arch/loongarch/kernel/lbt.S
+++ b/arch/loongarch/kernel/lbt.S
@@ -11,6 +11,7 @@
#include <asm/asm-offsets.h>
#include <asm/errno.h>
#include <asm/regdef.h>
+#include <asm/unwind_hints.h>
#define SCR_REG_WIDTH 8
@@ -153,3 +154,5 @@ SYM_FUNC_END(_restore_ftop_context)
.L_lbt_fault:
li.w a0, -EFAULT # failure
jr ra
+
+STACK_FRAME_NON_STANDARD _restore_ftop_context
diff --git a/arch/loongarch/kernel/mcount_dyn.S b/arch/loongarch/kernel/mcount_dyn.S
index 482aa553aa2d..0c65cf09110c 100644
--- a/arch/loongarch/kernel/mcount_dyn.S
+++ b/arch/loongarch/kernel/mcount_dyn.S
@@ -73,6 +73,7 @@ SYM_FUNC_START(ftrace_stub)
SYM_FUNC_END(ftrace_stub)
SYM_CODE_START(ftrace_common)
+ UNWIND_HINT_UNDEFINED
PTR_ADDI a0, ra, -8 /* arg0: ip */
move a1, t0 /* arg1: parent_ip */
la.pcrel t1, function_trace_op
@@ -113,12 +114,14 @@ ftrace_common_return:
SYM_CODE_END(ftrace_common)
SYM_CODE_START(ftrace_caller)
+ UNWIND_HINT_UNDEFINED
ftrace_regs_entry allregs=0
b ftrace_common
SYM_CODE_END(ftrace_caller)
#ifdef CONFIG_DYNAMIC_FTRACE_WITH_REGS
SYM_CODE_START(ftrace_regs_caller)
+ UNWIND_HINT_UNDEFINED
ftrace_regs_entry allregs=1
b ftrace_common
SYM_CODE_END(ftrace_regs_caller)
@@ -126,6 +129,7 @@ SYM_CODE_END(ftrace_regs_caller)
#ifdef CONFIG_FUNCTION_GRAPH_TRACER
SYM_CODE_START(ftrace_graph_caller)
+ UNWIND_HINT_UNDEFINED
PTR_L a0, sp, PT_ERA
PTR_ADDI a0, a0, -8 /* arg0: self_addr */
PTR_ADDI a1, sp, PT_R1 /* arg1: parent */
@@ -134,6 +138,7 @@ SYM_CODE_START(ftrace_graph_caller)
SYM_CODE_END(ftrace_graph_caller)
SYM_CODE_START(return_to_handler)
+ UNWIND_HINT_UNDEFINED
/* Save return value regs */
PTR_ADDI sp, sp, -FGRET_REGS_SIZE
PTR_S a0, sp, FGRET_REGS_A0
@@ -155,6 +160,7 @@ SYM_CODE_END(return_to_handler)
#ifdef CONFIG_DYNAMIC_FTRACE_WITH_DIRECT_CALLS
SYM_CODE_START(ftrace_stub_direct_tramp)
+ UNWIND_HINT_UNDEFINED
jr t0
SYM_CODE_END(ftrace_stub_direct_tramp)
#endif /* CONFIG_DYNAMIC_FTRACE_WITH_DIRECT_CALLS */
diff --git a/arch/loongarch/kernel/module.c b/arch/loongarch/kernel/module.c
index b13b2858fe39..c7d0338d12c1 100644
--- a/arch/loongarch/kernel/module.c
+++ b/arch/loongarch/kernel/module.c
@@ -20,6 +20,7 @@
#include <linux/kernel.h>
#include <asm/alternative.h>
#include <asm/inst.h>
+#include <asm/unwind.h>
static int rela_stack_push(s64 stack_value, s64 *rela_stack, size_t *rela_stack_top)
{
@@ -515,15 +516,28 @@ static void module_init_ftrace_plt(const Elf_Ehdr *hdr,
int module_finalize(const Elf_Ehdr *hdr,
const Elf_Shdr *sechdrs, struct module *mod)
{
- const Elf_Shdr *s, *se;
const char *secstrs = (void *)hdr + sechdrs[hdr->e_shstrndx].sh_offset;
+ const Elf_Shdr *s, *alt = NULL, *orc = NULL, *orc_ip = NULL, *ftrace = NULL;
