Re: kmemleak for MIPS

From: Maxin John
Date: Mon Mar 28 2011 - 17:16:01 EST


Hi,

> Just add "depends on MIPS" and give it a try.
As per your suggestion, I have tried it in my qemu environment (MIPS malta).

With a minor modification in arch/mips/kernel/vmlinux.lds.S (added the
symbol _sdata ), I was able to add kmemleak support for MIPS.

Output in MIPS (Malta):

debian-mips:~# uname -a
Linux debian-mips 2.6.38-08826-g1788c20-dirty #4 SMP Mon Mar 28
23:22:04 EEST 2011 mips GNU/Linux
debian-mips:~# mount -t debugfs nodev /sys/kernel/debug/
debian-mips:~# cat /sys/kernel/debug/kmemleak
unreferenced object 0x8f95d000 (size 4096):
comm "swapper", pid 1, jiffies 4294937330 (age 467.240s)
hex dump (first 32 bytes):
00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................
00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................
backtrace:
[<80529644>] alloc_large_system_hash+0x2f8/0x410
[<8053864c>] udp_table_init+0x4c/0x158
[<80538774>] udp_init+0x1c/0x94
[<80538b34>] inet_init+0x184/0x2a0
[<80100584>] do_one_initcall+0x174/0x1e0
[<8051f348>] kernel_init+0xe4/0x174
[<80103d4c>] kernel_thread_helper+0x10/0x18
unreferenced object 0x8f95e000 (size 4096):
comm "swapper", pid 1, jiffies 4294937330 (age 467.240s)
hex dump (first 32 bytes):
00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................
00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................
backtrace:
[<80529644>] alloc_large_system_hash+0x2f8/0x410
[<8053864c>] udp_table_init+0x4c/0x158
[<8053881c>] udplite4_register+0x24/0xa8
[<80538b3c>] inet_init+0x18c/0x2a0
[<80100584>] do_one_initcall+0x174/0x1e0
[<8051f348>] kernel_init+0xe4/0x174
[<80103d4c>] kernel_thread_helper+0x10/0x18
unreferenced object 0x8f982b80 (size 128):
comm "swapper", pid 1, jiffies 4294937331 (age 467.230s)
hex dump (first 32 bytes):
00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................
00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................
backtrace:
[<801b9b4c>] kmem_cache_alloc+0xe4/0x128
[<8052d960>] kmemleak_test_init+0x4c/0x298
[<80100584>] do_one_initcall+0x174/0x1e0
[<8051f348>] kernel_init+0xe4/0x174
[<80103d4c>] kernel_thread_helper+0x10/0x18
unreferenced object 0x8f982b00 (size 128):
comm "swapper", pid 1, jiffies 4294937331 (age 467.230s)
hex dump (first 32 bytes):
00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................
00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................
backtrace:
[<801b9b4c>] kmem_cache_alloc+0xe4/0x128
[<8052d97c>] kmemleak_test_init+0x68/0x298
[<80100584>] do_one_initcall+0x174/0x1e0
[<8051f348>] kernel_init+0xe4/0x174
[<80103d4c>] kernel_thread_helper+0x10/0x18
unreferenced object 0x8f980800 (size 1024):
comm "swapper", pid 1, jiffies 4294937331 (age 467.230s)
hex dump (first 32 bytes):
00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................
00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................
backtrace:
[<801b9b4c>] kmem_cache_alloc+0xe4/0x128
[<8052d998>] kmemleak_test_init+0x84/0x298
[<80100584>] do_one_initcall+0x174/0x1e0
[<8051f348>] kernel_init+0xe4/0x174
[<80103d4c>] kernel_thread_helper+0x10/0x18
unreferenced object 0x8f980400 (size 1024):
comm "swapper", pid 1, jiffies 4294937331 (age 467.240s)
hex dump (first 32 bytes):
00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................
00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................
backtrace:
[<801b9b4c>] kmem_cache_alloc+0xe4/0x128
[<8052d9b4>] kmemleak_test_init+0xa0/0x298
[<80100584>] do_one_initcall+0x174/0x1e0
[<8051f348>] kernel_init+0xe4/0x174
[<80103d4c>] kernel_thread_helper+0x10/0x18
unreferenced object 0x8f98a800 (size 2048):
comm "swapper", pid 1, jiffies 4294937331 (age 467.240s)
hex dump (first 32 bytes):
00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................
00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................
backtrace:
[<801b9b4c>] kmem_cache_alloc+0xe4/0x128
[<8052d9d0>] kmemleak_test_init+0xbc/0x298
[<80100584>] do_one_initcall+0x174/0x1e0
[<8051f348>] kernel_init+0xe4/0x174
[<80103d4c>] kernel_thread_helper+0x10/0x18
unreferenced object 0x8f98a000 (size 2048):
comm "swapper", pid 1, jiffies 4294937331 (age 467.270s)
hex dump (first 32 bytes):
00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................
00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................
backtrace:
[<801b9b4c>] kmem_cache_alloc+0xe4/0x128
[<8052d9ec>] kmemleak_test_init+0xd8/0x298
[<80100584>] do_one_initcall+0x174/0x1e0
[<8051f348>] kernel_init+0xe4/0x174
[<80103d4c>] kernel_thread_helper+0x10/0x18
unreferenced object 0x8f98b000 (size 4096):
comm "swapper", pid 1, jiffies 4294937331 (age 467.270s)
hex dump (first 32 bytes):
00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................
00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................
backtrace:
[<801b9b4c>] kmem_cache_alloc+0xe4/0x128
[<8052da24>] kmemleak_test_init+0x110/0x298
[<80100584>] do_one_initcall+0x174/0x1e0
[<8051f348>] kernel_init+0xe4/0x174
[<80103d4c>] kernel_thread_helper+0x10/0x18
unreferenced object 0xc0003000 (size 64):
comm "swapper", pid 1, jiffies 4294937331 (age 467.270s)
hex dump (first 32 bytes):
00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................
00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................
backtrace:
[<801b1b58>] __vmalloc_node_range+0x16c/0x1e0
[<801b1bfc>] __vmalloc_node+0x30/0x3c
[<801b1d94>] vmalloc+0x2c/0x38
[<8052da38>] kmemleak_test_init+0x124/0x298
[<80100584>] do_one_initcall+0x174/0x1e0
[<8051f348>] kernel_init+0xe4/0x174
[<80103d4c>] kernel_thread_helper+0x10/0x18
unreferenced object 0xc0006000 (size 64):
comm "swapper", pid 1, jiffies 4294937331 (age 467.270s)
hex dump (first 32 bytes):
00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................
00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................
backtrace:
[<801b1b58>] __vmalloc_node_range+0x16c/0x1e0
[<801b1bfc>] __vmalloc_node+0x30/0x3c
[<801b1d94>] vmalloc+0x2c/0x38
[<8052da4c>] kmemleak_test_init+0x138/0x298
[<80100584>] do_one_initcall+0x174/0x1e0
[<8051f348>] kernel_init+0xe4/0x174
[<80103d4c>] kernel_thread_helper+0x10/0x18
unreferenced object 0xc0009000 (size 64):
comm "swapper", pid 1, jiffies 4294937331 (age 467.270s)
hex dump (first 32 bytes):
00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................
00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................
backtrace:
[<801b1b58>] __vmalloc_node_range+0x16c/0x1e0
[<801b1bfc>] __vmalloc_node+0x30/0x3c
[<801b1d94>] vmalloc+0x2c/0x38
[<8052da60>] kmemleak_test_init+0x14c/0x298
[<80100584>] do_one_initcall+0x174/0x1e0
[<8051f348>] kernel_init+0xe4/0x174
[<80103d4c>] kernel_thread_helper+0x10/0x18
unreferenced object 0xc000c000 (size 64):
comm "swapper", pid 1, jiffies 4294937331 (age 467.270s)
hex dump (first 32 bytes):
00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................
00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................
backtrace:
[<801b1b58>] __vmalloc_node_range+0x16c/0x1e0
[<801b1bfc>] __vmalloc_node+0x30/0x3c
[<801b1d94>] vmalloc+0x2c/0x38
[<8052da74>] kmemleak_test_init+0x160/0x298
[<80100584>] do_one_initcall+0x174/0x1e0
[<8051f348>] kernel_init+0xe4/0x174
[<80103d4c>] kernel_thread_helper+0x10/0x18
unreferenced object 0xc000f000 (size 64):
comm "swapper", pid 1, jiffies 4294937331 (age 467.270s)
hex dump (first 32 bytes):
00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................
00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................
backtrace:
[<801b1b58>] __vmalloc_node_range+0x16c/0x1e0
[<801b1bfc>] __vmalloc_node+0x30/0x3c
[<801b1d94>] vmalloc+0x2c/0x38
[<8052da88>] kmemleak_test_init+0x174/0x298
[<80100584>] do_one_initcall+0x174/0x1e0
[<8051f348>] kernel_init+0xe4/0x174
[<80103d4c>] kernel_thread_helper+0x10/0x18
unreferenced object 0x8f072000 (size 4096):
comm "swapper", pid 1, jiffies 4294937680 (age 463.840s)
hex dump (first 32 bytes):
00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................
00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................
backtrace:
[<801ba3d8>] __kmalloc+0x130/0x180
[<805461bc>] flow_cache_cpu_prepare+0x50/0xa8
[<8053746c>] flow_cache_init_global+0x90/0x138
[<80100584>] do_one_initcall+0x174/0x1e0
[<8051f348>] kernel_init+0xe4/0x174
[<80103d4c>] kernel_thread_helper+0x10/0x18


