Merge branch 'sh/dwarf-unwinder'
Conflicts:
arch/sh/kernel/dwarf.c
diff --git a/arch/sh/kernel/dwarf.c b/arch/sh/kernel/dwarf.c
index 03b3616..c274039 100644
--- a/arch/sh/kernel/dwarf.c
+++ b/arch/sh/kernel/dwarf.c
@@ -529,7 +529,18 @@
}
/**
- * dwarf_unwind_stack - recursively unwind the stack
+ * dwarf_free_frame - free the memory allocated for @frame
+ * @frame: the frame to free
+ */
+void dwarf_free_frame(struct dwarf_frame *frame)
+{
+ dwarf_frame_free_regs(frame);
+ mempool_free(frame, dwarf_frame_pool);
+}
+
+/**
+ * dwarf_unwind_stack - unwind the stack
+ *
* @pc: address of the function to unwind
* @prev: struct dwarf_frame of the previous stackframe on the callstack
*
@@ -547,9 +558,9 @@
unsigned long addr;
/*
- * If this is the first invocation of this recursive function we
- * need get the contents of a physical register to get the CFA
- * in order to begin the virtual unwinding of the stack.
+ * If we're starting at the top of the stack we need get the
+ * contents of a physical register to get the CFA in order to
+ * begin the virtual unwinding of the stack.
*
* NOTE: the return address is guaranteed to be setup by the
* time this function makes its first function call.
@@ -571,9 +582,8 @@
fde = dwarf_lookup_fde(pc);
if (!fde) {
/*
- * This is our normal exit path - the one that stops the
- * recursion. There's two reasons why we might exit
- * here,
+ * This is our normal exit path. There are two reasons
+ * why we might exit here,
*
* a) pc has no asscociated DWARF frame info and so
* we don't know how to unwind this frame. This is
@@ -615,10 +625,10 @@
} else {
/*
- * Again, this is the first invocation of this
- * recurisve function. We need to physically
- * read the contents of a register in order to
- * get the Canonical Frame Address for this
+ * Again, we're starting from the top of the
+ * stack. We need to physically read
+ * the contents of a register in order to get
+ * the Canonical Frame Address for this
* function.
*/
frame->cfa = dwarf_read_arch_reg(frame->cfa_register);
@@ -648,13 +658,12 @@
return frame;
bail:
- dwarf_frame_free_regs(frame);
- mempool_free(frame, dwarf_frame_pool);
+ dwarf_free_frame(frame);
return NULL;
}
static int dwarf_parse_cie(void *entry, void *p, unsigned long len,
- unsigned char *end)
+ unsigned char *end, struct module *mod)
{
struct dwarf_cie *cie;
unsigned long flags;
@@ -750,6 +759,8 @@
cie->initial_instructions = p;
cie->instructions_end = end;
+ cie->mod = mod;
+
/* Add to list */
spin_lock_irqsave(&dwarf_cie_lock, flags);
list_add_tail(&cie->link, &dwarf_cie_list);
@@ -760,7 +771,7 @@
static int dwarf_parse_fde(void *entry, u32 entry_type,
void *start, unsigned long len,
- unsigned char *end)
+ unsigned char *end, struct module *mod)
{
struct dwarf_fde *fde;
struct dwarf_cie *cie;
@@ -809,6 +820,8 @@
fde->instructions = p;
fde->end = end;
+ fde->mod = mod;
+
/* Add to list. */
spin_lock_irqsave(&dwarf_fde_lock, flags);
list_add_tail(&fde->link, &dwarf_fde_list);
@@ -832,10 +845,8 @@
while (1) {
frame = dwarf_unwind_stack(return_addr, _frame);
- if (_frame) {
- dwarf_frame_free_regs(_frame);
- mempool_free(_frame, dwarf_frame_pool);
- }
+ if (_frame)
+ dwarf_free_frame(_frame);
_frame = frame;
@@ -845,6 +856,9 @@
return_addr = frame->return_addr;
ops->address(data, return_addr, 1);
}
+
+ if (frame)
+ dwarf_free_frame(frame);
}
static struct unwinder dwarf_unwinder = {
@@ -874,6 +888,124 @@
}
/**
+ * dwarf_parse_section - parse DWARF section
+ * @eh_frame_start: start address of the .eh_frame section
+ * @eh_frame_end: end address of the .eh_frame section
+ * @mod: the kernel module containing the .eh_frame section
+ *
+ * Parse the information in a .eh_frame section.
+ */
+int dwarf_parse_section(char *eh_frame_start, char *eh_frame_end,
+ struct module *mod)
+{
+ u32 entry_type;
+ void *p, *entry;
+ int count, err = 0;
+ unsigned long len;
+ unsigned int c_entries, f_entries;
+ unsigned char *end;
+
+ c_entries = 0;
+ f_entries = 0;
+ entry = eh_frame_start;
+
+ while ((char *)entry < eh_frame_end) {
+ p = entry;
+
+ count = dwarf_entry_len(p, &len);
+ if (count == 0) {
+ /*
+ * We read a bogus length field value. There is
+ * nothing we can do here apart from disabling
+ * the DWARF unwinder. We can't even skip this
+ * entry and move to the next one because 'len'
+ * tells us where our next entry is.
