I only tested v2. I confirm this solve the symptoms I was seeing in the bug report. Tested-by: Mathieu Malaterre <mathieu.malaterre@xxxxxxxxx> thanks, your patch is actually much cleaner! On Wed, Jun 15, 2016 at 10:42 PM, Frank Rowand <frowand.list@xxxxxxxxx> wrote: > From: Frank Rowand <frank.rowand@xxxxxxxxxxx> > > Fix a memory leak resulting from memory allocation in safe_name(). > This patch fixes all call sites of safe_name(). > > Mathieu Malaterre reported the memory leak on boot: > > On my PowerMac device-tree would generate a duplicate name: > > [ 0.023043] device-tree: Duplicate name in PowerPC,G4@0, renamed to "l2-cache#1" > > in this case a newly allocated name is generated by `safe_name`. However > in this case it is never deallocated. > > The bug was found using kmemleak reported as: > > unreferenced object 0xdf532e60 (size 32): > comm "swapper", pid 1, jiffies 4294892300 (age 1993.532s) > hex dump (first 32 bytes): > 6c 32 2d 63 61 63 68 65 23 31 00 dd e4 dd 1e c2 l2-cache#1...... > ec d4 ba ce 04 ec cc de 8e 85 e9 ca c4 ec cc 9e ................ > backtrace: > [<c02d3350>] kvasprintf+0x64/0xc8 > [<c02d3400>] kasprintf+0x4c/0x5c > [<c0453814>] safe_name.isra.1+0x80/0xc4 > [<c04545d8>] __of_attach_node_sysfs+0x6c/0x11c > [<c075f21c>] of_core_init+0x8c/0xf8 > [<c0729594>] kernel_init_freeable+0xd4/0x208 > [<c00047e8>] kernel_init+0x24/0x11c > [<c00158ec>] ret_from_kernel_thread+0x5c/0x64 > > Link: https://bugzilla.kernel.org/show_bug.cgi?id=120331 > > Signed-off-by: Frank Rowand <frank.rowand@xxxxxxxxxxx> > Reported-by: mathieu.malaterre@xxxxxxxxx > --- > > changes from v1 > Move the prototype of __of_sysfs_remove_bin_file() into of_private.h > > drivers/of/base.c | 29 ++++++++++++++++++++--------- > drivers/of/dynamic.c | 2 +- > drivers/of/of_private.h | 3 +++ > 3 files changed, 24 insertions(+), 10 deletions(-) > > Index: b/drivers/of/base.c > =================================================================== > --- a/drivers/of/base.c > +++ b/drivers/of/base.c > @@ -112,6 +112,7 @@ static ssize_t of_node_property_read(str > return memory_read_from_buffer(buf, count, &offset, pp->value, pp->length); > } > > +/* always return newly allocated name, caller must free after use */ > static const char *safe_name(struct kobject *kobj, const char *orig_name) > { > const char *name = orig_name; > @@ -126,9 +127,12 @@ static const char *safe_name(struct kobj > name = kasprintf(GFP_KERNEL, "%s#%i", orig_name, ++i); > } > > - if (name != orig_name) > + if (name == orig_name) { > + name = kstrdup(orig_name, GFP_KERNEL); > + } else { > pr_warn("device-tree: Duplicate name in %s, renamed to \"%s\"\n", > kobject_name(kobj), name); > + } > return name; > } > > @@ -159,6 +163,7 @@ int __of_add_property_sysfs(struct devic > int __of_attach_node_sysfs(struct device_node *np) > { > const char *name; > + struct kobject *parent; > struct property *pp; > int rc; > > @@ -171,15 +176,15 @@ int __of_attach_node_sysfs(struct device > np->kobj.kset = of_kset; > if (!np->parent) { > /* Nodes without parents are new top level trees */ > - rc = kobject_add(&np->kobj, NULL, "%s", > - safe_name(&of_kset->kobj, "base")); > + name = safe_name(&of_kset->kobj, "base"); > + parent = NULL; > } else { > name = safe_name(&np->parent->kobj, kbasename(np->full_name)); > - if (!name || !name[0]) > - return -EINVAL; > - > - rc = kobject_add(&np->kobj, &np->parent->kobj, "%s", name); > + parent = &np->parent->kobj; > } > + if (!name) > + return -ENOMEM; > + rc = kobject_add(&np->kobj, parent, "%s", name); > if (rc) > return rc; > > @@ -1815,6 +1820,12 @@ int __of_remove_property(struct device_n > return 0; > } > > +void __of_sysfs_remove_bin_file(struct device_node *np, struct property *prop) > +{ > + sysfs_remove_bin_file(&np->kobj, &prop->attr); > + kfree(prop->attr.attr.name); > +} > + > void __of_remove_property_sysfs(struct device_node *np, struct property *prop) > { > if (!IS_ENABLED(CONFIG_SYSFS)) > @@ -1822,7 +1833,7 @@ void __of_remove_property_sysfs(struct d > > /* at early boot, bail here and defer setup to of_init() */ > if (of_kset && of_node_is_attached(np)) > - sysfs_remove_bin_file(&np->kobj, &prop->attr); > + __of_sysfs_remove_bin_file(np, prop); > } > > /** > @@ -1895,7 +1906,7 @@ void __of_update_property_sysfs(struct d > return; > > if (oldprop) > - sysfs_remove_bin_file(&np->kobj, &oldprop->attr); > + __of_sysfs_remove_bin_file(np, oldprop); > __of_add_property_sysfs(np, newprop); > } > > Index: b/drivers/of/dynamic.c > =================================================================== > --- a/drivers/of/dynamic.c > +++ b/drivers/of/dynamic.c > @@ -55,7 +55,7 @@ void __of_detach_node_sysfs(struct devic > /* only remove properties if on sysfs */ > if (of_node_is_attached(np)) { > for_each_property_of_node(np, pp) > - sysfs_remove_bin_file(&np->kobj, &pp->attr); > + __of_sysfs_remove_bin_file(np, pp); > kobject_del(&np->kobj); > } > > Index: b/drivers/of/of_private.h > =================================================================== > --- a/drivers/of/of_private.h > +++ b/drivers/of/of_private.h > @@ -83,6 +83,9 @@ extern int __of_attach_node_sysfs(struct > extern void __of_detach_node(struct device_node *np); > extern void __of_detach_node_sysfs(struct device_node *np); > > +extern void __of_sysfs_remove_bin_file(struct device_node *np, > + struct property *prop); > + > /* iterators for transactions, used for overlays */ > /* forward iterator */ > #define for_each_transaction_entry(_oft, _te) \ -- Mathieu -- To unsubscribe from this list: send the line "unsubscribe devicetree" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
