diff mbox series

[Resend] mm: use stack_depot for recording kmemleak's backtrace

Message ID 1665450964-27487-1-git-send-email-zhaoyang.huang@unisoc.com (mailing list archive)
State New, archived
Headers show
Series [Resend] mm: use stack_depot for recording kmemleak's backtrace | expand

Commit Message

zhaoyang.huang Oct. 11, 2022, 1:16 a.m. UTC
From: Zhaoyang Huang <zhaoyang.huang@unisoc.com>

Using stack_depot to record kmemleak's backtrace which has been implemented
on slub for reducing redundant information.

Signed-off-by: Zhaoyang Huang <zhaoyang.huang@unisoc.com>
---
 mm/kmemleak.c | 43 +++++++++++++++++++++++++++++++++----------
 1 file changed, 33 insertions(+), 10 deletions(-)

Comments

Zhaoyang Huang Oct. 11, 2022, 1:32 a.m. UTC | #1
We can account and sort the output via backtrace under this change

On Tue, Oct 11, 2022 at 9:18 AM zhaoyang.huang
<zhaoyang.huang@unisoc.com> wrote:
>
> From: Zhaoyang Huang <zhaoyang.huang@unisoc.com>
>
> Using stack_depot to record kmemleak's backtrace which has been implemented
> on slub for reducing redundant information.
>
> Signed-off-by: Zhaoyang Huang <zhaoyang.huang@unisoc.com>
> ---
>  mm/kmemleak.c | 43 +++++++++++++++++++++++++++++++++----------
>  1 file changed, 33 insertions(+), 10 deletions(-)
>
> diff --git a/mm/kmemleak.c b/mm/kmemleak.c
> index 1eddc01..c9cee3a 100644
> --- a/mm/kmemleak.c
> +++ b/mm/kmemleak.c
> @@ -79,6 +79,7 @@
>  #include <linux/mutex.h>
>  #include <linux/rcupdate.h>
>  #include <linux/stacktrace.h>
> +#include <linux/stackdepot.h>
>  #include <linux/cache.h>
>  #include <linux/percpu.h>
>  #include <linux/memblock.h>
> @@ -159,8 +160,7 @@ struct kmemleak_object {
>         u32 checksum;
>         /* memory ranges to be scanned inside an object (empty for all) */
>         struct hlist_head area_list;
> -       unsigned long trace[MAX_TRACE];
> -       unsigned int trace_len;
> +       depot_stack_handle_t trace_handle;
>         unsigned long jiffies;          /* creation timestamp */
>         pid_t pid;                      /* pid of the current task */
>         char comm[TASK_COMM_LEN];       /* executable name */
> @@ -346,8 +346,11 @@ static void print_unreferenced(struct seq_file *seq,
>                                struct kmemleak_object *object)
>  {
>         int i;
> +       unsigned long *entries;
> +       unsigned int nr_entries;
>         unsigned int msecs_age = jiffies_to_msecs(jiffies - object->jiffies);
>
> +       nr_entries = stack_depot_fetch(object->trace_handle, &entries);
>         warn_or_seq_printf(seq, "unreferenced object 0x%08lx (size %zu):\n",
>                    object->pointer, object->size);
>         warn_or_seq_printf(seq, "  comm \"%s\", pid %d, jiffies %lu (age %d.%03ds)\n",
> @@ -356,10 +359,10 @@ static void print_unreferenced(struct seq_file *seq,
>         hex_dump_object(seq, object);
>         warn_or_seq_printf(seq, "  backtrace:\n");
>
> -       for (i = 0; i < object->trace_len; i++) {
> -               void *ptr = (void *)object->trace[i];
> -               warn_or_seq_printf(seq, "    [<%p>] %pS\n", ptr, ptr);
> -       }
> +       for (i = 0; i < nr_entries; i++) {
> +               void *ptr = (void *)entries[i];
> +               warn_or_seq_printf(seq, "    [<%p>] %pS\n", ptr, ptr);
> +       }
>  }
>
>  /*
> @@ -378,7 +381,8 @@ static void dump_object_info(struct kmemleak_object *object)
>         pr_notice("  flags = 0x%x\n", object->flags);
>         pr_notice("  checksum = %u\n", object->checksum);
>         pr_notice("  backtrace:\n");
> -       stack_trace_print(object->trace, object->trace_len, 4);
> +       if(object->trace_handle)
> +               stack_depot_print(object->trace_handle);
>  }
>
>  /*
> @@ -591,6 +595,25 @@ static struct kmemleak_object *find_and_remove_object(unsigned long ptr, int ali
>         return object;
>  }
>
> +#ifdef CONFIG_STACKDEPOT
> +static noinline depot_stack_handle_t set_track_prepare(void)
> +{
> +       depot_stack_handle_t trace_handle;
> +       unsigned long entries[MAX_TRACE];
> +       unsigned int nr_entries;
> +
> +       nr_entries = stack_trace_save(entries, ARRAY_SIZE(entries), 3);
> +       trace_handle = stack_depot_save(entries, nr_entries, GFP_NOWAIT);
> +
> +       return trace_handle;
> +}
> +#else
> +static inline depot_stack_handle_t set_track_prepare(void)
> +{
> +       return 0;
> +}
> +#endif
> +
>  /*
>   * Save stack trace to the given array of MAX_TRACE size.
>   */
> @@ -654,7 +677,7 @@ static struct kmemleak_object *__create_object(unsigned long ptr, size_t size,
>         }
>
>         /* kernel backtrace */
> -       object->trace_len = __save_stack_trace(object->trace);
> +       object->trace_handle = set_track_prepare();
>
>         raw_spin_lock_irqsave(&kmemleak_lock, flags);
>
> @@ -694,7 +717,6 @@ static struct kmemleak_object *__create_object(unsigned long ptr, size_t size,
>         rb_link_node(&object->rb_node, rb_parent, link);
>         rb_insert_color(&object->rb_node, is_phys ? &object_phys_tree_root :
>                                           &object_tree_root);
> -
>         list_add_tail_rcu(&object->object_list, &object_list);
>  out:
>         raw_spin_unlock_irqrestore(&kmemleak_lock, flags);
> @@ -1094,7 +1116,7 @@ void __ref kmemleak_update_trace(const void *ptr)
>         }
>
>         raw_spin_lock_irqsave(&object->lock, flags);
> -       object->trace_len = __save_stack_trace(object->trace);
> +       object->trace_handle = set_track_prepare();
>         raw_spin_unlock_irqrestore(&object->lock, flags);
>
>         put_object(object);
> @@ -2064,6 +2086,7 @@ void __init kmemleak_init(void)
>         if (kmemleak_error)
>                 return;
>
> +       stack_depot_init();
>         jiffies_min_age = msecs_to_jiffies(MSECS_MIN_AGE);
>         jiffies_scan_wait = msecs_to_jiffies(SECS_SCAN_WAIT * 1000);
>
> --
> 1.9.1
>
Zhaoyang Huang Oct. 12, 2022, 7:36 a.m. UTC | #2
This is introduced by a very early kmemleak_alloc before kmemleak_init
which gets an object from mem_pool, which could not be produced on my
v5.4 based environment, sorry for the disturbance. I would like to
send a fixup later.

