[PATCH] Enable mprotect on huge pages

[PATCH] Enable mprotect on huge pages

[Zhang, Yanmin]

From: Zhang, Yanmin <yanmin.zhang@intel.com>

2.6.16-rc3 uses hugetlb on-demand paging, but it doesn’t support hugetlb
mprotect. My patch against 2.6.16-rc3 enables this capability.

Signed-off-by: Zhang Yanmin <yanmin.zhang@intel.com> 

Discussion is welcomed.

---

diff -Nraup linux-2.6.16-rc3/include/linux/hugetlb.h linux-2.6.16-rc3_mprotect/include/linux/hugetlb.h
--- linux-2.6.16-rc3/include/linux/hugetlb.h	2006-02-14 16:43:50.000000000 +0800
+++ linux-2.6.16-rc3_mprotect/include/linux/hugetlb.h	2006-02-22 00:12:35.000000000 +0800
@@ -41,6 +41,8 @@ struct page *follow_huge_pmd(struct mm_s
 				pmd_t *pmd, int write);
 int is_aligned_hugepage_range(unsigned long addr, unsigned long len);
 int pmd_huge(pmd_t pmd);
+void hugetlb_change_protection(struct vm_area_struct *vma,
+		unsigned long address, unsigned long end, pgprot_t newprot);
 
 #ifndef ARCH_HAS_HUGEPAGE_ONLY_RANGE
 #define is_hugepage_only_range(mm, addr, len)	0
@@ -101,6 +103,8 @@ static inline unsigned long hugetlb_tota
 #define free_huge_page(p)			({ (void)(p); BUG(); })
 #define hugetlb_fault(mm, vma, addr, write)	({ BUG(); 0; })
 
+#define	hugetlb_change_protection(vma, address, end, newprot)
+
 #ifndef HPAGE_MASK
 #define HPAGE_MASK	PAGE_MASK		/* Keep the compiler happy */
 #define HPAGE_SIZE	PAGE_SIZE
diff -Nraup linux-2.6.16-rc3/mm/hugetlb.c linux-2.6.16-rc3_mprotect/mm/hugetlb.c
--- linux-2.6.16-rc3/mm/hugetlb.c	2006-02-14 16:43:50.000000000 +0800
+++ linux-2.6.16-rc3_mprotect/mm/hugetlb.c	2006-02-22 00:12:35.000000000 +0800
@@ -572,3 +572,32 @@ int follow_hugetlb_page(struct mm_struct
 
 	return i;
 }
+
+void hugetlb_change_protection(struct vm_area_struct *vma,
+		unsigned long address, unsigned long end, pgprot_t newprot)
+{
+	struct mm_struct *mm = vma->vm_mm;
+	unsigned long start = address;
+	pte_t *ptep;
+	pte_t pte;
+
+	BUG_ON(address >= end);
+	flush_cache_range(vma, address, end);
+
+	spin_lock(&mm->page_table_lock);
+	for (; address < end; address += HPAGE_SIZE) {
+		ptep = huge_pte_offset(mm, address);
+		if (!ptep)
+			continue;
+		if (pte_present(*ptep)) {
+			pte = ptep_get_and_clear(mm, address, ptep);
+			pte = pte_modify(pte, newprot);
+			set_huge_pte_at(mm, addr, ptep, pte);
+			lazy_mmu_prot_update(pte);
+		}
+	}
+	spin_unlock(&mm->page_table_lock);
+
+	flush_tlb_range(vma, start, end);
+}
+
diff -Nraup linux-2.6.16-rc3/mm/mprotect.c linux-2.6.16-rc3_mprotect/mm/mprotect.c
--- linux-2.6.16-rc3/mm/mprotect.c	2006-01-25 21:54:15.000000000 +0800
+++ linux-2.6.16-rc3_mprotect/mm/mprotect.c	2006-02-22 00:13:34.000000000 +0800
@@ -124,7 +124,7 @@ mprotect_fixup(struct vm_area_struct *vm
 	 * a MAP_NORESERVE private mapping to writable will now reserve.
 	 */
 	if (newflags & VM_WRITE) {
-		if (!(oldflags & (VM_ACCOUNT|VM_WRITE|VM_SHARED|VM_HUGETLB))) {
+		if (!(oldflags & (VM_ACCOUNT|VM_WRITE|VM_SHARED))) {
 			charged = nrpages;
 			if (security_vm_enough_memory(charged))
 				return -ENOMEM;
@@ -166,7 +166,10 @@ success:
 	 */
 	vma->vm_flags = newflags;
 	vma->vm_page_prot = newprot;
-	change_protection(vma, start, end, newprot);
+	if (is_vm_hugetlb_page(vma))
+		hugetlb_change_protection(vma, start, end, newprot);
+	else
+		change_protection(vma, start, end, newprot);
 	vm_stat_account(mm, oldflags, vma->vm_file, -nrpages);
 	vm_stat_account(mm, newflags, vma->vm_file, nrpages);
 	return 0;
@@ -240,11 +243,6 @@ sys_mprotect(unsigned long start, size_t
 
 		/* Here we know that  vma->vm_start <= nstart < vma->vm_end. */
 
-		if (is_vm_hugetlb_page(vma)) {
-			error = -EACCES;
-			goto out;
-		}
-
 		newflags = vm_flags | (vma->vm_flags & ~(VM_READ | VM_WRITE | VM_EXEC));
 
 		/* newflags >> 4 shift VM_MAY% in place of VM_% */
@@ -260,6 +258,12 @@ sys_mprotect(unsigned long start, size_t
 		tmp = vma->vm_end;
 		if (tmp > end)
 			tmp = end;
+		if (is_vm_hugetlb_page(vma) &&
+			is_aligned_hugepage_range(nstart, tmp - nstart)) {
+			error = -EINVAL;
+			goto out;
+		}
+
 		error = mprotect_fixup(vma, &prev, nstart, tmp, newflags);
 		if (error)
 			goto out;

Re: [PATCH] Enable mprotect on huge pages

[Andrew Morton]

"Zhang, Yanmin" <yanmin_zhang@linux.intel.com> wrote:
>
> From: Zhang, Yanmin <yanmin.zhang@intel.com>
> 
> 2.6.16-rc3 uses hugetlb on-demand paging, but it doesn_t support hugetlb
> mprotect. My patch against 2.6.16-rc3 enables this capability.
> 

Well I suppose that makes sense.  It does assume that the normal pte
protection-changing APIs do the right thing on all architectures which
implement huge pages.  That's quite possibly the case, but we should
confirm that.

