* [Linux-ia64] Re: Fixing /proc/kcore
@ 2002-10-25 18:00 Andi Kleen
2002-10-28 16:14 ` Mario Smarduch
` (2 more replies)
0 siblings, 3 replies; 4+ messages in thread
From: Andi Kleen @ 2002-10-25 18:00 UTC (permalink / raw)
To: linux-ia64
"Luck, Tony" <tony.luck@intel.com> writes:
> This message is in MIME format. Since your mail reader does not understand
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> ------_=_NextPart_000_01C27C4E.CD496DB0
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>
> /proc/kcore is what you need, but it is broken on ia64 (and
> has been since the dawn of time for access to region 5) because
> it assumes that all kernel virtual addresses are above PAGE+AF8-OFFSET.
> This isn't true on ia64, VMALLOC+AF8-START is smaller than PAGE+AF8-OFFSET.
I recently fixed a similar problem on x86-64. There the modules are outside
the vmalloc area, but also not in the direct mapping. I just changed
the module mapping and the kernel mapping to put themselves into the vmlist.
kcore checks vmlist first and then afterwards tries direct addresses.
Also the kernel addresses are negative, which needed some more changes
in seek.
Here is the 2.4.19 patch which should to 2.5 too.
I think it's a bit cleaner than yours and will probably help you too.
Just put everything special into vmlist too.
-Andi
Index: linux/fs/proc/inode.c
=================================RCS file: /home/cvs/Repository/linux/fs/proc/inode.c,v
retrieving revision 1.4
retrieving revision 1.5
diff -u -u -r1.4 -r1.5
--- linux/fs/proc/inode.c 2002/01/15 10:09:21 1.4
--- linux/fs/proc/inode.c 2002/10/17 13:02:13 1.5
@@ -186,6 +186,7 @@
s->s_blocksize_bits = 10;
s->s_magic = PROC_SUPER_MAGIC;
s->s_op = &proc_sops;
+ s->s_maxbytes = ~0ULL;
root_inode = proc_get_inode(s, PROC_ROOT_INO, &proc_root);
if (!root_inode)
Index: linux/fs/proc/kcore.c
=================================RCS file: /home/cvs/Repository/linux/fs/proc/kcore.c,v
retrieving revision 1.3
retrieving revision 1.4
diff -u -u -r1.3 -r1.4
--- linux/fs/proc/kcore.c 2002/03/21 11:54:59 1.3
--- linux/fs/proc/kcore.c 2002/10/17 13:02:13 1.4
@@ -27,11 +27,14 @@
return capable(CAP_SYS_RAWIO) ? 0 : -EPERM;
}
+static loff_t lseek_kcore(struct file * file, loff_t offset, int origin);
+
static ssize_t read_kcore(struct file *, char *, size_t, loff_t *);
struct file_operations proc_kcore_operations = {
read: read_kcore,
open: open_kcore,
+ lseek: lseek_kcore,
};
#ifdef CONFIG_KCORE_AOUT
@@ -112,9 +115,9 @@
extern char saved_command_line[];
-static size_t get_kcore_size(int *num_vma, size_t *elf_buflen)
+static unsigned long get_kcore_size(int *num_vma, size_t *elf_buflen)
{
- size_t try, size;
+ unsigned long try, size;
struct vm_struct *m;
*num_vma = 0;
@@ -125,7 +128,7 @@
}
for (m=vmlist; m; m=m->next) {
- try = (size_t)m->addr + m->size;
+ try = (unsigned long)m->addr + m->size;
if (try > size)
size = try;
*num_vma = *num_vma + 1;
@@ -313,14 +316,14 @@
static ssize_t read_kcore(struct file *file, char *buffer, size_t buflen, loff_t *fpos)
{
ssize_t acc = 0;
- size_t size, tsz;
+ unsigned long size, tsz;
size_t elf_buflen;
int num_vma;
unsigned long start;
read_lock(&vmlist_lock);
proc_root_kcore->size = size = get_kcore_size(&num_vma, &elf_buflen);
