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Diffstat (limited to 'arch')
-rw-r--r--arch/sh/include/asm/dwarf.h15
-rw-r--r--arch/sh/kernel/dwarf.c135
-rw-r--r--arch/sh/kernel/module.c32
3 files changed, 152 insertions, 30 deletions
diff --git a/arch/sh/include/asm/dwarf.h b/arch/sh/include/asm/dwarf.h
index c367ed3373c5..aacdc746d07c 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 +376,9 @@ static inline unsigned int DW_CFA_operand(unsigned long insn)
extern struct dwarf_frame *dwarf_unwind_stack(unsigned long,
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 577302f31e6a..981315c6d656 100644
--- a/arch/sh/kernel/dwarf.c
+++ b/arch/sh/kernel/dwarf.c
@@ -655,7 +655,7 @@ bail:
}
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;
@@ -751,6 +751,8 @@ 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);
@@ -761,7 +763,7 @@ 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;
@@ -810,6 +812,8 @@ 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);
@@ -875,15 +879,15 @@ 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;
@@ -891,29 +895,12 @@ 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, NULL);
- dwarf_reg_cachep = kmem_cache_create("dwarf_regs",
- sizeof(struct dwarf_reg), 0, SLAB_PANIC, 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);
@@ -925,6 +912,7 @@ 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;
@@ -936,13 +924,14 @@ 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
@@ -955,6 +944,92 @@ 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, NULL);
+ dwarf_reg_cachep = kmem_cache_create("dwarf_regs",
+ sizeof(struct dwarf_reg), 0, SLAB_PANIC, 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 c2efdcde266f..d297a148d16c 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 */
}
generated by cgit v1.2.3-58-ga151 (git 2.39.0) at 2024-12-19 03:14:38 +0000