> +
> +void hugetlb_change_protection(struct vm_area_struct *vma,
> +		unsigned long address, unsigned long end, pgprot_t newprot)
> +{
> +	struct mm_struct *mm = vma->vm_mm;
> +	unsigned long start = address;
> +	pte_t *ptep;
> +	pte_t pte;
> +
> +	BUG_ON(address >= end);
> +	flush_cache_range(vma, address, end);
> +
> +	spin_lock(&mm->page_table_lock);
> +	for (; address < end; address += HPAGE_SIZE) {
> +		ptep = huge_pte_offset(mm, address);
> +		if (!ptep)
> +			continue;
> +		if (pte_present(*ptep)) {
> +			pte = ptep_get_and_clear(mm, address, ptep);
> +			pte = pte_modify(pte, newprot);
> +			set_huge_pte_at(mm, addr, ptep, pte);
> +			lazy_mmu_prot_update(pte);
> +		}
> +	}
> +	spin_unlock(&mm->page_table_lock);
> +
> +	flush_tlb_range(vma, start, end);
> +}

Re: [PATCH] Enable mprotect on huge pages

[Christoph Hellwig]

On Thu, Feb 23, 2006 at 11:19:40AM +0800, Zhang, Yanmin wrote:
> From: Zhang, Yanmin <yanmin.zhang@intel.com>
> 
> 2.6.16-rc3 uses hugetlb on-demand paging, but it doesn?t support hugetlb
> mprotect. My patch against 2.6.16-rc3 enables this capability.

Adding another special case for hugetlb pages sounds rather bad.  Could
you try adding a mrotect vm_area_operation if that works out cleaner?

[2.4.32 - 2.6.15.4] e1000 - Fix mii interface

[Paul Rolland]

[-- Attachment #1: Type: text/plain, Size: 3477 bytes --]

Hello,

This patch is based on Linux 2.4.32, and I've verified the same problem
exists on 2.6.15.4.
Working on a machine with a 2.4.32 kernel, I was surprised to see the driver
complaining when setting the speed to 100FD using mii-tool, but accepting
the setting with ethtool.
Digging into the code, I found that there is some confusion with :
 - DUPLEX_FULL and FULL_DUPLEX,
 - DUPLEX_HALF and HALF_DUPLEX
in the code :
...
                           spddplx += (mii_reg & 0x100)
                                       ? FULL_DUPLEX :
                                       HALF_DUPLEX;
                           retval = e1000_set_spd_dplx(adapter,
                                                       spddplx);
...
and
int
e1000_set_spd_dplx(struct e1000_adapter *adapter, uint16_t spddplx)
{
        adapter->hw.autoneg = 0;

        switch(spddplx) {
        case SPEED_10 + DUPLEX_HALF:
                adapter->hw.forced_speed_duplex = e1000_10_half;
                break;
....
when the constants don't have the same value.

This patch is simply changing the code in the e1000_set_spd_dplx to use the
same constants as does the caller of the function : FULL_DUPLEX and
HALF_DUPLEX
whose values are not 0, to make sure we have had a successfull init
(DUPLEX_HALF value is 0, and the DUPLEX_xxx are defined in ethtool.h, thus
are probably not meant to be used in the mii interface).

Signed-off-by: Paul Rolland <rol@as2917.net>

diff -urN linux-2.4.32-orig/drivers/net/e1000/e1000_main.c
linux-2.4.32/drivers/net/e1000/e1000_main.c
--- linux-2.4.32-orig/drivers/net/e1000/e1000_main.c    Mon Apr  4 01:42:19
2005
+++ linux-2.4.32/drivers/net/e1000/e1000_main.c Sat Feb 25 09:36:23 2006
@@ -2944,23 +2944,23 @@
        adapter->hw.autoneg = 0;
 
        switch(spddplx) {
-       case SPEED_10 + DUPLEX_HALF:
+       case SPEED_10 + HALF_DUPLEX:
                adapter->hw.forced_speed_duplex = e1000_10_half;
                break;
-       case SPEED_10 + DUPLEX_FULL:
+       case SPEED_10 + FULL_DUPLEX:
                adapter->hw.forced_speed_duplex = e1000_10_full;
                break;
-       case SPEED_100 + DUPLEX_HALF:
+       case SPEED_100 + HALF_DUPLEX:
                adapter->hw.forced_speed_duplex = e1000_100_half;
                break;
-       case SPEED_100 + DUPLEX_FULL:
+       case SPEED_100 + FULL_DUPLEX:
                adapter->hw.forced_speed_duplex = e1000_100_full;
                break;
-       case SPEED_1000 + DUPLEX_FULL:
+       case SPEED_1000 + FULL_DUPLEX:
                adapter->hw.autoneg = 1;
                adapter->hw.autoneg_advertised = ADVERTISE_1000_FULL;
                break;
-       case SPEED_1000 + DUPLEX_HALF: /* not supported */
+       case SPEED_1000 + HALF_DUPLEX: /* not supported */
        default:
                DPRINTK(PROBE, ERR, 
                        "Unsupported Speed/Duplexity configuration\n");


Paul Rolland, rol(at)as2917.net
ex-AS2917 Network administrator and Peering Coordinator

--

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took freedom of the press away from the Internet?'"
--Mike Godwin, Electronic Frontier Foundation 
 

[-- Attachment #2: e1000.patch --]
[-- Type: application/octet-stream, Size: 1487 bytes --]

diff -urN linux-2.4.32-orig/drivers/net/e1000/e1000_main.c linux-2.4.32/drivers/net/e1000/e1000_main.c
--- linux-2.4.32-orig/drivers/net/e1000/e1000_main.c    Mon Apr  4 01:42:19 2005
+++ linux-2.4.32/drivers/net/e1000/e1000_main.c Sat Feb 25 09:36:23 2006
@@ -2944,23 +2944,23 @@
        adapter->hw.autoneg = 0;
 
        switch(spddplx) {
-       case SPEED_10 + DUPLEX_HALF:
+       case SPEED_10 + HALF_DUPLEX:
                adapter->hw.forced_speed_duplex = e1000_10_half;
                break;
-       case SPEED_10 + DUPLEX_FULL:
+       case SPEED_10 + FULL_DUPLEX:
                adapter->hw.forced_speed_duplex = e1000_10_full;
                break;
-       case SPEED_100 + DUPLEX_HALF:
+       case SPEED_100 + HALF_DUPLEX:
                adapter->hw.forced_speed_duplex = e1000_100_half;
                break;
-       case SPEED_100 + DUPLEX_FULL:
+       case SPEED_100 + FULL_DUPLEX:
                adapter->hw.forced_speed_duplex = e1000_100_full;
                break;
-       case SPEED_1000 + DUPLEX_FULL:
+       case SPEED_1000 + FULL_DUPLEX:
                adapter->hw.autoneg = 1;
                adapter->hw.autoneg_advertised = ADVERTISE_1000_FULL;
                break;
-       case SPEED_1000 + DUPLEX_HALF: /* not supported */
+       case SPEED_1000 + HALF_DUPLEX: /* not supported */
        default:
                DPRINTK(PROBE, ERR, 
                        "Unsupported Speed/Duplexity configuration\n");

Re: [2.4.32 - 2.6.15.4] e1000 - Fix mii interface

[Willy TARREAU]

Hello Paul,

On Sat, Feb 25, 2006 at 11:08:49AM +0100, Paul Rolland wrote:
> Hello,
> 
> This patch is based on Linux 2.4.32, and I've verified the same problem
> exists on 2.6.15.4.

it's mangled, tabs have been turned into whitespaces. I fixed it so please
use the appended one.