- if (buflen = 0 || *fpos >= size) {
+ if (buflen = 0 || (unsigned long long)*fpos >= size) {
read_unlock(&vmlist_lock);
return 0;
}
@@ -390,9 +393,16 @@
start = PAGE_OFFSET + (*fpos - elf_buflen);
if ((tsz = (PAGE_SIZE - (start & ~PAGE_MASK))) > buflen)
tsz = buflen;
-
while (buflen) {
- if ((start >= VMALLOC_START) && (start < VMALLOC_END)) {
+ int err;
+
+ if ((start > PAGE_OFFSET) && (start < (unsigned long)high_memory)) {
+ if (kern_addr_valid(start)) {
+ err = copy_to_user(buffer, (char *)start, tsz);
+ } else {
+ err = clear_user(buffer, tsz);
+ }
+ } else {
char * elf_buf;
struct vm_struct *m;
unsigned long curstart = start;
@@ -432,24 +442,11 @@
(char *)vmstart, vmsize);
}
read_unlock(&vmlist_lock);
- if (copy_to_user(buffer, elf_buf, tsz)) {
- kfree(elf_buf);
- return -EFAULT;
- }
+ err = copy_to_user(buffer, elf_buf, tsz);
kfree(elf_buf);
- } else if ((start > PAGE_OFFSET) && (start <
- (unsigned long)high_memory)) {
- if (kern_addr_valid(start)) {
- if (copy_to_user(buffer, (char *)start, tsz))
- return -EFAULT;
- } else {
- if (clear_user(buffer, tsz))
- return -EFAULT;
- }
- } else {
- if (clear_user(buffer, tsz))
- return -EFAULT;
- }
+ }
+ if (err)
+ return -EFAULT;
buflen -= tsz;
*fpos += tsz;
buffer += tsz;
@@ -461,3 +458,19 @@
return acc;
}
#endif /* CONFIG_KCORE_AOUT */
+
+static loff_t lseek_kcore(struct file * file, loff_t offset, int origin)
+{
+ long long retval;
+
+ switch (origin) {
+ case 2:
+ offset += file->f_dentry->d_inode->i_size;
+ break;
+ case 1:
+ offset += file->f_pos;
+ }
+ /* RED-PEN user can fake an error here by setting offset to >=-4095 && <0 */
+ file->f_pos = offset;
+ return offset;
+}
^ permalink raw reply [flat|nested] 4+ messages in thread* [Linux-ia64] Re: Fixing /proc/kcore
2002-10-25 18:00 [Linux-ia64] Re: Fixing /proc/kcore Andi Kleen
@ 2002-10-28 16:14 ` Mario Smarduch
2002-10-28 19:03 ` [Linux-ia64] " Luck, Tony
2002-10-28 19:10 ` [Linux-ia64] " Andi Kleen
2 siblings, 0 replies; 4+ messages in thread
From: Mario Smarduch @ 2002-10-28 16:14 UTC (permalink / raw)
To: linux-ia64
Tony, Andi thanks!
- mario
Andi Kleen wrote:
> "Luck, Tony" <tony.luck@intel.com> writes:
>
> > This message is in MIME format. Since your mail reader does not understand
> > this format, some or all of this message may not be legible.
> >
> > ------_=_NextPart_000_01C27C4E.CD496DB0
> > Content-Type: text/plain;
> > charset="utf-7"
> >
> > /proc/kcore is what you need, but it is broken on ia64 (and
> > has been since the dawn of time for access to region 5) because
> > it assumes that all kernel virtual addresses are above PAGE_OFFSET.
> > This isn't true on ia64, VMALLOC_START is smaller than PAGE_OFFSET.
>
> I recently fixed a similar problem on x86-64. There the modules are outside
> the vmalloc area, but also not in the direct mapping. I just changed
> the module mapping and the kernel mapping to put themselves into the vmlist.
> kcore checks vmlist first and then afterwards tries direct addresses.
>
> Also the kernel addresses are negative, which needed some more changes
> in seek.
>
> Here is the 2.4.19 patch which should to 2.5 too.
>
> I think it's a bit cleaner than yours and will probably help you too.
> Just put everything special into vmlist too.
