ext2_find_near()
Hi all,
Sorry to bother.
for ext2_find_near(), why we tro to find near block by tring priveous block?
Why not forward?
static ext2_fsblk_t ext2_find_near(struct inode *inode, Indirect *ind)
{
struct ext2_inode_info *ei = EXT2_I(inode);
__le32 *start = ind->bh ? (__le32 *) ind->bh->b_data : ei->i_data;
__le32 *p;
ext2_fsblk_t bg_start;
ext2_fsblk_t colour;
/* Try to find previous block */
for (p = ind->p - 1; p >= start; p--)
if (*p)
return le32_to_cpu(*p);
/* No such thing, so let's try location of indirect block */
if (ind->bh)
return ind->bh->b_blocknr;
Thank you!
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[junk] newbie test.
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Re: GPIO Watchdog device driver
On Tue, Nov 13, 2012 at 9:03 AM, Mulyadi Santosa wrote: > On Tue, Nov 13, 2012 at 10:37 PM, Andreas Schmidt > wrote: >> Hi all, >> I wrote a GPIO watchdog for a extern simple watchdog (LTC2917). It is a >> voltage supervisor with watchdog timer functionality. Do you think >> should I send this to maintainer? Could it be usefull for somebody else? You can put it in staging directory if you suspect the code quality and if someone is looking for some kernel work they will definitely add the bells and whistles so that it can be mainlined. I do think that you should just send the driver code to LKML.You will definitely get more responses and the right way of mainlining it. > > I am not familiar with Watchdog stuffs, but I think it might worth a > shot if you try to send it to the maintainer. > > As long as you are descriptive enough when explaining about the > patches, follow the patch sending's rules, I think it is likely to be > accepted. > -- > regards, > > Mulyadi Santosa > Freelance Linux trainer and consultant > > blog: the-hydra.blogspot.com > training: mulyaditraining.blogspot.com > > ___ > Kernelnewbies mailing list > Kernelnewbies@kernelnewbies.org > http://lists.kernelnewbies.org/mailman/listinfo/kernelnewbies ___ Kernelnewbies mailing list Kernelnewbies@kernelnewbies.org http://lists.kernelnewbies.org/mailman/listinfo/kernelnewbies
Re: Callback function from kernel module
Hi all,
You cand find number of example on how to use send_sig_info api.
please follow this link :
http://lxr.linux.no/linux+v3.6.6/kernel/pid_namespace.c#L179
Regarding this warning
jeshwanth@jeshwanth:~/linux/kernel_user_space/code/signals$ make
make -C /lib/modules/3.0.0-26-generic-pae/build
M=/home/jeshwanth/linux/kernel_user_space/code/signals modules
make[1]: Entering directory `/usr/src/linux-headers-3.0.0-26-generic-pae'
Building modules, stage 2.
MODPOST 1 modules
WARNING: "find_task_by_vpid"
[/home/jeshwanth/linux/kernel_user_space/code/signals/signal_kernel.ko]
undefined!
make[1]: Leaving directory `/usr/src/linux-headers-3.0.0-26-generic-pae'
[1]+ Donegedit signal_kernel.c
install Command:
root@jeshwanth:/home/jeshwanth/linux/kernel_user_space/code/signals# insmod
signal_kernel.ko
insmod: error inserting 'signal_kernel.ko': -1 Unknown symbol in module
/proc/kallsyms:
T find_task_by_pid_ns
T find_task_by_vpid
you need the export these functions so that you can use then in your module.
-Anand Moon
From: Jeshwanth Kumar N K Jeshu
To: SaNtosh kuLkarni ; moon.li...@yahoo.com
Cc: Bernd Petrovitsch ;
kernelnewbies@kernelnewbies.org
Sent: Saturday, November 10, 2012 1:47 PM
Subject: Re: Callback function from kernel module
Hello Santosh and Anand,
Thanks for the reply and very good suggestions.