> Working on a machine with a 2.4.32 kernel, I was surprised to see the driver
> complaining when setting the speed to 100FD using mii-tool, but accepting
> the setting with ethtool.
> Digging into the code, I found that there is some confusion with :
>  - DUPLEX_FULL and FULL_DUPLEX,
>  - DUPLEX_HALF and HALF_DUPLEX
> in the code :
> ...
>                            spddplx += (mii_reg & 0x100)
>                                        ? FULL_DUPLEX :
>                                        HALF_DUPLEX;
>                            retval = e1000_set_spd_dplx(adapter,
>                                                        spddplx);
> ...
> and
> int
> e1000_set_spd_dplx(struct e1000_adapter *adapter, uint16_t spddplx)
> {
>         adapter->hw.autoneg = 0;
> 
>         switch(spddplx) {
>         case SPEED_10 + DUPLEX_HALF:
>                 adapter->hw.forced_speed_duplex = e1000_10_half;
>                 break;
> ....
> when the constants don't have the same value.
> 
> This patch is simply changing the code in the e1000_set_spd_dplx to use the
> same constants as does the caller of the function : FULL_DUPLEX and
> HALF_DUPLEX
> whose values are not 0, to make sure we have had a successfull init
> (DUPLEX_HALF value is 0, and the DUPLEX_xxx are defined in ethtool.h, thus
> are probably not meant to be used in the mii interface).
> 
> Signed-off-by: Paul Rolland <rol@as2917.net>
> 
> diff -urN linux-2.4.32-orig/drivers/net/e1000/e1000_main.c
> linux-2.4.32/drivers/net/e1000/e1000_main.c
> --- linux-2.4.32-orig/drivers/net/e1000/e1000_main.c    Mon Apr  4 01:42:19
> 2005
> +++ linux-2.4.32/drivers/net/e1000/e1000_main.c Sat Feb 25 09:36:23 2006
> @@ -2944,23 +2944,23 @@
>         adapter->hw.autoneg = 0;
>  
>         switch(spddplx) {
> -       case SPEED_10 + DUPLEX_HALF:
> +       case SPEED_10 + HALF_DUPLEX:
>                 adapter->hw.forced_speed_duplex = e1000_10_half;
>                 break;
> -       case SPEED_10 + DUPLEX_FULL:
> +       case SPEED_10 + FULL_DUPLEX:
>                 adapter->hw.forced_speed_duplex = e1000_10_full;
>                 break;
> -       case SPEED_100 + DUPLEX_HALF:
> +       case SPEED_100 + HALF_DUPLEX:
>                 adapter->hw.forced_speed_duplex = e1000_100_half;
>                 break;
> -       case SPEED_100 + DUPLEX_FULL:
> +       case SPEED_100 + FULL_DUPLEX:
>                 adapter->hw.forced_speed_duplex = e1000_100_full;
>                 break;
> -       case SPEED_1000 + DUPLEX_FULL:
> +       case SPEED_1000 + FULL_DUPLEX:
>                 adapter->hw.autoneg = 1;
>                 adapter->hw.autoneg_advertised = ADVERTISE_1000_FULL;
>                 break;
> -       case SPEED_1000 + DUPLEX_HALF: /* not supported */
> +       case SPEED_1000 + HALF_DUPLEX: /* not supported */
>         default:
>                 DPRINTK(PROBE, ERR, 
>                         "Unsupported Speed/Duplexity configuration\n");
> 
> 
> Paul Rolland, rol(at)as2917.net
> ex-AS2917 Network administrator and Peering Coordinator

Regards,
Willy


diff -urN linux-2.4.32-orig/drivers/net/e1000/e1000_main.c linux-2.4.32/drivers/net/e1000/e1000_main.c
--- linux-2.4.32-orig/drivers/net/e1000/e1000_main.c    Mon Apr  4 01:42:19 2005
+++ linux-2.4.32/drivers/net/e1000/e1000_main.c Sat Feb 25 09:36:23 2006
@@ -2944,23 +2944,23 @@
 	adapter->hw.autoneg = 0;
 
 	switch(spddplx) {
-	case SPEED_10 + DUPLEX_HALF:
+	case SPEED_10 + HALF_DUPLEX:
 		adapter->hw.forced_speed_duplex = e1000_10_half;
 		break;
-	case SPEED_10 + DUPLEX_FULL:
+	case SPEED_10 + FULL_DUPLEX:
 		adapter->hw.forced_speed_duplex = e1000_10_full;
 		break;
-	case SPEED_100 + DUPLEX_HALF:
+	case SPEED_100 + HALF_DUPLEX:
 		adapter->hw.forced_speed_duplex = e1000_100_half;
 		break;
-	case SPEED_100 + DUPLEX_FULL:
+	case SPEED_100 + FULL_DUPLEX:
 		adapter->hw.forced_speed_duplex = e1000_100_full;
 		break;
-	case SPEED_1000 + DUPLEX_FULL:
+	case SPEED_1000 + FULL_DUPLEX:
 		adapter->hw.autoneg = 1;
 		adapter->hw.autoneg_advertised = ADVERTISE_1000_FULL;
 		break;
-	case SPEED_1000 + DUPLEX_HALF: /* not supported */
+	case SPEED_1000 + HALF_DUPLEX: /* not supported */
 	default:
 		DPRINTK(PROBE, ERR, 
 			"Unsupported Speed/Duplexity configuration\n");

Re: [2.4.32 - 2.6.15.4] e1000 - Fix mii interface

[Paul Rolland]

> it's mangled, tabs have been turned into whitespaces. I fixed 
> it so please
> use the appended one.

Sorry about that, thanks for the fix.

Paul

Re: [2.4.32 - 2.6.15.4] e1000 - Fix mii interface

[Jesper Juhl]

On 2/25/06, Paul Rolland <rol@as2917.net> wrote:
> Hello,
>
> This patch is based on Linux 2.4.32, and I've verified the same problem
> exists on 2.6.15.4.

are you planning a 2.6 patch as well ?