- for (s = sechdrs, se = sechdrs + hdr->e_shnum; s < se; s++) {
+ for (s = sechdrs; s < sechdrs + hdr->e_shnum; s++) {
if (!strcmp(".altinstructions", secstrs + s->sh_name))
- apply_alternatives((void *)s->sh_addr, (void *)s->sh_addr + s->sh_size);
+ alt = s;
+ if (!strcmp(".orc_unwind", secstrs + s->sh_name))
+ orc = s;
+ if (!strcmp(".orc_unwind_ip", secstrs + s->sh_name))
+ orc_ip = s;
if (!strcmp(".ftrace_trampoline", secstrs + s->sh_name))
- module_init_ftrace_plt(hdr, s, mod);
+ ftrace = s;
}
+ if (alt)
+ apply_alternatives((void *)alt->sh_addr, (void *)alt->sh_addr + alt->sh_size);
+
+ if (orc && orc_ip)
+ unwind_module_init(mod, (void *)orc_ip->sh_addr, orc_ip->sh_size, (void *)orc->sh_addr, orc->sh_size);
+
+ if (ftrace)
+ module_init_ftrace_plt(hdr, ftrace, mod);
+
return 0;
}
diff --git a/arch/loongarch/kernel/relocate_kernel.S b/arch/loongarch/kernel/relocate_kernel.S
index f49f6b053763..84e6de2fd973 100644
--- a/arch/loongarch/kernel/relocate_kernel.S
+++ b/arch/loongarch/kernel/relocate_kernel.S
@@ -15,6 +15,7 @@
#include <asm/addrspace.h>
SYM_CODE_START(relocate_new_kernel)
+ UNWIND_HINT_UNDEFINED
/*
* a0: EFI boot flag for the new kernel
* a1: Command line pointer for the new kernel
@@ -90,6 +91,7 @@ SYM_CODE_END(relocate_new_kernel)
* then start at the entry point from LOONGARCH_IOCSR_MBUF0.
*/
SYM_CODE_START(kexec_smp_wait)
+ UNWIND_HINT_UNDEFINED
1: li.w t0, 0x100 /* wait for init loop */
2: addi.w t0, t0, -1 /* limit mailbox access */
bnez t0, 2b
@@ -106,6 +108,5 @@ SYM_CODE_END(kexec_smp_wait)
relocate_new_kernel_end:
-SYM_DATA_START(relocate_new_kernel_size)
- PTR relocate_new_kernel_end - relocate_new_kernel
-SYM_DATA_END(relocate_new_kernel_size)
+ .section ".data"
+SYM_DATA(relocate_new_kernel_size, .long relocate_new_kernel_end - relocate_new_kernel)
diff --git a/arch/loongarch/kernel/rethook_trampoline.S b/arch/loongarch/kernel/rethook_trampoline.S
index bd5772c96338..d4ceb2fa2a5c 100644
--- a/arch/loongarch/kernel/rethook_trampoline.S
+++ b/arch/loongarch/kernel/rethook_trampoline.S
@@ -76,6 +76,7 @@
.endm
SYM_CODE_START(arch_rethook_trampoline)
+ UNWIND_HINT_UNDEFINED
addi.d sp, sp, -PT_SIZE
save_all_base_regs
diff --git a/arch/loongarch/kernel/setup.c b/arch/loongarch/kernel/setup.c
index 2b72eb326b44..60e0fe97f61a 100644
--- a/arch/loongarch/kernel/setup.c
+++ b/arch/loongarch/kernel/setup.c
@@ -47,6 +47,7 @@
#include <asm/sections.h>
#include <asm/setup.h>
#include <asm/time.h>
+#include <asm/unwind.h>
#define SMBIOS_BIOSSIZE_OFFSET 0x09
#define SMBIOS_BIOSEXTERN_OFFSET 0x13
@@ -587,6 +588,7 @@ static void __init prefill_possible_map(void)
void __init setup_arch(char **cmdline_p)
{
cpu_probe();
+ unwind_init();