>
> -Andi
>
> Index: linux/fs/proc/inode.c
> =================================> RCS file: /home/cvs/Repository/linux/fs/proc/inode.c,v
> retrieving revision 1.4
> retrieving revision 1.5
> diff -u -u -r1.4 -r1.5
> --- linux/fs/proc/inode.c 2002/01/15 10:09:21 1.4
> --- linux/fs/proc/inode.c 2002/10/17 13:02:13 1.5
> @@ -186,6 +184-,7 @@
> s->s_blocksize_bits = 10;
> s->s_magic = PROC_SUPER_MAGIC;
> s->s_op = &proc_sops;
> s->s_maxbytes = +AH4-0ULL;
>
> root_inode = proc_get_inode(s, PROC_ROOT_INO, &proc_root);
> if (!root_inode)
> Index: linux/fs/proc/kcore.c
> =================================> RCS file: /home/cvs/Repository/linux/fs/proc/kcore.c,v
> retrieving revision 1.3
> retrieving revision 1.4
> diff -u -u -r1.3 -r1.4
> --- linux/fs/proc/kcore.c 2002/03/21 11:54:59 1.3
> --- linux/fs/proc/kcore.c 2002/10/17 13:02:13 1.4
> @@ -27,11 ,14 @@
> return capable(CAP_SYS_RAWIO) ? 0 : -EPERM;
> }
>
> +statiQ- loff_t lseek_kcore(struct file * file, loff_t offset, int origin);
>
> static ssize_t read_kcore(struct file *, char *, size_t, loff_t *);
>
> struct file_operations proc_kcore_operations = {
> read: read_kcore,
> open: open_kcore,
> lseek: lseek_kcore,
> };
>
> #ifdef CONFIG_KCORE_AOUT
> @@ -112,9 +114-,9 @@
>
> extern char saved_command_line[];
>
> -static size_t get_kcore_size(int *num_vma, size_t *elf_buflen)
> +statiQ- unsigned long get_kcore_size(int *num_vma, size_t *elf_buflen)
> {
> - size_t try, size;
> unsigned long try, size;
> struct vm_struct *m;
>
> *num_vma = 0;
> @@ -125,7 +128-,7 @@
> }
>
> for (m=vmlist; m; m=m->next) {
> - try = (size_t)m->addr m->size;
> try = (unsigned long)m->addr m->size;
> if (try > size)
> size = try;
> *num_vma = *num_vma 1;
> @@ -313,14 +314-,14 @@
> static ssize_t read_kcore(struct file *file, char *buffer, size_t buflen, loff_t *fpos)
> {
> ssize_t acc = 0;
> - size_t size, tsz;
> unsigned long size, tsz;
> size_t elf_buflen;
> int num_vma;
> unsigned long start;
>
> read_lock(&vmlist_lock);
> proc_root_kcore->size = size = get_kcore_size(&num_vma, &elf_buflen);
> - if (buflen = 0 || *fpos >= size) {
> if (buflen = 0 || (unsigned long long)*fpos >= size) {
> read_unlock(&vmlist_lock);
> return 0;
> }
> @@ -390,9 +390-,16 @@
> start = PAGE_OFFSET (*fpos - elf_buflen);
> if ((tsz = (PAGE_SIZE - (start & +AH4-PAGE_MASK))) > buflen)
> tsz = buflen;
> -
> while (buflen) {
> - if ((start >= VMALLOC_START) && (start < VMALLOC_END)) {
> int err;
>
> if ((start > PAGE_OFFSET) && (start < (unsigned long)high_memory)) {
> if (kern_addr_valid(start)) {
> err = copy_to_user(buffer, (char *)start, tsz);
> } else {
> err = clear_user(buffer, tsz);
> }
> } else {
> char * elf_buf;
> struct vm_struct *m;
> unsigned long curstart = start;
> @@ -432,24 +440-,11 @@
> (char *)vmstart, vmsize);
> }
> read_unlock(&vmlist_lock);
> - if (copy_to_user(buffer, elf_buf, tsz)) {
> - kfree(elf_buf);
> - return -EFAULT;
> - }
> err = copy_to_user(buffer, elf_buf, tsz);
> kfree(elf_buf);
> - } else if ((start > PAGE_OFFSET) && (start <
> - (unsigned long)high_memory)) {
> - if (kern_addr_valid(start)) {
> - if (copy_to_user(buffer, (char *)start, tsz))
> - return -EFAULT;
> - } else {
> - if (clear_user(buffer, tsz))
> - return -EFAULT;
> - }
> - } else {
> - if (clear_user(buffer, tsz))
> - return -EFAULT;
> - }
> }
> if (err)
> return -EFAULT;
> buflen -= tsz;
> *fpos = tsz;
> buffer = tsz;
> @@ -461,3 +458-,19 @@
> return acc;
> }
> #endif /* CONFIG_KCORE_AOUT */
>