--
Jesper Juhl <jesper.juhl@gmail.com>
Don't top-post  http://www.catb.org/~esr/jargon/html/T/top-post.html
Plain text mails only, please      http://www.expita.com/nomime.html

Re: [2.4.32 - 2.6.15.4] e1000 - Fix mii interface

[Paul Rolland]

Hello,

> are you planning a 2.6 patch as well ?
> 
I'm preparing it, and I'll be carefull with Tab/space ;)

Paul

Re: [2.4.32 - 2.6.15.4] e1000 - Fix mii interface

[Jesper Juhl]

On 2/26/06, Paul Rolland <rol@witbe.net> wrote:
> Hello,
>
> > are you planning a 2.6 patch as well ?
> >
> I'm preparing it, and I'll be carefull with Tab/space ;)
>
Ok, great, I was just wondering since I would have made one if you had
no plans to do so.

--
Jesper Juhl <jesper.juhl@gmail.com>
Don't top-post  http://www.catb.org/~esr/jargon/html/T/top-post.html
Plain text mails only, please      http://www.expita.com/nomime.html

Re: [2.4.32 - 2.6.15.4] e1000 - Fix mii interface

[Paul Rolland]

[-- Attachment #1: Type: text/plain, Size: 359 bytes --]

Hello,

> Ok, great, I was just wondering since I would have made one if you had
> no plans to do so.

Well, I was just waiting to make sure it was interesting for someone ;)

Here is it, verified with tab and not spaces... but attached as my mailer
is likely to cripple anything I try to inline...

Signed-off-by: Paul Rolland <rol@as2917.net>

Cheers,
Paul

[-- Attachment #2: e1000.patch-2.6.15.4 --]
[-- Type: application/octet-stream, Size: 1507 bytes --]

diff -urN linux-2.6.15.4.orig/drivers/net/e1000/e1000_main.c linux-2.6.15.4/drivers/net/e1000/e1000_main.c
--- linux-2.6.15.4.orig/drivers/net/e1000/e1000_main.c	Fri Feb 10 07:22:48 2006
+++ linux-2.6.15.4/drivers/net/e1000/e1000_main.c	Sun Feb 26 15:04:40 2006
@@ -4153,29 +4153,29 @@
 
 	/* Fiber NICs only allow 1000 gbps Full duplex */
 	if((adapter->hw.media_type == e1000_media_type_fiber) &&
-		spddplx != (SPEED_1000 + DUPLEX_FULL)) {
+		spddplx != (SPEED_1000 + FULL_DUPLEX)) {
 		DPRINTK(PROBE, ERR, "Unsupported Speed/Duplex configuration\n");
 		return -EINVAL;
 	}
 
 	switch(spddplx) {
-	case SPEED_10 + DUPLEX_HALF:
+	case SPEED_10 + HALF_DUPLEX:
 		adapter->hw.forced_speed_duplex = e1000_10_half;
 		break;
-	case SPEED_10 + DUPLEX_FULL:
+	case SPEED_10 + FULL_DUPLEX:
 		adapter->hw.forced_speed_duplex = e1000_10_full;
 		break;
-	case SPEED_100 + DUPLEX_HALF:
+	case SPEED_100 + HALF_DUPLEX:
 		adapter->hw.forced_speed_duplex = e1000_100_half;
 		break;
-	case SPEED_100 + DUPLEX_FULL:
+	case SPEED_100 + FULL_DUPLEX:
 		adapter->hw.forced_speed_duplex = e1000_100_full;
 		break;
-	case SPEED_1000 + DUPLEX_FULL:
+	case SPEED_1000 + FULL_DUPLEX:
 		adapter->hw.autoneg = 1;
 		adapter->hw.autoneg_advertised = ADVERTISE_1000_FULL;
 		break;
-	case SPEED_1000 + DUPLEX_HALF: /* not supported */
+	case SPEED_1000 + HALF_DUPLEX: /* not supported */
 	default:
 		DPRINTK(PROBE, ERR, "Unsupported Speed/Duplex configuration\n");
 		return -EINVAL;

Re: [PATCH] Enable mprotect on huge pages

[David Gibson]

On Fri, Feb 24, 2006 at 02:28:44PM -0800, Andrew Morton wrote:
> "Zhang, Yanmin" <yanmin_zhang@linux.intel.com> wrote:
> >
> > From: Zhang, Yanmin <yanmin.zhang@intel.com>
> > 
> > 2.6.16-rc3 uses hugetlb on-demand paging, but it doesn_t support hugetlb
> > mprotect. My patch against 2.6.16-rc3 enables this capability.
> > 
> 
> Well I suppose that makes sense.  It does assume that the normal pte
> protection-changing APIs do the right thing on all architectures which
> implement huge pages.  That's quite possibly the case, but we should
> confirm that.

Well, it will need to be huge_ptep_get_and_clear() below, not the
normal version.  But pte_modify should be ok.  I'm not sure
pte_present() is safe, either, !pte_none() is what we use elsewhere in
hugetlb.c.

And.. looks like lazy_mmu_prot_update() is unsafe, too.  The only arch
which has something here (ia64) has a function which does icache
flushes on PAGE_SIZE only.

> > +
> > +void hugetlb_change_protection(struct vm_area_struct *vma,
> > +		unsigned long address, unsigned long end, pgprot_t newprot)
> > +{
> > +	struct mm_struct *mm = vma->vm_mm;
> > +	unsigned long start = address;
> > +	pte_t *ptep;
> > +	pte_t pte;
> > +
> > +	BUG_ON(address >= end);
> > +	flush_cache_range(vma, address, end);
> > +
> > +	spin_lock(&mm->page_table_lock);
> > +	for (; address < end; address += HPAGE_SIZE) {
> > +		ptep = huge_pte_offset(mm, address);
> > +		if (!ptep)
> > +			continue;
> > +		if (pte_present(*ptep)) {
> > +			pte = ptep_get_and_clear(mm, address, ptep);
> > +			pte = pte_modify(pte, newprot);
> > +			set_huge_pte_at(mm, addr, ptep, pte);
> > +			lazy_mmu_prot_update(pte);
> > +		}
> > +	}
> > +	spin_unlock(&mm->page_table_lock);
> > +
> > +	flush_tlb_range(vma, start, end);
> > +}
> 

-- 
David Gibson			| I'll have my music baroque, and my code
david AT gibson.dropbear.id.au	| minimalist, thank you.  NOT _the_ _other_
				| _way_ _around_!
http://www.ozlabs.org/~dgibson

Re: [PATCH] Enable mprotect on huge pages

[Zhang, Yanmin]

On Sat, 2006-02-25 at 16:54, Christoph Hellwig wrote:
> On Thu, Feb 23, 2006 at 11:19:40AM +0800, Zhang, Yanmin wrote:
> > From: Zhang, Yanmin <yanmin.zhang@intel.com>
> > 
> > 2.6.16-rc3 uses hugetlb on-demand paging, but it doesn?t support hugetlb
> > mprotect. My patch against 2.6.16-rc3 enables this capability.
> 
> Adding another special case for hugetlb pages sounds rather bad.  Could
> you try adding a mrotect vm_area_operation if that works out cleaner?
I don't quite understand your idea. vm_operations_struct has no mprotect function
pointer. Could you elaborate it?
In current kernel, sys_mprotect would bypass hugetlb if (is_vm_hugetlb_page(vma)).

