From: Paolo 'Blaisorblade' Giarrusso Date: Sat, 1 Jul 2006 11:36:19 +0000 (-0700) Subject: [PATCH] uml: make copy_*_user atomic X-Git-Tag: v2.6.18-rc1~207 X-Git-Url: http://review.tizen.org/git/?a=commitdiff_plain;h=47e5243afe0bd2a1aca1e1f05dfbcc214267fbc9;p=platform%2Fkernel%2Flinux-3.10.git [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 Cc: Jeff Dike Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- 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; 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