+ */
+ err = -EINVAL;
+ goto out;
+ } else
+ p += count;
+
+ /* initial length does not include itself */
+ end = p + len;
+
+ entry_type = get_unaligned((u32 *)p);
+ p += 4;
+
+ if (entry_type == DW_EH_FRAME_CIE) {
+ err = dwarf_parse_cie(entry, p, len, end, mod);
+ if (err < 0)
+ goto out;
+ else
+ c_entries++;
+ } else {
+ err = dwarf_parse_fde(entry, entry_type, p, len,
+ end, mod);
+ if (err < 0)
+ goto out;
+ else
+ f_entries++;
+ }
+
+ entry = (char *)entry + len + 4;
+ }
+
+ printk(KERN_INFO "DWARF unwinder initialised: read %u CIEs, %u FDEs\n",
+ c_entries, f_entries);
+
+ return 0;
+
+out:
+ return err;
+}
+
+/**
+ * dwarf_module_unload - remove FDE/CIEs associated with @mod
+ * @mod: the module that is being unloaded
+ *
+ * Remove any FDEs and CIEs from the global lists that came from
+ * @mod's .eh_frame section because @mod is being unloaded.
+ */
+void dwarf_module_unload(struct module *mod)
+{
+ struct dwarf_fde *fde;
+ struct dwarf_cie *cie;
+ unsigned long flags;
+
+ spin_lock_irqsave(&dwarf_cie_lock, flags);
+
+again_cie:
+ list_for_each_entry(cie, &dwarf_cie_list, link) {
+ if (cie->mod == mod)
+ break;
+ }
+
+ if (&cie->link != &dwarf_cie_list) {
+ list_del(&cie->link);
+ kfree(cie);
+ goto again_cie;
+ }
+
+ spin_unlock_irqrestore(&dwarf_cie_lock, flags);
+
+ spin_lock_irqsave(&dwarf_fde_lock, flags);
+
+again_fde:
+ list_for_each_entry(fde, &dwarf_fde_list, link) {
+ if (fde->mod == mod)
+ break;
+ }
+
+ if (&fde->link != &dwarf_fde_list) {
+ list_del(&fde->link);
+ kfree(fde);
+ goto again_fde;
+ }
+
+ spin_unlock_irqrestore(&dwarf_fde_lock, flags);
+}
+
+/**
* dwarf_unwinder_init - initialise the dwarf unwinder
*
* Build the data structures describing the .dwarf_frame section to
@@ -884,19 +1016,10 @@
*/
static int __init dwarf_unwinder_init(void)
{
- u32 entry_type;
- void *p, *entry;
- int count, err = 0;
- unsigned long len;
- unsigned int c_entries, f_entries;
- unsigned char *end;
+ int err;
INIT_LIST_HEAD(&dwarf_cie_list);
INIT_LIST_HEAD(&dwarf_fde_list);
- c_entries = 0;
- f_entries = 0;
- entry = &__start_eh_frame;
-
dwarf_frame_cachep = kmem_cache_create("dwarf_frames",
sizeof(struct dwarf_frame), 0,
SLAB_PANIC | SLAB_HWCACHE_ALIGN | SLAB_NOTRACK, NULL);
@@ -915,47 +1038,9 @@
mempool_free_slab,
dwarf_reg_cachep);
- while ((char *)entry < __stop_eh_frame) {
- p = entry;
-
- count = dwarf_entry_len(p, &len);
- if (count == 0) {
- /*
- * We read a bogus length field value. There is
- * nothing we can do here apart from disabling
- * the DWARF unwinder. We can't even skip this
- * entry and move to the next one because 'len'
- * tells us where our next entry is.
- */
- goto out;
- } else
- p += count;
-
- /* initial length does not include itself */
- end = p + len;
-
- entry_type = get_unaligned((u32 *)p);
- p += 4;
-
- if (entry_type == DW_EH_FRAME_CIE) {
- err = dwarf_parse_cie(entry, p, len, end);
- if (err < 0)
- goto out;
- else
- c_entries++;
- } else {
- err = dwarf_parse_fde(entry, entry_type, p, len, end);
- if (err < 0)
- goto out;
- else
- f_entries++;
- }
-
- entry = (char *)entry + len + 4;
- }
-
- printk(KERN_INFO "DWARF unwinder initialised: read %u CIEs, %u FDEs\n",
- c_entries, f_entries);
+ err = dwarf_parse_section(__start_eh_frame, __stop_eh_frame, NULL);
+ if (err)
+ goto out;
err = unwinder_register(&dwarf_unwinder);
if (err)