Re: [PATCH] Enable mprotect on huge pages

[Zhang, Yanmin]

On Mon, 2006-02-27 at 07:09, David Gibson wrote:
> On Fri, Feb 24, 2006 at 02:28:44PM -0800, Andrew Morton wrote:
> > "Zhang, Yanmin" <yanmin_zhang@linux.intel.com> wrote:
> > >
> > > From: Zhang, Yanmin <yanmin.zhang@intel.com>
> > > 
> > > 2.6.16-rc3 uses hugetlb on-demand paging, but it doesn_t support hugetlb
> > > mprotect. My patch against 2.6.16-rc3 enables this capability.
> > > 
> > 
> > Well I suppose that makes sense.  It does assume that the normal pte
> > protection-changing APIs do the right thing on all architectures which
> > implement huge pages.  That's quite possibly the case, but we should
> > confirm that.
> 
> Well, it will need to be huge_ptep_get_and_clear() below, not the
> normal version.
I will change it.


>   But pte_modify should be ok.  I'm not sure
> pte_present() is safe, either, !pte_none() is what we use elsewhere in
> hugetlb.c.
pte_present is used in some files while !pte_none is used 
in other files. Anyway, I will change it to !pte_none.


> 
> And.. looks like lazy_mmu_prot_update() is unsafe, too.  The only arch
> which has something here (ia64) has a function which does icache
> flushes on PAGE_SIZE only.
I already sent another patch to ia64 maillist to fix the issue.
See http://marc.theaimsgroup.com/?l=linux-ia64&m=114066414720468&w=2

Thanks.

Re: [PATCH] Enable mprotect on huge pages

[Zhang, Yanmin]

On Mon, 2006-02-27 at 13:36, Zhang, Yanmin wrote:
> On Mon, 2006-02-27 at 07:09, David Gibson wrote:
> > On Fri, Feb 24, 2006 at 02:28:44PM -0800, Andrew Morton wrote:
> > > "Zhang, Yanmin" <yanmin_zhang@linux.intel.com> wrote:
> > > >
> > > > From: Zhang, Yanmin <yanmin.zhang@intel.com>
> > > > 
> > > > 2.6.16-rc3 uses hugetlb on-demand paging, but it doesn_t support hugetlb
> > > > mprotect. My patch against 2.6.16-rc3 enables this capability.

Based on David's comments, I worked out a new patch against 2.6.16-rc4.
Thank David.

Signed-off-by: Zhang Yanmin <yanmin.zhang@intel.com>

I tested it on i386/x86_64/ia64. Who could help test it on other
platforms, such like PPC64?

---

diff -Nraup linux-2.6.16-rc4/include/linux/hugetlb.h linux-2.6.16-rc4_mprotect/include/linux/hugetlb.h
--- linux-2.6.16-rc4/include/linux/hugetlb.h	2006-02-22 19:19:04.000000000 +0800
+++ linux-2.6.16-rc4_mprotect/include/linux/hugetlb.h	2006-02-27 20:58:33.000000000 +0800
@@ -41,6 +41,8 @@ struct page *follow_huge_pmd(struct mm_s
 				pmd_t *pmd, int write);
 int is_aligned_hugepage_range(unsigned long addr, unsigned long len);
 int pmd_huge(pmd_t pmd);
+void hugetlb_change_protection(struct vm_area_struct *vma,
+		unsigned long address, unsigned long end, pgprot_t newprot);
 
 #ifndef ARCH_HAS_HUGEPAGE_ONLY_RANGE
 #define is_hugepage_only_range(mm, addr, len)	0
@@ -101,6 +103,8 @@ static inline unsigned long hugetlb_tota
 #define free_huge_page(p)			({ (void)(p); BUG(); })
 #define hugetlb_fault(mm, vma, addr, write)	({ BUG(); 0; })
 
+#define hugetlb_change_protection(vma, address, end, newprot)
+
 #ifndef HPAGE_MASK
 #define HPAGE_MASK	PAGE_MASK		/* Keep the compiler happy */
 #define HPAGE_SIZE	PAGE_SIZE
diff -Nraup linux-2.6.16-rc4/mm/hugetlb.c linux-2.6.16-rc4_mprotect/mm/hugetlb.c
--- linux-2.6.16-rc4/mm/hugetlb.c	2006-02-22 19:19:05.000000000 +0800
+++ linux-2.6.16-rc4_mprotect/mm/hugetlb.c	2006-02-27 20:57:17.000000000 +0800
@@ -572,3 +572,32 @@ int follow_hugetlb_page(struct mm_struct
 
 	return i;
 }
+
+void hugetlb_change_protection(struct vm_area_struct *vma,
+		unsigned long address, unsigned long end, pgprot_t newprot)
+{
+	struct mm_struct *mm = vma->vm_mm;
+	unsigned long start = address;
+	pte_t *ptep;
+	pte_t pte;
+
+	BUG_ON(address >= end);
+	flush_cache_range(vma, address, end);
+
+	spin_lock(&mm->page_table_lock);
+	for (; address < end; address += HPAGE_SIZE) {
+		ptep = huge_pte_offset(mm, address);
+		if (!ptep)
+			continue;
+		if (!pte_none(*ptep)) {
+			pte = huge_ptep_get_and_clear(mm, address, ptep);
+			pte = pte_modify(pte, newprot);
+			set_huge_pte_at(mm, addr, ptep, pte);
+			lazy_mmu_prot_update(pte);
+		}
+	}
+	spin_unlock(&mm->page_table_lock);
+
+	flush_tlb_range(vma, start, end);
+}
+
diff -Nraup linux-2.6.16-rc4/mm/mprotect.c linux-2.6.16-rc4_mprotect/mm/mprotect.c
--- linux-2.6.16-rc4/mm/mprotect.c	2006-02-22 19:18:21.000000000 +0800
+++ linux-2.6.16-rc4_mprotect/mm/mprotect.c	2006-02-27 20:55:10.000000000 +0800
@@ -124,7 +124,7 @@ mprotect_fixup(struct vm_area_struct *vm
 	 * a MAP_NORESERVE private mapping to writable will now reserve.
 	 */
 	if (newflags & VM_WRITE) {
-		if (!(oldflags & (VM_ACCOUNT|VM_WRITE|VM_SHARED|VM_HUGETLB))) {
+		if (!(oldflags & (VM_ACCOUNT|VM_WRITE|VM_SHARED))) {
 			charged = nrpages;
 			if (security_vm_enough_memory(charged))
 				return -ENOMEM;
@@ -166,7 +166,10 @@ success:
 	 */
 	vma->vm_flags = newflags;
 	vma->vm_page_prot = newprot;
-	change_protection(vma, start, end, newprot);
+	if (is_vm_hugetlb_page(vma))
+		hugetlb_change_protection(vma, start, end, newprot);
+	else
+		change_protection(vma, start, end, newprot);
 	vm_stat_account(mm, oldflags, vma->vm_file, -nrpages);
 	vm_stat_account(mm, newflags, vma->vm_file, nrpages);
 	return 0;
@@ -240,11 +243,6 @@ sys_mprotect(unsigned long start, size_t
 
