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author | Paolo 'Blaisorblade' Giarrusso <blaisorblade@yahoo.it> | 2006-07-01 11:36:19 (GMT) |
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committer | Linus Torvalds <torvalds@g5.osdl.org> | 2006-07-01 16:56:03 (GMT) |
commit | 47e5243afe0bd2a1aca1e1f05dfbcc214267fbc9 (patch) | |
tree | 4c71d9b03077f597bc627393ea24099b838a4db9 /arch/um/kernel | |
parent | 8ec4d41f88872e6a5980558e362c0174dce54e40 (diff) | |
download | linux-fsl-qoriq-47e5243afe0bd2a1aca1e1f05dfbcc214267fbc9.tar.xz |
[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>
Diffstat (limited to 'arch/um/kernel')
-rw-r--r-- | arch/um/kernel/skas/uaccess.c | 15 |
1 files changed, 9 insertions, 6 deletions
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 @@ static unsigned long maybe_map(unsigned long virt, int is_write) 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 @@ static int do_op(unsigned long addr, int len, int is_write, 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 @@ static void do_buffer_op(void *jmpbuf, void *arg_ptr) 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 @@ static void do_buffer_op(void *jmpbuf, void *arg_ptr) } 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 @@ static void do_buffer_op(void *jmpbuf, void *arg_ptr) 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; |