#include <linux/list.h>
#include <linux/mempool.h>
#include <linux/mm.h>
+#include <linux/elf.h>
+#include <linux/ftrace.h>
#include <asm/dwarf.h>
#include <asm/unwinder.h>
#include <asm/sections.h>
static struct kmem_cache *dwarf_reg_cachep;
static mempool_t *dwarf_reg_pool;
-static LIST_HEAD(dwarf_cie_list);
+static struct rb_root cie_root;
static DEFINE_SPINLOCK(dwarf_cie_lock);
-static LIST_HEAD(dwarf_fde_list);
+static struct rb_root fde_root;
static DEFINE_SPINLOCK(dwarf_fde_lock);
static struct dwarf_cie *cached_cie;
*/
static struct dwarf_cie *dwarf_lookup_cie(unsigned long cie_ptr)
{
- struct dwarf_cie *cie;
+ struct rb_node **rb_node = &cie_root.rb_node;
+ struct dwarf_cie *cie = NULL;
unsigned long flags;
spin_lock_irqsave(&dwarf_cie_lock, flags);
goto out;
}
- list_for_each_entry(cie, &dwarf_cie_list, link) {
- if (cie->cie_pointer == cie_ptr) {
- cached_cie = cie;
- break;
+ while (*rb_node) {
+ struct dwarf_cie *cie_tmp;
+
+ cie_tmp = rb_entry(*rb_node, struct dwarf_cie, node);
+ BUG_ON(!cie_tmp);
+
+ if (cie_ptr == cie_tmp->cie_pointer) {
+ cie = cie_tmp;
+ cached_cie = cie_tmp;
+ goto out;
+ } else {
+ if (cie_ptr < cie_tmp->cie_pointer)
+ rb_node = &(*rb_node)->rb_left;
+ else
+ rb_node = &(*rb_node)->rb_right;
}
}
- /* Couldn't find the entry in the list. */
- if (&cie->link == &dwarf_cie_list)
- cie = NULL;
out:
spin_unlock_irqrestore(&dwarf_cie_lock, flags);
return cie;
*/
struct dwarf_fde *dwarf_lookup_fde(unsigned long pc)
{
- struct dwarf_fde *fde;
+ struct rb_node **rb_node = &fde_root.rb_node;
+ struct dwarf_fde *fde = NULL;
unsigned long flags;
spin_lock_irqsave(&dwarf_fde_lock, flags);
- list_for_each_entry(fde, &dwarf_fde_list, link) {
- unsigned long start, end;
+ while (*rb_node) {
+ struct dwarf_fde *fde_tmp;
+ unsigned long tmp_start, tmp_end;
- start = fde->initial_location;
- end = fde->initial_location + fde->address_range;
+ fde_tmp = rb_entry(*rb_node, struct dwarf_fde, node);
+ BUG_ON(!fde_tmp);
- if (pc >= start && pc < end)
- break;
- }
+ tmp_start = fde_tmp->initial_location;
+ tmp_end = fde_tmp->initial_location + fde_tmp->address_range;
- /* Couldn't find the entry in the list. */
- if (&fde->link == &dwarf_fde_list)
- fde = NULL;
+ if (pc < tmp_start) {
+ rb_node = &(*rb_node)->rb_left;
+ } else {
+ if (pc < tmp_end) {
+ fde = fde_tmp;
+ goto out;
+ } else
+ rb_node = &(*rb_node)->rb_right;
+ }
+ }
+out:
spin_unlock_irqrestore(&dwarf_fde_lock, flags);
return fde;
mempool_free(frame, dwarf_frame_pool);
}
+extern void ret_from_irq(void);
+
/**
* dwarf_unwind_stack - unwind the stack
*
* on the callstack. Each of the lower (older) stack frames are
* linked via the "prev" member.
*/
-struct dwarf_frame * dwarf_unwind_stack(unsigned long pc,
- struct dwarf_frame *prev)
+struct dwarf_frame *dwarf_unwind_stack(unsigned long pc,
+ struct dwarf_frame *prev)
{
struct dwarf_frame *frame;
struct dwarf_cie *cie;
* NOTE: the return address is guaranteed to be setup by the
* time this function makes its first function call.