On Wed, Oct 12, 2022 at 2:34 PM kernel test robot <oliver.sang@intel.com> wrote:
>
>
> Greeting,
>
> FYI, we noticed the following commit (built with gcc-11):
>
> commit: 0e949320dbee7ffe242b1a9b4fc59661e954e6e5 ("[Resend PATCH] mm: use stack_depot for recording kmemleak's backtrace")
> url: https://github.com/intel-lab-lkp/linux/commits/zhaoyang-huang/mm-use-stack_depot-for-recording-kmemleak-s-backtrace/20221011-091833
> base: https://git.kernel.org/cgit/linux/kernel/git/akpm/mm.git mm-everything
> patch link: https://lore.kernel.org/linux-mm/1665450964-27487-1-git-send-email-zhaoyang.huang@unisoc.com
> patch subject: [Resend PATCH] mm: use stack_depot for recording kmemleak's backtrace
>
> in testcase: boot
>
> on test machine: qemu-system-x86_64 -enable-kvm -cpu SandyBridge -smp 2 -m 16G
>
> caused below changes (please refer to attached dmesg/kmsg for entire log/backtrace):
>
>
> +---------------------------------------------+------------+------------+
> |                                             | 029cc2b410 | 0e949320db |
> +---------------------------------------------+------------+------------+
> | boot_successes                              | 6          | 0          |
> | boot_failures                               | 0          | 6          |
> | BUG:kernel_NULL_pointer_dereference,address | 0          | 6          |
> | Oops:#[##]                                  | 0          | 6          |
> | RIP:__stack_depot_save                      | 0          | 6          |
> | Kernel_panic-not_syncing:Fatal_exception    | 0          | 6          |
> +---------------------------------------------+------------+------------+
>
>
> If you fix the issue, kindly add following tag
> | Reported-by: kernel test robot <oliver.sang@intel.com>
> | Link: https://lore.kernel.org/r/202210121406.d4ebc9bc-oliver.sang@intel.com
>
>
> [    0.244585][    T0] BUG: kernel NULL pointer dereference, address: 0000000000000000
> [    0.246464][    T0] #PF: supervisor read access in kernel mode
> [    0.247823][    T0] #PF: error_code(0x0000) - not-present page
> [    0.249179][    T0] PGD 0 P4D 0
> [    0.249986][    T0] Oops: 0000 [#1] SMP PTI
> [    0.251025][    T0] CPU: 0 PID: 0 Comm: swapper Not tainted 6.0.0-rc3-00707-g0e949320dbee #4
> [    0.252895][    T0] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.16.0-debian-1.16.0-4 04/01/2014
> [ 0.255242][ T0] RIP: 0010:__stack_depot_save (kbuild/src/x86_64-2/lib/stackdepot.c:452)
> [ 0.256583][ T0] Code: 03 48 c7 c7 ec 17 b3 84 e8 91 e8 85 ff 44 89 e0 23 05 74 a8 01 03 48 8d 04 c3 48 89 c3 48 89 c7 48 89 44 24 28 e8 d4 f9 85 ff <4c> 8b 33 4d 85 f6 0f 84 b6 00 00 00 8b 04 24 83 e8 01 48 8d 04 c5
> All code
> ========
>    0:   03 48 c7                add    -0x39(%rax),%ecx
>    3:   c7                      (bad)
>    4:   ec                      in     (%dx),%al
>    5:   17                      (bad)
>    6:   b3 84                   mov    $0x84,%bl
>    8:   e8 91 e8 85 ff          callq  0xffffffffff85e89e
>    d:   44 89 e0                mov    %r12d,%eax
>   10:   23 05 74 a8 01 03       and    0x301a874(%rip),%eax        # 0x301a88a
>   16:   48 8d 04 c3             lea    (%rbx,%rax,8),%rax
>   1a:   48 89 c3                mov    %rax,%rbx
>   1d:   48 89 c7                mov    %rax,%rdi
