Re: memory mapping of vmalloc
Hi Hugh, rvmallaoc is working. Very Very Thanks. Regards, Prakash --- Hugh Dickins <[EMAIL PROTECTED]> wrote: > On Tue, 1 Mar 2005, Prakash Bhurke wrote: > > I am trying to map a vmalloc kernel buffer to > user > > space using remap_page_range(). In my module, this > > function returns success if we call mmap() from > user > > space, but i can not access content of vmalloc > buffer > > from user space. Pointer returned by mmap() > syscall > > seems pointing to other memory page which contains > > zeros. I am using linux 2.6.10 kernel on Pentium 4 > > system. > > Look for "rvmalloc" in various drivers in the kernel > source tree: > you must SetPageReserved before remap_pfn_range (or > remap_page_range) > agrees to map the page, and ClearPageReserved before > freeing after. > > Hugh > - > To unsubscribe from this list: send the line > "unsubscribe linux-kernel" in > the body of a message to [EMAIL PROTECTED] > More majordomo info at > http://vger.kernel.org/majordomo-info.html > Please read the FAQ at http://www.tux.org/lkml/ > __ Celebrate Yahoo!'s 10th Birthday! Yahoo! Netrospective: 100 Moments of the Web http://birthday.yahoo.com/netrospective/ - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [EMAIL PROTECTED] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
Re: memory mapping of vmalloc
Hi Hugh, rvmallaoc is working. Very Very Thanks. Regards, Prakash --- Hugh Dickins [EMAIL PROTECTED] wrote: On Tue, 1 Mar 2005, Prakash Bhurke wrote: I am trying to map a vmalloc kernel buffer to user space using remap_page_range(). In my module, this function returns success if we call mmap() from user space, but i can not access content of vmalloc buffer from user space. Pointer returned by mmap() syscall seems pointing to other memory page which contains zeros. I am using linux 2.6.10 kernel on Pentium 4 system. Look for rvmalloc in various drivers in the kernel source tree: you must SetPageReserved before remap_pfn_range (or remap_page_range) agrees to map the page, and ClearPageReserved before freeing after. Hugh - To unsubscribe from this list: send the line unsubscribe linux-kernel in the body of a message to [EMAIL PROTECTED] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/ __ Celebrate Yahoo!'s 10th Birthday! Yahoo! Netrospective: 100 Moments of the Web http://birthday.yahoo.com/netrospective/ - To unsubscribe from this list: send the line unsubscribe linux-kernel in the body of a message to [EMAIL PROTECTED] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
Re: memory mapping of vmalloc
On Tue, 1 Mar 2005, Prakash Bhurke wrote: > I am trying to map a vmalloc kernel buffer to user > space using remap_page_range(). In my module, this > function returns success if we call mmap() from user > space, but i can not access content of vmalloc buffer > from user space. Pointer returned by mmap() syscall > seems pointing to other memory page which contains > zeros. I am using linux 2.6.10 kernel on Pentium 4 > system. Look for "rvmalloc" in various drivers in the kernel source tree: you must SetPageReserved before remap_pfn_range (or remap_page_range) agrees to map the page, and ClearPageReserved before freeing after. Hugh - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [EMAIL PROTECTED] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
memory mapping of vmalloc
Hi ,
I am facing a problem -- memory mapping of proc
entry into user space using mmap syscall.
I have written a module which creates a proc entry &
provides read, write, mmap, etc.
Normal read, write etc file operation works, but
mmap is not working.
I am trying to map a vmalloc kernel buffer to user
space using remap_page_range(). In my module, this
function returns success if we call mmap() from user
space, but i can not access content of vmalloc buffer
from user space. Pointer returned by mmap() syscall
seems pointing to other memory page which contains
zeros. I am using linux 2.6.10 kernel on Pentium 4
system.