As Anand Moon
suggestedhttp://people.ee.ethz.ch/%7Earkeller/linux/multi/kernel_user_space_howto-3.html
link in
http://lists.kernelnewbies.org/pipermail/kernelnewbies/2012-November/006489.html
previous thread,
I read all the kernel to user space communication mechanism ( ExceptUpcall , ll
read it). As of now for my application,
the signals passing from kernel to user space is enough. I was trying the
sample code provided in signals section of above link.
1. In the code he used find_task_by_pid_type, but find_task_by_pid_type not
available in sched.h. So I have changed it to
find_task_by_vpid(pid), is this right way ?
2. I tried to install the module but it is not finding the symbol, but the
symbol is present in /proc/kallsyms.
Anything I am missing while compiling ? as I am getting warning.
Compile:
jeshwanth@jeshwanth:~/linux/kernel_user_space/code/signals$ make
make -C /lib/modules/3.0.0-26-generic-pae/build
M=/home/jeshwanth/linux/kernel_user_space/code/signals modules
make[1]: Entering directory `/usr/src/linux-headers-3.0.0-26-generic-pae'
Building modules, stage 2.
MODPOST 1 modules
WARNING: "find_task_by_vpid"
[/home/jeshwanth/linux/kernel_user_space/code/signals/signal_kernel.ko]
undefined!
make[1]: Leaving directory `/usr/src/linux-headers-3.0.0-26-generic-pae'
[1]+ Done gedit signal_kernel.c
install Command:
root@jeshwanth:/home/jeshwanth/linux/kernel_user_space/code/signals# insmod
signal_kernel.ko
insmod: error inserting 'signal_kernel.ko': -1 Unknown symbol in module
/proc/kallsyms:
T find_task_by_pid_ns
T find_task_by_vpid
dmesg:
[15012.556740] signal_kernel: Unknown symbol find_task_by_vpid (err 0)
Code:
#include
#include
#include
#include //siginfo
#include //rcu_read_lock
#include //find_task_by_pid_type
#include
#include
#define SIG_TEST 44 // we choose 44 as our signal number (real-time signals
are in the range of 33 to 64)
struct dentry *file;
static ssize_t write_pid(struct file *file, const char __user *buf,
size_t count, loff_t *ppos)
{
char mybuf[10];
int pid = 0;
int ret;
struct siginfo info;
struct task_struct *t;
/* read the value from user space */
if(count > 10)
return -EINVAL;
copy_from_user(mybuf, buf, count);
sscanf(mybuf, "%d", &pid);
printk("pid = %d\n", pid);
/* send the signal */
memset(&info, 0, sizeof(struct siginfo));
info.si_signo = SIG_TEST;
info.si_code = SI_QUEUE; // this is bit of a trickery: SI_QUEUE is
normally used by sigqueue from user space,
// and kernel space should use SI_KERNEL. But if SI_KERNEL
is used the real_time data
// is not delivered to the user space signal handler
function.
info.si_int = 1234; //real time signals may have 32 bits of data.
rcu_read_lock();
//t = find_task_by_pid_type(PIDTYPE_PID, pid); //find the task_struct
associated with this pid
t = find_task_by_vpid(pid);
if(t == NULL){
printk("no such pid\n");
rcu_read_unlock();
return -ENODEV;
}
rcu_read_unlock();
ret = send_sig_info(SIG_TEST, &info, t); //send the signal
if (ret < 0) {
printk("error sending signal\n");
return ret;
}
return count;
}
static const struct file_operations my_fops
Re: GPIO Watchdog device driver
On Tue, Nov 13, 2012 at 10:37 PM, Andreas Schmidt wrote: > Hi all, > I wrote a GPIO watchdog for a extern simple watchdog (LTC2917). It is a > voltage supervisor with watchdog timer functionality. Do you think > should I send this to maintainer? Could it be usefull for somebody else? I am not familiar with Watchdog stuffs, but I think it might worth a shot if you try to send it to the maintainer. As long as you are descriptive enough when explaining about the patches, follow the patch sending's rules, I think it is likely to be accepted. -- regards, Mulyadi Santosa Freelance Linux trainer and consultant blog: the-hydra.blogspot.com training: mulyaditraining.blogspot.com ___ Kernelnewbies mailing list Kernelnewbies@kernelnewbies.org http://lists.kernelnewbies.org/mailman/listinfo/kernelnewbies
