* [uml-devel] [PATCH 7/8] UML - add virt_to_pte
@ 2007-11-16 21:42 ` Jeff Dike
0 siblings, 0 replies; 6+ messages in thread
From: Jeff Dike @ 2007-11-16 21:42 UTC (permalink / raw)
To: Andrew Morton; +Cc: LKML, uml-devel
Turn um_virt_to_phys into virt_to_pte, cleaning up a horrid interface.
It's also made non-static and declared in pgtable.h because it'll be
needed when the stubs get a vma.
Signed-off-by: Jeff Dike <jdike@linux.intel.com>
---
arch/um/kernel/skas/uaccess.c | 56 +++++++++++++++++-------------------------
include/asm-um/pgtable.h | 3 ++
2 files changed, 26 insertions(+), 33 deletions(-)
Index: linux-2.6.22/arch/um/kernel/skas/uaccess.c
===================================================================
--- linux-2.6.22.orig/arch/um/kernel/skas/uaccess.c 2007-11-16 15:16:54.000000000 -0500
+++ linux-2.6.22/arch/um/kernel/skas/uaccess.c 2007-11-16 15:40:25.000000000 -0500
@@ -13,70 +13,60 @@
#include "kern_util.h"
#include "os.h"
-static void *um_virt_to_phys(struct task_struct *task, unsigned long addr,
- pte_t *pte_out)
+pte_t *virt_to_pte(struct mm_struct *mm, unsigned long addr)
{
pgd_t *pgd;
pud_t *pud;
pmd_t *pmd;
- pte_t *pte;
- pte_t ptent;
- if (task->mm == NULL)
- return ERR_PTR(-EINVAL);
- pgd = pgd_offset(task->mm, addr);
+ if (mm == NULL)
+ return NULL;
+
+ pgd = pgd_offset(mm, addr);
if (!pgd_present(*pgd))
- return ERR_PTR(-EINVAL);
+ return NULL;
pud = pud_offset(pgd, addr);
if (!pud_present(*pud))
- return ERR_PTR(-EINVAL);
+ return NULL;
pmd = pmd_offset(pud, addr);
if (!pmd_present(*pmd))
- return ERR_PTR(-EINVAL);
-
- pte = pte_offset_kernel(pmd, addr);
- ptent = *pte;
- if (!pte_present(ptent))
- return ERR_PTR(-EINVAL);
+ return NULL;
- if (pte_out != NULL)
- *pte_out = ptent;
- return (void *) (pte_val(ptent) & PAGE_MASK) + (addr & ~PAGE_MASK);
+ return pte_offset_kernel(pmd, addr);
}
-static unsigned long maybe_map(unsigned long virt, int is_write)
+static pte_t *maybe_map(unsigned long virt, int is_write)
{
- pte_t pte;
- int err;
+ pte_t *pte = virt_to_pte(current->mm, virt);
+ int err, dummy_code;
- void *phys = um_virt_to_phys(current, virt, &pte);
- int dummy_code;
-
- if (IS_ERR(phys) || (is_write && !pte_write(pte))) {
+ if ((pte == NULL) || !pte_present(*pte) ||
+ (is_write && !pte_write(*pte))) {
err = handle_page_fault(virt, 0, is_write, 1, &dummy_code);
if (err)
- return -1UL;
- phys = um_virt_to_phys(current, virt, NULL);
+ return NULL;
+ pte = virt_to_pte(current->mm, virt);
}
- if (IS_ERR(phys))
- phys = (void *) -1;
+ if (!pte_present(*pte))
+ pte = NULL;
- return (unsigned long) phys;
+ return pte;
}
static int do_op_one_page(unsigned long addr, int len, int is_write,
int (*op)(unsigned long addr, int len, void *arg), void *arg)
{
struct page *page;
+ pte_t *pte;
int n;
- addr = maybe_map(addr, is_write);
- if (addr == -1UL)
+ pte = maybe_map(addr, is_write);
+ if (pte == NULL)
return -1;
- page = phys_to_page(addr);
+ page = pte_page(*pte);
addr = (unsigned long) kmap_atomic(page, KM_UML_USERCOPY) +
(addr & ~PAGE_MASK);
Index: linux-2.6.22/include/asm-um/pgtable.h
===================================================================
--- linux-2.6.22.orig/include/asm-um/pgtable.h 2007-11-16 15:35:38.000000000 -0500
+++ linux-2.6.22/include/asm-um/pgtable.h 2007-11-16 15:39:44.000000000 -0500
@@ -323,6 +323,9 @@ static inline pte_t pte_modify(pte_t pte
#define pte_unmap(pte) do { } while (0)
#define pte_unmap_nested(pte) do { } while (0)
+struct mm_struct;
+extern pte_t *virt_to_pte(struct mm_struct *mm, unsigned long addr);
+
#define update_mmu_cache(vma,address,pte) do ; while (0)
/* Encode and de-code a swap entry */
-------------------------------------------------------------------------
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^ permalink raw reply [flat|nested] 6+ messages in thread
* [PATCH 7/8] UML - add virt_to_pte
@ 2007-11-16 21:42 ` Jeff Dike
0 siblings, 0 replies; 6+ messages in thread
From: Jeff Dike @ 2007-11-16 21:42 UTC (permalink / raw)
To: Andrew Morton; +Cc: LKML, uml-devel
Turn um_virt_to_phys into virt_to_pte, cleaning up a horrid interface.
