From 32253f00ac8a8073bf6db4bfe9d6511cc93c4aef Mon Sep 17 00:00:00 2001 From: Vincent Whitchurch <vincent.whitchurch@axis.com> Date: Fri, 1 Sep 2023 15:35:43 +0200 Subject: um: virt-pci: fix platform map offset The offset is currently always zero so the backend can't distinguish between accesses to different ioremapped areas. Fixes: 522c532c4fe7 ("virt-pci: add platform bus support") Signed-off-by: Vincent Whitchurch <vincent.whitchurch@axis.com> Signed-off-by: Richard Weinberger <richard@nod.at> --- arch/um/drivers/virt-pci.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'arch/um') diff --git a/arch/um/drivers/virt-pci.c b/arch/um/drivers/virt-pci.c index ffe2ee8a0246..97a37c062997 100644 --- a/arch/um/drivers/virt-pci.c +++ b/arch/um/drivers/virt-pci.c @@ -971,7 +971,7 @@ static long um_pci_map_platform(unsigned long offset, size_t size, *ops = &um_pci_device_bar_ops; *priv = &um_pci_platform_device->resptr[0]; - return 0; + return offset; } static const struct logic_iomem_region_ops um_pci_platform_ops = { -- cgit v1.2.3-58-ga151 From 541d4e4d435c8b9bfd29f70a1da4a2db97794e0a Mon Sep 17 00:00:00 2001 From: Anton Ivanov <anton.ivanov@cambridgegreys.com> Date: Thu, 21 Sep 2023 15:34:44 +0100 Subject: um: Fix naming clash between UML and scheduler __cant_sleep was already used and exported by the scheduler. The name had to be changed to a UML specific one. Signed-off-by: Anton Ivanov <anton.ivanov@cambridgegreys.com> Reviewed-by: Peter Lafreniere <peter@n8pjl.ca> Signed-off-by: Richard Weinberger <richard@nod.at> --- arch/um/include/shared/kern_util.h | 2 +- arch/um/kernel/process.c | 2 +- arch/um/os-Linux/helper.c | 6 +++--- 3 files changed, 5 insertions(+), 5 deletions(-) (limited to 'arch/um') diff --git a/arch/um/include/shared/kern_util.h b/arch/um/include/shared/kern_util.h index d8b8b4f07e42..444bae755b16 100644 --- a/arch/um/include/shared/kern_util.h +++ b/arch/um/include/shared/kern_util.h @@ -50,7 +50,7 @@ extern void do_uml_exitcalls(void); * Are we disallowed to sleep? Used to choose between GFP_KERNEL and * GFP_ATOMIC. */ -extern int __cant_sleep(void); +extern int __uml_cant_sleep(void); extern int get_current_pid(void); extern int copy_from_user_proc(void *to, void *from, int size); extern char *uml_strdup(const char *string); diff --git a/arch/um/kernel/process.c b/arch/um/kernel/process.c index 106b7da2f8d6..6daffb9d8a8d 100644 --- a/arch/um/kernel/process.c +++ b/arch/um/kernel/process.c @@ -220,7 +220,7 @@ void arch_cpu_idle(void) um_idle_sleep(); } -int __cant_sleep(void) { +int __uml_cant_sleep(void) { return in_atomic() || irqs_disabled() || in_interrupt(); /* Is in_interrupt() really needed? */ } diff --git a/arch/um/os-Linux/helper.c b/arch/um/os-Linux/helper.c index b459745f52e2..3cb8ac63be6e 100644 --- a/arch/um/os-Linux/helper.c +++ b/arch/um/os-Linux/helper.c @@ -46,7 +46,7 @@ int run_helper(void (*pre_exec)(void *), void *pre_data, char **argv) unsigned long stack, sp; int pid, fds[2], ret, n; - stack = alloc_stack(0, __cant_sleep()); + stack = alloc_stack(0, __uml_cant_sleep()); if (stack == 0) return -ENOMEM; @@ -70,7 +70,7 @@ int run_helper(void (*pre_exec)(void *), void *pre_data, char **argv) data.pre_data = pre_data; data.argv = argv; data.fd = fds[1]; - data.buf = __cant_sleep() ? uml_kmalloc(PATH_MAX, UM_GFP_ATOMIC) : + data.buf = __uml_cant_sleep() ? uml_kmalloc(PATH_MAX, UM_GFP_ATOMIC) : uml_kmalloc(PATH_MAX, UM_GFP_KERNEL); pid = clone(helper_child, (void *) sp, CLONE_VM, &data); if (pid < 0) { @@ -121,7 +121,7 @@ int run_helper_thread(int (*proc)(void *), void *arg, unsigned int flags, unsigned long stack, sp; int pid, status, err; - stack = alloc_stack(0, __cant_sleep()); + stack = alloc_stack(0, __uml_cant_sleep()); if (stack == 0) return -ENOMEM; -- cgit v1.2.3-58-ga151 From 085bc003baab8223b87649ee56aa0db05c33b5b8 Mon Sep 17 00:00:00 2001 From: Johannes Berg <johannes.berg@intel.com> Date: Mon, 25 Sep 2023 21:29:48 +0200 Subject: um: mmu: remove stub_pages I removed all the users of this some time ago, but evidently forgot the pointers. Remove them from the data structure too. Fixes: bfc58e2b98e9 ("um: remove process stub VMA") Signed-off-by: Johannes Berg <johannes.berg@intel.com> Signed-off-by: Richard Weinberger <richard@nod.at> --- arch/um/include/asm/mmu.h | 1 - 1 file changed, 1 deletion(-) (limited to 'arch/um') diff --git a/arch/um/include/asm/mmu.h b/arch/um/include/asm/mmu.h index 5b072aba5b65..a7555e43ed14 100644 --- a/arch/um/include/asm/mmu.h +++ b/arch/um/include/asm/mmu.h @@ -12,7 +12,6 @@ typedef struct mm_context { struct mm_id id; struct uml_arch_mm_context arch; - struct page *stub_pages[2]; } mm_context_t; extern void __switch_mm(struct mm_id * mm_idp); -- cgit v1.2.3-58-ga151 From a8e75902f4d7d342350ea3f79e3e65f2bbfa4c8d Mon Sep 17 00:00:00 2001 From: Anton Ivanov <anton.ivanov@cambridgegreys.com> Date: Tue, 17 Oct 2023 09:32:01 +0100 Subject: um: document arch_futex_atomic_op_inuser arch_futex_atomic_op_inuser was not documented correctly resulting in build time warnings. Signed-off-by: Anton Ivanov <anton.ivanov@cambridgegreys.com> Signed-off-by: Richard Weinberger <richard@nod.at> --- arch/um/kernel/skas/uaccess.c | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-) (limited to 'arch/um') diff --git a/arch/um/kernel/skas/uaccess.c b/arch/um/kernel/skas/uaccess.c index aaee96f07172..198269e384c4 100644 --- a/arch/um/kernel/skas/uaccess.c +++ b/arch/um/kernel/skas/uaccess.c @@ -236,7 +236,9 @@ EXPORT_SYMBOL(strnlen_user); * argument and comparison of the previous * futex value with another constant. * - * @encoded_op: encoded operation to execute + * @op: operation to execute + * @oparg: argument to operation + * @oval: old value at uaddr * @uaddr: pointer to user space address * * Return: -- cgit v1.2.3-58-ga151 From a55719847da0a780baa84d0baee745358f144c39 Mon Sep 17 00:00:00 2001 From: Benjamin Berg <benjamin@sipsolutions.net> Date: Fri, 10 Nov 2023 12:03:38 +0100 Subject: um: Drop support for hosts without SYSEMU_SINGLESTEP support These features have existed since Linux 2.6.14 and can be considered widely available at this point. Also drop the backward compatibility code for PTRACE_SETOPTIONS. Signed-off-by: Benjamin Berg <benjamin@sipsolutions.net> ---- v2: * Continue to define PTRACE_SYSEMU_SINGLESTEP as glibc only added it in version 2.27. Signed-off-by: Richard Weinberger <richard@nod.at> --- arch/um/include/asm/processor-generic.h | 1 - arch/um/include/shared/kern_util.h | 3 +- arch/um/include/shared/ptrace_user.h | 41 ------------------- arch/um/kernel/process.c | 12 +----- arch/um/kernel/ptrace.c | 2 - arch/um/kernel/signal.c | 12 ------ arch/um/os-Linux/skas/process.c | 60 +++++----------------------- arch/um/os-Linux/start_up.c | 70 +++------------------------------ arch/x86/um/ptrace_32.c | 24 ----------- arch/x86/um/ptrace_64.c | 26 ------------ arch/x86/um/shared/sysdep/ptrace_32.h | 4 -- arch/x86/um/shared/sysdep/ptrace_user.h | 12 +++--- 12 files changed, 24 insertions(+), 243 deletions(-) (limited to 'arch/um') diff --git a/arch/um/include/asm/processor-generic.h b/arch/um/include/asm/processor-generic.h index 7414154b8e9a..6c3779541845 100644 --- a/arch/um/include/asm/processor-generic.h +++ b/arch/um/include/asm/processor-generic.h @@ -22,7 +22,6 @@ struct mm_struct; struct thread_struct { struct pt_regs regs; struct pt_regs *segv_regs; - int singlestep_syscall; void *fault_addr; jmp_buf *fault_catcher; struct task_struct *prev_sched; diff --git a/arch/um/include/shared/kern_util.h b/arch/um/include/shared/kern_util.h index 444bae755b16..789b83013f35 100644 --- a/arch/um/include/shared/kern_util.h +++ b/arch/um/include/shared/kern_util.h @@ -34,7 +34,6 @@ extern int handle_page_fault(unsigned long address, unsigned long ip, extern unsigned int do_IRQ(int irq, struct uml_pt_regs *regs); extern void initial_thread_cb(void (*proc)(void *), void *arg); -extern int is_syscall(unsigned long addr); extern void timer_handler(int sig, struct siginfo *unused_si, struct uml_pt_regs *regs); @@ -58,7 +57,7 @@ extern char *uml_strdup(const char *string); extern unsigned long to_irq_stack(unsigned long *mask_out); extern unsigned long from_irq_stack(int nested); -extern int singlestepping(void *t); +extern int singlestepping(void); extern void segv_handler(int sig, struct siginfo *unused_si, struct uml_pt_regs *regs); extern void bus_handler(int sig, struct siginfo *si, struct uml_pt_regs *regs); diff --git a/arch/um/include/shared/ptrace_user.h b/arch/um/include/shared/ptrace_user.h index 95455e8996e7..8a705d8f96ce 100644 --- a/arch/um/include/shared/ptrace_user.h +++ b/arch/um/include/shared/ptrace_user.h @@ -12,45 +12,4 @@ extern int ptrace_getregs(long pid, unsigned long *regs_out); extern int ptrace_setregs(long pid, unsigned long *regs_in); -/* syscall emulation path in ptrace */ - -#ifndef PTRACE_SYSEMU -#define PTRACE_SYSEMU 31 -#endif -#ifndef PTRACE_SYSEMU_SINGLESTEP -#define PTRACE_SYSEMU_SINGLESTEP 32 -#endif - -/* On architectures, that started to support PTRACE_O_TRACESYSGOOD - * in linux 2.4, there are two different definitions of - * PTRACE_SETOPTIONS: linux 2.4 uses 21 while linux 2.6 uses 0x4200. - * For binary compatibility, 2.6 also supports the old "21", named - * PTRACE_OLDSETOPTION. On these architectures, UML always must use - * "21", to ensure the kernel runs on 2.4 and 2.6 host without - * recompilation. So, we use PTRACE_OLDSETOPTIONS in UML. - * We also want to be able to build the kernel on 2.4, which doesn't - * have PTRACE_OLDSETOPTIONS. So, if it is missing, we declare - * PTRACE_OLDSETOPTIONS to be the same as PTRACE_SETOPTIONS. - * - * On architectures, that start to support PTRACE_O_TRACESYSGOOD on - * linux 2.6, PTRACE_OLDSETOPTIONS never is defined, and also isn't - * supported by the host kernel. In that case, our trick lets us use - * the new 0x4200 with the name PTRACE_OLDSETOPTIONS. - */ -#ifndef PTRACE_OLDSETOPTIONS -#define PTRACE_OLDSETOPTIONS PTRACE_SETOPTIONS -#endif - -void set_using_sysemu(int value); -int get_using_sysemu(void); -extern int sysemu_supported; - -#define SELECT_PTRACE_OPERATION(sysemu_mode, singlestep_mode) \ - (((int[3][3] ) { \ - { PTRACE_SYSCALL, PTRACE_SYSCALL, PTRACE_SINGLESTEP }, \ - { PTRACE_SYSEMU, PTRACE_SYSEMU, PTRACE_SINGLESTEP }, \ - { PTRACE_SYSEMU, PTRACE_SYSEMU_SINGLESTEP, \ - PTRACE_SYSEMU_SINGLESTEP } }) \ - [sysemu_mode][singlestep_mode]) - #endif diff --git a/arch/um/kernel/process.c b/arch/um/kernel/process.c index 6daffb9d8a8d..ab95648e93e1 100644 --- a/arch/um/kernel/process.c +++ b/arch/um/kernel/process.c @@ -332,17 +332,9 @@ int __init make_proc_sysemu(void) late_initcall(make_proc_sysemu); -int singlestepping(void * t) +int singlestepping(void) { - struct task_struct *task = t ? t : current; - - if (!test_thread_flag(TIF_SINGLESTEP)) - return 0; - - if (task->thread.singlestep_syscall) - return 1; - - return 2; + return test_thread_flag(TIF_SINGLESTEP); } /* diff --git a/arch/um/kernel/ptrace.c b/arch/um/kernel/ptrace.c index 5154b27de580..6600a2782796 100644 --- a/arch/um/kernel/ptrace.c +++ b/arch/um/kernel/ptrace.c @@ -12,7 +12,6 @@ void user_enable_single_step(struct task_struct *child) { set_tsk_thread_flag(child, TIF_SINGLESTEP); - child->thread.singlestep_syscall = 0; #ifdef SUBARCH_SET_SINGLESTEPPING SUBARCH_SET_SINGLESTEPPING(child, 1); @@ -22,7 +21,6 @@ void user_enable_single_step(struct task_struct *child) void user_disable_single_step(struct task_struct *child) { clear_tsk_thread_flag(child, TIF_SINGLESTEP); - child->thread.singlestep_syscall = 0; #ifdef SUBARCH_SET_SINGLESTEPPING SUBARCH_SET_SINGLESTEPPING(child, 0); diff --git a/arch/um/kernel/signal.c b/arch/um/kernel/signal.c index ae4658f576ab..a56b44522766 100644 --- a/arch/um/kernel/signal.c +++ b/arch/um/kernel/signal.c @@ -120,18 +120,6 @@ void do_signal(struct pt_regs *regs) } } - /* - * This closes a way to execute a system call on the host. If - * you set a breakpoint on a system call instruction and singlestep - * from it, the tracing thread used to PTRACE_SINGLESTEP the process - * rather than PTRACE_SYSCALL it, allowing the system call to execute - * on the host. The tracing thread will check this flag and - * PTRACE_SYSCALL if necessary. - */ - if (test_thread_flag(TIF_SINGLESTEP)) - current->thread.singlestep_syscall = - is_syscall(PT_REGS_IP(¤t->thread.regs)); - /* * if there's no signal to deliver, we just put the saved sigmask * back diff --git a/arch/um/os-Linux/skas/process.c b/arch/um/os-Linux/skas/process.c index 9464833e741a..43168c51850c 100644 --- a/arch/um/os-Linux/skas/process.c +++ b/arch/um/os-Linux/skas/process.c @@ -177,48 +177,11 @@ static void handle_segv(int pid, struct uml_pt_regs *regs, unsigned long *aux_fp segv(regs->faultinfo, 0, 1, NULL); } -/* - * To use the same value of using_sysemu as the caller, ask it that value - * (in local_using_sysemu - */ -static void handle_trap(int pid, struct uml_pt_regs *regs, - int local_using_sysemu) +static void handle_trap(int pid, struct uml_pt_regs *regs) { - int err, status; - if ((UPT_IP(regs) >= STUB_START) && (UPT_IP(regs) < STUB_END)) fatal_sigsegv(); - if (!local_using_sysemu) - { - err = ptrace(PTRACE_POKEUSER, pid, PT_SYSCALL_NR_OFFSET, - __NR_getpid); - if (err < 0) { - printk(UM_KERN_ERR "%s - nullifying syscall failed, errno = %d\n", - __func__, errno); - fatal_sigsegv(); - } - - err = ptrace(PTRACE_SYSCALL, pid, 0, 0); - if (err < 0) { - printk(UM_KERN_ERR "%s - continuing to end of syscall failed, errno = %d\n", - __func__, errno); - fatal_sigsegv(); - } - - CATCH_EINTR(err = waitpid(pid, &status, WUNTRACED | __WALL)); - if ((err < 0) || !WIFSTOPPED(status) || - (WSTOPSIG(status) != SIGTRAP + 0x80)) { - err = ptrace_dump_regs(pid); - if (err) - printk(UM_KERN_ERR "Failed to get registers from process, errno = %d\n", - -err); - printk(UM_KERN_ERR "%s - failed to wait at end of syscall, errno = %d, status = %d\n", - __func__, errno, status); - fatal_sigsegv(); - } - } - handle_syscall(regs); } @@ -355,10 +318,10 @@ int start_userspace(unsigned long stub_stack) goto out_kill; } - if (ptrace(PTRACE_OLDSETOPTIONS, pid, NULL, + if (ptrace(PTRACE_SETOPTIONS, pid, NULL, (void *) PTRACE_O_TRACESYSGOOD) < 0) { err = -errno; - printk(UM_KERN_ERR "%s : PTRACE_OLDSETOPTIONS failed, errno = %d\n", + printk(UM_KERN_ERR "%s : PTRACE_SETOPTIONS failed, errno = %d\n", __func__, errno); goto out_kill; } @@ -380,8 +343,6 @@ int start_userspace(unsigned long stub_stack) void userspace(struct uml_pt_regs *regs, unsigned long *aux_fp_regs) { int err, status, op, pid = userspace_pid[0]; - /* To prevent races if using_sysemu changes under us.*/ - int local_using_sysemu; siginfo_t si; /* Handle any immediate reschedules or signals */ @@ -411,11 +372,10 @@ void userspace(struct uml_pt_regs *regs, unsigned long *aux_fp_regs) fatal_sigsegv(); } - /* Now we set local_using_sysemu to be used for one loop */ - local_using_sysemu = get_using_sysemu(); - - op = SELECT_PTRACE_OPERATION(local_using_sysemu, - singlestepping(NULL)); + if (singlestepping()) + op = PTRACE_SYSEMU_SINGLESTEP; + else + op = PTRACE_SYSEMU; if (ptrace(op, pid, 0, 0)) { printk(UM_KERN_ERR "%s - ptrace continue failed, op = %d, errno = %d\n", @@ -474,7 +434,7 @@ void userspace(struct uml_pt_regs *regs, unsigned long *aux_fp_regs) else handle_segv(pid, regs, aux_fp_regs); break; case SIGTRAP + 0x80: - handle_trap(pid, regs, local_using_sysemu); + handle_trap(pid, regs); break; case SIGTRAP: relay_signal(SIGTRAP, (struct siginfo *)&si, regs); @@ -597,10 +557,10 @@ int copy_context_skas0(unsigned long new_stack, int pid) goto out_kill; } - if (ptrace(PTRACE_OLDSETOPTIONS, pid, NULL, + if (ptrace(PTRACE_SETOPTIONS, pid, NULL, (void *)PTRACE_O_TRACESYSGOOD) < 0) { err = -errno; - printk(UM_KERN_ERR "%s : PTRACE_OLDSETOPTIONS failed, errno = %d\n", + printk(UM_KERN_ERR "%s : PTRACE_SETOPTIONS failed, errno = %d\n", __func__, errno); goto out_kill; } diff --git a/arch/um/os-Linux/start_up.c b/arch/um/os-Linux/start_up.c index e3ee4db58b40..561c08e0cc9c 100644 --- a/arch/um/os-Linux/start_up.c +++ b/arch/um/os-Linux/start_up.c @@ -143,71 +143,16 @@ static int stop_ptraced_child(int pid, int exitcode, int mustexit) return ret; } -/* Changed only during early boot */ -static int force_sysemu_disabled = 0; - -static int __init nosysemu_cmd_param(char *str, int* add) -{ - force_sysemu_disabled = 1; - return 0; -} - -__uml_setup("nosysemu", nosysemu_cmd_param, -"nosysemu\n" -" Turns off syscall emulation patch for ptrace (SYSEMU).\n" -" SYSEMU is a performance-patch introduced by Laurent Vivier. It changes\n" -" behaviour of ptrace() and helps reduce host context switch rates.\n" -" To make it work, you need a kernel patch for your host, too.\n" -" See http://perso.wanadoo.fr/laurent.vivier/UML/ for further \n" -" information.\n\n"); - static void __init check_sysemu(void) { - unsigned long regs[MAX_REG_NR]; int pid, n, status, count=0; - os_info("Checking syscall emulation patch for ptrace..."); - sysemu_supported = 0; - pid = start_ptraced_child(); - - if (ptrace(PTRACE_SYSEMU, pid, 0, 0) < 0) - goto fail; - - CATCH_EINTR(n = waitpid(pid, &status, WUNTRACED)); - if (n < 0) - fatal_perror("check_sysemu : wait failed"); - if (!WIFSTOPPED(status) || (WSTOPSIG(status) != SIGTRAP)) - fatal("check_sysemu : expected SIGTRAP, got status = %d\n", - status); - - if (ptrace(PTRACE_GETREGS, pid, 0, regs) < 0) - fatal_perror("check_sysemu : PTRACE_GETREGS failed"); - if (PT_SYSCALL_NR(regs) != __NR_getpid) { - non_fatal("check_sysemu got system call number %d, " - "expected %d...", PT_SYSCALL_NR(regs), __NR_getpid); - goto fail; - } - - n = ptrace(PTRACE_POKEUSER, pid, PT_SYSCALL_RET_OFFSET, os_getpid()); - if (n < 0) { - non_fatal("check_sysemu : failed to modify system call " - "return"); - goto fail; - } - - if (stop_ptraced_child(pid, 0, 0) < 0) - goto fail_stopped; - - sysemu_supported = 1; - os_info("OK\n"); - set_using_sysemu(!force_sysemu_disabled); - - os_info("Checking advanced syscall emulation patch for ptrace..."); + os_info("Checking syscall emulation for ptrace..."); pid = start_ptraced_child(); - if ((ptrace(PTRACE_OLDSETOPTIONS, pid, 0, + if ((ptrace(PTRACE_SETOPTIONS, pid, 0, (void *) PTRACE_O_TRACESYSGOOD) < 0)) - fatal_perror("check_sysemu: PTRACE_OLDSETOPTIONS failed"); + fatal_perror("check_sysemu: PTRACE_SETOPTIONS failed"); while (1) { count++; @@ -243,17 +188,14 @@ static void __init check_sysemu(void) if (stop_ptraced_child(pid, 0, 0) < 0) goto fail_stopped; - sysemu_supported = 2; os_info("OK\n"); - if (!force_sysemu_disabled) - set_using_sysemu(sysemu_supported); return; fail: stop_ptraced_child(pid, 1, 0); fail_stopped: - non_fatal("missing\n"); + fatal("missing\n"); } static void __init check_ptrace(void) @@ -263,9 +205,9 @@ static void __init check_ptrace(void) os_info("Checking that ptrace can change system call numbers..."); pid = start_ptraced_child(); - if ((ptrace(PTRACE_OLDSETOPTIONS, pid, 0, + if ((ptrace(PTRACE_SETOPTIONS, pid, 0, (void *) PTRACE_O_TRACESYSGOOD) < 0)) - fatal_perror("check_ptrace: PTRACE_OLDSETOPTIONS failed"); + fatal_perror("check_ptrace: PTRACE_SETOPTIONS failed"); while (1) { if (ptrace(PTRACE_SYSCALL, pid, 0, 0) < 0) diff --git a/arch/x86/um/ptrace_32.c b/arch/x86/um/ptrace_32.c index 0bc4b73a9cde..7f1abde2c84b 100644 --- a/arch/x86/um/ptrace_32.c +++ b/arch/x86/um/ptrace_32.c @@ -25,30 +25,6 @@ void arch_switch_to(struct task_struct *to) printk(KERN_WARNING "arch_switch_tls failed, errno = EINVAL\n"); } -int is_syscall(unsigned long addr) -{ - unsigned short instr; - int n; - - n = copy_from_user(&instr, (void __user *) addr, sizeof(instr)); - if (n) { - /* access_process_vm() grants access to vsyscall and stub, - * while copy_from_user doesn't. Maybe access_process_vm is - * slow, but that doesn't matter, since it will be called only - * in case of singlestepping, if copy_from_user failed. - */ - n = access_process_vm(current, addr, &instr, sizeof(instr), - FOLL_FORCE); - if (n != sizeof(instr)) { - printk(KERN_ERR "is_syscall : failed to read " - "instruction from 0x%lx\n", addr); - return 1; - } - } - /* int 0x80 or sysenter */ - return (instr == 0x80cd) || (instr == 0x340f); -} - /* determines which flags the user has access to. */ /* 1 = access 0 = no access */ #define