Hello At the beggining I want say clear that I am not a kernel developer and I don't studied anything directly related to IT so I don't know how to properly debug kernel. For some reasons (example Debian Jessie will have 3.16) I would like to stick with 3.16 kernel on my laptop, so I tried to configure it. After all I wanted to test kernel using memory tests in kernel. Kmemcheck caught read from unallocated memory. I compiled two kernels with slightly different configuration and both had same issue. I don't have config or binary file for first kernel, I have only this message: dmesg: [ 114.392483] WARNING: kmemcheck: Caught 64-bit read from unallocated memory (ffff880099c1e7c8) [ 114.393740] 88004000070000000000000000000000a075825e0188ffffc0c3c1990088fffffac2a6f909000000b8e7c1990088ffff10fd78590188ffff71756575652e62696e00ffffffffffffffffffffffffffffffffffffffffff0003000000ffffffff402b6181ffffffff00f06f590188ffffffffffffffffffff0000000000000000 [ 114.396915] i i i i i i i i i i i i i i i i i i i i i i i i i i i i i i i i i i i i i i i i i i i i i i i i i i i i i i i i i i i i i i i i i i i i i i i i a a a a a a a a a a a a a a a i i i i i a a a a i i i i i i i i i i i i i i i i a a a a a a a a i i i i i i i i [ 114.400234] ^ [ 114.401672] RIP: 0010:[<ffffffff810d7fe2>] [<ffffffff810d7fe2>] switch_names+0xd2/0x100 [ 114.403107] RSP: 0018:ffff88009a023cf0 EFLAGS: 00010287 [ 114.404542] RAX: ffff880099c1e840 RBX: ffff880099c1e780 RCX: 0000000000000010 [ 114.405977] RDX: ffff880099c1e780 RSI: ffff880099c1e7b8 RDI: ffffffffffff0070 [ 114.407407] RBP: ffff88009a023cf0 R08: ffff880099c1e878 R09: ffffffffffff006e [ 114.408823] R10: ffff880099c1e7b8 R11: ffff880099c1e840 R12: ffff880099c1e840 [ 114.410227] R13: 0000000000000000 R14: ffff88015978e918 R15: ffff880099c1e780 [ 114.411627] FS: 0000000000000000(0000) GS:ffffffff81820000(0000) knlGS:0000000000000000 [ 114.413032] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [ 114.414431] CR2: ffff880159b3d130 CR3: 000000009a04a000 CR4: 00000000000407f0 [ 114.415845] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 [ 114.417257] DR3: 0000000000000000 DR6: 00000000ffff4ff0 DR7: 0000000000000400 [ 114.418647] [<ffffffff810d8b80>] __d_move+0x1a0/0x370 [ 114.420032] [<ffffffff810da6a2>] d_move+0x12/0x20 [ 114.421403] [<ffffffff810d4037>] vfs_rename+0x637/0x670 [ 114.422779] [<ffffffff810d444f>] SyS_renameat2+0x3df/0x4a0 [ 114.424152] [<ffffffff810d4539>] SyS_rename+0x19/0x20 [ 114.425514] [<ffffffff814d6144>] tracesys+0xcf/0xd4 [ 114.426849] [<ffffffffffffffff>] 0xffffffffffffffff bash-4.2# addr2line -e vmlinux -i ffffffff810d7fe2 /home/slack/kernel/linux-3.16.1/fs/dcache.c:2440 (discriminator 2) for second I have config: http://pastebin.ca/2833888 I have vmlinux with debug info: vmlinux 86.1 MB https://mega.co.nz/#!lx9EhDSb!7azlKwAJ9K4ictCx-07P-ky9yNSNH-iKxdQQBUoRGTM I have /boot/vmlinuz: vmlinuz 2.7 MB https://mega.co.nz/#!5k9yHYxY!CiCxAAY_o-yPbg1N63cQymjRlA-764zDRhJ1oXc9Dmo and full dmesg: http://pastebin.ca/2833906 and cutted message: [ 4.199236] kmemcheck: Initialized [ 113.813070] WARNING: kmemcheck: Caught 64-bit read from unallocated memory (ffff880099ccd108) [ 113.814321] 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 [ 113.820725] i i i i i i i i a a a a a a a a a a a a a a a i i i i i a a a a i i i i i i i i i i i i i i i i a a a a a a a a