It's also made non-static and declared in pgtable.h because it'll be
needed when the stubs get a vma.
Signed-off-by: Jeff Dike <jdike@linux.intel.com>
---
arch/um/kernel/skas/uaccess.c | 56 +++++++++++++++++-------------------------
include/asm-um/pgtable.h | 3 ++
2 files changed, 26 insertions(+), 33 deletions(-)
Index: linux-2.6.22/arch/um/kernel/skas/uaccess.c
===================================================================
--- linux-2.6.22.orig/arch/um/kernel/skas/uaccess.c 2007-11-16 15:16:54.000000000 -0500
+++ linux-2.6.22/arch/um/kernel/skas/uaccess.c 2007-11-16 15:40:25.000000000 -0500
@@ -13,70 +13,60 @@
#include "kern_util.h"
#include "os.h"
-static void *um_virt_to_phys(struct task_struct *task, unsigned long addr,
- pte_t *pte_out)
+pte_t *virt_to_pte(struct mm_struct *mm, unsigned long addr)
{
pgd_t *pgd;
pud_t *pud;
pmd_t *pmd;
- pte_t *pte;
- pte_t ptent;
- if (task->mm == NULL)
- return ERR_PTR(-EINVAL);
- pgd = pgd_offset(task->mm, addr);
+ if (mm == NULL)
+ return NULL;
+
+ pgd = pgd_offset(mm, addr);
if (!pgd_present(*pgd))
- return ERR_PTR(-EINVAL);
+ return NULL;
pud = pud_offset(pgd, addr);
if (!pud_present(*pud))
- return ERR_PTR(-EINVAL);
+ return NULL;
pmd = pmd_offset(pud, addr);
if (!pmd_present(*pmd))
- return ERR_PTR(-EINVAL);
-
- pte = pte_offset_kernel(pmd, addr);
- ptent = *pte;
- if (!pte_present(ptent))
- return ERR_PTR(-EINVAL);
+ return NULL;
- if (pte_out != NULL)
- *pte_out = ptent;
- return (void *) (pte_val(ptent) & PAGE_MASK) + (addr & ~PAGE_MASK);
+ return pte_offset_kernel(pmd, addr);
}
-static unsigned long maybe_map(unsigned long virt, int is_write)
+static pte_t *maybe_map(unsigned long virt, int is_write)
{
- pte_t pte;
- int err;
+ pte_t *pte = virt_to_pte(current->mm, virt);
+ int err, dummy_code;
- void *phys = um_virt_to_phys(current, virt, &pte);
- int dummy_code;
-
- if (IS_ERR(phys) || (is_write && !pte_write(pte))) {
+ if ((pte == NULL) || !pte_present(*pte) ||
+ (is_write && !pte_write(*pte))) {
err = handle_page_fault(virt, 0, is_write, 1, &dummy_code);
if (err)
- return -1UL;
- phys = um_virt_to_phys(current, virt, NULL);
+ return NULL;
+ pte = virt_to_pte(current->mm, virt);
}
- if (IS_ERR(phys))
- phys = (void *) -1;
+ if (!pte_present(*pte))
+ pte = NULL;
- return (unsigned long) phys;
+ return pte;
}
static int do_op_one_page(unsigned long addr, int len, int is_write,
int (*op)(unsigned long addr, int len, void *arg), void *arg)
{
struct page *page;
+ pte_t *pte;
int n;
- addr = maybe_map(addr, is_write);
- if (addr == -1UL)
+ pte = maybe_map(addr, is_write);
+ if (pte == NULL)
return -1;
- page = phys_to_page(addr);
+ page = pte_page(*pte);
addr = (unsigned long) kmap_atomic(page, KM_UML_USERCOPY) +
(addr & ~PAGE_MASK);
Index: linux-2.6.22/include/asm-um/pgtable.h
===================================================================
--- linux-2.6.22.orig/include/asm-um/pgtable.h 2007-11-16 15:35:38.000000000 -0500
+++ linux-2.6.22/include/asm-um/pgtable.h 2007-11-16 15:39:44.000000000 -0500