init_environ();
efi_init();
diff --git a/arch/loongarch/kernel/stacktrace.c b/arch/loongarch/kernel/stacktrace.c
index f623feb2129f..9a038d1070d7 100644
--- a/arch/loongarch/kernel/stacktrace.c
+++ b/arch/loongarch/kernel/stacktrace.c
@@ -29,6 +29,7 @@ void arch_stack_walk(stack_trace_consume_fn consume_entry, void *cookie,
regs->csr_era = thread_saved_ra(task);
}
regs->regs[1] = 0;
+ regs->regs[22] = 0;
}
for (unwind_start(&state, task, regs);
@@ -39,6 +40,46 @@ void arch_stack_walk(stack_trace_consume_fn consume_entry, void *cookie,
}
}
+int arch_stack_walk_reliable(stack_trace_consume_fn consume_entry,
+ void *cookie, struct task_struct *task)
+{
+ unsigned long addr;
+ struct pt_regs dummyregs;
+ struct pt_regs *regs = &dummyregs;
+ struct unwind_state state;
+
+ if (task == current) {
+ regs->regs[3] = (unsigned long)__builtin_frame_address(0);
+ regs->csr_era = (unsigned long)__builtin_return_address(0);
+ } else {
+ regs->regs[3] = thread_saved_fp(task);
+ regs->csr_era = thread_saved_ra(task);
+ }
+ regs->regs[1] = 0;
+ regs->regs[22] = 0;
+
+ for (unwind_start(&state, task, regs);
+ !unwind_done(&state) && !unwind_error(&state); unwind_next_frame(&state)) {
+ addr = unwind_get_return_address(&state);
+
+ /*
+ * A NULL or invalid return address probably means there's some
+ * generated code which __kernel_text_address() doesn't know about.
+ */
+ if (!addr)
+ return -EINVAL;
+
+ if (!consume_entry(cookie, addr))
+ return -EINVAL;
+ }
+
+ /* Check for stack corruption */
+ if (unwind_error(&state))
+ return -EINVAL;
+
+ return 0;
+}
+
static int
copy_stack_frame(unsigned long fp, struct stack_frame *frame)
{
diff --git a/arch/loongarch/kernel/traps.c b/arch/loongarch/kernel/traps.c
index aebfc3733a76..f9f4eb00c92e 100644
--- a/arch/loongarch/kernel/traps.c
+++ b/arch/loongarch/kernel/traps.c
@@ -53,6 +53,32 @@
#include "access-helper.h"
+void *exception_table[EXCCODE_INT_START] = {
+ [0 ... EXCCODE_INT_START - 1] = handle_reserved,
+
+ [EXCCODE_TLBI] = handle_tlb_load,
+ [EXCCODE_TLBL] = handle_tlb_load,
+ [EXCCODE_TLBS] = handle_tlb_store,
+ [EXCCODE_TLBM] = handle_tlb_modify,
+ [EXCCODE_TLBNR] = handle_tlb_protect,
+ [EXCCODE_TLBNX] = handle_tlb_protect,
+ [EXCCODE_TLBPE] = handle_tlb_protect,
+ [EXCCODE_ADE] = handle_ade,
+ [EXCCODE_ALE] = handle_ale,
+ [EXCCODE_BCE] = handle_bce,
+ [EXCCODE_SYS] = handle_sys,
+ [EXCCODE_BP] = handle_bp,
+ [EXCCODE_INE] = handle_ri,
+ [EXCCODE_IPE] = handle_ri,
+ [EXCCODE_FPDIS] = handle_fpu,
+ [EXCCODE_LSXDIS] = handle_lsx,
+ [EXCCODE_LASXDIS] = handle_lasx,
+ [EXCCODE_FPE] = handle_fpe,
+ [EXCCODE_WATCH] = handle_watch,
+ [EXCCODE_BTDIS] = handle_lbt,
+};
+EXPORT_SYMBOL_GPL(exception_table);