>   20:   48 89 44 24 28          mov    %rax,0x28(%rsp)
>   25:   e8 d4 f9 85 ff          callq  0xffffffffff85f9fe
>   2a:*  4c 8b 33                mov    (%rbx),%r14              <-- trapping instruction
>   2d:   4d 85 f6                test   %r14,%r14
>   30:   0f 84 b6 00 00 00       je     0xec
>   36:   8b 04 24                mov    (%rsp),%eax
>   39:   83 e8 01                sub    $0x1,%eax
>   3c:   48                      rex.W
>   3d:   8d                      .byte 0x8d
>   3e:   04 c5                   add    $0xc5,%al
>
> Code starting with the faulting instruction
> ===========================================
>    0:   4c 8b 33                mov    (%rbx),%r14
>    3:   4d 85 f6                test   %r14,%r14
>    6:   0f 84 b6 00 00 00       je     0xc2
>    c:   8b 04 24                mov    (%rsp),%eax
>    f:   83 e8 01                sub    $0x1,%eax
>   12:   48                      rex.W
>   13:   8d                      .byte 0x8d
>   14:   04 c5                   add    $0xc5,%al
> [    0.261023][    T0] RSP: 0000:ffffffff83603ca8 EFLAGS: 00010046
> [    0.262337][    T0] RAX: ffffffff83613cd8 RBX: 0000000000000000 RCX: ffffffff81b16f8c
> [    0.264139][    T0] RDX: 0000000000000b64 RSI: 0000000000000000 RDI: 0000000000000000
> [    0.265948][    T0] RBP: 00000000c5a6b597 R08: ffffffff8479d118 R09: 0000000000000000
> [    0.267668][    T0] R10: 0000000000000004 R11: 0001ffffffffffff R12: 0000000027b2cd0a
> [    0.269492][    T0] R13: 0000000000000003 R14: 000000004954f68c R15: ffffffff83603d54
> [    0.271315][    T0] FS:  0000000000000000(0000) GS:ffffffff842c9000(0000) knlGS:0000000000000000
> [    0.273215][    T0] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
> [    0.274736][    T0] CR2: 0000000000000000 CR3: 000000000360a000 CR4: 00000000000406b0
> [    0.276558][    T0] Call Trace:
> [    0.277339][    T0]  <TASK>
> [ 0.278031][ T0] stack_depot_save (kbuild/src/x86_64-2/lib/stackdepot.c:534)
> [ 0.279163][ T0] set_track_prepare (kbuild/src/x86_64-2/mm/slub.c:752)
> [ 0.280296][ T0] ? memblock_alloc_range_nid (kbuild/src/x86_64-2/mm/memblock.c:1424)
> [ 0.281692][ T0] ? memblock_alloc_internal (kbuild/src/x86_64-2/mm/memblock.c:1514)
> [ 0.282985][ T0] ? memblock_alloc_try_nid (kbuild/src/x86_64-2/mm/memblock.c:1614 (discriminator 3))
> [ 0.286557][ T0] ? setup_command_line (kbuild/src/x86_64-2/init/main.c:631)
> [ 0.287706][ T0] ? start_kernel (kbuild/src/x86_64-2/init/main.c:965)
> [ 0.288803][ T0] ? secondary_startup_64_no_verify (kbuild/src/x86_64-2/arch/x86/kernel/head_64.S:358)
> [ 0.290257][ T0] ? __raw_callee_save___native_queued_spin_unlock (??:?)
> [ 0.291867][ T0] ? write_comp_data (kbuild/src/x86_64-2/kernel/kcov.c:236)
> [ 0.292883][ T0] ? strncpy (kbuild/src/x86_64-2/lib/string.c:115)
> [ 0.293763][ T0] __create_object (kbuild/src/x86_64-2/mm/kmemleak.c:681)
> [ 0.294761][ T0] kmemleak_alloc_phys (kbuild/src/x86_64-2/mm/kmemleak.c:1212)
> [ 0.295882][ T0] memblock_alloc_range_nid (kbuild/src/x86_64-2/mm/memblock.c:1424)
> [ 0.297105][ T0] memblock_alloc_internal (kbuild/src/x86_64-2/mm/memblock.c:1514)
> [ 0.298293][ T0] memblock_alloc_try_nid (kbuild/src/x86_64-2/mm/memblock.c:1614 (discriminator 3))
> [ 0.299516][ T0] setup_command_line (kbuild/src/x86_64-2/init/main.c:631)