> +statiQ- loff_t lseek_kcore(struct file * file, loff_t offset, int origin)
> {
> long long retval;
>
> switch (origin) {
> case 2:
> offset = file->f_dentry->d_inode->i_size;
> break;
> case 1:
> offset = file->f_pos;
> }
> /* RED-PEN user can fake an error here by setting offset to >=-4095 && <0 */
> file->f_pos = offset;
> return offset;
> }
^ permalink raw reply [flat|nested] 4+ messages in thread* [Linux-ia64] RE: Fixing /proc/kcore
2002-10-25 18:00 [Linux-ia64] Re: Fixing /proc/kcore Andi Kleen
2002-10-28 16:14 ` Mario Smarduch
@ 2002-10-28 19:03 ` Luck, Tony
2002-10-28 19:10 ` [Linux-ia64] " Andi Kleen
2 siblings, 0 replies; 4+ messages in thread
From: Luck, Tony @ 2002-10-28 19:03 UTC (permalink / raw)
To: linux-ia64
Andi Kleen wrote:
> On Fri, Oct 25, 2002 at 02:14:44PM -0700, Luck, Tony wrote:
> > Putting everything into the vmlist looks to be a good idea. Perhaps
> > there should be an entry for the "direct addresses" too?
>
> Yes that would make sense.
>
> >
> > So what does:
> >
> > # objdump -p /proc/kcore
> >
> > look like for you?
>
> Very messy because of the negative addresses and still some sign problems
> in binutils :-)
Oops, I didn't mean to take this discussion off the mailing list.
What about a combined approach ... architecture dependent code
should add all the interesting stuff to the vmlist, so kcore just
needs to walk the list to cover everything. We could also keep the
KCORE_BASE concept from my patch, but turn it into a variable that
the architecture dependent code can set to some suitable offset to
keep all the offsets in /proc/kcore positive. This will avoid
having to fixup binutils (at least until someone comes up with an
architecture where kernel space scatters across a wide enough range
that we can't keep the offsets positive).
-Tony
^ permalink raw reply [flat|nested] 4+ messages in thread
* [Linux-ia64] Re: Fixing /proc/kcore
2002-10-25 18:00 [Linux-ia64] Re: Fixing /proc/kcore Andi Kleen
2002-10-28 16:14 ` Mario Smarduch
2002-10-28 19:03 ` [Linux-ia64] " Luck, Tony
@ 2002-10-28 19:10 ` Andi Kleen
2 siblings, 0 replies; 4+ messages in thread
From: Andi Kleen @ 2002-10-28 19:10 UTC (permalink / raw)
To: linux-ia64
On Mon, Oct 28, 2002 at 11:03:42AM -0800, Luck, Tony wrote:
> What about a combined approach ... architecture dependent code
> should add all the interesting stuff to the vmlist, so kcore just
> needs to walk the list to cover everything. We could also keep the
Works for me. You just have to make sure to keep vmlist ordered
and make sure all users of vmlist check for their correct address
range (vmalloc.c does, but some arch specific code may not)
> KCORE_BASE concept from my patch, but turn it into a variable that
> the architecture dependent code can set to some suitable offset to
> keep all the offsets in /proc/kcore positive. This will avoid
> having to fixup binutils (at least until someone comes up with an
> architecture where kernel space scatters across a wide enough range
> that we can't keep the offsets positive).
x86-64 is such an architecture, so binutils will need to be fixed anyways.
-andi
^ permalink raw reply [flat|nested] 4+ messages in thread
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2002-10-25 18:00 [Linux-ia64] Re: Fixing /proc/kcore Andi Kleen
2002-10-28 16:14 ` Mario Smarduch
2002-10-28 19:03 ` [Linux-ia64] " Luck, Tony
2002-10-28 19:10 ` [Linux-ia64] " Andi Kleen
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