FLAG_MASK 0x00044dd5 diff --git a/arch/x86/um/ptrace_64.c b/arch/x86/um/ptrace_64.c index 289d0159b041..aa68d83d3f44 100644 --- a/arch/x86/um/ptrace_64.c +++ b/arch/x86/um/ptrace_64.c @@ -188,32 +188,6 @@ int peek_user(struct task_struct *child, long addr, long data) return put_user(tmp, (unsigned long *) data); } -/* XXX Mostly copied from sys-i386 */ -int is_syscall(unsigned long addr) -{ - unsigned short instr; - int n; - - n = copy_from_user(&instr, (void __user *) addr, sizeof(instr)); - if (n) { - /* - * access_process_vm() grants access to vsyscall and stub, - * while copy_from_user doesn't. Maybe access_process_vm is - * slow, but that doesn't matter, since it will be called only - * in case of singlestepping, if copy_from_user failed. - */ - n = access_process_vm(current, addr, &instr, sizeof(instr), - FOLL_FORCE); - if (n != sizeof(instr)) { - printk("is_syscall : failed to read instruction from " - "0x%lx\n", addr); - return 1; - } - } - /* sysenter */ - return instr == 0x050f; -} - static int get_fpregs(struct user_i387_struct __user *buf, struct task_struct *child) { int err, n, cpu = ((struct thread_info *) child->stack)->cpu; diff --git a/arch/x86/um/shared/sysdep/ptrace_32.h b/arch/x86/um/shared/sysdep/ptrace_32.h index db8478a83a09..0c4989842fbe 100644 --- a/arch/x86/um/shared/sysdep/ptrace_32.h +++ b/arch/x86/um/shared/sysdep/ptrace_32.h @@ -8,10 +8,6 @@ #define MAX_FP_NR HOST_FPX_SIZE -void set_using_sysemu(int value); -int get_using_sysemu(void); -extern int sysemu_supported; - #define UPT_SYSCALL_ARG1(r) UPT_BX(r) #define UPT_SYSCALL_ARG2(r) UPT_CX(r) #define UPT_SYSCALL_ARG3(r) UPT_DX(r) diff --git a/arch/x86/um/shared/sysdep/ptrace_user.h b/arch/x86/um/shared/sysdep/ptrace_user.h index 44782bbad41e..1d1a824fa652 100644 --- a/arch/x86/um/shared/sysdep/ptrace_user.h +++ b/arch/x86/um/shared/sysdep/ptrace_user.h @@ -15,14 +15,12 @@ #define FP_SIZE ((HOST_FPX_SIZE > HOST_FP_SIZE) ? HOST_FPX_SIZE : HOST_FP_SIZE) #else #define FP_SIZE HOST_FP_SIZE +#endif /* - * x86_64 FC3 doesn't define this in /usr/include/linux/ptrace.h even though - * it's defined in the kernel's include/linux/ptrace.h. Additionally, use the - * 2.4 name and value for 2.4 host compatibility. + * glibc before 2.27 does not include PTRACE_SYSEMU_SINGLESTEP in its enum, + * ensure we have a definition by (re-)defining it here. */ -#ifndef PTRACE_OLDSETOPTIONS -#define PTRACE_OLDSETOPTIONS 21 -#endif - +#ifndef PTRACE_SYSEMU_SINGLESTEP +#define PTRACE_SYSEMU_SINGLESTEP 32 #endif -- cgit v1.2.3-58-ga151 From 571353379470f1d0aaad3cce4ad4db4b6c8f9ada Mon Sep 17 00:00:00 2001 From: Benjamin Berg <benjamin@sipsolutions.net> Date: Fri, 10 Nov 2023 12:03:39 +0100 Subject: um: Drop NULL check from start_userspace start_userspace is only called from exactly one location, and the passed pointer for the userspace process stack cannot be NULL. Remove the check, without changing the control flow. Signed-off-by: Benjamin Berg <benjamin@sipsolutions.net> Signed-off-by: Richard Weinberger <richard@nod.at> --- arch/um/os-Linux/skas/process.c | 53 +++++++++++++++++++---------------------- 1 file changed, 24 insertions(+), 29 deletions(-) (limited to 'arch/um') diff --git a/arch/um/os-Linux/skas/process.c b/arch/um/os-Linux/skas/process.c index 43168c51850c..ed20cefb2963 100644 --- a/arch/um/os-Linux/skas/process.c +++ b/arch/um/os-Linux/skas/process.c @@ -189,7 +189,7 @@ extern char __syscall_stub_start[]; /** * userspace_tramp() - userspace trampoline - * @stack: pointer to the new userspace stack page, can be NULL, if? FIXME: + * @stack: pointer to the new userspace stack page * * The userspace trampoline is used to setup a new userspace process in start_userspace() after it was clone()'ed. * This function will run on a temporary stack page. @@ -204,9 +204,13 @@ extern char __syscall_stub_start[]; */ static int userspace_tramp(void *stack) { + struct sigaction sa; void *addr; int fd; unsigned long long offset; + unsigned long segv_handler = STUB_CODE + + (unsigned long) stub_segv_handler - + (unsigned long) __syscall_stub_start; ptrace(PTRACE_TRACEME, 0, 0, 0); @@ -222,34 +226,25 @@ static int userspace_tramp(void *stack) exit(1); } - if (stack != NULL) { - fd = phys_mapping(uml_to_phys(stack), &offset); - addr = mmap((void *) STUB_DATA, - STUB_DATA_PAGES * UM_KERN_PAGE_SIZE, PROT_READ | PROT_WRITE, - MAP_FIXED | MAP_SHARED, fd, offset); - if (addr == MAP_FAILED) { - printk(UM_KERN_ERR "mapping segfault stack at 0x%lx failed, errno = %d\n", - STUB_DATA, errno); - exit(1); - } + fd = phys_mapping(uml_to_phys(stack), &offset); + addr = mmap((void *) STUB_DATA, + STUB_DATA_PAGES * UM_KERN_PAGE_SIZE, PROT_READ | PROT_WRITE, + MAP_FIXED | MAP_SHARED, fd, offset); + if (addr == MAP_FAILED) { + printk(UM_KERN_ERR "mapping segfault stack at 0x%lx failed, errno = %d\n", + STUB_DATA, errno); + exit(1); } - if (stack != NULL) { - struct sigaction sa; - - unsigned long v = STUB_CODE + - (unsigned long) stub_segv_handler - - (unsigned long) __syscall_stub_start; - - set_sigstack((void *) STUB_DATA, STUB_DATA_PAGES * UM_KERN_PAGE_SIZE); - sigemptyset(&sa.sa_mask); - sa.sa_flags = SA_ONSTACK | SA_NODEFER | SA_SIGINFO; - sa.sa_sigaction = (void *) v; - sa.sa_restorer = NULL; - if (sigaction(SIGSEGV, &sa, NULL) < 0) { - printk(UM_KERN_ERR "%s - setting SIGSEGV handler failed - errno = %d\n", - __func__, errno); - exit(1); - } + + set_sigstack((void *) STUB_DATA, STUB_DATA_PAGES * UM_KERN_PAGE_SIZE); + sigemptyset(&sa.sa_mask); + sa.sa_flags = SA_ONSTACK | SA_NODEFER | SA_SIGINFO; + sa.sa_sigaction = (void *) segv_handler; + sa.sa_restorer = NULL; + if (sigaction(SIGSEGV, &sa, NULL) < 0) { + printk(UM_KERN_ERR "%s - setting SIGSEGV handler failed - errno = %d\n", + __func__, errno); + exit(1); } kill(os_getpid(), SIGSTOP); @@ -261,7 +256,7 @@ int kill_userspace_mm[NR_CPUS]; /** * start_userspace() - prepare a new userspace process - * @stub_stack: pointer to the stub stack. Can be NULL, if? FIXME: + * @stub_stack: pointer to the stub stack. * * Setups a new temporary stack page that is used while userspace_tramp() runs * Clones the kernel process into a new userspace process, with FDs only. -- cgit v1.2.3-58-ga151 From 9e16fb933fd1f2132c0d137f3666ebf20f93e33a Mon Sep 17 00:00:00 2001 From: Benjamin Berg <benjamin@sipsolutions.net> Date: Fri, 10 Nov 2023 12:03:40 +0100 Subject: um: Make errors to stop ptraced child fatal during startup For the detection code to check whether SYSEMU_SINGLESTEP works correctly we needed some error cases while stopping to be non-fatal. However, at this point stop_ptraced_child must always succeed, and we can therefore simplify it slightly to exit immediately on error. Signed-off-by: Benjamin Berg <benjamin@sipsolutions.net> Signed-off-by: Richard