> [ 0.300691][ T0] start_kernel (kbuild/src/x86_64-2/init/main.c:965)
> [ 0.301806][ T0] ? load_ucode_bsp (kbuild/src/x86_64-2/arch/x86/kernel/cpu/microcode/core.c:176)
> [ 0.302954][ T0] secondary_startup_64_no_verify (kbuild/src/x86_64-2/arch/x86/kernel/head_64.S:358)
> [    0.304315][    T0]  </TASK>
> [    0.305039][    T0] Modules linked in:
> [    0.305938][    T0] CR2: 0000000000000000
> [    0.306882][    T0] ---[ end trace 0000000000000000 ]---
> [ 0.307913][ T0] RIP: 0010:__stack_depot_save (kbuild/src/x86_64-2/lib/stackdepot.c:452)
> [ 0.309033][ T0] Code: 03 48 c7 c7 ec 17 b3 84 e8 91 e8 85 ff 44 89 e0 23 05 74 a8 01 03 48 8d 04 c3 48 89 c3 48 89 c7 48 89 44 24 28 e8 d4 f9 85 ff <4c> 8b 33 4d 85 f6 0f 84 b6 00 00 00 8b 04 24 83 e8 01 48 8d 04 c5
> All code
> ========
>    0:   03 48 c7                add    -0x39(%rax),%ecx
>    3:   c7                      (bad)
>    4:   ec                      in     (%dx),%al
>    5:   17                      (bad)
>    6:   b3 84                   mov    $0x84,%bl
>    8:   e8 91 e8 85 ff          callq  0xffffffffff85e89e
>    d:   44 89 e0                mov    %r12d,%eax
>   10:   23 05 74 a8 01 03       and    0x301a874(%rip),%eax        # 0x301a88a
>   16:   48 8d 04 c3             lea    (%rbx,%rax,8),%rax
>   1a:   48 89 c3                mov    %rax,%rbx
>   1d:   48 89 c7                mov    %rax,%rdi
>   20:   48 89 44 24 28          mov    %rax,0x28(%rsp)
>   25:   e8 d4 f9 85 ff          callq  0xffffffffff85f9fe
>   2a:*  4c 8b 33                mov    (%rbx),%r14              <-- trapping instruction
>   2d:   4d 85 f6                test   %r14,%r14
>   30:   0f 84 b6 00 00 00       je     0xec
>   36:   8b 04 24                mov    (%rsp),%eax
>   39:   83 e8 01                sub    $0x1,%eax
>   3c:   48                      rex.W
>   3d:   8d                      .byte 0x8d
>   3e:   04 c5                   add    $0xc5,%al
>
> Code starting with the faulting instruction
> ===========================================
>    0:   4c 8b 33                mov    (%rbx),%r14
>    3:   4d 85 f6                test   %r14,%r14
>    6:   0f 84 b6 00 00 00       je     0xc2
>    c:   8b 04 24                mov    (%rsp),%eax
>    f:   83 e8 01                sub    $0x1,%eax
>   12:   48                      rex.W
>   13:   8d                      .byte 0x8d
>   14:   04 c5                   add    $0xc5,%al
>
>
> To reproduce:
>
>         # build kernel
>         cd linux
>         cp config-6.0.0-rc3-00707-g0e949320dbee .config
>         make HOSTCC=gcc-11 CC=gcc-11 ARCH=x86_64 olddefconfig prepare modules_prepare bzImage modules
>         make HOSTCC=gcc-11 CC=gcc-11 ARCH=x86_64 INSTALL_MOD_PATH=<mod-install-dir> modules_install
>         cd <mod-install-dir>
>         find lib/ | cpio -o -H newc --quiet | gzip > modules.cgz
>
>
>         git clone https://github.com/intel/lkp-tests.git
>         cd lkp-tests
>         bin/lkp qemu -k <bzImage> -m modules.cgz job-script # job-script is attached in this email
>
>         # if come across any failure that blocks the test,
>         # please remove ~/.lkp and /lkp dir to run from a clean state.
>
>
>
> --
> 0-DAY CI Kernel Test Service
> https://01.org/lkp
>
>
diff mbox series

