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authorPaul Mundt <lethal@linux-sh.org>2009-10-12 01:50:07 +0200
committerPaul Mundt <lethal@linux-sh.org>2009-10-12 01:50:07 +0200
commit8ec006c58775869175edee3d23f4525b6df2935a (patch)
treee70b8d0d191cd97276aa4b370e055485a6a98010 /arch/sh/kernel/dwarf.c
parentsh: Reinstate ILSEL -> IRL intc mappings for SH-X3 proto CPU. (diff)
parentMerge branch 'sh/dwarf-unwinder' of git://github.com/mfleming/linux-2.6 into ... (diff)
downloadlinux-8ec006c58775869175edee3d23f4525b6df2935a.tar.xz
linux-8ec006c58775869175edee3d23f4525b6df2935a.zip
Merge branch 'sh/dwarf-unwinder'
Conflicts: arch/sh/kernel/dwarf.c
Diffstat (limited to 'arch/sh/kernel/dwarf.c')
-rw-r--r--arch/sh/kernel/dwarf.c185
1 files changed, 135 insertions, 50 deletions
diff --git a/arch/sh/kernel/dwarf.c b/arch/sh/kernel/dwarf.c
index 03b3616c80a5..c274039e9c8d 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;