From: Andrew Morton <akpm@linux-foundation.org>
To: david@redhat.com,dan.j.williams@intel.com,apopple@nvidia.com,linmiaohe@huawei.com,akpm@linux-foundation.org,patches@lists.linux.dev,linux-mm@kvack.org,mm-commits@vger.kernel.org,torvalds@linux-foundation.org,akpm@linux-foundation.org
Subject: [patch 40/41] kernel/resource: fix kfree() of bootmem memory again
Date: Wed, 23 Mar 2022 16:07:18 -0700 [thread overview]
Message-ID: <20220323230719.5168EC340EE@smtp.kernel.org> (raw)
In-Reply-To: <20220323160453.65922ced539cbf445b191555@linux-foundation.org>
From: Miaohe Lin <linmiaohe@huawei.com>
Subject: kernel/resource: fix kfree() of bootmem memory again
Since commit ebff7d8f270d ("mem hotunplug: fix kfree() of bootmem
memory"), we could get a resource allocated during boot via
alloc_resource(). And it's required to release the resource using
free_resource(). Howerver, many people use kfree directly which will
result in kernel BUG. In order to fix this without fixing every call
site, just leak a couple of bytes in such corner case.
Link: https://lkml.kernel.org/r/20220217083619.19305-1-linmiaohe@huawei.com
Fixes: ebff7d8f270d ("mem hotunplug: fix kfree() of bootmem memory")
Signed-off-by: Miaohe Lin <linmiaohe@huawei.com>
Suggested-by: David Hildenbrand <david@redhat.com>
Cc: Dan Williams <dan.j.williams@intel.com>
Cc: Alistair Popple <apopple@nvidia.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
---
kernel/resource.c | 41 ++++++++---------------------------------
1 file changed, 8 insertions(+), 33 deletions(-)
--- a/kernel/resource.c~kernel-resource-fix-kfree-of-bootmem-memory-again
+++ a/kernel/resource.c
@@ -56,14 +56,6 @@ struct resource_constraint {
static DEFINE_RWLOCK(resource_lock);
-/*
- * For memory hotplug, there is no way to free resource entries allocated
- * by boot mem after the system is up. So for reusing the resource entry
- * we need to remember the resource.
- */
-static struct resource *bootmem_resource_free;
-static DEFINE_SPINLOCK(bootmem_resource_lock);
-
static struct resource *next_resource(struct resource *p)
{
if (p->child)
@@ -160,36 +152,19 @@ __initcall(ioresources_init);
static void free_resource(struct resource *res)
{
- if (!res)
- return;
-
- if (!PageSlab(virt_to_head_page(res))) {
- spin_lock(&bootmem_resource_lock);
- res->sibling = bootmem_resource_free;
- bootmem_resource_free = res;
- spin_unlock(&bootmem_resource_lock);
- } else {
+ /**
+ * If the resource was allocated using memblock early during boot
+ * we'll leak it here: we can only return full pages back to the
+ * buddy and trying to be smart and reusing them eventually in
+ * alloc_resource() overcomplicates resource handling.
+ */
+ if (res && PageSlab(virt_to_head_page(res)))
kfree(res);
- }
}
static struct resource *alloc_resource(gfp_t flags)
{
- struct resource *res = NULL;
-
- spin_lock(&bootmem_resource_lock);
- if (bootmem_resource_free) {
- res = bootmem_resource_free;
- bootmem_resource_free = res->sibling;
- }
- spin_unlock(&bootmem_resource_lock);
-
- if (res)
- memset(res, 0, sizeof(struct resource));
- else
- res = kzalloc(sizeof(struct resource), flags);
-
- return res;
+ return kzalloc(sizeof(struct resource), flags);
}
/* Return the conflict entry if you can't request it */
_
next prev parent reply other threads:[~2022-03-23 23:07 UTC|newest]
Thread overview: 42+ messages / expand[flat|nested] mbox.gz Atom feed top
2022-03-23 23:04 incoming Andrew Morton
2022-03-23 23:05 ` [patch 01/41] proc: alloc PATH_MAX bytes for /proc/${pid}/fd/ symlinks Andrew Morton
2022-03-23 23:05 ` [patch 02/41] proc/vmcore: fix possible deadlock on concurrent mmap and read Andrew Morton
2022-03-23 23:05 ` [patch 03/41] proc/vmcore: fix vmcore_alloc_buf() kernel-doc comment Andrew Morton