i i i i i i i i i i i i i i i i i i i i i i i i i i i i i i i i i i i i i i i i i i i i i i i i i i i i i i i i i i i i i i i i i i i i i i i i i i i i i i i i i i i i i i i i i i i i i i i i i i i i i i i i i i i i i i i i i i i i i i i i i i i i i i i i i i i i i i i i i i i i i i i i a a a a a a a a a a a a a a a i i i i i a a a a i i i i i i i i i i i i i i i i a a a a a a a a i i i i i i i i [ 113.827766] ^ [ 113.829261] RIP: 0010:[<ffffffff810da652>] [<ffffffff810da652>] switch_names+0xb2/0xe0 [ 113.830784] RSP: 0018:ffff88009992fcf0 EFLAGS: 00010287 [ 113.832299] RAX: ffff880099ccd180 RBX: ffff880099ccd0c0 RCX: 0000000000000010 [ 113.833816] RDX: ffff880099ccd0c0 RSI: ffff880099ccd0f8 RDI: ffffffffffff0070 [ 113.835323] RBP: ffff88009992fcf0 R08: ffff880099ccd1b8 R09: ffffffffffff006e [ 113.836823] R10: ffff880099ccd0f8 R11: ffff880099ccd180 R12: ffff880099ccd180 [ 113.838317] R13: 0000000000000000 R14: ffff8801006b6918 R15: ffff880099ccd0c0 [ 113.839797] FS: 0000000000000000(0000) GS:ffffffff81820000(0000) knlGS:0000000000000000 [ 113.841274] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [ 113.842733] CR2: ffff88009a00a510 CR3: 00000000998fb000 CR4: 00000000000407f0 [ 113.844201] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 [ 113.845674] DR3: 0000000000000000 DR6: 00000000ffff4ff0 DR7: 0000000000000400 [ 113.847152] [<ffffffff810db49c>] __d_moFrom dve+0x1ec/0x340 [ 113.848629] [<ffffffff810dcd32>] d_move+0x12/0x20 [ 113.850076] [<ffffffff810d643e>] vfs_rename+0x3be/0x640 [ 113.851493] [<ffffffff810d69af>] SyS_renameat2+0x2ef/0x4e0 [ 113.852881] [<ffffffff810d6bc9>] SyS_rename+0x19/0x20 [ 113.854236] [<ffffffff814dfc04>] tracesys+0xcf/0xd4 [ 113.855591] [<ffffffffffffffff>] 0xffffffffffffffff bash-4.2# addr2line -e vmlinux -i ffffffff810da652 /home/slack/kernel/linux-3.16.1/fs/dcache.c:2440 (discriminator 2) So in two kmemcheck reports from 2 kernels adresses are different but they point to the same line in same file. Other adresses on stack point to: bash-4.2$ ./addr2l ffffffff810db49c /home/slack/kernel/linux-3.16.1/fs/dcache.c:2544 --- ffffffff810dcd32 /home/slack/kernel/linux-3.16.1/include/linux/seqlock.h:219 /home/slack/kernel/linux-3.16.1/include/linux/seqlock.h:240 /home/slack/kernel/linux-3.16.1/include/linux/seqlock.h:306 /home/slack/kernel/linux-3.16.1/fs/dcache.c:2584 --- ffffffff810d643e /home/slack/kernel/linux-3.16.1/fs/namei.c:4154 --- ffffffff810d69af /home/slack/kernel/linux-3.16.1/fs/namei.c:4286 /home/slack/kernel/linux-3.16.1/fs/namei.c:4178 --- ffffffff810d6bc9 /home/slack/kernel/linux-3.16.1/fs/namei.c:4324 --- ffffffff814dfc04 /home/slack/kernel/linux-3.16.1/arch/x86/kernel/entry_64.S:543 --- I caught this error in one-shot mode. In enabled mode I have inifinite loop of kmemcheck two warnings. First is the same, second points to address ffffffff810da656 which points to the same line: bash-4.2# addr2line -e vmlinux -i ffffffff810da656 /home/slack/kernel/linux-3.16.1/fs/dcache.c:2440 (discriminator 2) Other adresses are the same in second warning (I don't have and thus don't provide all informations from second warning because I can't login to shell without one-shot mode. I written adresses by pen on paper manually from screen). -- To unsubscribe from this list: send the line "unsubscribe linux-fsdevel" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