 		/* Here we know that  vma->vm_start <= nstart < vma->vm_end. */
 
-		if (is_vm_hugetlb_page(vma)) {
-			error = -EACCES;
-			goto out;
-		}
-
 		newflags = vm_flags | (vma->vm_flags & ~(VM_READ | VM_WRITE | VM_EXEC));
 
 		/* newflags >> 4 shift VM_MAY% in place of VM_% */
@@ -260,6 +258,12 @@ sys_mprotect(unsigned long start, size_t
 		tmp = vma->vm_end;
 		if (tmp > end)
 			tmp = end;
+		if (is_vm_hugetlb_page(vma) &&
+			is_aligned_hugepage_range(nstart, tmp - nstart)) {
+			error = -EINVAL;
+			goto out;
+		}
+
 		error = mprotect_fixup(vma, &prev, nstart, tmp, newflags);
 		if (error)
 			goto out;

Re: [PATCH] Enable mprotect on huge pages

[David Gibson]

On Mon, Feb 27, 2006 at 01:36:32PM +0800, Zhang, Yanmin wrote:
> On Mon, 2006-02-27 at 07:09, David Gibson wrote:
> > On Fri, Feb 24, 2006 at 02:28:44PM -0800, Andrew Morton wrote:
> > > "Zhang, Yanmin" <yanmin_zhang@linux.intel.com> wrote:
> > > >
> > > > From: Zhang, Yanmin <yanmin.zhang@intel.com>
> > > > 
> > > > 2.6.16-rc3 uses hugetlb on-demand paging, but it doesn_t support hugetlb
> > > > mprotect. My patch against 2.6.16-rc3 enables this capability.
> > > > 
> > > 
> > > Well I suppose that makes sense.  It does assume that the normal pte
> > > protection-changing APIs do the right thing on all architectures which
> > > implement huge pages.  That's quite possibly the case, but we should
> > > confirm that.
> > 
> > Well, it will need to be huge_ptep_get_and_clear() below, not the
> > normal version.
> I will change it.
> 
> 
> >   But pte_modify should be ok.  I'm not sure
> > pte_present() is safe, either, !pte_none() is what we use elsewhere in
> > hugetlb.c.
> pte_present is used in some files while !pte_none is used 
> in other files. Anyway, I will change it to !pte_none.

But most importantly, pte_present() is not used in mm/hugetlb.c, the
generic part of the code.

> > And.. looks like lazy_mmu_prot_update() is unsafe, too.  The only arch
> > which has something here (ia64) has a function which does icache
> > flushes on PAGE_SIZE only.
> I already sent another patch to ia64 maillist to fix the issue.
> See http://marc.theaimsgroup.com/?l=linux-ia64&m=114066414720468&w=2
> 
> Thanks.
> 
> 

-- 
David Gibson			| I'll have my music baroque, and my code
david AT gibson.dropbear.id.au	| minimalist, thank you.  NOT _the_ _other_
				| _way_ _around_!
http://www.ozlabs.org/~dgibson

Re: [2.4.32 - 2.6.15.4] e1000 - Fix mii interface

[Jesse Brandeburg]

On 2/26/06, Paul Rolland <rol@witbe.net> wrote:
> Hello,
>
> > Ok, great, I was just wondering since I would have made one if you had
> > no plans to do so.
>
> Well, I was just waiting to make sure it was interesting for someone ;)
>
> Here is it, verified with tab and not spaces... but attached as my mailer
> is likely to cripple anything I try to inline...
>
> Signed-off-by: Paul Rolland <rol@as2917.net>

I've got an issue with this, as the same function is called in
e1000_ethtool.c.  I think the correct fix is to fix the caller in the
mii-tool case, but I am working on verifiying my assumptions.

In the meantime can you send the exact command you were having the problem with?

Re: [PATCH] Enable mprotect on huge pages

[Andrew Morton]

"Zhang, Yanmin" <yanmin_zhang@linux.intel.com> wrote:
>
> > > > > 2.6.16-rc3 uses hugetlb on-demand paging, but it doesn_t support hugetlb
>  > > > > mprotect. My patch against 2.6.16-rc3 enables this capability.
> 
>  Based on David's comments, I worked out a new patch against 2.6.16-rc4.
>  Thank David.
> 

Please always send an updated changelog when sending an updated patch. 
Otherwise I have to go trolling back through the email thread to find it,
then work out what needs to be changed.

> 
>  I tested it on i386/x86_64/ia64. Who could help test it on other
>  platforms, such like PPC64?

I can do that - please send me your test app?

Re: [2.4.32 - 2.6.15.4] e1000 - Fix mii interface

[Jesse Brandeburg]

> From: Paul Rolland <rol@as2917.net>
> 
> Hello,
> 
> This patch is based on Linux 2.4.32, and I've verified the same problem
> exists on 2.6.15.4.
> Working on a machine with a 2.4.32 kernel, I was surprised to see the driver
> complaining when setting the speed to 100FD using mii-tool, but accepting
> the setting with ethtool.
> Digging into the code, I found that there is some confusion with :
>  - DUPLEX_FULL and FULL_DUPLEX,
>  - DUPLEX_HALF and HALF_DUPLEX
> in the code :
> ...
>                            spddplx += (mii_reg & 0x100)
>                                        ? FULL_DUPLEX :
>                                        HALF_DUPLEX;
>                            retval = e1000_set_spd_dplx(adapter,
>                                                        spddplx);

Please try this patch:

e1000: fix mii-tool access to setting speed and duplex

Paul Rolland reported that e1000 was having a hard time using mii-tool to
set speed and duplex.  This patch fixes the issue on both newer hardware as
well as fixing the code issue that originally caused the problem.