Weinberger <richard@nod.at> --- arch/um/os-Linux/start_up.c | 41 ++++++++++++----------------------------- 1 file changed, 12 insertions(+), 29 deletions(-) (limited to 'arch/um') diff --git a/arch/um/os-Linux/start_up.c b/arch/um/os-Linux/start_up.c index 561c08e0cc9c..8b0e98ab842c 100644 --- a/arch/um/os-Linux/start_up.c +++ b/arch/um/os-Linux/start_up.c @@ -112,35 +112,20 @@ static int start_ptraced_child(void) return pid; } -/* When testing for SYSEMU support, if it is one of the broken versions, we - * must 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 void stop_ptraced_child(int pid, int exitcode) { - int status, n, ret = 0; + int status, n; + + if (ptrace(PTRACE_CONT, pid, 0, 0) < 0) + fatal_perror("stop_ptraced_child : ptrace failed"); - if (ptrace(PTRACE_CONT, pid, 0, 0) < 0) { - perror("stop_ptraced_child : ptrace failed"); - return -1; - } CATCH_EINTR(n = waitpid(pid, &status, 0)); if (!WIFEXITED(status) || (WEXITSTATUS(status) != exitcode)) { int exit_with = WEXITSTATUS(status); - if (exit_with == 2) - non_fatal("check_ptrace : child exited with status 2. " - "\nDisabling SYSEMU support.\n"); - non_fatal("check_ptrace : child exited with exitcode %d, while " - "expecting %d; status 0x%x\n", exit_with, - exitcode, status); - if (mustexit) - exit(1); - ret = -1; + fatal("stop_ptraced_child : child exited with exitcode %d, " + "while expecting %d; status 0x%x\n", exit_with, + exitcode, status); } - - return ret; } static void __init check_sysemu(void) @@ -185,16 +170,14 @@ static void __init check_sysemu(void) goto fail; } } - if (stop_ptraced_child(pid, 0, 0) < 0) - goto fail_stopped; + stop_ptraced_child(pid, 0); os_info("OK\n"); return; fail: - stop_ptraced_child(pid, 1, 0); -fail_stopped: + stop_ptraced_child(pid, 1); fatal("missing\n"); } @@ -233,7 +216,7 @@ static void __init check_ptrace(void) break; } } - stop_ptraced_child(pid, 0, 1); + stop_ptraced_child(pid, 0); os_info("OK\n"); check_sysemu(); } @@ -312,7 +295,7 @@ void __init os_early_checks(void) pid = start_ptraced_child(); if (init_pid_registers(pid)) fatal("Failed to initialize default registers"); - stop_ptraced_child(pid, 1, 1); + stop_ptraced_child(pid, 1); } int __init parse_iomem(char *str, int *add) -- cgit v1.2.3-58-ga151 From 236f9fe39b02c15fa5530b53e9cca48354394389 Mon Sep 17 00:00:00 2001 From: Benjamin Berg <benjamin@sipsolutions.net> Date: Fri, 10 Nov 2023 12:03:41 +0100 Subject: um: Don't use vfprintf() for os_info() The threads allocated inside the kernel have only a single page of stack. Unfortunately, the vfprintf function in standard glibc may use too much stack-space, overflowing it. To make os_info safe to be used by helper threads, use the kernel vscnprintf function into a smallish buffer and write out the information to stderr. Signed-off-by: Benjamin Berg <benjamin@sipsolutions.net> Signed-off-by: Richard Weinberger <richard@nod.at> --- arch/um/os-Linux/util.c | 19 +++++++++++++++++-- 1 file changed, 17 insertions(+), 2 deletions(-) (limited to 'arch/um') diff --git a/arch/um/os-Linux/util.c b/arch/um/os-Linux/util.c index fc0f2a9dee5a..1dca4ffbd572 100644 --- a/arch/um/os-Linux/util.c +++ b/arch/um/os-Linux/util.c @@ -173,23 +173,38 @@ __uml_setup("quiet", quiet_cmd_param, "quiet\n" " Turns off information messages during boot.\n\n"); +/* + * The os_info/os_warn functions will be called by helper threads. These + * have a very limited stack size and using the libc formatting functions + * may overflow the stack. + * So pull in the kernel vscnprintf and use that instead with a fixed + * on-stack buffer. + */ +int vscnprintf(char *buf, size_t size, const char *fmt, va_list args); + void os_info(const char *fmt, ...) { + char buf[256]; va_list list; + int len; if (quiet_info) return; va_start(list, fmt); - vfprintf(stderr, fmt, list); + len = vscnprintf(buf, sizeof(buf), fmt, list); + fwrite(buf, len, 1, stderr); va_end(list); } void os_warn(const char *fmt, ...) { + char buf[256]; va_list list; + int len; va_start(list, fmt); - vfprintf(stderr, fmt, list); + len = vscnprintf(buf, sizeof(buf), fmt, list); + fwrite(buf, len, 1, stderr); va_end(list); } -- cgit v1.2.3-58-ga151 From 1818b8406678a78b823dad44c91580f859403ced Mon Sep 17 00:00:00 2001 From: Benjamin Berg <benjamin@sipsolutions.net> Date: Fri, 10 Nov 2023 12:03:42 +0100 Subject: um: Do not use printk in SIGWINCH helper thread The thread is running outside of the UML kernel scope and is a helper. As such, printk cannot work and os_info must be used instead. Signed-off-by: Benjamin Berg <benjamin@sipsolutions.net> Signed-off-by: Richard Weinberger <richard@nod.at> --- arch/um/drivers/chan_user.c | 26 +++++++++++++------------- 1 file changed, 13 insertions(+), 13 deletions(-) (limited to 'arch/um') diff --git a/arch/um/drivers/chan_user.c b/arch/um/drivers/chan_user.c index 25727ed648b7..c2b83cb99aae 100644 --- a/arch/um/drivers/chan_user.c +++ b/arch/um/drivers/chan_user.c @@ -153,8 +153,8 @@ static int winch_thread(void *arg) pipe_fd = data->pipe_fd; count = write(pipe_fd, &c, sizeof(c)); if (count != sizeof(c)) - printk(UM_KERN_ERR "winch_thread : failed to write " - "synchronization byte, err = %d\n", -count); + os_info("winch_thread : failed to write synchronization byte, err = %d\n", + -count); /* * We are not using SIG_IGN on purpose, so don't fix it as I thought to @@ -166,28 +166,28 @@ static int winch_thread(void *arg) sigfillset(&sigs); /* Block all signals possible. */ if (sigprocmask(SIG_SETMASK, &sigs, NULL) < 0) { - printk(UM_KERN_ERR "winch_thread : sigprocmask failed, " - "errno = %d\n", errno); + os_info("winch_thread : sigprocmask failed, errno = %d\n", + errno); exit(1); } /* In sigsuspend(), block anything else than SIGWINCH. */ sigdelset(&sigs, SIGWINCH); if (setsid() < 0) { - printk(UM_KERN_ERR "winch_thread : setsid failed, errno = %d\n", + os_info("winch_thread : setsid failed, errno = %d\n", errno); exit(1); } if (ioctl(pty_fd, TIOCSCTTY, 0) < 0) { - printk(UM_KERN_ERR "winch_thread : TIOCSCTTY failed on " - "fd %d err = %d\n", pty_fd, errno); + os_info("winch_thread : TIOCSCTTY failed on " + "fd %d err = %d\n", pty_fd, errno); exit(1); } if (tcsetpgrp(pty_fd, os_getpid()) < 0) { - printk(UM_KERN_ERR "winch_thread : tcsetpgrp failed on " - "fd %d err = %d\n", pty_fd, errno); + os_info("winch_thread : tcsetpgrp failed on fd %d err = %d\n", + pty_fd, errno); exit(1); } @@ -199,8 +199,8 @@ static int winch_thread(void *arg) */ count = read(pipe_fd, &c, sizeof(c)); if (count != sizeof(c)) - printk(UM_KERN_ERR "winch_thread : failed to read " - "synchronization byte, err = %d\n", errno); + os_info("winch_thread : failed to read synchronization byte, err = %d\n", + errno); while(1) { /* @@ -211,8 +211,8 @@ static int winch_thread(void *arg) count = write(pipe_fd, &c, sizeof(c)); if (count != sizeof(c)) - printk(UM_KERN_ERR "winch_thread : write failed, " - "err = %d\n", errno); + os_info("winch_thread : write failed, err = %d\n", + errno); } } -- cgit v1.2.3-58-ga151 From 139e6e8ef6ee9a56fc1737240ecd8402fbcadd82 Mon Sep 17 00:00:00 2001 From: Benjamin Berg <benjamin@sipsolutions.net> Date: Fri, 10 Nov 2023 12:03:43 +0100 Subject: um: Reap winch thread if it fails When the winch thread runs into an error condition, it would exit(1) and never be reaped until shutdown time. Change this to write a command byte which causes the driver to kill it, therefore reaping the child. Signed-off-by: Benjamin Berg <benjamin@sipsolutions.net> Signed-off-by: Richard Weinberger <richard@nod.at> --- arch/um/drivers/chan_user.c | 16 +++++++++++----- arch/um/drivers/line.c | 13 ++++++++----- 2 files changed, 19 insertions(+), 10 deletions(-) (limited to 'arch/um') diff --git a/arch/um/drivers/chan_user.c b/arch/um/drivers/chan_user.c index c2b83cb99aae..ed7cc830b3e7 100644 --- a/arch/um/drivers/chan_user.c +++ b/arch/um/drivers/chan_user.c @@ -141,7 +141,7 @@ struct winch_data { int pipe_fd; }; -static int winch_thread(void *arg) +static __noreturn int winch_thread(void *arg) { struct winch_data *data = arg; sigset_t sigs; @@ -168,7 +168,7 @@ static int winch_thread(void *arg) if (sigprocmask(SIG_SETMASK, &sigs, NULL) < 0) { os_info("winch_thread : sigprocmask failed, errno = %d\n", errno); - exit(1); + goto wait_kill; } /* In sigsuspend(), block anything else than SIGWINCH. */ sigdelset(&sigs, SIGWINCH); @@ -176,19 +176,19 @@ static int winch_thread(void *arg) if (setsid() < 0) { os_info("winch_thread : setsid failed, errno = %d\n", errno); - exit(1); + goto wait_kill; } if (ioctl(pty_fd, TIOCSCTTY, 0) < 0) { os_info("winch_thread : TIOCSCTTY failed on " "fd %d err = %d\n", pty_fd, errno); - exit(1); + goto wait_kill; } if (tcsetpgrp(pty_fd, os_getpid()) < 0) { os_info("winch_thread : tcsetpgrp failed on fd %d err = %d\n", pty_fd, errno); - exit(1); + goto wait_kill; } /* @@ -214,6 +214,12 @@ static int winch_thread(void *arg) os_info("winch_thread : write failed, err = %d\n", errno); } + +wait_kill: + c = 2; + count = write(pipe_fd, &c, sizeof(c)); + while (1) + pause(); } static int winch_tramp(int fd, struct tty_port *port, int *fd_out, diff --git a/arch/um/drivers/line.c b/arch/um/drivers/line.c index b98545f3edb5..449d320c3f55 100644 --- a/arch/um/drivers/line.c +++ b/arch/um/drivers/line.c @@ -629,15 +629,18 @@ static irqreturn_t winch_interrupt(int irq, void *data) if (fd != -1) { err = generic_read(fd, &c, NULL); - if (err < 0) { + /* A read of 2 means the winch thread failed and has warned */ + if (err < 0 || (err == 1 && c == 2)) { if (err != -EAGAIN) { winch->fd = -1; list_del(&winch->list); os_close_file(fd); - printk(KERN_ERR "winch_interrupt : " - "read failed, errno = %d\n", -err); - printk(KERN_ERR "fd %d is losing SIGWINCH " - "support\n", winch->tty_fd); + if (err < 0) { + printk(KERN_ERR "winch_interrupt : read failed, errno = %d\n", + -err); + printk(KERN_ERR "fd %d is losing SIGWINCH support\n", + winch->tty_fd); + } INIT_WORK(&winch->work, __free_winch); schedule_work(&winch->work); return IRQ_HANDLED; -- cgit v1.2.3-58-ga151 From 6d64095ea8698e3cb1698ec4e81acb2aa1500322 Mon Sep 17 00:00:00 2001 From: Benjamin Berg <benjamin@sipsolutions.net> Date: Fri, 10 Nov 2023 12:03:44 +0100 Subject: um: Do not use printk in userspace trampoline The trampoline is running in a cloned process. It is not safe to use printk for error printing there. Signed-off-by: Benjamin Berg <benjamin@sipsolutions.net> Signed-off-by: Richard Weinberger <richard@nod.at> --- arch/um/os-Linux/skas/process.c | 12 ++++++------ 1 file changed, 6 insertions(+), 6 deletions(-) (limited to 'arch/um') diff --git a/arch/um/os-Linux/skas/process.c b/arch/um/os-Linux/skas/process.c index ed20cefb2963..1f5c3f2523d1 100644 --- a/arch/um/os-Linux/skas/process.c +++ b/arch/um/os-Linux/skas/process.c @@ -221,8 +221,8 @@ static int userspace_tramp(void *stack) addr = mmap64((void *) STUB_CODE, UM_KERN_PAGE_SIZE, PROT_EXEC, MAP_FIXED | MAP_PRIVATE, fd, offset); if (addr == MAP_FAILED) { - printk(UM_KERN_ERR "mapping mmap stub at 0x%lx failed, errno = %d\n", - STUB_CODE, errno); + os_info("mapping mmap stub at 0x%lx failed, errno = %d\n", + STUB_CODE, errno); exit(1); } @@ -231,8 +231,8 @@ static int userspace_tramp(void *stack) STUB_DATA_PAGES * UM_KERN_PAGE_SIZE, PROT_READ | PROT_WRITE, MAP_FIXED | MAP_SHARED, fd, offset); if (addr == MAP_FAILED) { - printk(UM_KERN_ERR "mapping segfault stack at 0x%lx failed, errno = %d\n", - STUB_DATA, errno); + os_info("mapping segfault stack at 0x%lx failed, errno = %d\n", + STUB_DATA, errno); exit(1); } @@ -242,8 +242,8 @@ static int userspace_tramp(void *stack) sa.sa_sigaction = (void *) segv_handler; sa.sa_restorer = NULL; if (sigaction(SIGSEGV, &sa, NULL) < 0) { - printk(UM_KERN_ERR "%s - setting SIGSEGV handler failed - errno = %d\n", - __func__, errno); + os_info("%s - setting SIGSEGV handler failed - errno = %d\n", + __func__, errno); exit(1); } -- cgit v1.2.3-58-ga151 From 7d748f60a4b82b50bf25fad1bd42d33f049f76aa Mon Sep 17 00:00:00 2001 From: Nathan Chancellor <nathan@kernel.org> Date: Wed, 6 Dec 2023 09:49:46 -0700 Subject: um: net: Fix return type of uml_net_start_xmit() With clang's kernel control flow integrity (kCFI, CONFIG_CFI_CLANG), indirect call targets are validated against the expected function pointer prototype to make sure the call target is valid to help mitigate ROP attacks. If they are not identical, there is a failure at run time, which manifests as either a kernel panic or thread getting killed. A warning in clang aims to catch these at compile time, which reveals: arch/um/drivers/net_kern.c:353:21: warning: incompatible function pointer types initializing 'netdev_tx_t (*)(struct sk_buff *, struct net_device *)' (aka 'enum netdev_tx (*)(struct sk_buff *, struct net_device *)') with an expression of type 'int (struct sk_buff *, struct net_device *)' [-Wincompatible-function-pointer-types-strict] 353 | .ndo_start_xmit = uml_net_start_xmit, | ^~~~~~~~~~~~~~~~~~ 1 warning generated. ->ndo_start_xmit() in 'struct net_device_ops' expects a return type of 'netdev_tx_t', not 'int'. Adjust the return type of uml_net_start_xmit() to match the prototype's to resolve the warning. While UML does not currently implement support for kCFI, it could in the future, which means this warning becomes a fatal CFI failure at run time. Reported-by: kernel test robot <lkp@intel.com> Closes: https://lore.kernel.org/oe-kbuild-all/202310031340.v1vPh207-lkp@intel.com/ Acked-by: Anton Ivanov <anton.ivanov@cambridgegreys.com> Signed-off-by: Nathan Chancellor <nathan@kernel.org> Signed-off-by: Richard Weinberger <richard@nod.at> --- arch/um/drivers/net_kern.