diff options
| -rw-r--r-- | arch/sh/include/asm/dwarf.h | 16 | ||||
| -rw-r--r-- | arch/sh/kernel/dwarf.c | 185 | ||||
| -rw-r--r-- | arch/sh/kernel/module.c | 32 |
3 files changed, 183 insertions, 50 deletions
diff --git a/arch/sh/include/asm/dwarf.h b/arch/sh/include/asm/dwarf.h index ced6795891a..fc51e66f238 100644 --- a/arch/sh/include/asm/dwarf.h +++ b/arch/sh/include/asm/dwarf.h @@ -241,6 +241,12 @@ struct dwarf_cie { unsigned long flags; #define DWARF_CIE_Z_AUGMENTATION (1 << 0) + + /* + * 'mod' will be non-NULL if this CIE came from a module's + * .eh_frame section. + */ + struct module *mod; }; /** @@ -255,6 +261,12 @@ struct dwarf_fde { unsigned char *instructions; unsigned char *end; struct list_head link; + + /* + * 'mod' will be non-NULL if this FDE came from a module's + * .eh_frame section. + */ + struct module *mod; }; /** @@ -364,6 +376,10 @@ static inline unsigned int DW_CFA_operand(unsigned long insn) extern struct dwarf_frame *dwarf_unwind_stack(unsigned long, struct dwarf_frame *); +extern void dwarf_free_frame(struct dwarf_frame *); +extern int dwarf_parse_section(char *, char *, struct module *); +extern void dwarf_module_unload(struct module *); + #endif /* !__ASSEMBLY__ */ #define CFI_STARTPROC .cfi_startproc diff --git a/arch/sh/kernel/dwarf.c b/arch/sh/kernel/dwarf.c index 03b3616c80a..c274039e9c8 100644 --- a/arch/sh/kernel/dwarf.c +++ b/arch/sh/kernel/dwarf.c @@ -529,7 +529,18 @@ static int dwarf_cfa_execute_insns(unsigned char *insn_start, } /** - * 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 @@ struct dwarf_frame * dwarf_unwind_stack(unsigned long pc, 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 @@ struct dwarf_frame * dwarf_unwind_stack(unsigned long pc, 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 @@ struct dwarf_frame * dwarf_unwind_stack(unsigned long pc, } 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 @@ struct dwarf_frame * dwarf_unwind_stack(unsigned long pc, 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 @@ 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); @@ -760,7 +771,7 @@ static int dwarf_parse_cie(void *entry, void *p, unsigned long len, 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 @@ 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); @@ -832,10 +845,8 @@ static void dwarf_unwinder_dump(struct task_struct *task, 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 @@ static void dwarf_unwinder_dump(struct task_struct *task, return_addr = frame->return_addr; ops->address(data, return_addr, 1); } + + if (frame) + dwarf_free_frame(frame); } static struct unwinder dwarf_unwinder = { @@ -874,15 +888,15 @@ static void dwarf_unwinder_cleanup(void) } /** - * dwarf_unwinder_init - initialise the dwarf unwinder + * 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 * - * Build the data structures describing the .dwarf_frame section to - * make it easier to lookup CIE and FDE entries. Because the - * .eh_frame section is packed as tightly as possible it is not - * easy to lookup the FDE for a given PC, so we build a list of FDE - * and CIE entries that make it easier. + * Parse the information in a .eh_frame section. */ -static int __init dwarf_unwinder_init(void) +int dwarf_parse_section(char *eh_frame_start, char *eh_frame_end, + struct module *mod) { u32 entry_type; void *p, *entry; @@ -890,32 +904,12 @@ static int __init dwarf_unwinder_init(void) unsigned long len; unsigned int c_entries, f_entries; unsigned char *end; - 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); - - dwarf_reg_cachep = kmem_cache_create("dwarf_regs", - sizeof(struct dwarf_reg), 0, - SLAB_PANIC | SLAB_HWCACHE_ALIGN | SLAB_NOTRACK, NULL); - - dwarf_frame_pool = mempool_create(DWARF_FRAME_MIN_REQ, - mempool_alloc_slab, - mempool_free_slab, - dwarf_frame_cachep); + entry = eh_frame_start; - dwarf_reg_pool = mempool_create(DWARF_REG_MIN_REQ, - mempool_alloc_slab, - mempool_free_slab, - dwarf_reg_cachep); - - while ((char *)entry < __stop_eh_frame) { + while ((char *)entry < eh_frame_end) { p = entry; count = dwarf_entry_len(p, &len); @@ -927,6 +921,7 @@ static int __init dwarf_unwinder_init(void) * entry and move to the next one because 'len' * tells us where our next entry is. */ + err = -EINVAL; goto out; } else p += count; @@ -938,13 +933,14 @@ static int __init dwarf_unwinder_init(void) p += 4; if (entry_type == DW_EH_FRAME_CIE) { - err = dwarf_parse_cie(entry, p, len, end); + 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); + err = dwarf_parse_fde(entry, entry_type, p, len, + end, mod); if (err < 0) goto out; else @@ -957,6 +953,95 @@ static int __init dwarf_unwinder_init(void) 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 + * make it easier to lookup CIE and FDE entries. Because the + * .eh_frame section is packed as tightly as possible it is not + * easy to lookup the FDE for a given PC, so we build a list of FDE + * and CIE entries that make it easier. + */ +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, + SLAB_PANIC | SLAB_HWCACHE_ALIGN | SLAB_NOTRACK, NULL); + + dwarf_reg_cachep = kmem_cache_create("dwarf_regs", + sizeof(struct dwarf_reg), 0, + SLAB_PANIC | SLAB_HWCACHE_ALIGN | SLAB_NOTRACK, NULL); + + dwarf_frame_pool = mempool_create(DWARF_FRAME_MIN_REQ, + mempool_alloc_slab, + mempool_free_slab, + dwarf_frame_cachep); + + dwarf_reg_pool = mempool_create(DWARF_REG_MIN_REQ, + mempool_alloc_slab, + mempool_free_slab, + dwarf_reg_cachep); + + err = dwarf_parse_section(__start_eh_frame, __stop_eh_frame, NULL); + if (err) + goto out; + err = unwinder_register(&dwarf_unwinder); if (err) goto out; diff --git a/arch/sh/kernel/module.c b/arch/sh/kernel/module.c index c2efdcde266..d297a148d16 100644 --- a/arch/sh/kernel/module.c +++ b/arch/sh/kernel/module.c @@ -32,6 +32,7 @@ #include <linux/string.h> #include <linux/kernel.h> #include <asm/unaligned.h> +#include <asm/dwarf.h> void *module_alloc(unsigned long size) { @@ -145,10 +146,41 @@ int module_finalize(const Elf_Ehdr *hdr, const Elf_Shdr *sechdrs, struct module *me) { +#ifdef CONFIG_DWARF_UNWINDER + 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) { + err = dwarf_parse_section((char *)start, (char *)end, me); + if (err) + printk(KERN_WARNING "%s: failed to parse DWARF info\n", + me->name); + } + +#endif /* CONFIG_DWARF_UNWINDER */ + return module_bug_finalize(hdr, sechdrs, me); } void module_arch_cleanup(struct module *mod) { module_bug_cleanup(mod); + +#ifdef CONFIG_DWARF_UNWINDER + dwarf_module_unload(mod); +#endif /* CONFIG_DWARF_UNWINDER */ } |