Please let me know your comments.

Signed-off-by: Maxin B. John <maxin.john@xxxxxxxxx>
---
diff --git a/arch/mips/kernel/vmlinux.lds.S b/arch/mips/kernel/vmlinux.lds.S
index 832afbb..f5356fc 100644
--- a/arch/mips/kernel/vmlinux.lds.S
+++ b/arch/mips/kernel/vmlinux.lds.S
@@ -68,6 +68,7 @@ SECTIONS
RODATA

/* writeable */
+ _sdata = .; /* Start of data section */
.data : { /* Data */
. = . + DATAOFFSET; /* for CONFIG_MAPPED_KERNEL */

diff --git a/lib/Kconfig.debug b/lib/Kconfig.debug
index df9234c..5042421 100644
--- a/lib/Kconfig.debug
+++ b/lib/Kconfig.debug
@@ -398,7 +398,7 @@ config SLUB_STATS
config DEBUG_KMEMLEAK
bool "Kernel memory leak detector"
depends on DEBUG_KERNEL && EXPERIMENTAL && !MEMORY_HOTPLUG && \
- (X86 || ARM || PPC || S390 || SPARC64 || SUPERH ||
MICROBLAZE || TILE)
+ (X86 || ARM || PPC || MIPS || S390 || SPARC64 ||
SUPERH || MICROBLAZE || TILE)

select DEBUG_FS if SYSFS
select STACKTRACE if STACKTRACE_SUPPORT
--
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