+
static void show_backtrace(struct task_struct *task, const struct pt_regs *regs,
const char *loglvl, bool user)
{
@@ -1150,19 +1176,9 @@ void __init trap_init(void)
for (i = EXCCODE_INT_START; i <= EXCCODE_INT_END; i++)
set_handler(i * VECSIZE, handle_vint, VECSIZE);
- set_handler(EXCCODE_ADE * VECSIZE, handle_ade, VECSIZE);
- set_handler(EXCCODE_ALE * VECSIZE, handle_ale, VECSIZE);
- set_handler(EXCCODE_BCE * VECSIZE, handle_bce, VECSIZE);
- set_handler(EXCCODE_SYS * VECSIZE, handle_sys, VECSIZE);
- set_handler(EXCCODE_BP * VECSIZE, handle_bp, VECSIZE);
- set_handler(EXCCODE_INE * VECSIZE, handle_ri, VECSIZE);
- set_handler(EXCCODE_IPE * VECSIZE, handle_ri, VECSIZE);
- set_handler(EXCCODE_FPDIS * VECSIZE, handle_fpu, VECSIZE);
- set_handler(EXCCODE_LSXDIS * VECSIZE, handle_lsx, VECSIZE);
- set_handler(EXCCODE_LASXDIS * VECSIZE, handle_lasx, VECSIZE);
- set_handler(EXCCODE_FPE * VECSIZE, handle_fpe, VECSIZE);
- set_handler(EXCCODE_BTDIS * VECSIZE, handle_lbt, VECSIZE);
- set_handler(EXCCODE_WATCH * VECSIZE, handle_watch, VECSIZE);
+ /* Set exception vector handler */
+ for (i = EXCCODE_ADE; i <= EXCCODE_BTDIS; i++)
+ set_handler(i * VECSIZE, exception_table[i], VECSIZE);
cache_error_setup();
diff --git a/arch/loongarch/kernel/unwind_orc.c b/arch/loongarch/kernel/unwind_orc.c
new file mode 100644
index 000000000000..b25722876331
--- /dev/null
+++ b/arch/loongarch/kernel/unwind_orc.c
@@ -0,0 +1,528 @@
+// SPDX-License-Identifier: GPL-2.0-only
+#include <linux/objtool.h>
+#include <linux/module.h>
+#include <linux/sort.h>
+#include <asm/exception.h>
+#include <asm/orc_header.h>
+#include <asm/orc_lookup.h>
+#include <asm/orc_types.h>
+#include <asm/ptrace.h>
+#include <asm/setup.h>
+#include <asm/stacktrace.h>
+#include <asm/tlb.h>
+#include <asm/unwind.h>
+
+ORC_HEADER;
+
+#define orc_warn(fmt, ...) \
+ printk_deferred_once(KERN_WARNING "WARNING: " fmt, ##__VA_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 bool orc_init __ro_after_init;
+static unsigned int lookup_num_blocks __ro_after_init;
+
+/* Fake frame pointer entry -- used as a fallback for generated code */
+static struct orc_entry orc_fp_entry = {
+ .sp_reg = ORC_REG_FP,
+ .sp_offset = 16,
+ .fp_reg = ORC_REG_PREV_SP,
+ .fp_offset = -16,
+ .ra_reg = ORC_REG_PREV_SP,
+ .ra_offset = -8,
+ .type = ORC_TYPE_CALL
+};
+
+/*
+ * If we crash with IP==0, the last successfully executed instruction
+ * was probably an indirect function call with a NULL function pointer,
+ * and we don't have unwind information for NULL.
+ * This hardcoded ORC entry for IP==0 allows us to unwind from a NULL function
+ * pointer into its parent and then continue normally from there.
