From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from sc8-sf-mx1-b.sourceforge.net ([10.3.1.91] helo=sc8-sf-mx1.sourceforge.net) by sc8-sf-list1.sourceforge.net with esmtp (Exim 4.30) id 1DsmE5-00037l-Ad for user-mode-linux-devel@lists.sourceforge.net; Wed, 13 Jul 2005 11:44:57 -0700 Received: from mail.kroah.org ([69.55.234.183] helo=perch.kroah.org) by sc8-sf-mx1.sourceforge.net with esmtp (Exim 4.44) id 1DsmE5-0005ye-20 for user-mode-linux-devel@lists.sourceforge.net; Wed, 13 Jul 2005 11:44:57 -0700 From: Greg KH Message-ID: <20050713184406.GK9330@kroah.com> References: <20050713184130.GA9330@kroah.com> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20050713184130.GA9330@kroah.com> Subject: [uml-devel] [09/11] uml: fix TT mode by reverting "use fork instead of clone" Sender: user-mode-linux-devel-admin@lists.sourceforge.net Errors-To: user-mode-linux-devel-admin@lists.sourceforge.net List-Unsubscribe: , List-Id: The user-mode Linux development list List-Post: List-Help: List-Subscribe: , List-Archive: Date: Wed, 13 Jul 2005 11:44:06 -0700 To: blaisorblade@yahoo.it, jdike@addtoit.com, user-mode-linux-devel@lists.sourceforge.net Cc: linux-kernel@vger.kernel.org, stable@kernel.org, Justin Forbes , Zwane Mwaikambo , rdunlap@xenotime.net, Chuck Wolber , torvalds@osdl.org, akpm@osdl.org, alan@lxorguk.ukuu.org.uk -stable review patch. If anyone has any objections, please let us know. ------------------ From: Jeff Dike , Paolo 'Blaisorblade' Giarrusso Revert the following patch, because of miscompilation problems in different environments leading to UML not working *at all* in TT mode; it was merged lately in 2.6 development cycle, a little after being written, and has caused problems to lots of people; I know it's a bit too long, but it shouldn't have been merged in first place, so I still apply for inclusion in the -stable tree. Anyone using this feature currently is either using some older kernel (some reports even used 2.6.12-rc4-mm2) or using this patch, as included in my -bs patchset. For now there's not yet a fix for this patch, so for now the best thing is to drop it (which was widely reported to give a working kernel). "Convert the boot-time host ptrace testing from clone to fork. They were essentially doing fork anyway. This cleans up the code a bit, and makes valgrind a bit happier about grinding it." URL: http://www.kernel.org/git/?p=linux/kernel/git/torvalds/linux-2.6.git;a=commit;h=98fdffccea6cc3fe9dba32c0fcc310bcb5d71529 Signed-off-by: Jeff Dike Signed-off-by: Paolo 'Blaisorblade' Giarrusso Signed-off-by: Chris Wright Signed-off-by: Greg Kroah-Hartman --- arch/um/kernel/process.c | 48 ++++++++++++++++++++++++++++------------------- 1 files changed, 29 insertions(+), 19 deletions(-) --- linux-2.6.12.2.orig/arch/um/kernel/process.c 2005-06-17 12:48:29.000000000 -0700 +++ linux-2.6.12.2/arch/um/kernel/process.c 2005-07-13 10:56:41.000000000 -0700 @@ -130,7 +130,7 @@ return(arg.pid); } -static int ptrace_child(void) +static int ptrace_child(void *arg) { int ret; int pid = os_getpid(), ppid = getppid(); @@ -159,16 +159,20 @@ _exit(ret); } -static int start_ptraced_child(void) +static int start_ptraced_child(void **stack_out) { + void *stack; + unsigned long sp; int pid, n, status; - pid = fork(); - if(pid == 0) - ptrace_child(); - + stack = mmap(NULL, PAGE_SIZE, PROT_READ | PROT_WRITE | PROT_EXEC, + MAP_PRIVATE | MAP_ANONYMOUS, -1, 0); + if(stack == MAP_FAILED) + panic("check_ptrace : mmap failed, errno = %d", errno); + sp = (unsigned long) stack + PAGE_SIZE - sizeof(void *); + pid = clone(ptrace_child, (void *) sp, SIGCHLD, NULL); if(pid < 0) - panic("check_ptrace : fork failed, errno = %d", errno); + panic("check_ptrace : clone failed, errno = %d", errno); CATCH_EINTR(n = waitpid(pid, &status, WUNTRACED)); if(n < 0) panic("check_ptrace : wait failed, errno = %d", errno); @@ -176,6 +180,7 @@ panic("check_ptrace : expected SIGSTOP, got status = %d", status); + *stack_out = stack; return(pid); } @@ -183,12 +188,12 @@ * just avoid using sysemu, not panic, but only if SYSEMU features are broken. * So only for SYSEMU features we test mustpanic, while normal host features * must work anyway!*/ -static int stop_ptraced_child(int pid, int exitcode, int mustexit) +static int stop_ptraced_child(int pid, void *stack, int exitcode, int mustpanic) { int status, n, ret = 0; if(ptrace(PTRACE_CONT, pid, 0, 0) < 0) - panic("stop_ptraced_child : ptrace failed, errno = %d", errno); + panic("check_ptrace : ptrace failed, errno = %d", errno); CATCH_EINTR(n = waitpid(pid, &status, 0)); if(!WIFEXITED(status) || (WEXITSTATUS(status) != exitcode)) { int exit_with = WEXITSTATUS(status); @@ -199,13 +204,15 @@ printk("check_ptrace : child exited with exitcode %d, while " "expecting %d; status 0x%x", exit_with, exitcode, status); - if (mustexit) + if (mustpanic) panic("\n"); else printk("\n"); ret = -1; } + if(munmap(stack, PAGE_SIZE) < 0) + panic("check_ptrace : munmap failed, errno = %d", errno); return ret; } @@ -227,11 +234,12 @@ static void __init check_sysemu(void) { + void *stack; int pid, syscall, n, status, count=0; printk("Checking syscall emulation patch for ptrace..."); sysemu_supported = 0; - pid = start_ptraced_child(); + pid = start_ptraced_child(&stack); if(ptrace(PTRACE_SYSEMU, pid, 0, 0) < 0) goto fail; @@ -249,7 +257,7 @@ panic("check_sysemu : failed to modify system " "call return, errno = %d", errno); - if (stop_ptraced_child(pid, 0, 0) < 0) + if (stop_ptraced_child(pid, stack, 0, 0) < 0) goto fail_stopped; sysemu_supported = 1; @@ -257,7 +265,7 @@ set_using_sysemu(!force_sysemu_disabled); printk("Checking advanced syscall emulation patch for ptrace..."); - pid = start_ptraced_child(); + pid = start_ptraced_child(&stack); while(1){ count++; if(ptrace(PTRACE_SYSEMU_SINGLESTEP, pid, 0, 0) < 0) @@ -282,7 +290,7 @@ break; } } - if (stop_ptraced_child(pid, 0, 0) < 0) + if (stop_ptraced_child(pid, stack, 0, 0) < 0) goto fail_stopped; sysemu_supported = 2; @@ -293,17 +301,18 @@ return; fail: - stop_ptraced_child(pid, 1, 0); + stop_ptraced_child(pid, stack, 1, 0); fail_stopped: printk("missing\n"); } void __init check_ptrace(void) { + void *stack; int pid, syscall, n, status; printk("Checking that ptrace can change system call numbers..."); - pid = start_ptraced_child(); + pid = start_ptraced_child(&stack); if (ptrace(PTRACE_OLDSETOPTIONS, pid, 0, (void *)PTRACE_O_TRACESYSGOOD) < 0) panic("check_ptrace: PTRACE_SETOPTIONS failed, errno = %d", errno); @@ -330,7 +339,7 @@ break; } } - stop_ptraced_child(pid, 0, 1); + stop_ptraced_child(pid, stack, 0, 1); printk("OK\n"); check_sysemu(); } @@ -362,10 +371,11 @@ static inline int check_skas3_ptrace_support(void) { struct ptrace_faultinfo fi; + void *stack; int pid, n, ret = 1; printf("Checking for the skas3 patch in the host..."); - pid = start_ptraced_child(); + pid = start_ptraced_child(&stack); n = ptrace(PTRACE_FAULTINFO, pid, 0, &fi); if (n < 0) { @@ -380,7 +390,7 @@ } init_registers(pid); - stop_ptraced_child(pid, 1, 1); + stop_ptraced_child(pid, stack, 1, 1); return(ret); } ------------------------------------------------------- This SF.Net email is sponsored by the 'Do More With Dual!' webinar happening July 14 at 8am PDT/11am EDT. 