1 files changed, 97 insertions, 130 deletions

diff --git a/arch/um/os-Linux/skas/process.c b/arch/um/os-Linux/skas/process.c
index c316c993a949..1f5c3f2523d1 100644
--- a/arch/um/os-Linux/skas/process.c
+++ b/arch/um/os-Linux/skas/process.c
@@ -5,6 +5,7 @@
  */
 
 #include <stdlib.h>
+#include <stdbool.h>
 #include <unistd.h>
 #include <sched.h>
 #include <errno.h>
@@ -117,8 +118,8 @@ void wait_stub_done(int pid)
 
 		err = ptrace(PTRACE_CONT, pid, 0, 0);
 		if (err) {
-			printk(UM_KERN_ERR "wait_stub_done : continue failed, "
-			       "errno = %d\n", errno);
+			printk(UM_KERN_ERR "%s : continue failed, errno = %d\n",
+			       __func__, errno);
 			fatal_sigsegv();
 		}
 	}
@@ -129,11 +130,10 @@ void wait_stub_done(int pid)
 bad_wait:
 	err = ptrace_dump_regs(pid);
 	if (err)
-		printk(UM_KERN_ERR "Failed to get registers from stub, "
-		       "errno = %d\n", -err);
-	printk(UM_KERN_ERR "wait_stub_done : failed to wait for SIGTRAP, "
-	       "pid = %d, n = %d, errno = %d, status = 0x%x\n", pid, n, errno,
-	       status);
+		printk(UM_KERN_ERR "Failed to get registers from stub, errno = %d\n",
+		       -err);
+	printk(UM_KERN_ERR "%s : failed to wait for SIGTRAP, pid = %d, n = %d, errno = %d, status = 0x%x\n",
+	       __func__, pid, n, errno, status);
 	fatal_sigsegv();
 }
 
@@ -177,49 +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 "handle_trap - nullifying syscall "
-			       "failed, errno = %d\n", errno);
-			fatal_sigsegv();
-		}
-
-		err = ptrace(PTRACE_SYSCALL, pid, 0, 0);
-		if (err < 0) {
-			printk(UM_KERN_ERR "handle_trap - continuing to end of "
-			       "syscall failed, errno = %d\n", 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 "handle_trap - failed to wait at "
-			       "end of syscall, errno = %d, status = %d\n",
-			       errno, status);
-			fatal_sigsegv();
-		}
-	}
-
 	handle_syscall(regs);
 }
 
@@ -227,7 +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.
@@ -242,9 +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);
 
@@ -255,40 +221,30 @@ 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);
 	}
 
-	if (stack != NULL) {
-		fd = phys_mapping(uml_to_phys(stack), &offset);
-		addr = mmap((void *) STUB_DATA,
-			    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) {
+		os_info("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, 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 "userspace_tramp - setting SIGSEGV "
-			       "handler failed - errno = %d\n", 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) {
+		os_info("%s - setting SIGSEGV handler failed - errno = %d\n",
+			__func__, errno);
+		exit(1);
 	}
 
 	kill(os_getpid(), SIGSTOP);
@@ -300,7 +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.
@@ -321,8 +277,8 @@ int start_userspace(unsigned long stub_stack)
 		     MAP_PRIVATE | MAP_ANONYMOUS, -1, 0);
 	if (stack == MAP_FAILED) {
 		err = -errno;
-		printk(UM_KERN_ERR "start_userspace : mmap failed, "
-		       "errno = %d\n", errno);
+		printk(UM_KERN_ERR "%s : mmap failed, errno = %d\n",
+		       __func__, errno);
 		return err;
 	}
 
@@ -335,8 +291,8 @@ int start_userspace(unsigned long stub_stack)
 	pid = clone(userspace_tramp, (void *) sp, flags, (void *) stub_stack);
 	if (pid < 0) {
 		err = -errno;
-		printk(UM_KERN_ERR "start_userspace : clone failed, "
-		       "errno = %d\n", errno);
+		printk(UM_KERN_ERR "%s : clone failed, errno = %d\n",
+		       __func__, errno);
 		return err;
 	}
 
@@ -344,31 +300,31 @@ int start_userspace(unsigned long stub_stack)
 		CATCH_EINTR(n = waitpid(pid, &status, WUNTRACED | __WALL));
 		if (n < 0) {
 			err = -errno;
-			printk(UM_KERN_ERR "start_userspace : wait failed, "
-			       "errno = %d\n", errno);
+			printk(UM_KERN_ERR "%s : wait failed, errno = %d\n",
+			       __func__, errno);
 			goto out_kill;
 		}
 	} while (WIFSTOPPED(status) && (WSTOPSIG(status) == SIGALRM));
 
 	if (!WIFSTOPPED(status) || (WSTOPSIG(status) != SIGSTOP)) {
 		err = -EINVAL;
-		printk(UM_KERN_ERR "start_userspace : expected SIGSTOP, got "
-		       "status = %d\n", status);
+		printk(UM_KERN_ERR "%s : expected SIGSTOP, got status = %d\n",
+		       __func__, status);
 		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 "start_userspace : PTRACE_OLDSETOPTIONS "
-		       "failed, errno = %d\n", errno);
+		printk(UM_KERN_ERR "%s : PTRACE_SETOPTIONS failed, errno = %d\n",
+		       __func__, errno);
 		goto out_kill;
 	}
 
 	if (munmap(stack, UM_KERN_PAGE_SIZE) < 0) {
 		err = -errno;
-		printk(UM_KERN_ERR "start_userspace : munmap failed, "
-		       "errno = %d\n", errno);
+		printk(UM_KERN_ERR "%s : munmap failed, errno = %d\n",
+		       __func__, errno);
 		goto out_kill;
 	}
 
