ARC: dw2 unwind: Reinstante unwinding out of modules

[firefly-linux-kernel-4.4.55.git] / arch / arc / kernel / unwind.c

diff --git a/arch/arc/kernel/unwind.c b/arch/arc/kernel/unwind.c
index 93c6ea52b6719e4e238d6076fda6c3b981ac48fe..9f9ecc15556e5afb1b706f80c854b9d2d78d8892 100644 (file)
--- a/arch/arc/kernel/unwind.c
+++ b/arch/arc/kernel/unwind.c
@@ -170,6 +170,23 @@ static struct unwind_table *find_table(unsigned long pc)
 
 static unsigned long read_pointer(const u8 **pLoc,
                                  const void *end, signed ptrType);
+static void init_unwind_hdr(struct unwind_table *table,
+                           void *(*alloc) (unsigned long));
+
+/*
+ * wrappers for header alloc (vs. calling one vs. other at call site)
+ * to elide section mismatches warnings
+ */
+static void *__init unw_hdr_alloc_early(unsigned long sz)
+{
+       return __alloc_bootmem_nopanic(sz, sizeof(unsigned int),
+                                      MAX_DMA_ADDRESS);
+}
+
+static void *unw_hdr_alloc(unsigned long sz)
+{
+       return kmalloc(sz, GFP_KERNEL);
+}
 
 static void init_unwind_table(struct unwind_table *table, const char *name,
                              const void *core_start, unsigned long core_size,
@@ -209,6 +226,8 @@ void __init arc_unwind_init(void)
                          __start_unwind, __end_unwind - __start_unwind,
                          NULL, 0);
          /*__start_unwind_hdr, __end_unwind_hdr - __start_unwind_hdr);*/
+
+       init_unwind_hdr(&root_table, unw_hdr_alloc_early);
 }
 
 static const u32 bad_cie, not_fde;
@@ -241,8 +260,8 @@ static void swap_eh_frame_hdr_table_entries(void *p1, void *p2, int size)
        e2->fde = v;
 }
 
-static void __init setup_unwind_table(struct unwind_table *table,
-                                     void *(*alloc) (unsigned long))
+static void init_unwind_hdr(struct unwind_table *table,
+                           void *(*alloc) (unsigned long))
 {
        const u8 *ptr;
        unsigned long tableSize = table->size, hdrSize;
@@ -300,9 +319,11 @@ static void __init setup_unwind_table(struct unwind_table *table,
 
        hdrSize = 4 + sizeof(unsigned long) + sizeof(unsigned int)
            + 2 * n * sizeof(unsigned long);
+
        header = alloc(hdrSize);
        if (!header)
                return;
+
        header->version = 1;
        header->eh_frame_ptr_enc = DW_EH_PE_abs | DW_EH_PE_native;
        header->fde_count_enc = DW_EH_PE_abs | DW_EH_PE_data4;
@@ -342,18 +363,6 @@ static void __init setup_unwind_table(struct unwind_table *table,
        table->header = (const void *)header;
 }
 
-static void *__init balloc(unsigned long sz)
-{
-       return __alloc_bootmem_nopanic(sz,
-                                      sizeof(unsigned int),
-                                      __pa(MAX_DMA_ADDRESS));
-}
-
-void __init arc_unwind_setup(void)
-{
-       setup_unwind_table(&root_table, balloc);
-}
-
 #ifdef CONFIG_MODULES
 
 static struct unwind_table *last_table;
@@ -377,6 +386,8 @@ void *unwind_add_table(struct module *module, const void *table_start,
                          table_start, table_size,
                          NULL, 0);
 
+       init_unwind_hdr(table, unw_hdr_alloc);
+
 #ifdef UNWIND_DEBUG
        unw_debug("Table added for [%s] %lx %lx\n",
                module->name, table->core.pc, table->core.range);
@@ -439,6 +450,7 @@ void unwind_remove_table(void *handle, int init_only)
        info.init_only = init_only;
 
        unlink_table(&info); /* XXX: SMP */
+       kfree(table->header);
        kfree(table);
 }
 
@@ -986,42 +998,13 @@ int arc_unwind(struct unwind_frame_info *frame)
                                                            (const u8 *)(fde +
                                                                         1) +
                                                            *fde, ptrType);
-                               if (pc >= endLoc)
+                               if (pc >= endLoc) {
                                        fde = NULL;
-                       } else
-                               fde = NULL;
-               }
-               if (fde == NULL) {
-                       for (fde = table->address, tableSize = table->size;
-                            cie = NULL, tableSize > sizeof(*fde)
-                            && tableSize - sizeof(*fde) >= *fde;
-                            tableSize -= sizeof(*fde) + *fde,
-                            fde += 1 + *fde / sizeof(*fde)) {
-                               cie = cie_for_fde(fde, table);
-                               if (cie == &bad_cie) {
                                        cie = NULL;
-                                       break;
                                }
-                               if (cie == NULL
-                                   || cie == &not_fde
-                                   || (ptrType = fde_pointer_type(cie)) < 0)
-                                       continue;
-                               ptr = (const u8 *)(fde + 2);
-                               startLoc = read_pointer(&ptr,
-                                                       (const u8 *)(fde + 1) +
-                                                       *fde, ptrType);
-                               if (!startLoc)
-                                       continue;
-                               if (!(ptrType & DW_EH_PE_indirect))
-                                       ptrType &=
-                                           DW_EH_PE_FORM | DW_EH_PE_signed;
-                               endLoc =
-                                   startLoc + read_pointer(&ptr,
-                                                           (const u8 *)(fde +
-                                                                        1) +
-                                                           *fde, ptrType);
-                               if (pc >= startLoc && pc < endLoc)
-                                       break;
+                       } else {
+                               fde = NULL;
+                               cie = NULL;
                        }
                }
        }