@@ -323,6 +323,9 @@ static inline pte_t pte_modify(pte_t pte
#define pte_unmap(pte) do { } while (0)
#define pte_unmap_nested(pte) do { } while (0)
+struct mm_struct;
+extern pte_t *virt_to_pte(struct mm_struct *mm, unsigned long addr);
+
#define update_mmu_cache(vma,address,pte) do ; while (0)
/* Encode and de-code a swap entry */
^ permalink raw reply [flat|nested] 6+ messages in thread
* Re: [uml-devel] [PATCH 7/8] UML - add virt_to_pte
2007-11-16 21:42 ` Jeff Dike
@ 2007-11-17 10:50 ` Roel Kluin
-1 siblings, 0 replies; 6+ messages in thread
From: Roel Kluin @ 2007-11-17 10:50 UTC (permalink / raw)
To: Jeff Dike; +Cc: Andrew Morton, LKML, uml-devel
Jeff Dike wrote:
> Turn um_virt_to_phys into virt_to_pte, cleaning up a horrid interface.
>
> It's also made non-static and declared in pgtable.h because it'll be
> needed when the stubs get a vma.
>
> Signed-off-by: Jeff Dike <jdike@linux.intel.com>
> ---
> arch/um/kernel/skas/uaccess.c | 56 +++++++++++++++++-------------------------
> include/asm-um/pgtable.h | 3 ++
> 2 files changed, 26 insertions(+), 33 deletions(-)
>
> Index: linux-2.6.22/arch/um/kernel/skas/uaccess.c
> ===================================================================
> --- linux-2.6.22.orig/arch/um/kernel/skas/uaccess.c 2007-11-16 15:16:54.000000000 -0500
> +++ linux-2.6.22/arch/um/kernel/skas/uaccess.c 2007-11-16 15:40:25.000000000 -0500
> @@ -13,70 +13,60 @@
> #include "kern_util.h"
> #include "os.h"
>
> -static void *um_virt_to_phys(struct task_struct *task, unsigned long addr,
> - pte_t *pte_out)
> +pte_t *virt_to_pte(struct mm_struct *mm, unsigned long addr)
> {
> pgd_t *pgd;
> pud_t *pud;
> pmd_t *pmd;
> - pte_t *pte;
> - pte_t ptent;
>
> - if (task->mm == NULL)
> - return ERR_PTR(-EINVAL);
> - pgd = pgd_offset(task->mm, addr);
> + if (mm == NULL)
> + return NULL;
> +
> + pgd = pgd_offset(mm, addr);
> if (!pgd_present(*pgd))
> - return ERR_PTR(-EINVAL);
> + return NULL;
>
> pud = pud_offset(pgd, addr);
> if (!pud_present(*pud))
> - return ERR_PTR(-EINVAL);
> + return NULL;
>
> pmd = pmd_offset(pud, addr);
> if (!pmd_present(*pmd))
> - return ERR_PTR(-EINVAL);
> -
> - pte = pte_offset_kernel(pmd, addr);
> - ptent = *pte;
> - if (!pte_present(ptent))
> - return ERR_PTR(-EINVAL);
> + return NULL;
>
> - if (pte_out != NULL)
> - *pte_out = ptent;
> - return (void *) (pte_val(ptent) & PAGE_MASK) + (addr & ~PAGE_MASK);
> + return pte_offset_kernel(pmd, addr);
> }
>
> -static unsigned long maybe_map(unsigned long virt, int is_write)
> +static pte_t *maybe_map(unsigned long virt, int is_write)
> {
> - pte_t pte;
> - int err;
> + pte_t *pte = virt_to_pte(current->mm, virt);
> + int err, dummy_code;
>
> - void *phys = um_virt_to_phys(current, virt, &pte);
> - int dummy_code;
> -
> - if (IS_ERR(phys) || (is_write && !pte_write(pte))) {
> + if ((pte == NULL) || !pte_present(*pte) ||
> + (is_write && !pte_write(*pte))) {
> err = handle_page_fault(virt, 0, is_write, 1, &dummy_code);