+ */
+static struct orc_entry orc_null_entry = {
+ .sp_reg = ORC_REG_SP,
+ .sp_offset = sizeof(long),
+ .fp_reg = ORC_REG_UNDEFINED,
+ .type = ORC_TYPE_CALL
+};
+
+static inline unsigned long orc_ip(const int *ip)
+{
+ return (unsigned long)ip + *ip;
+}
+
+static struct orc_entry *__orc_find(int *ip_table, struct orc_entry *u_table,
+ unsigned int num_entries, unsigned long ip)
+{
+ int *first = ip_table;
+ int *mid = first, *found = first;
+ int *last = ip_table + num_entries - 1;
+
+ if (!num_entries)
+ return NULL;
+
+ /*
+ * Do a binary range search to find the rightmost duplicate of a given
+ * starting address. Some entries are section terminators which are
+ * "weak" entries for ensuring there are no gaps. They should be
+ * ignored when they conflict with a real entry.
+ */
+ while (first <= last) {
+ mid = first + ((last - first) / 2);
+
+ if (orc_ip(mid) <= ip) {
+ found = mid;
+ first = mid + 1;
+ } else
+ last = mid - 1;
+ }
+
+ return u_table + (found - ip_table);
+}
+
+#ifdef CONFIG_MODULES
+static struct orc_entry *orc_module_find(unsigned long ip)
+{
+ struct module *mod;
+
+ mod = __module_address(ip);
+ if (!mod || !mod->arch.orc_unwind || !mod->arch.orc_unwind_ip)
+ return NULL;
+
+ return __orc_find(mod->arch.orc_unwind_ip, mod->arch.orc_unwind, mod->arch.num_orcs, ip);
+}
+#else
+static struct orc_entry *orc_module_find(unsigned long ip)
+{
+ return NULL;
+}
+#endif
+
+#ifdef CONFIG_DYNAMIC_FTRACE
+static struct orc_entry *orc_find(unsigned long ip);
+
+/*
+ * Ftrace dynamic trampolines do not have orc entries of their own.
+ * But they are copies of the ftrace entries that are static and
+ * defined in ftrace_*.S, which do have orc entries.
+ *
+ * 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 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 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)
+ tramp_addr = (unsigned long)ftrace_regs_caller;
+ else
+ 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 == tramp_addr)
+ return NULL;
+
+ return orc_find(tramp_addr);
+}
+#else
+static struct orc_entry *orc_ftrace_find(unsigned long ip)
+{
+ return NULL;
+}
+#endif
+
+static struct orc_entry *orc_find(unsigned long ip)
+{
+ static struct orc_entry *orc;
+
+ if (ip == 0)
+ return &orc_null_entry;
+
+ /* For non-init vmlinux addresses, use the fast lookup table: */
+ if (ip >= LOOKUP_START_IP && ip < LOOKUP_STOP_IP) {
+ unsigned int idx, start, stop;
+
+ idx = (ip - LOOKUP_START_IP) / LOOKUP_BLOCK_SIZE;
+
+ if (unlikely((idx >= lookup_num_blocks-1))) {
+ orc_warn("WARNING: bad lookup idx: idx=%u num=%u ip=%pB\n",
+ idx, lookup_num_blocks, (void *)ip);
+ return NULL;
+ }
+
+ start = orc_lookup[idx];
+ stop = orc_lookup[idx + 1] + 1;
+
+ if (unlikely((__start_orc_unwind + start >= __stop_orc_unwind) ||
+ (__start_orc_unwind + stop > __stop_orc_unwind))) {
+ orc_warn("WARNING: bad lookup value: idx=%u num=%u start=%u stop=%u ip=%pB\n",
+ idx, lookup_num_blocks, start, stop, (void *)ip);
+ return NULL;
+ }