Signed-off-by: Jesse Brandeburg <jesse.brandeburg@intel.com>
CC: Paul Rolland <rol@as2917.net>

---

  drivers/net/e1000/e1000_main.c |    6 +++---
  1 files changed, 3 insertions(+), 3 deletions(-)

diff --git a/drivers/net/e1000/e1000_main.c b/drivers/net/e1000/e1000_main.c
index 31e3329..9730c2e 100644
--- a/drivers/net/e1000/e1000_main.c
+++ b/drivers/net/e1000/e1000_main.c
@@ -4269,7 +4269,7 @@ e1000_mii_ioctl(struct net_device *netde
  			spin_unlock_irqrestore(&adapter->stats_lock, flags);
  			return -EIO;
  		}
-		if (adapter->hw.phy_type == e1000_phy_m88) {
+		if (adapter->hw.media_type == e1000_media_type_copper) {
  			switch (data->reg_num) {
  			case PHY_CTRL:
  				if (mii_reg & MII_CR_POWER_DOWN)
@@ -4285,8 +4285,8 @@ e1000_mii_ioctl(struct net_device *netde
  					else
  						spddplx = SPEED_10;
  					spddplx += (mii_reg & 0x100)
-						   ? FULL_DUPLEX :
-						   HALF_DUPLEX;
+						   ? DUPLEX_FULL :
+						   DUPLEX_HALF;
  					retval = e1000_set_spd_dplx(adapter,
  								    spddplx);
  					if (retval) {

Re: [PATCH] Enable mprotect on huge pages

[Zhang, Yanmin]

[-- Attachment #1: Type: text/plain, Size: 1109 bytes --]

On Tue, 2006-02-28 at 09:34, Andrew Morton wrote:
> "Zhang, Yanmin" <yanmin_zhang@linux.intel.com> wrote:
> >
> > > > > > 2.6.16-rc3 uses hugetlb on-demand paging, but it doesn_t support hugetlb
> >  > > > > mprotect. My patch against 2.6.16-rc3 enables this capability.
> > 
> >  Based on David's comments, I worked out a new patch against 2.6.16-rc4.
> >  Thank David.
> > 
> 
> Please always send an updated changelog when sending an updated patch. 
> Otherwise I have to go trolling back through the email thread to find it,
> then work out what needs to be changed.
Thanks for your kind reminder. I would do so next time.

> 
> > 
> >  I tested it on i386/x86_64/ia64. Who could help test it on other
> >  platforms, such like PPC64?
> 
> I can do that - please send me your test app?
I attach a test case. It will create directory /mnt/hugepages and delete it
after testing automatically.

To run it by user root:
#gcc -o mprotect_testcase mprotect_testcase.c
#echo "5">/proc/sys/vm/nr_hugepages
#./mprotect_testcase

You could use gdb to step it to see the changing of the process vma maps.

Thanks.



[-- Attachment #2: mprotect_testcase.c --]
[-- Type: text/x-c, Size: 3514 bytes --]

#include <stdio.h>
#include <stdlib.h>
#include <sys/types.h>
#include <sys/shm.h>
#include <sys/types.h>
#include <sys/mman.h>
#include <errno.h>
#include <sys/stat.h>
#include <fcntl.h>
#include <sys/wait.h>
#include <setjmp.h>

#define WORK_DIR "/mnt/hugepages"
#define MMAP_DIR "/mnt/hugepages/mmap"
#define MMAP_FILE "/mnt/hugepages/mmap/mmap_file"

char buff[2000];

int get_htlb_mem_stat(int *total_pages, int *free_pages, long *page_size)
{
        int fd=0;
        int size1=0;
        char *start=0;

        buff[0] = '\0';
        if((fd=open("/proc/meminfo", O_RDONLY)) < 0)
        {
                printf("Current kernel does not support Huge TLB!\n");
                exit(-1);
        }

        size1 = pread(fd, buff, sizeof(buff), 0);
        if(size1>=sizeof(buff))
        {
                size1 = sizeof(buff)-1;
        }
        if(size1<0)
                size1 = 0;

        buff[size1] = '\0';
	start = buff;
	while(*start) {
		if(isupper(*start))
			*start = tolower(*start);
		start ++;
	}

	start = strstr(buff, "hugepagesize:");
	if(start==NULL)
	{
                printf("Current kernel does not support Huge TLB!\n");
                exit(-1);
        }
        start += sizeof("hugepagesize:");
        if(sscanf(start,"%ld", page_size) != 1)
        {
                printf("Current kernel does not support Huge TLB!\n");
                exit(-1);
        }
        *page_size *= 1024; /*Convert to BYTE from KB*/

        close(fd);

        return 0;
}


int mmap_open_mmap(int *fd, void **addr, size_t length, int prot, int flags)
{
	*fd = open(MMAP_FILE, O_CREAT|O_RDWR, 0755);
	if (*fd < 0) {
		/*perror("Open failed");*/
		exit(errno);
	}
	*addr = mmap(NULL, length, prot, flags, *fd, 0);
	if( *addr == (void *)-1 ) {
		/*perror("mmap failed");*/
		close(*fd);
		*fd = -1;
		return -1;
	}

	return 0;
}

int mmap_unmap(void *start, size_t length)
{
	int     result=0;

	result = munmap(start, length);
	if(result == -1 ) {
		/*perror("mmap_unmap failed");*/
		return -1;
	}

	return 0;
}

int test_mmap_mprotect()
{
	int result = -1;
	void *addr=0;
	long tt001;
	int	fd=-1;

	int	total_pages;
	int	free_pages;
	long	LPAGE_SIZE;

	printf("Test mmap mprotect ...");
	get_htlb_mem_stat(&total_pages, &free_pages, &LPAGE_SIZE);
	result = mount("none", MMAP_DIR, "hugetlbfs", 0, NULL);
	if(result != 0) {
		perror("Mount fail:");
		goto out1;
	}

	result = mmap_open_mmap(&fd, &addr, LPAGE_SIZE*3, PROT_READ|PROT_WRITE, MAP_SHARED);
	if(result < 0)
		goto out2;

	munmap(addr, LPAGE_SIZE*3);
	close(fd);

	result = mmap_open_mmap(&fd, &addr, LPAGE_SIZE*3, PROT_NONE, MAP_SHARED);
	if(result < 0)
		goto out2;

	if(mprotect(addr, LPAGE_SIZE*3, PROT_READ)) {
		printf("fail!\n");
		goto out2;
	}

	tt001 = ((long *)addr)[0];