here is code of module_mmap();
static inline unsigned long kvirt_to_pa(unsigned long
adr)
{
unsigned long kva, ret;
kva = (unsigned long)
page_address(vmalloc_to_page((void *)adr));
kva |= adr & (PAGE_SIZE-1); /* restore the offset */
ret = __pa(kva);
return ret;
}
static int module_mmap(struct file *file, struct
vm_area_struct *vma)
{
unsigned long offset = vma->vm_pgoff << PAGE_SHIFT;
unsigned long len = vma->vm_end - vma->vm_start;
unsigned long pos = (unsigned long) test_tsc +
offset;
printk(KERN_INFO "PROCINFO : in mmap started, length
= %ld\n", len);
if (!tscinfo)
return -ENODEV;
if ((offset + len) > PAGE_ALIGN(sizeof(sizeof(struct
test_tsc_info)
return -ENXIO;
if ((vma->vm_flags & (VM_SHARED|VM_WRITE)) ==
(VM_SHARED|VM_WRITE)) {
printk("PROCINFO : in mmap attempt to write to
mapping\n");
return -EPERM;
}
vma->vm_flags |= VM_SHM | VM_LOCKED ;
if (remap_pfn_range(vma, vma->vm_start,
kvirt_to_pa(pos) >> PAGE_SHIFT, \
len, vma->vm_page_prot)) {
printk(KERN_INFO "PROCINFO : in mmap remap_pfn_range
returns error\n");
return -EAGAIN;
}
printk(KERN_INFO "PROCINFO : in mmap ret 0 end\n");
return 0;
}
>From user space program i mapping kernel memory like
this
proc_fd = open("/proc/"PROC_ENTRY_FILENAME, O_RDONLY);
mem_base = mmap(NULL, sizeof(struct test_tsc_info),
PROT_READ, MAP_SHARED, proc_fd, 0);
Please let me know what wrong thing i m doing.
Regards,
Prakash.
__
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Please read the FAQ at http://www.tux.org/lkml/
memory mapping of vmalloc
Hi ,
I am facing a problem -- memory mapping of proc
entry into user space using mmap syscall.
I have written a module which creates a proc entry
provides read, write, mmap, etc.
Normal read, write etc file operation works, but
mmap is not working.
I am trying to map a vmalloc kernel buffer to user
space using remap_page_range(). In my module, this
function returns success if we call mmap() from user
space, but i can not access content of vmalloc buffer
from user space. Pointer returned by mmap() syscall
seems pointing to other memory page which contains
zeros. I am using linux 2.6.10 kernel on Pentium 4
system.
here is code of module_mmap();
static inline unsigned long kvirt_to_pa(unsigned long
adr)
{
unsigned long kva, ret;
kva = (unsigned long)
page_address(vmalloc_to_page((void *)adr));
kva |= adr (PAGE_SIZE-1); /* restore the offset */
ret = __pa(kva);
return ret;
}
static int module_mmap(struct file *file, struct
vm_area_struct *vma)
{
unsigned long offset = vma-vm_pgoff PAGE_SHIFT;
unsigned long len = vma-vm_end - vma-vm_start;
unsigned long pos = (unsigned long) test_tsc +
offset;
printk(KERN_INFO PROCINFO : in mmap started, length
= %ld\n, len);
if (!tscinfo)
return -ENODEV;
if ((offset + len) PAGE_ALIGN(sizeof(sizeof(struct
test_tsc_info)
return -ENXIO;
if ((vma-vm_flags (VM_SHARED|VM_WRITE)) ==
(VM_SHARED|VM_WRITE)) {
printk(PROCINFO : in mmap attempt to write to
mapping\n);
return -EPERM;
}
vma-vm_flags |= VM_SHM | VM_LOCKED ;
if (remap_pfn_range(vma, vma-vm_start,
kvirt_to_pa(pos) PAGE_SHIFT, \
len, vma-vm_page_prot)) {
printk(KERN_INFO PROCINFO : in mmap remap_pfn_range
returns error\n);
return -EAGAIN;
}
printk(KERN_INFO PROCINFO : in mmap ret 0 end\n);
return 0;
}
From user space program i mapping kernel memory like
this
proc_fd = open(/proc/PROC_ENTRY_FILENAME, O_RDONLY);
mem_base = mmap(NULL, sizeof(struct test_tsc_info),
PROT_READ, MAP_SHARED, proc_fd, 0);
Please let me know what wrong thing i m doing.
Regards,
Prakash.
__
Do you Yahoo!?
Yahoo! Sports - Sign up for Fantasy Baseball.
http://baseball.fantasysports.yahoo.com/
-
To unsubscribe from this list: send the line unsubscribe linux-kernel in
the body of a message to [EMAIL PROTECTED]
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/
Re: memory mapping of vmalloc
On Tue, 1 Mar 2005, Prakash Bhurke wrote: I am trying to map a vmalloc kernel buffer to user space using remap_page_range(). In my module, this function returns success if we call mmap() from user space, but i can not access content of vmalloc buffer from user space. Pointer returned by mmap() syscall seems pointing to other memory page which contains zeros. I am using linux 2.6.10 kernel on Pentium 4 system. Look for rvmalloc in various drivers in the kernel source tree: you must SetPageReserved before remap_pfn_range (or remap_page_range) agrees to map the page, and ClearPageReserved before freeing after. Hugh - To unsubscribe from this list: send the line unsubscribe linux-kernel in the body of a message to [EMAIL PROTECTED] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