2022-03-23 23:05 ` [patch 04/41] linux/types.h: remove unnecessary __bitwise__ Andrew Morton
2022-03-23 23:05 ` [patch 05/41] Documentation/sparse: add hints about __CHECKER__ Andrew Morton
2022-03-23 23:05 ` [patch 06/41] kernel/ksysfs.c: use helper macro __ATTR_RW Andrew Morton
2022-03-23 23:05 ` [patch 07/41] Kconfig.debug: make DEBUG_INFO selectable from a choice Andrew Morton
2022-03-23 23:05 ` [patch 08/41] include: drop pointless __compiler_offsetof indirection Andrew Morton
2022-03-23 23:05 ` [patch 09/41] ilog2: force inlining of __ilog2_u32() and __ilog2_u64() Andrew Morton
2022-03-23 23:05 ` [patch 10/41] bitfield: add explicit inclusions to the example Andrew Morton
2022-03-23 23:05 ` [patch 11/41] lib/Kconfig.debug: add ARCH dependency for FUNCTION_ALIGN option Andrew Morton
2022-03-23 23:05 ` [patch 12/41] lib: bitmap: fix many kernel-doc warnings Andrew Morton
2022-03-23 23:05 ` [patch 13/41] checkpatch: prefer MODULE_LICENSE("GPL") over MODULE_LICENSE("GPL v2") Andrew Morton
2022-03-23 23:05 ` [patch 14/41] checkpatch: add --fix option for some TRAILING_STATEMENTS Andrew Morton
2022-03-23 23:06 ` [patch 15/41] checkpatch: add early_param exception to blank line after struct/function test Andrew Morton
2022-03-23 23:06 ` [patch 16/41] checkpatch: use python3 to find codespell dictionary Andrew Morton
2022-03-23 23:06 ` [patch 17/41] init: use ktime_us_delta() to make initcall_debug log more precise Andrew Morton
2022-03-23 23:06 ` [patch 18/41] init.h: improve __setup and early_param documentation Andrew Morton
2022-03-23 23:06 ` [patch 19/41] init/main.c: return 1 from handled __setup() functions Andrew Morton
2022-03-23 23:06 ` [patch 20/41] fs/pipe: use kvcalloc to allocate a pipe_buffer array Andrew Morton
2022-03-23 23:06 ` [patch 21/41] fs/pipe.c: local vars have to match types of proper pipe_inode_info fields Andrew Morton
2022-03-23 23:06 ` [patch 22/41] minix: fix bug when opening a file with O_DIRECT Andrew Morton
2022-03-23 23:06 ` [patch 23/41] fat: use pointer to simple type in put_user() Andrew Morton
2022-03-23 23:06 ` [patch 24/41] cgroup: use irqsave in cgroup_rstat_flush_locked() Andrew Morton
2022-03-23 23:06 ` [patch 25/41] kexec: make crashk_res, crashk_low_res and crash_notes symbols always visible Andrew Morton
2022-03-23 23:06 ` [patch 26/41] riscv: mm: init: use IS_ENABLED(CONFIG_KEXEC_CORE) instead of #ifdef Andrew Morton
2022-03-23 23:06 ` [patch 27/41] x86/setup: " Andrew Morton
2022-03-23 23:06 ` [patch 28/41] arm64: mm: " Andrew Morton
2022-03-23 23:06 ` [patch 29/41] docs: kdump: update description about sysfs file system support Andrew Morton
2022-03-23 23:06 ` [patch 30/41] docs: kdump: add scp example to write out the dump file Andrew Morton
2022-03-23 23:06 ` [patch 31/41] panic: unset panic_on_warn inside panic() Andrew Morton
2022-03-23 23:06 ` [patch 32/41] ubsan: no need to unset panic_on_warn in ubsan_epilogue() Andrew Morton
2022-03-23 23:06 ` [patch 33/41] kasan: no need to unset panic_on_warn in end_report() Andrew Morton
2022-03-23 23:07 ` [patch 34/41] taskstats: remove unneeded dead assignment Andrew Morton
2022-03-23 23:07 ` [patch 35/41] docs: sysctl/kernel: add missing bit to panic_print Andrew Morton
2022-03-23 23:07 ` [patch 36/41] panic: add option to dump all CPUs backtraces in panic_print Andrew Morton
2022-03-23 23:07 ` [patch 37/41] panic: move panic_print before kmsg dumpers Andrew Morton
2022-03-23 23:07 ` [patch 38/41] kcov: split ioctl handling into locked and unlocked parts Andrew Morton
2022-03-23 23:07 ` [patch 39/41] kcov: properly handle subsequent mmap calls Andrew Morton
2022-03-23 23:07 ` Andrew Morton [this message]
2022-03-23 23:07 ` [patch 41/41] Revert "ubsan, kcsan: Don't combine sanitizer with kcov on clang" Andrew Morton
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