+
+ return __orc_find(__start_orc_unwind_ip + start,
+ __start_orc_unwind + start, stop - start, ip);
+ }
+
+ /* vmlinux .init slow lookup: */
+ if (is_kernel_inittext(ip))
+ return __orc_find(__start_orc_unwind_ip, __start_orc_unwind,
+ __stop_orc_unwind_ip - __start_orc_unwind_ip, ip);
+
+ /* Module lookup: */
+ orc = orc_module_find(ip);
+ if (orc)
+ return orc;
+
+ 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)
+{
+ int delta = _b - _a;
+ int *a = _a, *b = _b, tmp;
+ struct orc_entry *orc_a, *orc_b;
+
+ /* Swap the .orc_unwind_ip entries: */
+ tmp = *a;
+ *a = *b + delta;
+ *b = tmp - delta;
+
+ /* Swap the corresponding .orc_unwind entries: */
+ orc_a = cur_orc_table + (a - cur_orc_ip_table);
+ orc_b = cur_orc_table + (b - cur_orc_ip_table);
+ swap(*orc_a, *orc_b);
+}
+
+static int orc_sort_cmp(const void *_a, const void *_b)
+{
+ const int *a = _a, *b = _b;
+ unsigned long a_val = orc_ip(a);
+ unsigned long b_val = orc_ip(b);
+ struct orc_entry *orc_a;
+
+ if (a_val > b_val)
+ return 1;
+ if (a_val < b_val)
+ return -1;
+
+ /*
+ * The "weak" section terminator entries need to always be first
+ * to ensure the lookup code skips them in favor of real entries.
+ * These terminator entries exist to handle any gaps created by
+ * whitelisted .o files which didn't get objtool generation.
+ */
+ orc_a = cur_orc_table + (a - cur_orc_ip_table);
+
+ return orc_a->type == ORC_TYPE_UNDEFINED ? -1 : 1;
+}
+
+void unwind_module_init(struct module *mod, void *_orc_ip, size_t orc_ip_size,
+ void *_orc, size_t orc_size)
+{
+ int *orc_ip = _orc_ip;
+ struct orc_entry *orc = _orc;
+ unsigned int num_entries = orc_ip_size / sizeof(int);
+
+ WARN_ON_ONCE(orc_ip_size % sizeof(int) != 0 ||
+ orc_size % sizeof(*orc) != 0 ||
+ num_entries != orc_size / sizeof(*orc));
+
+ /*
+ * The 'cur_orc_*' globals allow the orc_sort_swap() callback to
+ * associate an .orc_unwind_ip table entry with its corresponding
+ * .orc_unwind entry so they can both be swapped.
+ */
+ mutex_lock(&sort_mutex);
+ cur_orc_ip_table = orc_ip;
+ cur_orc_table = orc;
+ sort(orc_ip, num_entries, sizeof(int), orc_sort_cmp, orc_sort_swap);
+ mutex_unlock(&sort_mutex);
+
+ mod->arch.orc_unwind_ip = orc_ip;
+ mod->arch.orc_unwind = orc;
+ mod->arch.num_orcs = num_entries;
+}
+#endif
+
+void __init unwind_init(void)
+{
+ int i;
+ size_t orc_size = (void *)__stop_orc_unwind - (void *)__start_orc_unwind;
+ size_t orc_ip_size = (void *)__stop_orc_unwind_ip - (void *)__start_orc_unwind_ip;
+ size_t num_entries = orc_ip_size / sizeof(int);
+ struct orc_entry *orc;
+
+ if (!num_entries || orc_ip_size % sizeof(int) != 0 ||
+ orc_size % sizeof(struct orc_entry) != 0 ||
+ num_entries != orc_size / sizeof(struct orc_entry)) {
+ orc_warn("WARNING: Bad or missing .orc_unwind table. Disabling unwinder.\n");
+ return;
+ }
+
+ /*
+ * 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;
+ for (i = 0; i < lookup_num_blocks-1; i++) {
+ orc = __orc_find(__start_orc_unwind_ip, __start_orc_unwind,