> if (err)
> - return -1UL;
> - phys = um_virt_to_phys(current, virt, NULL);
> + return NULL;
> + pte = virt_to_pte(current->mm, virt);
> }
> - if (IS_ERR(phys))
> - phys = (void *) -1;
> + if (!pte_present(*pte))
> + pte = NULL;
shouldn't you check again for (pte == NULL)?
>
> - return (unsigned long) phys;
> + return pte;
> }
-------------------------------------------------------------------------
This SF.net email is sponsored by: Microsoft
Defy all challenges. Microsoft(R) Visual Studio 2005.
http://clk.atdmt.com/MRT/go/vse0120000070mrt/direct/01/
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^ permalink raw reply [flat|nested] 6+ messages in thread
* Re: [PATCH 7/8] UML - add virt_to_pte
@ 2007-11-17 10:50 ` Roel Kluin
0 siblings, 0 replies; 6+ messages in thread
From: Roel Kluin @ 2007-11-17 10:50 UTC (permalink / raw)
To: Jeff Dike; +Cc: Andrew Morton, LKML, uml-devel
Jeff Dike wrote:
> Turn um_virt_to_phys into virt_to_pte, cleaning up a horrid interface.
>
> It's also made non-static and declared in pgtable.h because it'll be
> needed when the stubs get a vma.
>
> Signed-off-by: Jeff Dike <jdike@linux.intel.com>
> ---
> arch/um/kernel/skas/uaccess.c | 56 +++++++++++++++++-------------------------
> include/asm-um/pgtable.h | 3 ++
> 2 files changed, 26 insertions(+), 33 deletions(-)
>
> Index: linux-2.6.22/arch/um/kernel/skas/uaccess.c
> ===================================================================
> --- linux-2.6.22.orig/arch/um/kernel/skas/uaccess.c 2007-11-16 15:16:54.000000000 -0500
> +++ linux-2.6.22/arch/um/kernel/skas/uaccess.c 2007-11-16 15:40:25.000000000 -0500
> @@ -13,70 +13,60 @@
> #include "kern_util.h"
> #include "os.h"
>
> -static void *um_virt_to_phys(struct task_struct *task, unsigned long addr,
> - pte_t *pte_out)
> +pte_t *virt_to_pte(struct mm_struct *mm, unsigned long addr)
> {
> pgd_t *pgd;
> pud_t *pud;
> pmd_t *pmd;
> - pte_t *pte;
> - pte_t ptent;
>
> - if (task->mm == NULL)
> - return ERR_PTR(-EINVAL);
> - pgd = pgd_offset(task->mm, addr);
> + if (mm == NULL)
> + return NULL;
> +
> + pgd = pgd_offset(mm, addr);
> if (!pgd_present(*pgd))
> - return ERR_PTR(-EINVAL);
> + return NULL;
>
> pud = pud_offset(pgd, addr);
> if (!pud_present(*pud))
> - return ERR_PTR(-EINVAL);
> + return NULL;
>
> pmd = pmd_offset(pud, addr);
> if (!pmd_present(*pmd))
> - return ERR_PTR(-EINVAL);
> -
> - pte = pte_offset_kernel(pmd, addr);
> - ptent = *pte;
> - if (!pte_present(ptent))
> - return ERR_PTR(-EINVAL);
> + return NULL;
>
> - if (pte_out != NULL)
> - *pte_out = ptent;
> - return (void *) (pte_val(ptent) & PAGE_MASK) + (addr & ~PAGE_MASK);
> + return pte_offset_kernel(pmd, addr);
> }
>
> -static unsigned long maybe_map(unsigned long virt, int is_write)
> +static pte_t *maybe_map(unsigned long virt, int is_write)
> {
> - pte_t pte;
> - int err;
> + pte_t *pte = virt_to_pte(current->mm, virt);
> + int err, dummy_code;
>
> - void *phys = um_virt_to_phys(current, virt, &pte);
> - int dummy_code;
