lkml.org 
[lkml]   [2006]   [Nov]   [30]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
Patch in this message
/
From
Subject[PATCH 2.6.19 04/10] Modules support for kmemleak
Date
This patch handles the kmemleak operations needed for modules loading so
that memory allocations from inside a module are properly tracked.

Signed-off-by: Catalin Marinas <catalin.marinas@gmail.com>
---
kernel/module.c | 56 +++++++++++++++++++++++++++++++++++++++++++++++++++++++
1 files changed, 56 insertions(+), 0 deletions(-)
diff --git a/kernel/module.c b/kernel/module.c
index f016656..b2b9526 100644
--- a/kernel/module.c
+++ b/kernel/module.c
@@ -345,6 +345,7 @@ static void *percpu_modalloc(unsigned lo
unsigned long extra;
unsigned int i;
void *ptr;
+ int cpu;

if (align > SMP_CACHE_BYTES) {
printk(KERN_WARNING "%s: per-cpu alignment %li > %i\n",
@@ -374,6 +375,10 @@ static void *percpu_modalloc(unsigned lo
if (!split_block(i, size))
return NULL;

+ /* add the per-cpu scanning areas */
+ for_each_possible_cpu(cpu)
+ memleak_alloc(ptr + per_cpu_offset(cpu), size, 0);
+
/* Mark allocated */
pcpu_size[i] = -pcpu_size[i];
return ptr;
@@ -388,6 +393,7 @@ static void percpu_modfree(void *freeme)
{
unsigned int i;
void *ptr = __per_cpu_start + block_size(pcpu_size[0]);
+ int cpu;

/* First entry is core kernel percpu data. */
for (i = 1; i < pcpu_num_used; ptr += block_size(pcpu_size[i]), i++) {
@@ -399,6 +405,10 @@ static void percpu_modfree(void *freeme)
BUG();

free:
+ /* remove the per-cpu scanning areas */
+ for_each_possible_cpu(cpu)
+ memleak_free(freeme + per_cpu_offset(cpu));
+
/* Merge with previous? */
if (pcpu_size[i-1] >= 0) {
pcpu_size[i-1] += pcpu_size[i];
@@ -1477,6 +1487,42 @@ static inline void add_kallsyms(struct m
}
#endif /* CONFIG_KALLSYMS */

+#ifdef CONFIG_DEBUG_MEMLEAK
+static void memleak_load_module(struct module *mod, Elf_Ehdr *hdr,
+ Elf_Shdr *sechdrs, char *secstrings)
+{
+ unsigned int mloffindex, i;
+
+ /* insert any new pointer aliases */
+ mloffindex = find_sec(hdr, sechdrs, secstrings, ".init.memleak_offsets");
+ if (mloffindex)
+ memleak_insert_aliases((void *)sechdrs[mloffindex].sh_addr,
+ (void *)sechdrs[mloffindex].sh_addr
+ + sechdrs[mloffindex].sh_size);
+
+ /* only scan the sections containing data */
+ memleak_scan_area(mod->module_core,
+ (unsigned long)mod - (unsigned long)mod->module_core,
+ sizeof(struct module));
+
+ for (i = 1; i < hdr->e_shnum; i++) {
+ if (!(sechdrs[i].sh_flags & SHF_ALLOC))
+ continue;
+ if (strncmp(secstrings + sechdrs[i].sh_name, ".data", 5) != 0
+ && strncmp(secstrings + sechdrs[i].sh_name, ".bss", 4) != 0)
+ continue;
+
+ memleak_scan_area(mod->module_core,
+ sechdrs[i].sh_addr - (unsigned long)mod->module_core,
+ sechdrs[i].sh_size);
+ }
+}
+#else
+static inline void memleak_load_module(struct module *mod, Elf_Ehdr *hdr,
+ Elf_Shdr *sechdrs, char *secstrings)
+{ }
+#endif
+
/* Allocate and load the module: note that size of section 0 is always
zero, and we rely on this for optional sections. */
static struct module *load_module(void __user *umod,
@@ -1672,6 +1718,10 @@ static struct module *load_module(void _

/* Do the allocs. */
ptr = module_alloc(mod->core_size);
+ /* the pointer to this block is stored in the module structure
+ * which is inside the block. Just mark it as not being a
+ * leak */
+ memleak_not_leak(ptr);
if (!ptr) {
err = -ENOMEM;
goto free_percpu;
@@ -1680,6 +1730,11 @@ static struct module *load_module(void _
mod->module_core = ptr;

ptr = module_alloc(mod->init_size);
+ /* the pointer to this block is stored in the module structure
+ * which is inside the block. This block doesn't need to be
+ * scanned as it contains data and code that will be freed
+ * after the module is initialized */
+ memleak_ignore(ptr);
if (!ptr && mod->init_size) {
err = -ENOMEM;
goto free_core;
@@ -1710,6 +1765,7 @@ static struct module *load_module(void _
}
/* Module has been moved. */
mod = (void *)sechdrs[modindex].sh_addr;
+ memleak_load_module(mod, hdr, sechdrs, secstrings);

/* Now we've moved module, initialize linked lists, etc. */
module_unload_init(mod);
-
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@vger.kernel.org
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/
\
 
 \ /
  Last update: 2006-12-01 00:03    [from the cache]
©2003-2011 Jasper Spaans