+ num_entries, LOOKUP_START_IP + (LOOKUP_BLOCK_SIZE * i));
+ if (!orc) {
+ orc_warn("WARNING: Corrupt .orc_unwind table. Disabling unwinder.\n");
+ return;
+ }
+
+ orc_lookup[i] = orc - __start_orc_unwind;
+ }
+
+ /* Initialize the ending block: */
+ orc = __orc_find(__start_orc_unwind_ip, __start_orc_unwind, num_entries, LOOKUP_STOP_IP);
+ if (!orc) {
+ orc_warn("WARNING: Corrupt .orc_unwind table. Disabling unwinder.\n");
+ return;
+ }
+ orc_lookup[lookup_num_blocks-1] = orc - __start_orc_unwind;
+
+ orc_init = true;
+}
+
+static inline bool on_stack(struct stack_info *info, unsigned long addr, size_t len)
+{
+ unsigned long begin = info->begin;
+ unsigned long end = info->end;
+
+ return (info->type != STACK_TYPE_UNKNOWN &&
+ addr >= begin && addr < end && addr + len > begin && addr + len <= end);
+}
+
+static bool stack_access_ok(struct unwind_state *state, unsigned long addr, size_t len)
+{
+ struct stack_info *info = &state->stack_info;
+
+ if (on_stack(info, addr, len))
+ return true;
+
+ return !get_stack_info(addr, state->task, info) && on_stack(info, addr, len);
+}
+
+unsigned long unwind_get_return_address(struct unwind_state *state)
+{
+ return __unwind_get_return_address(state);
+}
+EXPORT_SYMBOL_GPL(unwind_get_return_address);
+
+void unwind_start(struct unwind_state *state, struct task_struct *task,
+ struct pt_regs *regs)
+{
+ __unwind_start(state, task, regs);
+ state->type = UNWINDER_ORC;
+ if (!unwind_done(state) && !__kernel_text_address(state->pc))
+ unwind_next_frame(state);
+}
+EXPORT_SYMBOL_GPL(unwind_start);
+
+static bool is_entry_func(unsigned long addr)
+{
+ extern u32 kernel_entry;
+ extern u32 kernel_entry_end;
+
+ return addr >= (unsigned long)&kernel_entry && addr < (unsigned long)&kernel_entry_end;
+}
+
+static inline unsigned long bt_address(unsigned long ra)
+{
+ extern unsigned long eentry;
+
+ if (__kernel_text_address(ra))
+ return ra;
+
+ if (__module_text_address(ra))
+ return ra;
+
+ if (ra >= eentry && ra < eentry + EXCCODE_INT_END * VECSIZE) {
+ unsigned long func;
+ unsigned long type = (ra - eentry) / VECSIZE;
+ unsigned long offset = (ra - eentry) % VECSIZE;
+
+ switch (type) {
+ case 0 ... EXCCODE_INT_START - 1:
+ func = (unsigned long)exception_table[type];
+ break;
+ case EXCCODE_INT_START ... EXCCODE_INT_END:
+ func = (unsigned long)handle_vint;
+ break;
+ default:
+ func = (unsigned long)handle_reserved;
+ break;
+ }
+
+ return func + offset;
+ }
+
+ return ra;
+}
+
+bool unwind_next_frame(struct unwind_state *state)
+{
+ unsigned long *p, pc;
+ struct pt_regs *regs;
+ struct orc_entry *orc;
+ struct stack_info *info = &state->stack_info;
+
+ if (unwind_done(state))
+ return false;
+
+ /* Don't let modules unload while we're reading their ORC data. */
+ preempt_disable();
+
+ if (is_entry_func(state->pc))
+ goto end;
+
+ orc = orc_find(state->pc);
+ 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;
+ } else {
+ if (orc->type == ORC_TYPE_UNDEFINED)
+ goto err;
+
+ if (orc->type == ORC_TYPE_END_OF_STACK)