Patch

diff --git a/mm/kmemleak.c b/mm/kmemleak.c
index 1eddc01..c9cee3a 100644
--- a/mm/kmemleak.c
+++ b/mm/kmemleak.c
@@ -79,6 +79,7 @@ 
 #include <linux/mutex.h>
 #include <linux/rcupdate.h>
 #include <linux/stacktrace.h>
+#include <linux/stackdepot.h>
 #include <linux/cache.h>
 #include <linux/percpu.h>
 #include <linux/memblock.h>
@@ -159,8 +160,7 @@  struct kmemleak_object {
 	u32 checksum;
 	/* memory ranges to be scanned inside an object (empty for all) */
 	struct hlist_head area_list;
-	unsigned long trace[MAX_TRACE];
-	unsigned int trace_len;
+	depot_stack_handle_t trace_handle;
 	unsigned long jiffies;		/* creation timestamp */
 	pid_t pid;			/* pid of the current task */
 	char comm[TASK_COMM_LEN];	/* executable name */
@@ -346,8 +346,11 @@  static void print_unreferenced(struct seq_file *seq,
 			       struct kmemleak_object *object)
 {
 	int i;
+	unsigned long *entries;
+	unsigned int nr_entries;
 	unsigned int msecs_age = jiffies_to_msecs(jiffies - object->jiffies);
 