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'arch/um') diff --git a/arch/um/drivers/net_kern.c b/arch/um/drivers/net_kern.c index 3d7836c46507..cabcc501b448 100644 --- a/arch/um/drivers/net_kern.c +++ b/arch/um/drivers/net_kern.c @@ -204,7 +204,7 @@ static int uml_net_close(struct net_device *dev) return 0; } -static int uml_net_start_xmit(struct sk_buff *skb, struct net_device *dev) +static netdev_tx_t uml_net_start_xmit(struct sk_buff *skb, struct net_device *dev) { struct uml_net_private *lp = netdev_priv(dev); unsigned long flags; -- cgit v1.2.3-58-ga151 From abe4eaa8618bb36c2b33e9cdde0499296a23448c Mon Sep 17 00:00:00 2001 From: Johannes Berg <johannes.berg@intel.com> Date: Wed, 25 Oct 2023 22:45:05 +0200 Subject: um: time-travel: fix time corruption In 'basic' time-travel mode (without =inf-cpu or =ext), we still get timer interrupts. These can happen at arbitrary points in time, i.e. while in timer_read(), which pushes time forward just a little bit. Then, if we happen to get the interrupt after calculating the new time to push to, but before actually finishing that, the interrupt will set the time to a value that's incompatible with the forward, and we'll crash because time goes backwards when we do the forwarding. Fix this by reading the time_travel_time, calculating the adjustment, and doing the adjustment all with interrupts disabled. Reported-by: Vincent Whitchurch <Vincent.Whitchurch@axis.com> Signed-off-by: Johannes Berg <johannes.berg@intel.com> Signed-off-by: Richard Weinberger <richard@nod.at> --- arch/um/kernel/time.c | 32 +++++++++++++++++++++++++++----- 1 file changed, 27 insertions(+), 5 deletions(-) (limited to 'arch/um') diff --git a/arch/um/kernel/time.c b/arch/um/kernel/time.c index fddd1dec27e6..3e270da6b6f6 100644 --- a/arch/um/kernel/time.c +++ b/arch/um/kernel/time.c @@ -432,9 +432,29 @@ static void time_travel_update_time(unsigned long long next, bool idle) time_travel_del_event(&ne); } +static void time_travel_update_time_rel(unsigned long long offs) +{ + unsigned long flags; + + /* + * Disable interrupts before calculating the new time so + * that a real timer interrupt (signal) can't happen at + * a bad time e.g. after we read time_travel_time but + * before we've completed updating the time. + */ + local_irq_save(flags); + time_travel_update_time(time_travel_time + offs, false); + local_irq_restore(flags); +} + void time_travel_ndelay(unsigned long nsec) { - time_travel_update_time(time_travel_time + nsec, false); + /* + * Not strictly needed to use _rel() version since this is + * only used in INFCPU/EXT modes, but it doesn't hurt and + * is more readable too. + */ + time_travel_update_time_rel(nsec); } EXPORT_SYMBOL(time_travel_ndelay); @@ -568,7 +588,11 @@ static void time_travel_set_start(void) #define time_travel_time 0 #define time_travel_ext_waiting 0 -static inline void time_travel_update_time(unsigned long long ns, bool retearly) +static inline void time_travel_update_time(unsigned long long ns, bool idle) +{ +} + +static inline void time_travel_update_time_rel(unsigned long long offs) { } @@ -720,9 +744,7 @@ static u64 timer_read(struct clocksource *cs) */ if (!irqs_disabled() && !in_interrupt() && !in_softirq() && !time_travel_ext_waiting) - time_travel_update_time(time_travel_time + - TIMER_MULTIPLIER, - false); + time_travel_update_time_rel(TIMER_MULTIPLIER); return time_travel_time / TIMER_MULTIPLIER; } -- cgit v1.2.3-58-ga151 From 32a84cfc6caf830431375c5182391284986d4066 Mon Sep 17 00:00:00 2001 From: Michał Winiarski <michal.winiarski@intel.com> Date: Fri, 20 Oct 2023 11:21:58 +0200 Subject: arch: um: Add Clang coverage support MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Clang uses a different set of command line arguments for enabling coverage. Signed-off-by: Michał Winiarski <michal.winiarski@intel.com> Tested-by: David Gow <davidgow@google.com> Signed-off-by: Richard Weinberger <richard@nod.at> --- arch/um/Makefile-skas | 5 +++++ 1 file changed, 5 insertions(+) (limited to 'arch/um') diff --git a/arch/um/Makefile-skas b/arch/um/Makefile-skas index ac35de5316a6..67323b028999 100644 --- a/arch/um/Makefile-skas +++ b/arch/um/Makefile-skas @@ -4,7 +4,12 @@ # GPROF_OPT += -pg + +ifdef CONFIG_CC_IS_CLANG +GCOV_OPT += -fprofile-instr-generate -fcoverage-mapping +else GCOV_OPT += -fprofile-arcs -ftest-coverage +endif CFLAGS-$(CONFIG_GCOV) += $(GCOV_OPT) CFLAGS-$(CONFIG_GPROF) += $(GPROF_OPT) -- cgit v1.2.3-58-ga151 From 1ca1443570e4085c180ecc657d319c21b22a76f6 Mon Sep 17 00:00:00 2001 From: Benjamin Berg <benjamin@sipsolutions.net> Date: Fri, 10 Nov 2023 12:03:46 +0100 Subject: um: Rely on PTRACE_SETREGSET to set FS/GS base registers These registers are saved/restored together with the other general registers using ptrace. In arch_set_tls we then just need to set the register and it will be synced back normally. Most of this logic was introduced in commit f355559cf7845 ("[PATCH] uml: x86_64 thread fixes"). However, at least today we can rely on ptrace to restore the base registers for us. As such, only the part of the patch that tracks the FS register for use as thread local storage is actually needed. Signed-off-by: Benjamin Berg <benjamin@sipsolutions.net> Signed-off-by: Richard Weinberger <richard@nod.at> --- arch/um/include/shared/os.h | 3 -- arch/x86/um/asm/elf.h | 4 +-- arch/x86/um/asm/processor_64.h | 3 -- arch/x86/um/os-Linux/Makefile | 1 - arch/x86/um/os-Linux/prctl.c | 12 -------- arch/x86/um/syscalls_64.c | 62 +++++++++--------------------------------- arch/x86/um/tls_64.c | 2 +- 7 files changed, 16 insertions(+), 71 deletions(-) delete mode 100644 arch/x86/um/os-Linux/prctl.c (limited to 'arch/um') diff --git a/arch/um/include/shared/os.h b/arch/um/include/shared/os.h index 0df646c6651e..aff8906304ea 100644 --- a/arch/um/include/shared/os.h +++ b/arch/um/include/shared/os.h @@ -323,9 +323,6 @@ extern void sigio_broken(int fd); extern int __add_sigio_fd(int fd); extern int __ignore_sigio_fd(int fd); -/* prctl.c */ -extern int os_arch_prctl(int pid, int option, unsigned long *arg2); - /* tty.c */ extern int get_pty(void); diff --git a/arch/x86/um/asm/elf.h b/arch/x86/um/asm/elf.h index 6523eb7c3bd1..6052200fe925 100644 --- a/arch/x86/um/asm/elf.h +++ b/arch/x86/um/asm/elf.h @@ -168,8 +168,8 @@ do { \ (pr_reg)[18] = (_regs)->regs.gp[18]; \ (pr_reg)[19] = (_regs)->regs.gp[19]; \ (pr_reg)[20] = (_regs)->regs.gp[20]; \ - (pr_reg)[21] = current->thread.arch.fs; \ - (pr_reg)[22] = 0; \ + (pr_reg)[21] = (_regs)->regs.gp[21]; \ + (pr_reg)[22] = (_regs)->regs.gp[22]; \ (pr_reg)[23] = 0; \ (pr_reg)[24] = 0; \ (pr_reg)[25] = 0; \ diff --git a/arch/x86/um/asm/processor_64.h b/arch/x86/um/asm/processor_64.h index 1ef9c21877bc..f90159508936 100644 --- a/arch/x86/um/asm/processor_64.h +++ b/arch/x86/um/asm/processor_64.h @@ -10,13 +10,11 @@ struct arch_thread { unsigned long debugregs[8]; int debugregs_seq; - unsigned long fs; struct faultinfo faultinfo; }; #define INIT_ARCH_THREAD { .debugregs = { [ 0 ... 