Manually accessing file contents from bprm->file
Hello, I am trying to boot a custom linux-2.6.37 port, but I am stuck at the point where the kernel launches /init executable (since the initial filesystem was mounted with initramfs support). After investigations, it appears that a problem occurs during prepare_binprm() function. This function is responsible for copying the 128 bytes header of the executable to bprm->buf. However in my case, bprm->buf is filled with zeroes after this step. The kernel_read() function receives bprm->buf and bprm->file as operand. So the address in memory (in the initramfs) of the executable should be accessible from bprm->file (file object of /init). My question is: How can I manually (e.g. in the debugger) access the contents of the /init file (stored in memory, in the initramfs), from the bprm->file structure? (I'd like to check the data structures are in good shape and correctly point to the /init contents). Thanks in advance for your help. ___ Kernelnewbies mailing list Kernelnewbies@kernelnewbies.org http://lists.kernelnewbies.org/mailman/listinfo/kernelnewbies
GPIO Watchdog device driver
Hi all, I wrote a GPIO watchdog for a extern simple watchdog (LTC2917). It is a voltage supervisor with watchdog timer functionality. Do you think should I send this to maintainer? Could it be usefull for somebody else? Thanks Andreas ___ Kernelnewbies mailing list Kernelnewbies@kernelnewbies.org http://lists.kernelnewbies.org/mailman/listinfo/kernelnewbies
Re: Linux stable test kernels
On Tue, Nov 13, 2012 at 11:31 AM, Luis R. Rodriguez wrote: > On Tue, Nov 13, 2012 at 2:28 AM, WANG Chao wrote: >> On 11/13/2012 05:36 PM, Peter Senna Tschudin wrote: >>> Dear list, >>> >>> Where / how can I get latest Linux stable test kernels like >>> 3.0.51-rc1, 3.4.18-rc1, and 3.6.6-rc1? >>> >> >> http://www.kernel.org/ > > To be more exact: > > http://www.kernel.org/pub/linux/kernel/v3.x/stable-review/ Thank you! > > Luis -- Peter ___ Kernelnewbies mailing list Kernelnewbies@kernelnewbies.org http://lists.kernelnewbies.org/mailman/listinfo/kernelnewbies
Re: Linux stable test kernels
On Tue, Nov 13, 2012 at 2:28 AM, WANG Chao wrote: > On 11/13/2012 05:36 PM, Peter Senna Tschudin wrote: >> Dear list, >> >> Where / how can I get latest Linux stable test kernels like >> 3.0.51-rc1, 3.4.18-rc1, and 3.6.6-rc1? >> > > http://www.kernel.org/ To be more exact: http://www.kernel.org/pub/linux/kernel/v3.x/stable-review/ Luis ___ Kernelnewbies mailing list Kernelnewbies@kernelnewbies.org http://lists.kernelnewbies.org/mailman/listinfo/kernelnewbies
Re: Linux stable test kernels
On 11/13/2012 05:36 PM, Peter Senna Tschudin wrote: > Dear list, > > Where / how can I get latest Linux stable test kernels like > 3.0.51-rc1, 3.4.18-rc1, and 3.6.6-rc1? > http://www.kernel.org/ > Thanks, > > Peter > > -- > Peter > > ___ > Kernelnewbies mailing list > Kernelnewbies@kernelnewbies.org > http://lists.kernelnewbies.org/mailman/listinfo/kernelnewbies > -- Thanks, WANG Chao ___ Kernelnewbies mailing list Kernelnewbies@kernelnewbies.org http://lists.kernelnewbies.org/mailman/listinfo/kernelnewbies
Linux stable test kernels
Dear list, Where / how can I get latest Linux stable test kernels like 3.0.51-rc1, 3.4.18-rc1, and 3.6.6-rc1? Thanks, Peter -- Peter ___ Kernelnewbies mailing list Kernelnewbies@kernelnewbies.org http://lists.kernelnewbies.org/mailman/listinfo/kernelnewbies
