ARC: dw2 unwind: Reinstante unwinding out of modules

The fix which removed linear searching of dwarf (because binary lookup
data always exists) missed out on the fact that modules don't get the
binary lookup tables info. This caused unwinding out of modules to stop
working.

So add binary lookup header setup (equivalent of eh_frame_hdr setup) to
modules as well.

While at it, confine the header setup to within unwinder code,
reducing one API exposed out of unwinder code.

Fixes: 2e22502c080f ARC: dw2 unwind: Remove falllback linear search thru FDE entries
Cc: <stable@vger.kernel.org>
Signed-off-by: Vineet Gupta <vgupta@synopsys.com>

diff --git a/arch/arc/include/asm/unwind.h b/arch/arc/include/asm/unwind.h
index 7ca628b6ee2aa6d1e02f6ad01363990439ec10b7..c11a25bb8158dee7f60a5f00ca8ec0addaf54b56 100644 (file)
--- a/arch/arc/include/asm/unwind.h
+++ b/arch/arc/include/asm/unwind.h
@@ -112,7 +112,6 @@ struct unwind_frame_info {
 
 extern int arc_unwind(struct unwind_frame_info *frame);
 extern void arc_unwind_init(void);
-extern void arc_unwind_setup(void);
 extern void *unwind_add_table(struct module *module, const void *table_start,
                              unsigned long table_size);
 extern void unwind_remove_table(void *handle, int init_only);
@@ -152,9 +151,6 @@ static inline void arc_unwind_init(void)
 {
 }
 
-static inline void arc_unwind_setup(void)
-{
-}
 #define unwind_add_table(a, b, c)
 #define unwind_remove_table(a, b)
 

diff --git a/arch/arc/kernel/setup.c b/arch/arc/kernel/setup.c
index c33e77c0ad3e9eb60367b6c2510c4e35c60d3b52..e1b87444ea9a0740b9651ad6b68fd39f701121a0 100644 (file)
--- a/arch/arc/kernel/setup.c
+++ b/arch/arc/kernel/setup.c
@@ -429,7 +429,6 @@ void __init setup_arch(char **cmdline_p)
 #endif
 
        arc_unwind_init();
-       arc_unwind_setup();
 }
 
 static int __init customize_machine(void)

diff --git a/arch/arc/kernel/unwind.c b/arch/arc/kernel/unwind.c
index 7352475451f6c3798885c97b04c11ddd53146990..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);
 }