*/
- if (!pc && !prev)
+ if (!pc || !prev)
pc = (unsigned long)current_text_addr();
+#ifdef CONFIG_FUNCTION_GRAPH_TRACER
+ /*
+ * If our stack has been patched by the function graph tracer
+ * then we might see the address of return_to_handler() where we
+ * expected to find the real return address.
+ */
+ if (pc == (unsigned long)&return_to_handler) {
+ int index = current->curr_ret_stack;
+
+ /*
+ * We currently have no way of tracking how many
+ * return_to_handler()'s we've seen. If there is more
+ * than one patched return address on our stack,
+ * complain loudly.
+ */
+ WARN_ON(index > 0);
+
+ pc = current->ret_stack[index].ret;
+ }
+#endif
+
frame = mempool_alloc(dwarf_frame_pool, GFP_ATOMIC);
if (!frame) {
printk(KERN_ERR "Unable to allocate a dwarf frame\n");
addr = frame->cfa + reg->addr;
frame->return_addr = __raw_readl(addr);
+ /*
+ * Ah, the joys of unwinding through interrupts.
+ *
+ * Interrupts are tricky - the DWARF info needs to be _really_
+ * accurate and unfortunately I'm seeing a lot of bogus DWARF
+ * info. For example, I've seen interrupts occur in epilogues
+ * just after the frame pointer (r14) had been restored. The
+ * problem was that the DWARF info claimed that the CFA could be
+ * reached by using the value of the frame pointer before it was
+ * restored.
+ *
+ * So until the compiler can be trusted to produce reliable
+ * DWARF info when it really matters, let's stop unwinding once
+ * we've calculated the function that was interrupted.
+ */
+ if (prev && prev->pc == (unsigned long)ret_from_irq)
+ frame->return_addr = 0;
+
return frame;
bail:
static int dwarf_parse_cie(void *entry, void *p, unsigned long len,
unsigned char *end, struct module *mod)
{
+ struct rb_node **rb_node = &cie_root.rb_node;
+ struct rb_node *parent;
struct dwarf_cie *cie;
unsigned long flags;
int count;
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);
+
+ while (*rb_node) {
+ struct dwarf_cie *cie_tmp;
+
+ cie_tmp = rb_entry(*rb_node, struct dwarf_cie, node);
+
+ parent = *rb_node;
+
+ if (cie->cie_pointer < cie_tmp->cie_pointer)
+ rb_node = &parent->rb_left;
+ else if (cie->cie_pointer >= cie_tmp->cie_pointer)
+ rb_node = &parent->rb_right;
+ else
+ WARN_ON(1);
+ }
+
+ rb_link_node(&cie->node, parent, rb_node);
+ rb_insert_color(&cie->node, &cie_root);
+
+ if (mod != NULL)
+ list_add_tail(&cie->link, &mod->arch.cie_list);
+
spin_unlock_irqrestore(&dwarf_cie_lock, flags);
return 0;
void *start, unsigned long len,
unsigned char *end, struct module *mod)
{
+ struct rb_node **rb_node = &fde_root.rb_node;
+ struct rb_node *parent;
struct dwarf_fde *fde;
struct dwarf_cie *cie;
unsigned long flags;
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);
+
+ while (*rb_node) {
+ struct dwarf_fde *fde_tmp;
+ unsigned long tmp_start, tmp_end;
+ unsigned long start, end;
+
+ fde_tmp = rb_entry(*rb_node, struct dwarf_fde, node);
+
+ start = fde->initial_location;
+ end = fde->initial_location + fde->address_range;
+
+ tmp_start = fde_tmp->initial_location;
+ tmp_end = fde_tmp->initial_location + fde_tmp->address_range;
+
+ parent = *rb_node;
+
+ if (start < tmp_start)
+ rb_node = &parent->rb_left;
+ else if (start >= tmp_end)
+ rb_node = &parent->rb_right;
+ else
+ WARN_ON(1);
+ }
+
+ rb_link_node(&fde->node, parent, rb_node);
+ rb_insert_color(&fde->node, &fde_root);
+
+ if (mod != NULL)
+ list_add_tail(&fde->link, &mod->arch.fde_list);
+
spin_unlock_irqrestore(&dwarf_fde_lock, flags);
return 0;
static void dwarf_unwinder_cleanup(void)
{
- struct dwarf_cie *cie;
- struct dwarf_fde *fde;
+ struct rb_node **fde_rb_node = &fde_root.rb_node;
+ struct rb_node **cie_rb_node = &cie_root.rb_node;
/*
* Deallocate all the memory allocated for the DWARF unwinder.