> -
> - if (IS_ERR(phys) || (is_write && !pte_write(pte))) {
> + if ((pte == NULL) || !pte_present(*pte) ||
> + (is_write && !pte_write(*pte))) {
> err = handle_page_fault(virt, 0, is_write, 1, &dummy_code);
> if (err)
> - return -1UL;
> - phys = um_virt_to_phys(current, virt, NULL);
> + return NULL;
> + pte = virt_to_pte(current->mm, virt);
> }
> - if (IS_ERR(phys))
> - phys = (void *) -1;
> + if (!pte_present(*pte))
> + pte = NULL;
shouldn't you check again for (pte == NULL)?
>
> - return (unsigned long) phys;
> + return pte;
> }
^ permalink raw reply [flat|nested] 6+ messages in thread
* Re: [uml-devel] [PATCH 7/8] UML - add virt_to_pte
2007-11-17 10:50 ` Roel Kluin
@ 2007-11-17 18:49 ` Jeff Dike
-1 siblings, 0 replies; 6+ messages in thread
From: Jeff Dike @ 2007-11-17 18:49 UTC (permalink / raw)
To: Roel Kluin; +Cc: Andrew Morton, LKML, uml-devel
On Sat, Nov 17, 2007 at 11:50:07AM +0100, Roel Kluin wrote:
> > + if (!pte_present(*pte))
> > + pte = NULL;
>
> shouldn't you check again for (pte == NULL)?
No, because if the page isn't mapped, handle_page_fault would have
returned non-zero, and we would have already returned.
This is leaving aside issues of whether the page could have been
unmapped by another CPU (which isn't an issue right now, and for which
I have a patch to fix anyway).
Jeff
--
Work email - jdike at linux dot intel dot com
-------------------------------------------------------------------------
This SF.net email is sponsored by: Microsoft
Defy all challenges. Microsoft(R) Visual Studio 2005.
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https://lists.sourceforge.net/lists/listinfo/user-mode-linux-devel
^ permalink raw reply [flat|nested] 6+ messages in thread
* Re: [PATCH 7/8] UML - add virt_to_pte
@ 2007-11-17 18:49 ` Jeff Dike
0 siblings, 0 replies; 6+ messages in thread
From: Jeff Dike @ 2007-11-17 18:49 UTC (permalink / raw)
To: Roel Kluin; +Cc: Andrew Morton, LKML, uml-devel
On Sat, Nov 17, 2007 at 11:50:07AM +0100, Roel Kluin wrote:
> > + if (!pte_present(*pte))
> > + pte = NULL;
>
> shouldn't you check again for (pte == NULL)?
No, because if the page isn't mapped, handle_page_fault would have
returned non-zero, and we would have already returned.
This is leaving aside issues of whether the page could have been
unmapped by another CPU (which isn't an issue right now, and for which
I have a patch to fix anyway).
Jeff
--
Work email - jdike at linux dot intel dot com
^ permalink raw reply [flat|nested] 6+ messages in thread
end of thread, other threads:[~2007-11-17 18:50 UTC | newest]
Thread overview: 6+ messages (download: mbox.gz follow: Atom feed
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2007-11-16 21:42 [uml-devel] [PATCH 7/8] UML - add virt_to_pte Jeff Dike
2007-11-16 21:42 ` Jeff Dike
2007-11-17 10:50 ` [uml-devel] " Roel Kluin
2007-11-17 10:50 ` Roel Kluin
2007-11-17 18:49 ` [uml-devel] " Jeff Dike
2007-11-17 18:49 ` Jeff Dike
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