+ goto end;
+ }
+
+ switch (orc->sp_reg) {
+ case ORC_REG_SP:
+ if (info->type == STACK_TYPE_IRQ && state->sp == info->end)
+ orc->type = ORC_TYPE_REGS;
+ else
+ state->sp = state->sp + orc->sp_offset;
+ break;
+ case ORC_REG_FP:
+ state->sp = state->fp;
+ break;
+ default:
+ orc_warn("unknown SP base reg %d at %pB\n", orc->sp_reg, (void *)state->pc);
+ goto err;
+ }
+
+ switch (orc->fp_reg) {
+ case ORC_REG_PREV_SP:
+ p = (unsigned long *)(state->sp + orc->fp_offset);
+ if (!stack_access_ok(state, (unsigned long)p, sizeof(unsigned long)))
+ goto err;
+
+ state->fp = *p;
+ break;
+ case ORC_REG_UNDEFINED:
+ /* Nothing. */
+ break;
+ default:
+ orc_warn("unknown FP base reg %d at %pB\n", orc->fp_reg, (void *)state->pc);
+ goto err;
+ }
+
+ switch (orc->type) {
+ case ORC_TYPE_CALL:
+ if (orc->ra_reg == ORC_REG_PREV_SP) {
+ p = (unsigned long *)(state->sp + orc->ra_offset);
+ if (!stack_access_ok(state, (unsigned long)p, sizeof(unsigned long)))
+ goto err;
+
+ pc = unwind_graph_addr(state, *p, state->sp);
+ pc -= LOONGARCH_INSN_SIZE;
+ } else if (orc->ra_reg == ORC_REG_UNDEFINED) {
+ if (!state->ra || state->ra == state->pc)
+ goto err;
+
+ pc = unwind_graph_addr(state, state->ra, state->sp);
+ pc -= LOONGARCH_INSN_SIZE;
+ state->ra = 0;
+ } else {
+ orc_warn("unknown ra base reg %d at %pB\n", orc->ra_reg, (void *)state->pc);
+ goto err;
+ }
+ break;
+ case ORC_TYPE_REGS:
+ if (info->type == STACK_TYPE_IRQ && state->sp == info->end)
+ regs = (struct pt_regs *)info->next_sp;
+ else
+ regs = (struct pt_regs *)state->sp;
+
+ if (!stack_access_ok(state, (unsigned long)regs, sizeof(*regs)))
+ goto err;
+
+ if ((info->end == (unsigned long)regs + sizeof(*regs)) &&
+ !regs->regs[3] && !regs->regs[1])
+ goto end;
+
+ if (user_mode(regs))
+ goto end;
+
+ pc = regs->csr_era;
+ if (!__kernel_text_address(pc))
+ goto err;
+
+ state->sp = regs->regs[3];
+ state->ra = regs->regs[1];
+ state->fp = regs->regs[22];
+ get_stack_info(state->sp, state->task, info);
+
+ break;
+ default:
+ orc_warn("unknown .orc_unwind entry type %d at %pB\n", orc->type, (void *)state->pc);
+ goto err;
+ }
+
+ state->pc = bt_address(pc);
+ if (!state->pc) {
+ pr_err("cannot find unwind pc at %pK\n", (void *)pc);
+ goto err;
+ }
+
+ if (!__kernel_text_address(state->pc))
+ goto err;
+
+ preempt_enable();
+ return true;
+
+err:
+ state->error = true;
+
+end:
+ preempt_enable();
+ state->stack_info.type = STACK_TYPE_UNKNOWN;
+ return false;
+}
+EXPORT_SYMBOL_GPL(unwind_next_frame);
diff --git a/arch/loongarch/kernel/vmlinux.lds.S b/arch/loongarch/kernel/vmlinux.lds.S
index a5d0cd2035da..e8e97dbf9ca4 100644
--- a/arch/loongarch/kernel/vmlinux.lds.S
+++ b/arch/loongarch/kernel/vmlinux.lds.S
@@ -2,6 +2,7 @@
#include <linux/sizes.h>
#include <asm/asm-offsets.h>
#include <asm/thread_info.h>
+#include <asm/orc_lookup.h>
#define PAGE_SIZE _PAGE_SIZE
#define RO_EXCEPTION_TABLE_ALIGN 4
@@ -122,6 +123,8 @@ SECTIONS
}
#endif
+ ORC_UNWIND_TABLE
+
.sdata : {
*(.sdata)
}