Re: [perfmon2] [PATCH] perfmon: fix getname() error handler

[stephane e. <er...@go...>]

Robert,

This patch was applied to perfmon2 and perfmon3
Thanks.


On Wed, Feb 4, 2009 at 10:31 AM, Robert Richter <rob...@am...> wrote:
> This patch fixes the following bug:
>
> BUG: unable to handle kernel paging request at fffffffffffffffe
> IP: [<ffffffff8032e80e>] strcmp+0x5/0x19
> PGD 203067 PUD 204067 PMD 0
> Oops: 0000 [#1] SMP
> last sysfs file: /sys/kernel/perfmon/version
> CPU 7
> Modules linked in:
> Pid: 5135, comm: ibs_sampling Not tainted 2.6.28-perfmon-x86_64-standard-00431-gec92131 #1
> RIP: 0010:[<ffffffff8032e80e>]  [<ffffffff8032e80e>] strcmp+0x5/0x19
> RSP: 0018:ffff88042f1d1e60  EFLAGS: 00010287
> RAX: 0000000000000064 RBX: ffffffff807430e0 RCX: ffff88042f1d1f10
> RDX: 0000000000000064 RSI: fffffffffffffffe RDI: ffffffff806b37b4
> RBP: fffffffffffffffe R08: ffff88042f1d1f10 R09: 0000000000000000
> R10: 00007fc1561cc6f0 R11: 0000000000000206 R12: 00007fc1561cc6f0
> R13: 0000000000000000 R14: ffff88042f1d1f18 R15: 0000000000000040
> FS:  00007fc1561cc6f0(0000) GS:ffff88042f99df40(0000) knlGS:0000000000000000
> CS:  0010 DS: 0000 ES: 0000 CR0: 000000008005003b
> CR2: fffffffffffffffe CR3: 000000042d990000 CR4: 00000000000006e0
> DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
> DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000400
> Process ibs_sampling (pid: 5135, threadinfo ffff88042f1d0000, task ffff88042fb5d8d0)
> Stack:
>  ffffffff803299c4 ffff88042f1d1f10 fffffffffffffffe 00007fc1561cc6f0
>  ffffffff80329a05 fffffffffffffffe ffffffff80328501 ffff88042db0d1e0
>  ffff88042f1d1f10 ffff88042f1d1f08 00007fff5e1d2110 00007fff5e1d1fc0
> Call Trace:
>  [<ffffffff803299c4>] ? pfm_find_fmt+0x2c/0x55
>  [<ffffffff80329a05>] ? pfm_smpl_fmt_get+0x18/0x5c
>  [<ffffffff80328501>] ? pfm_get_smpl_arg+0x84/0x1c7
>  [<ffffffff803224a6>] ? sys_pfm_create_context+0xcd/0x109
>  [<ffffffff802652ed>] ? do_munmap+0x298/0x2b3
>  [<ffffffff8020b20b>] ? system_call_fastpath+0x16/0x1b
> Code: 14 08 72 04 0f 0b eb fe 4d 29 c1 4d 01 c2 49 8d 41 ff 4c 39 c9 4c 89 d7 fc 48 0f 43 c8 48 89 d0 f3 a4 c6 07 00 c3 0f b6 17 89 d0 <2a> 06 48 ff c6 84 c0 75 07 48 ff c7 84 d2 75 eb 0f be c0 c3 31
> RIP  [<ffffffff8032e80e>] strcmp+0x5/0x19
>  RSP <ffff88042f1d1e60>
> CR2: fffffffffffffffe
> ---[ end trace 548f9728b73203d7 ]---
>
> Signed-off-by: Robert Richter <rob...@am...>
> ---
>  perfmon/perfmon_smpl.c |    7 ++++---
>  1 files changed, 4 insertions(+), 3 deletions(-)
>
> diff --git a/perfmon/perfmon_smpl.c b/perfmon/perfmon_smpl.c
> index e31fb15..a6e26d7 100644
> --- a/perfmon/perfmon_smpl.c
> +++ b/perfmon/perfmon_smpl.c
> @@ -811,9 +811,10 @@ int pfm_get_smpl_arg(char __user *fmt_uname, void __user *fmt_uarg, size_t usize
>        int ret;
>
>        fmt_name = getname(fmt_uname);
> -       if (!fmt_name) {
> -               PFM_DBG("getname failed");
> -               return -ENOMEM;
> +       ret = PTR_ERR(fmt_name);
> +       if (IS_ERR(fmt_name)) {
> +               PFM_DBG("getname failed: %d", ret);
> +               return ret;
>        }
>
>        /*
> --
> 1.6.1
>
>
>