[PATCH] uml: make copy_*_user atomic
Make __copy_*_user_inatomic really atomic to avoid "Sleeping function called in
atomic context" warnings, especially from futex code.
This is made by adding another kmap_atomic slot and making copy_*_user_skas
use kmap_atomic; also copy_*_user() becomes atomic, but that's true and is not
a problem for i386 (and we can always add might_sleep there as done
elsewhere). For TT mode kmap is not used, so there's no need for this.
I've had to use another slot since both KM_USER0 and KM_USER1 are used
elsewhere and could cause conflicts. Till now we reused the kmap_atomic slot
list from the subarch, but that's not needed as that list must contain the
common ones (used by generic code) + the ones used in architecture specific
code (and Uml till now used none); so I've taken the i386 one after comparing
it with ones from other archs, and added KM_UML_USERCOPY.
Signed-off-by: Paolo 'Blaisorblade' Giarrusso <blaisorblade@yahoo.it>
Cc: Jeff Dike <jdike@addtoit.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
diff --git a/arch/um/kernel/skas/uaccess.c b/arch/um/kernel/skas/uaccess.c
index 5992c32..8912cec 100644
--- a/arch/um/kernel/skas/uaccess.c
+++ b/arch/um/kernel/skas/uaccess.c
@@ -8,6 +8,7 @@
#include "linux/kernel.h"
#include "linux/string.h"
#include "linux/fs.h"
+#include "linux/hardirq.h"
#include "linux/highmem.h"
#include "asm/page.h"
#include "asm/pgtable.h"
@@ -38,7 +39,7 @@
return((unsigned long) phys);
}
-static int do_op(unsigned long addr, int len, int is_write,
+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;
@@ -49,9 +50,11 @@
return(-1);
page = phys_to_page(addr);
- addr = (unsigned long) kmap(page) + (addr & ~PAGE_MASK);
+ addr = (unsigned long) kmap_atomic(page, KM_UML_USERCOPY) + (addr & ~PAGE_MASK);
+
n = (*op)(addr, len, arg);
- kunmap(page);
+
+ kunmap_atomic(page, KM_UML_USERCOPY);
return(n);
}
@@ -77,7 +80,7 @@
remain = len;
current->thread.fault_catcher = jmpbuf;
- n = do_op(addr, size, is_write, op, arg);
+ n = do_op_one_page(addr, size, is_write, op, arg);
if(n != 0){
*res = (n < 0 ? remain : 0);
goto out;
@@ -91,7 +94,7 @@
}
while(addr < ((addr + remain) & PAGE_MASK)){
- n = do_op(addr, PAGE_SIZE, is_write, op, arg);
+ n = do_op_one_page(addr, PAGE_SIZE, is_write, op, arg);
if(n != 0){
*res = (n < 0 ? remain : 0);
goto out;
@@ -105,7 +108,7 @@
goto out;
}
- n = do_op(addr, remain, is_write, op, arg);
+ n = do_op_one_page(addr, remain, is_write, op, arg);
if(n != 0)
*res = (n < 0 ? remain : 0);
else *res = 0;
diff --git a/include/asm-um/kmap_types.h b/include/asm-um/kmap_types.h
index 0b22ad7..6c03acd 100644
--- a/include/asm-um/kmap_types.h
+++ b/include/asm-um/kmap_types.h
@@ -6,6 +6,24 @@
#ifndef __UM_KMAP_TYPES_H
#define __UM_KMAP_TYPES_H
-#include "asm/arch/kmap_types.h"
+/* No more #include "asm/arch/kmap_types.h" ! */
+
+enum km_type {
+ KM_BOUNCE_READ,
+ KM_SKB_SUNRPC_DATA,
+ KM_SKB_DATA_SOFTIRQ,
+ KM_USER0,
+ KM_USER1,
+ KM_UML_USERCOPY, /* UML specific, for copy_*_user - used in do_op_one_page */
+ KM_BIO_SRC_IRQ,
+ KM_BIO_DST_IRQ,
+ KM_PTE0,
+ KM_PTE1,
+ KM_IRQ0,
+ KM_IRQ1,
+ KM_SOFTIRQ0,
+ KM_SOFTIRQ1,
+ KM_TYPE_NR
+};
#endif