Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1756572AbXLJSB1 (ORCPT ); Mon, 10 Dec 2007 13:01:27 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1753964AbXLJSA6 (ORCPT ); Mon, 10 Dec 2007 13:00:58 -0500 Received: from [198.99.130.12] ([198.99.130.12]:55197 "EHLO saraswathi.solana.com" rhost-flags-FAIL-FAIL-OK-OK) by vger.kernel.org with ESMTP id S1753771AbXLJSA4 (ORCPT ); Mon, 10 Dec 2007 13:00:56 -0500 Date: Mon, 10 Dec 2007 13:00:08 -0500 From: Jeff Dike To: Andrew Morton Cc: LKML , uml-devel Subject: [PATCH 3/5] UML - Eliminate setjmp_wrapper Message-ID: <20071210180008.GA9343@c2.user-mode-linux.org> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline User-Agent: Mutt/1.4.2.3i Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 5371 Lines: 186 setjmp_wrapper existed to provide setjmp to kernel code when UML used libc's setjmp and longjmp. Now that UML has its own implementation, this isn't needed and kernel code can invoke setjmp directly. do_buffer_op is massively cleaned up since it is no longer a callback from setjmp_wrapper and given a va_list from which it must extract its arguments. The actual setjmp is moved from buffer_op to do_op_one_page because the copy operation is inside an atomic section (kmap_atomic to kunmap_atomic) and it shouldn't be longjmp-ed out of. Signed-off-by: Jeff Dike --- arch/um/include/os.h | 1 arch/um/kernel/skas/uaccess.c | 73 +++++++++++++++--------------------------- arch/um/os-Linux/util.c | 15 -------- 3 files changed, 27 insertions(+), 62 deletions(-) Index: linux-2.6-git/arch/um/include/os.h =================================================================== --- linux-2.6-git.orig/arch/um/include/os.h 2007-12-10 12:37:04.000000000 -0500 +++ linux-2.6-git/arch/um/include/os.h 2007-12-10 12:37:59.000000000 -0500 @@ -237,7 +237,6 @@ extern void stack_protections(unsigned l extern int raw(int fd); extern void setup_machinename(char *machine_out); extern void setup_hostinfo(char *buf, int len); -extern int setjmp_wrapper(void (*proc)(void *, void *), ...); extern void os_dump_core(void); /* time.c */ Index: linux-2.6-git/arch/um/kernel/skas/uaccess.c =================================================================== --- linux-2.6-git.orig/arch/um/kernel/skas/uaccess.c 2007-12-10 12:36:31.000000000 -0500 +++ linux-2.6-git/arch/um/kernel/skas/uaccess.c 2007-12-10 12:37:59.000000000 -0500 @@ -58,9 +58,10 @@ static pte_t *maybe_map(unsigned long vi 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) { + jmp_buf buf; struct page *page; pte_t *pte; - int n; + int n, faulted; pte = maybe_map(addr, is_write); if (pte == NULL) @@ -70,82 +71,62 @@ static int do_op_one_page(unsigned long addr = (unsigned long) kmap_atomic(page, KM_UML_USERCOPY) + (addr & ~PAGE_MASK); - n = (*op)(addr, len, arg); + current->thread.fault_catcher = &buf; + + faulted = UML_SETJMP(&buf); + if (faulted == 0) + n = (*op)(addr, len, arg); + else + n = -1; + + current->thread.fault_catcher = NULL; kunmap_atomic(page, KM_UML_USERCOPY); return n; } -static void do_buffer_op(void *jmpbuf, void *arg_ptr) +static int buffer_op(unsigned long addr, int len, int is_write, + int (*op)(unsigned long, int, void *), void *arg) { - va_list args; - unsigned long addr; - int len, is_write, size, remain, n; - int (*op)(unsigned long, int, void *); - void *arg; - int *res; - - va_copy(args, *(va_list *)arg_ptr); - addr = va_arg(args, unsigned long); - len = va_arg(args, int); - is_write = va_arg(args, int); - op = va_arg(args, void *); - arg = va_arg(args, void *); - res = va_arg(args, int *); - va_end(args); + int size, remain, n; + size = min(PAGE_ALIGN(addr) - addr, (unsigned long) len); remain = len; - current->thread.fault_catcher = jmpbuf; n = do_op_one_page(addr, size, is_write, op, arg); if (n != 0) { - *res = (n < 0 ? remain : 0); + remain = (n < 0 ? remain : 0); goto out; } addr += size; remain -= size; - if (remain == 0) { - *res = 0; + if (remain == 0) goto out; - } - while(addr < ((addr + remain) & PAGE_MASK)) { + while (addr < ((addr + remain) & PAGE_MASK)) { n = do_op_one_page(addr, PAGE_SIZE, is_write, op, arg); if (n != 0) { - *res = (n < 0 ? remain : 0); + remain = (n < 0 ? remain : 0); goto out; } addr += PAGE_SIZE; remain -= PAGE_SIZE; } - if (remain == 0) { - *res = 0; + if (remain == 0) goto out; - } n = do_op_one_page(addr, remain, is_write, op, arg); - if (n != 0) - *res = (n < 0 ? remain : 0); - else *res = 0; - out: - current->thread.fault_catcher = NULL; -} - -static int buffer_op(unsigned long addr, int len, int is_write, - int (*op)(unsigned long addr, int len, void *arg), - void *arg) -{ - int faulted, res; - - faulted = setjmp_wrapper(do_buffer_op, addr, len, is_write, op, arg, - &res); - if (!faulted) - return res; + if (n != 0) { + remain = (n < 0 ? remain : 0); + goto out; + } - return addr + len - (unsigned long) current->thread.fault_addr; + return 0; + out: + return remain; } static int copy_chunk_from_user(unsigned long from, int len, void *arg) Index: linux-2.6-git/arch/um/os-Linux/util.c =================================================================== --- linux-2.6-git.orig/arch/um/os-Linux/util.c 2007-12-10 12:36:31.000000000 -0500 +++ linux-2.6-git/arch/um/os-Linux/util.c 2007-12-10 12:37:59.000000000 -0500 @@ -88,21 +88,6 @@ void setup_hostinfo(char *buf, int len) host.release, host.version, host.machine); } -int setjmp_wrapper(void (*proc)(void *, void *), ...) -{ - va_list args; - jmp_buf buf; - int n; - - n = UML_SETJMP(&buf); - if(n == 0){ - va_start(args, proc); - (*proc)(&buf, &args); - } - va_end(args); - return n; -} - void os_dump_core(void) { int pid; -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/