#include <asm/unwinder.h>
#include <asm/sections.h>
#include <asm/unaligned.h>
-#include <asm/dwarf.h>
#include <asm/stacktrace.h>
/* Reserve enough memory for two stack frames */
}
/**
- * 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
*
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.
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
} 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);
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;
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);
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;
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 (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;
return_addr = frame->return_addr;
ops->address(data, return_addr, 1);
}
+
+ if (frame)
+ dwarf_free_frame(frame);
}
static struct unwinder dwarf_unwinder = {
}
/**
- * 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;
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;
+ entry = eh_frame_start;
- 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);
-
- while ((char *)entry < __stop_eh_frame) {
+ while ((char *)entry < eh_frame_end) {
p = entry;
count = dwarf_entry_len(p, &len);
* entry and move to the next one because 'len'
* tells us where our next entry is.
*/
+ err = -EINVAL;
goto out;
} else
p += count;
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
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;
git.openpandora.org / pandora-kernel.git / blobdiff