7 ] = 0 }, \ .debugregs_seq = 0, \ - .fs = 0, \ .faultinfo = { 0, 0, 0 } } #define STACKSLOTS_PER_LINE 4 @@ -28,7 +26,6 @@ static inline void arch_flush_thread(struct arch_thread *thread) static inline void arch_copy_thread(struct arch_thread *from, struct arch_thread *to) { - to->fs = from->fs; } #define current_sp() ({ void *sp; __asm__("movq %%rsp, %0" : "=r" (sp) : ); sp; }) diff --git a/arch/x86/um/os-Linux/Makefile b/arch/x86/um/os-Linux/Makefile index ae169125d03f..5249bbc30dcd 100644 --- a/arch/x86/um/os-Linux/Makefile +++ b/arch/x86/um/os-Linux/Makefile @@ -6,7 +6,6 @@ obj-y = registers.o task_size.o mcontext.o obj-$(CONFIG_X86_32) += tls.o -obj-$(CONFIG_64BIT) += prctl.o USER_OBJS := $(obj-y) diff --git a/arch/x86/um/os-Linux/prctl.c b/arch/x86/um/os-Linux/prctl.c deleted file mode 100644 index 8431e87ac333..000000000000 --- a/arch/x86/um/os-Linux/prctl.c +++ /dev/null @@ -1,12 +0,0 @@ -/* - * Copyright (C) 2007 Jeff Dike (jdike@{addtoit.com,linux.intel.com}) - * Licensed under the GPL - */ - -#include <sys/ptrace.h> -#include <asm/ptrace.h> - -int os_arch_prctl(int pid, int option, unsigned long *arg2) -{ - return ptrace(PTRACE_ARCH_PRCTL, pid, (unsigned long) arg2, option); -} diff --git a/arch/x86/um/syscalls_64.c b/arch/x86/um/syscalls_64.c index 27b29ae6c471..6a00a28c9cca 100644 --- a/arch/x86/um/syscalls_64.c +++ b/arch/x86/um/syscalls_64.c @@ -16,60 +16,24 @@ long arch_prctl(struct task_struct *task, int option, unsigned long __user *arg2) { - unsigned long *ptr = arg2, tmp; - long ret; - int pid = task->mm->context.id.u.pid; - - /* - * With ARCH_SET_FS (and ARCH_SET_GS is treated similarly to - * be safe), we need to call arch_prctl on the host because - * setting %fs may result in something else happening (like a - * GDT or thread.fs being set instead). So, we let the host - * fiddle the registers and thread struct and restore the - * registers afterwards. - * - * So, the saved registers are stored to the process (this - * needed because a stub may have been the last thing to run), - * arch_prctl is run on the host, then the registers are read - * back. - */ - switch (option) { - case ARCH_SET_FS: - case ARCH_SET_GS: - ret = restore_pid_registers(pid, ¤t->thread.regs.regs); - if (ret) - return ret; - break; - case ARCH_GET_FS: - case ARCH_GET_GS: - /* - * With these two, we read to a local pointer and - * put_user it to the userspace pointer that we were - * given. If addr isn't valid (because it hasn't been - * faulted in or is just bogus), we want put_user to - * fault it in (or return -EFAULT) instead of having - * the host return -EFAULT. - */ - ptr = &tmp; - } - - ret = os_arch_prctl(pid, option, ptr); - if (ret) - return ret; + long ret = -EINVAL; switch (option) { case ARCH_SET_FS: - current->thread.arch.fs = (unsigned long) ptr; - ret = save_registers(pid, ¤t->thread.regs.regs); + current->thread.regs.regs.gp[FS_BASE / sizeof(unsigned long)] = + (unsigned long) arg2; + ret = 0; break; case ARCH_SET_GS: - ret = save_registers(pid, ¤t->thread.regs.regs); + current->thread.regs.regs.gp[GS_BASE / sizeof(unsigned long)] = + (unsigned long) arg2; + ret = 0; break; case ARCH_GET_FS: - ret = put_user(tmp, arg2); + ret = put_user(current->thread.regs.regs.gp[FS_BASE / sizeof(unsigned long)], arg2); break; case ARCH_GET_GS: - ret = put_user(tmp, arg2); + ret = put_user(current->thread.regs.regs.gp[GS_BASE / sizeof(unsigned long)], arg2); break; } @@ -83,10 +47,10 @@ SYSCALL_DEFINE2(arch_prctl, int, option, unsigned long, arg2) void arch_switch_to(struct task_struct *to) { - if ((to->thread.arch.fs == 0) || (to->mm == NULL)) - return; - - arch_prctl(to, ARCH_SET_FS, (void __user *) to->thread.arch.fs); + /* + * Nothing needs to be done on x86_64. + * The FS_BASE/GS_BASE registers are saved in the ptrace register set. + */ } SYSCALL_DEFINE6(mmap, unsigned long, addr, unsigned long, len, diff --git a/arch/x86/um/tls_64.c b/arch/x86/um/tls_64.c index ebd3855d9b13..c51a613f6f5c 100644 --- a/arch/x86/um/tls_64.c +++ b/arch/x86/um/tls_64.c @@ -12,7 +12,7 @@ int arch_set_tls(struct task_struct *t, unsigned long tls) * If CLONE_SETTLS is set, we need to save the thread id * so it can be set during context switches. */ - t->thread.arch.fs = tls; + t->thread.regs.regs.gp[FS_BASE / sizeof(unsigned long)] = tls; return 0; } -- cgit v1.2.3-58-ga151 From 1e41c415e21ff03ddf5c3725b608d0e4f0c239e3 Mon Sep 17 00:00:00 2001 From: Benjamin Berg <benjamin@sipsolutions.net> Date: Fri, 10 Nov 2023 12:03:47 +0100 Subject: um: Remove unused register save/restore functions These functions were only used when calling PTRACE_ARCH_PRCTL, but this code has been removed. Signed-off-by: Benjamin Berg <benjamin@sipsolutions.net> Signed-off-by: Richard Weinberger <richard@nod.at> --- arch/um/include/shared/registers.h | 2 -- arch/um/os-Linux/registers.c | 20 -------------------- 2 files changed, 22 deletions(-) (limited to 'arch/um') diff --git a/arch/um/include/shared/registers.h b/arch/um/include/shared/registers.h index 2f9c3ce5b45e..a0450326521c 100644 --- a/arch/um/include/shared/registers.h +++ b/arch/um/include/shared/registers.h @@ -14,8 +14,6 @@ extern int save_fp_registers(int pid, unsigned long *fp_regs); extern int restore_fp_registers(int pid, unsigned long *fp_regs); extern int save_fpx_registers(int pid, unsigned long *fp_regs); extern int restore_fpx_registers(int pid, unsigned long *fp_regs); -extern int save_registers(int pid, struct uml_pt_regs *regs); -extern int restore_pid_registers(int pid, struct uml_pt_regs *regs); extern int init_pid_registers(int pid); extern void get_safe_registers(unsigned long *regs, unsigned long *fp_regs); extern int get_fp_registers(int pid, unsigned long *regs); diff --git a/arch/um/os-Linux/registers.c b/arch/um/os-Linux/registers.c index b123955be7ac..bd80b921add0 100644 --- a/arch/um/os-Linux/registers.c +++ b/arch/um/os-Linux/registers.c @@ -11,26 +11,6 @@ #include <sysdep/ptrace_user.h> #include <registers.h> -int save_registers(int pid, struct uml_pt_regs *regs) -{ - int err; - - err = ptrace(PTRACE_GETREGS, pid, 0, regs->gp); - if (err < 0) - return -errno; - return 0; -} - -int restore_pid_registers(int pid, struct uml_pt_regs *regs) -{ - int err; - - err = ptrace(PTRACE_SETREGS, pid, 0, regs->gp); - if (err < 0) - return -errno; - return 0; -} - /* This is set once at boot time and not changed thereafter */ static unsigned long exec_regs[MAX_REG_NR]; -- cgit v1.2.3-58-ga151