+	nr_entries = stack_depot_fetch(object->trace_handle, &entries);
 	warn_or_seq_printf(seq, "unreferenced object 0x%08lx (size %zu):\n",
 		   object->pointer, object->size);
 	warn_or_seq_printf(seq, "  comm \"%s\", pid %d, jiffies %lu (age %d.%03ds)\n",
@@ -356,10 +359,10 @@  static void print_unreferenced(struct seq_file *seq,
 	hex_dump_object(seq, object);
 	warn_or_seq_printf(seq, "  backtrace:\n");
 
-	for (i = 0; i < object->trace_len; i++) {
-		void *ptr = (void *)object->trace[i];
-		warn_or_seq_printf(seq, "    [<%p>] %pS\n", ptr, ptr);
-	}
+       for (i = 0; i < nr_entries; i++) {
+               void *ptr = (void *)entries[i];
+               warn_or_seq_printf(seq, "    [<%p>] %pS\n", ptr, ptr);
+       }
 }
 
 /*
@@ -378,7 +381,8 @@  static void dump_object_info(struct kmemleak_object *object)
 	pr_notice("  flags = 0x%x\n", object->flags);
 	pr_notice("  checksum = %u\n", object->checksum);
 	pr_notice("  backtrace:\n");
-	stack_trace_print(object->trace, object->trace_len, 4);
+	if(object->trace_handle)
+		stack_depot_print(object->trace_handle);
 }
 
 /*
@@ -591,6 +595,25 @@  static struct kmemleak_object *find_and_remove_object(unsigned long ptr, int ali
 	return object;
 }
 
+#ifdef CONFIG_STACKDEPOT
+static noinline depot_stack_handle_t set_track_prepare(void)
+{
+	depot_stack_handle_t trace_handle;
+	unsigned long entries[MAX_TRACE];
+	unsigned int nr_entries;
+
+	nr_entries = stack_trace_save(entries, ARRAY_SIZE(entries), 3);
+	trace_handle = stack_depot_save(entries, nr_entries, GFP_NOWAIT);
+
+	return trace_handle;
+}
+#else
+static inline depot_stack_handle_t set_track_prepare(void)
+{
+	return 0;
+}
+#endif
+
 /*
  * Save stack trace to the given array of MAX_TRACE size.
  */
@@ -654,7 +677,7 @@  static struct kmemleak_object *__create_object(unsigned long ptr, size_t size,
 	}
 
 	/* kernel backtrace */
-	object->trace_len = __save_stack_trace(object->trace);
+	object->trace_handle = set_track_prepare();
 
 	raw_spin_lock_irqsave(&kmemleak_lock, flags);
 
@@ -694,7 +717,6 @@  static struct kmemleak_object *__create_object(unsigned long ptr, size_t size,
 	rb_link_node(&object->rb_node, rb_parent, link);
 	rb_insert_color(&object->rb_node, is_phys ? &object_phys_tree_root :
 					  &object_tree_root);
-
 	list_add_tail_rcu(&object->object_list, &object_list);
 out:
 	raw_spin_unlock_irqrestore(&kmemleak_lock, flags);
@@ -1094,7 +1116,7 @@  void __ref kmemleak_update_trace(const void *ptr)
 	}
 
 	raw_spin_lock_irqsave(&object->lock, flags);
-	object->trace_len = __save_stack_trace(object->trace);
+	object->trace_handle = set_track_prepare();
 	raw_spin_unlock_irqrestore(&object->lock, flags);
 
 	put_object(object);
@@ -2064,6 +2086,7 @@  void __init kmemleak_init(void)
 	if (kmemleak_error)
 		return;
 
+	stack_depot_init();
 	jiffies_min_age = msecs_to_jiffies(MSECS_MIN_AGE);
 	jiffies_scan_wait = msecs_to_jiffies(SECS_SCAN_WAIT * 1000);