	if(mprotect(addr+LPAGE_SIZE, LPAGE_SIZE, PROT_READ|PROT_WRITE)) {
		printf("fail!\n");
		goto out2;
	}
	((char *)addr)[LPAGE_SIZE+100] = tt001;

	if(mprotect(addr+LPAGE_SIZE, LPAGE_SIZE, PROT_READ)) {
		printf("fail!\n");
		goto out2;
	}

	printf("pass!\n");

out3:
	if(result < 0)
		mmap_unmap(addr, LPAGE_SIZE*3);
	else
		result = mmap_unmap(addr, LPAGE_SIZE*3);
out2:
	close(fd);
	if(result < 0)
		umount(MMAP_DIR);
	else
		result = umount(MMAP_DIR);
out1:
	return result;
}

void init()
{
	mkdir(WORK_DIR, 0777);
	mkdir(MMAP_DIR, 0755);
}

void uninit()
{
	rmdir(MMAP_DIR);
	rmdir(WORK_DIR);
}

int main(int argc, char * argv)
{
	int	total_pages=0;
	int	free_pages=0;
	int	result=0;

	init();

	test_mmap_mprotect();

	uninit();
	return 0;
}

Re: [PATCH] Enable mprotect on huge pages

[David Gibson]

On Tue, Feb 28, 2006 at 11:23:54AM +0800, Zhang, Yanmin wrote:
> On Tue, 2006-02-28 at 09:34, Andrew Morton wrote:
> > "Zhang, Yanmin" <yanmin_zhang@linux.intel.com> wrote:
> > >
> > > > > > > 2.6.16-rc3 uses hugetlb on-demand paging, but it doesn_t support hugetlb
> > >  > > > > mprotect. My patch against 2.6.16-rc3 enables this capability.
> > > 
> > >  Based on David's comments, I worked out a new patch against 2.6.16-rc4.
> > >  Thank David.
> > > 
> > 
> > Please always send an updated changelog when sending an updated patch. 
> > Otherwise I have to go trolling back through the email thread to find it,
> > then work out what needs to be changed.
> Thanks for your kind reminder. I would do so next time.
> 
> > 
> > > 
> > >  I tested it on i386/x86_64/ia64. Who could help test it on other
> > >  platforms, such like PPC64?
> > 
> > I can do that - please send me your test app?
> I attach a test case. It will create directory /mnt/hugepages and delete it
> after testing automatically.
> 
> To run it by user root:
> #gcc -o mprotect_testcase mprotect_testcase.c
> #echo "5">/proc/sys/vm/nr_hugepages
> #./mprotect_testcase

If you could adapt this testcase to fit into the libhugetlbfs
testsuite, that would be really great (from
git://ozlabs.org/~dgibson/git/libhugetlbfs.git).  Otherwise I guess I
will..

-- 
David Gibson			| I'll have my music baroque, and my code
david AT gibson.dropbear.id.au	| minimalist, thank you.  NOT _the_ _other_
				| _way_ _around_!
http://www.ozlabs.org/~dgibson

Re: [PATCH] Enable mprotect on huge pages

[Zhang, Yanmin]

On Tue, 2006-02-28 at 11:32, David Gibson wrote:
> On Tue, Feb 28, 2006 at 11:23:54AM +0800, Zhang, Yanmin wrote:
> > On Tue, 2006-02-28 at 09:34, Andrew Morton wrote:
> > > "Zhang, Yanmin" <yanmin_zhang@linux.intel.com> wrote:
> > > >
> > > > > > > > 2.6.16-rc3 uses hugetlb on-demand paging, but it doesn_t support hugetlb
> > > >  > > > > mprotect. My patch against 2.6.16-rc3 enables this capability.
> > > > 

> If you could adapt this testcase to fit into the libhugetlbfs
> testsuite, that would be really great (from
> git://ozlabs.org/~dgibson/git/libhugetlbfs.git).  Otherwise I guess I
> will..
Frankly, I wrote a hugetlb test suite with dozens of test cases. It could
run on i386/x86_64/ia64 and caught many hugetlb bugs effectively. I am
not sure if I could distribute it out of intel.

Re: [PATCH] Enable mprotect on huge pages

[David Gibson]

On Tue, Feb 28, 2006 at 11:23:54AM +0800, Zhang, Yanmin wrote:
> On Tue, 2006-02-28 at 09:34, Andrew Morton wrote:
> > "Zhang, Yanmin" <yanmin_zhang@linux.intel.com> wrote:
> > >
> > > > > > > 2.6.16-rc3 uses hugetlb on-demand paging, but it doesn_t support hugetlb
> > >  > > > > mprotect. My patch against 2.6.16-rc3 enables this capability.
> > > 
> > >  Based on David's comments, I worked out a new patch against 2.6.16-rc4.
> > >  Thank David.
> > > 
> > 
> > Please always send an updated changelog when sending an updated patch. 
> > Otherwise I have to go trolling back through the email thread to find it,
> > then work out what needs to be changed.
> Thanks for your kind reminder. I would do so next time.
> 
> > 
> > > 
> > >  I tested it on i386/x86_64/ia64. Who could help test it on other
> > >  platforms, such like PPC64?
> > 
> > I can do that - please send me your test app?
> I attach a test case. It will create directory /mnt/hugepages and delete it
> after testing automatically.
> 
> To run it by user root:
> #gcc -o mprotect_testcase mprotect_testcase.c
> #echo "5">/proc/sys/vm/nr_hugepages
> #./mprotect_testcase
> 
> You could use gdb to step it to see the changing of the process vma maps.

I've just added a simpler testcase than this one to the libhugetlbfs
testsuite.  Both R->RW and RW->R transitions appear to work (I haven't
tested EXEC transitions yet, that's hairier).

-- 
David Gibson			| I'll have my music baroque, and my code
david AT gibson.dropbear.id.au	| minimalist, thank you.  NOT _the_ _other_
				| _way_ _around_!
http://www.ozlabs.org/~dgibson

Re: [2.4.32 - 2.6.15.4] e1000 - Fix mii interface

[Paul Rolland]

Hello Jesse,

>   					spddplx += (mii_reg & 0x100)
> -						   ? FULL_DUPLEX :
> -						   HALF_DUPLEX;
> +						   ? DUPLEX_FULL :
> +						   DUPLEX_HALF;

As I said in my first mail, I didn't want to go that way as one of the
two DUPLEX_FULL or DUPLEX_HALF is defined as being 0, which prevents
detecting incorrect/incomplete initializations.

The problem I had came from :
mii-tool -F 100BaseTx-FD eth0
when at the same time the ethtool interface was OK.

But you are right, the change I made missed the second caller.

The correct change is yours, though for the reason I put above, I think
it'll make it harder to spot other bugs ;)

Well done,
Paul