diff options
Diffstat (limited to 'arch/sh/kernel/dwarf.c')
| -rw-r--r-- | arch/sh/kernel/dwarf.c | 219 |
1 files changed, 163 insertions, 56 deletions
diff --git a/arch/sh/kernel/dwarf.c b/arch/sh/kernel/dwarf.c index 3576b709f052..49c09c7d5b77 100644 --- a/arch/sh/kernel/dwarf.c +++ b/arch/sh/kernel/dwarf.c @@ -22,6 +22,8 @@ #include <linux/mm.h> #include <linux/elf.h> #include <linux/ftrace.h> +#include <linux/module.h> +#include <linux/slab.h> #include <asm/dwarf.h> #include <asm/unwinder.h> #include <asm/sections.h> @@ -39,14 +41,16 @@ static mempool_t *dwarf_frame_pool; 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 unsigned int dwarf_unwinder_ready; + /** * dwarf_frame_alloc_reg - allocate memory for a DWARF register * @frame: the DWARF frame whose list of registers we insert on @@ -301,7 +305,8 @@ static inline int dwarf_entry_len(char *addr, unsigned long *len) */ 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); @@ -315,16 +320,24 @@ static struct dwarf_cie *dwarf_lookup_cie(unsigned long cie_ptr) 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; @@ -336,25 +349,34 @@ out: */ 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; @@ -540,6 +562,8 @@ void dwarf_free_frame(struct dwarf_frame *frame) mempool_free(frame, dwarf_frame_pool); } +extern void ret_from_irq(void); + /** * dwarf_unwind_stack - unwind the stack * @@ -550,8 +574,8 @@ void dwarf_free_frame(struct dwarf_frame *frame) * 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; @@ -560,6 +584,13 @@ struct dwarf_frame * dwarf_unwind_stack(unsigned long pc, unsigned long addr; /* + * If we've been called in to before initialization has + * completed, bail out immediately. + */ + if (!dwarf_unwinder_ready) + return NULL; + + /* * 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. @@ -678,6 +709,24 @@ struct dwarf_frame * dwarf_unwind_stack(unsigned long pc, 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: @@ -688,6 +737,8 @@ 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 = *rb_node; struct dwarf_cie *cie; unsigned long flags; int count; @@ -782,11 +833,32 @@ static int dwarf_parse_cie(void *entry, void *p, unsigned long len, 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); + +#ifdef CONFIG_MODULES + if (mod != NULL) + list_add_tail(&cie->link, &mod->arch.cie_list); +#endif + spin_unlock_irqrestore(&dwarf_cie_lock, flags); return 0; @@ -796,6 +868,8 @@ static int dwarf_parse_fde(void *entry, u32 entry_type, void *start, unsigned long len, unsigned char *end, struct module *mod) { + struct rb_node **rb_node = &fde_root.rb_node; + struct rb_node *parent = *rb_node; struct dwarf_fde *fde; struct dwarf_cie *cie; unsigned long flags; @@ -843,11 +917,40 @@ static int dwarf_parse_fde(void *entry, u32 entry_type, 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); + +#ifdef CONFIG_MODULES + if (mod != NULL) + list_add_tail(&fde->link, &mod->arch.fde_list); +#endif + spin_unlock_irqrestore(&dwarf_fde_lock, flags); return 0; @@ -892,19 +995,29 @@ static struct unwinder dwarf_unwinder = { 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); @@ -1004,6 +1117,8 @@ int module_dwarf_finalize(const Elf_Ehdr *hdr, const Elf_Shdr *sechdrs, /* 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", @@ -1024,38 +1139,26 @@ int module_dwarf_finalize(const Elf_Ehdr *hdr, const Elf_Shdr *sechdrs, */ 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); @@ -1073,9 +1176,7 @@ again_fde: */ static int __init dwarf_unwinder_init(void) { - int err; - INIT_LIST_HEAD(&dwarf_cie_list); - INIT_LIST_HEAD(&dwarf_fde_list); + int err = -ENOMEM; dwarf_frame_cachep = kmem_cache_create("dwarf_frames", sizeof(struct dwarf_frame), 0, @@ -1089,11 +1190,15 @@ static int __init dwarf_unwinder_init(void) mempool_alloc_slab, mempool_free_slab, dwarf_frame_cachep); + if (!dwarf_frame_pool) + goto out; dwarf_reg_pool = mempool_create(DWARF_REG_MIN_REQ, mempool_alloc_slab, mempool_free_slab, dwarf_reg_cachep); + if (!dwarf_reg_pool) + goto out; err = dwarf_parse_section(__start_eh_frame, __stop_eh_frame, NULL); if (err) @@ -1103,11 +1208,13 @@ static int __init dwarf_unwinder_init(void) if (err) goto out; + dwarf_unwinder_ready = 1; + return 0; out: printk(KERN_ERR "Failed to initialise DWARF unwinder: %d\n", err); dwarf_unwinder_cleanup(); - return -EINVAL; + return err; } early_initcall(dwarf_unwinder_init); |