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To register visit http://www.hp.com/go/dualwebinar _______________________________________________ User-mode-linux-devel mailing list User-mode-linux-devel@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/user-mode-linux-devel From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S262302AbVGMWMI (ORCPT ); Wed, 13 Jul 2005 18:12:08 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S262257AbVGMWJn (ORCPT ); Wed, 13 Jul 2005 18:09:43 -0400 Received: from mail.kroah.org ([69.55.234.183]:26083 "EHLO perch.kroah.org") by vger.kernel.org with ESMTP id S262300AbVGMSpD (ORCPT ); Wed, 13 Jul 2005 14:45:03 -0400 Date: Wed, 13 Jul 2005 11:44:06 -0700 From: Greg KH To: blaisorblade@yahoo.it, jdike@addtoit.com, user-mode-linux-devel@lists.sourceforge.net Cc: linux-kernel@vger.kernel.org, stable@kernel.org, Justin Forbes , Zwane Mwaikambo , "Theodore Ts'o" , "Randy.Dunlap" , Chuck Wolber , torvalds@osdl.org, akpm@osdl.org, alan@lxorguk.ukuu.org.uk Subject: [09/11] uml: fix TT mode by reverting "use fork instead of clone" Message-ID: <20050713184406.GK9330@kroah.com> References: <20050713184130.GA9330@kroah.com> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20050713184130.GA9330@kroah.com> User-Agent: Mutt/1.5.8i Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org -stable review patch. If anyone has any objections, please let us know. ------------------ From: Jeff Dike , Paolo 'Blaisorblade' Giarrusso Revert the following patch, because of miscompilation problems in different environments leading to UML not working *at all* in TT mode; it was merged lately in 2.6 development cycle, a little after being written, and has caused problems to lots of people; I know it's a bit too long, but it shouldn't have been merged in first place, so I still apply for inclusion in the -stable tree. Anyone using this feature currently is either using some older kernel (some reports even used 2.6.12-rc4-mm2) or using this patch, as included in my -bs patchset. For now there's not yet a fix for this patch, so for now the best thing is to drop it (which was widely reported to give a working kernel). "Convert the boot-time host ptrace testing from clone to fork. They were essentially doing fork anyway. This cleans up the code a bit, and makes valgrind a bit happier about grinding it." URL: http://www.kernel.org/git/?p=linux/kernel/git/torvalds/linux-2.6.git;a=commit;h=98fdffccea6cc3fe9dba32c0fcc310bcb5d71529 Signed-off-by: Jeff Dike Signed-off-by: Paolo 'Blaisorblade' Giarrusso Signed-off-by: Chris Wright Signed-off-by: Greg Kroah-Hartman --- arch/um/kernel/process.c | 48 ++++++++++++++++++++++++++++------------------- 1 files changed, 29 insertions(+), 19 deletions(-) --- linux-2.6.12.2.orig/arch/um/kernel/process.c 2005-06-17 12:48:29.000000000 -0700 +++ linux-2.6.12.2/arch/um/kernel/process.c 2005-07-13 10:56:41.000000000 -0700 @@ -130,7 +130,7 @@ return(arg.pid); } -static int ptrace_child(void) +static int ptrace_child(void *arg) { int ret; int pid = os_getpid(), ppid = getppid(); @@ -159,16 +159,20 @@ _exit(ret); } -static int start_ptraced_child(void) +static int start_ptraced_child(void **stack_out) { + void *stack; + unsigned long sp; int pid, n, status; - pid = fork(); - if(pid == 0) - ptrace_child(); - + stack = mmap(NULL, PAGE_SIZE, PROT_READ | PROT_WRITE | PROT_EXEC, + MAP_PRIVATE | MAP_ANONYMOUS, -1, 0); + if(stack == MAP_FAILED) + panic("check_ptrace : mmap failed, errno = %d", errno); + sp = (unsigned long) stack + PAGE_SIZE - sizeof(void *); + pid = clone(ptrace_child, (void *) sp, SIGCHLD, NULL); if(pid < 0) - panic("check_ptrace : fork failed, errno = %d", errno); + panic("check_ptrace : clone failed, errno = %d", errno); CATCH_EINTR(n = waitpid(pid, &status, WUNTRACED)); if(n < 0) panic("check_ptrace : wait failed, errno = %d", errno); @@ -176,6 +180,7 @@ panic("check_ptrace : expected SIGSTOP, got status = %d", status); + *stack_out = stack; return(pid); } @@ -183,12 +188,12 @@ * just avoid using sysemu, not panic, but only if SYSEMU features are broken. * So only for SYSEMU features we test mustpanic, while normal host features * must work anyway!*/ -static int stop_ptraced_child(int pid, int exitcode, int mustexit) +static int stop_ptraced_child(int pid, void *stack, int exitcode, int mustpanic) { int status, n, ret = 0; if(ptrace(PTRACE_CONT, pid, 0, 0) < 0) - panic("stop_ptraced_child : ptrace failed, errno = %d", errno); + panic("check_ptrace : ptrace failed, errno = %d", errno); CATCH_EINTR(n = waitpid(pid, &status, 0)); if(!WIFEXITED(status) || (WEXITSTATUS(status) != exitcode)) { int exit_with = WEXITSTATUS(status); @@ -199,13 +204,15 @@ printk("check_ptrace : child exited with exitcode %d, while " "expecting %d; status 0x%x", exit_with, exitcode, status); - if (mustexit) + if (mustpanic) panic("\n"); else printk("\n"); ret = -1; } + if(munmap(stack, PAGE_SIZE) < 0) + panic("check_ptrace : munmap failed, errno = %d", errno); return ret; } @@ -227,11 +234,12 @@ static void __init check_sysemu(void) { + void *stack; int pid, syscall, n, status, count=0; printk("Checking syscall emulation patch for ptrace..."); sysemu_supported = 0; - pid = start_ptraced_child(); + pid = start_ptraced_child(&stack); if(ptrace(PTRACE_SYSEMU, pid, 0, 0) < 0) goto fail; @@ -249,7 +257,7 @@ panic("check_sysemu : failed to modify system " "call return, errno = %d", errno); - if (stop_ptraced_child(pid, 0, 0) < 0) + if (stop_ptraced_child(pid, stack, 0, 0) < 0) goto fail_stopped; sysemu_supported = 1; @@ -257,7 +265,7 @@ set_using_sysemu(!force_sysemu_disabled); printk("Checking advanced syscall emulation patch for ptrace..."); - pid = start_ptraced_child(); + pid = start_ptraced_child(&stack); while(1){ count++; if(ptrace(PTRACE_SYSEMU_SINGLESTEP, pid, 0, 0) < 0) @@ -282,7 +290,7 @@ break; } } - if (stop_ptraced_child(pid, 0, 0) < 0) + if (stop_ptraced_child(pid, stack, 0, 0) < 0) goto fail_stopped; sysemu_supported = 2; @@ -293,17 +301,18 @@ return; fail: - stop_ptraced_child(pid, 1, 0); + stop_ptraced_child(pid, stack, 1, 0); fail_stopped: printk("missing\n"); } void __init check_ptrace(void) { + void *stack; int pid, syscall, n, status; printk("Checking that ptrace can change system call numbers..."); - pid = start_ptraced_child(); + pid = start_ptraced_child(&stack); if (ptrace(PTRACE_OLDSETOPTIONS, pid, 0, (void *)PTRACE_O_TRACESYSGOOD) < 0) panic("check_ptrace: PTRACE_SETOPTIONS failed, errno = %d", errno); @@ -330,7 +339,7 @@ break; } } - stop_ptraced_child(pid, 0, 1); + stop_ptraced_child(pid, stack, 0, 1); printk("OK\n"); check_sysemu(); } @@ -362,10 +371,11 @@ static inline int check_skas3_ptrace_support(void) { struct ptrace_faultinfo fi; + void *stack; int pid, n, ret = 1; printf("Checking for the skas3 patch in the host..."); - pid = start_ptraced_child(); + pid = start_ptraced_child(&stack); n = ptrace(PTRACE_FAULTINFO, pid, 0, &fi); if (n < 0) { @@ -380,7 +390,7 @@ } init_registers(pid); - stop_ptraced_child(pid, 1, 1); + stop_ptraced_child(pid, stack, 1, 1); return(ret); }