* Traverse all the FDE/CIE lists and remove and free all the
* memory associated with those data structures.
*/
- list_for_each_entry(cie, &dwarf_cie_list, link)
- kfree(cie);
+ while (*fde_rb_node) {
+ struct dwarf_fde *fde;
- list_for_each_entry(fde, &dwarf_fde_list, link)
+ fde = rb_entry(*fde_rb_node, struct dwarf_fde, node);
+ rb_erase(*fde_rb_node, &fde_root);
kfree(fde);
+ }
+
+ while (*cie_rb_node) {
+ struct dwarf_cie *cie;
+
+ cie = rb_entry(*cie_rb_node, struct dwarf_cie, node);
+ rb_erase(*cie_rb_node, &cie_root);
+ kfree(cie);
+ }
kmem_cache_destroy(dwarf_reg_cachep);
kmem_cache_destroy(dwarf_frame_cachep);
*
* Parse the information in a .eh_frame section.
*/
-int dwarf_parse_section(char *eh_frame_start, char *eh_frame_end,
- struct module *mod)
+static 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 long len = 0;
unsigned int c_entries, f_entries;
unsigned char *end;
return err;
}
+#ifdef CONFIG_MODULES
+int module_dwarf_finalize(const Elf_Ehdr *hdr, const Elf_Shdr *sechdrs,
+ struct module *me)
+{
+ unsigned int i, err;
+ unsigned long start, end;
+ char *secstrings = (void *)hdr + sechdrs[hdr->e_shstrndx].sh_offset;
+
+ start = end = 0;
+
+ for (i = 1; i < hdr->e_shnum; i++) {
+ /* Alloc bit cleared means "ignore it." */
+ if ((sechdrs[i].sh_flags & SHF_ALLOC)
+ && !strcmp(secstrings+sechdrs[i].sh_name, ".eh_frame")) {
+ start = sechdrs[i].sh_addr;
+ end = start + sechdrs[i].sh_size;
+ break;
+ }
+ }
+
+ /* Did we find the .eh_frame section? */
+ if (i != hdr->e_shnum) {
+ INIT_LIST_HEAD(&me->arch.cie_list);
+ INIT_LIST_HEAD(&me->arch.fde_list);
+ err = dwarf_parse_section((char *)start, (char *)end, me);
+ if (err) {
+ printk(KERN_WARNING "%s: failed to parse DWARF info\n",
+ me->name);
+ return err;
+ }
+ }
+
+ return 0;
+}
+
/**
- * dwarf_module_unload - remove FDE/CIEs associated with @mod
+ * module_dwarf_cleanup - 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)
+void module_dwarf_cleanup(struct module *mod)
{
- struct dwarf_fde *fde;
- struct dwarf_cie *cie;
+ struct dwarf_fde *fde, *ftmp;
+ struct dwarf_cie *cie, *ctmp;
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_for_each_entry_safe(cie, ctmp, &mod->arch.cie_list, link) {
list_del(&cie->link);
+ rb_erase(&cie->node, &cie_root);
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_for_each_entry_safe(fde, ftmp, &mod->arch.fde_list, link) {
list_del(&fde->link);
+ rb_erase(&fde->node, &fde_root);
kfree(fde);
- goto again_fde;
}
spin_unlock_irqrestore(&dwarf_fde_lock, flags);
}
+#endif /* CONFIG_MODULES */
/**
* dwarf_unwinder_init - initialise the dwarf unwinder
static int __init dwarf_unwinder_init(void)
{
int err;
- INIT_LIST_HEAD(&dwarf_cie_list);
- INIT_LIST_HEAD(&dwarf_fde_list);
dwarf_frame_cachep = kmem_cache_create("dwarf_frames",
sizeof(struct dwarf_frame), 0,
git://ftp.safe.ca / safe / jmp / linux-2.6 / blobdiff