@@ -382,8 +338,6 @@ 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 */
@@ -402,46 +356,45 @@ void userspace(struct uml_pt_regs *regs, unsigned long *aux_fp_regs)
 		 * just kill the process.
 		 */
 		if (ptrace(PTRACE_SETREGS, pid, 0, regs->gp)) {
-			printk(UM_KERN_ERR "userspace - ptrace set regs "
-			       "failed, errno = %d\n", errno);
+			printk(UM_KERN_ERR "%s - ptrace set regs failed, errno = %d\n",
+			       __func__, errno);
 			fatal_sigsegv();
 		}
 
 		if (put_fp_registers(pid, regs->fp)) {
-			printk(UM_KERN_ERR "userspace - ptrace set fp regs "
-			       "failed, errno = %d\n", errno);
+			printk(UM_KERN_ERR "%s - ptrace set fp regs failed, errno = %d\n",
+			       __func__, errno);
 			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 "userspace - ptrace continue "
-			       "failed, op = %d, errno = %d\n", op, errno);
+			printk(UM_KERN_ERR "%s - ptrace continue failed, op = %d, errno = %d\n",
+			       __func__, op, errno);
 			fatal_sigsegv();
 		}
 
 		CATCH_EINTR(err = waitpid(pid, &status, WUNTRACED | __WALL));
 		if (err < 0) {
-			printk(UM_KERN_ERR "userspace - wait failed, "
-			       "errno = %d\n", errno);
+			printk(UM_KERN_ERR "%s - wait failed, errno = %d\n",
+			       __func__, errno);
 			fatal_sigsegv();
 		}
 
 		regs->is_user = 1;
 		if (ptrace(PTRACE_GETREGS, pid, 0, regs->gp)) {
-			printk(UM_KERN_ERR "userspace - PTRACE_GETREGS failed, "
-			       "errno = %d\n", errno);
+			printk(UM_KERN_ERR "%s - PTRACE_GETREGS failed, errno = %d\n",
+			       __func__, errno);
 			fatal_sigsegv();
 		}
 
 		if (get_fp_registers(pid, regs->fp)) {
-			printk(UM_KERN_ERR "userspace -  get_fp_registers failed, "
-			       "errno = %d\n", errno);
+			printk(UM_KERN_ERR "%s -  get_fp_registers failed, errno = %d\n",
+			       __func__, errno);
 			fatal_sigsegv();
 		}
 
@@ -476,7 +429,7 @@ 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);
@@ -493,8 +446,8 @@ void userspace(struct uml_pt_regs *regs, unsigned long *aux_fp_regs)
 				unblock_signals_trace();
 				break;
 			default:
-				printk(UM_KERN_ERR "userspace - child stopped "
-				       "with signal %d\n", sig);
+				printk(UM_KERN_ERR "%s - child stopped with signal %d\n",
+				       __func__, sig);
 				fatal_sigsegv();
 			}
 			pid = userspace_pid[0];
@@ -517,7 +470,7 @@ static int __init init_thread_regs(void)
 	thread_regs[REGS_IP_INDEX] = STUB_CODE +
 				(unsigned long) stub_clone_handler -
 				(unsigned long) __syscall_stub_start;
-	thread_regs[REGS_SP_INDEX] = STUB_DATA + UM_KERN_PAGE_SIZE -
+	thread_regs[REGS_SP_INDEX] = STUB_DATA + STUB_DATA_PAGES * UM_KERN_PAGE_SIZE -
 		sizeof(void *);
 #ifdef __SIGNAL_FRAMESIZE
 	thread_regs[REGS_SP_INDEX] -= __SIGNAL_FRAMESIZE;
@@ -554,15 +507,15 @@ int copy_context_skas0(unsigned long new_stack, int pid)
 	err = ptrace_setregs(pid, thread_regs);
 	if (err < 0) {
 		err = -errno;
-		printk(UM_KERN_ERR "copy_context_skas0 : PTRACE_SETREGS "
-		       "failed, pid = %d, errno = %d\n", pid, -err);
+		printk(UM_KERN_ERR "%s : PTRACE_SETREGS failed, pid = %d, errno = %d\n",
+		      __func__, pid, -err);
 		return err;
 	}
 
 	err = put_fp_registers(pid, thread_fp_regs);
 	if (err < 0) {
-		printk(UM_KERN_ERR "copy_context_skas0 : put_fp_registers "
-		       "failed, pid = %d, err = %d\n", pid, err);
+		printk(UM_KERN_ERR "%s : put_fp_registers failed, pid = %d, err = %d\n",
+		       __func__, pid, err);
 		return err;
 	}
 
@@ -573,8 +526,8 @@ int copy_context_skas0(unsigned long new_stack, int pid)
 	err = ptrace(PTRACE_CONT, pid, 0, 0);
 	if (err) {
 		err = -errno;
-		printk(UM_KERN_ERR "Failed to continue new process, pid = %d, "
-		       "errno = %d\n", pid, errno);
+		printk(UM_KERN_ERR "Failed to continue new process, pid = %d, errno = %d\n",
+		       pid, errno);
 		return err;
 	}
 
@@ -582,8 +535,8 @@ int copy_context_skas0(unsigned long new_stack, int pid)
 
 	pid = data->parent_err;
 	if (pid < 0) {
-		printk(UM_KERN_ERR "copy_context_skas0 - stub-parent reports "
-		       "error %d\n", -pid);
+		printk(UM_KERN_ERR "%s - stub-parent reports error %d\n",
+		      __func__, -pid);
 		return pid;
 	}
 
@@ -593,17 +546,17 @@ int copy_context_skas0(unsigned long new_stack, int pid)
 	 */
 	wait_stub_done(pid);
 	if (child_data->child_err != STUB_DATA) {
-		printk(UM_KERN_ERR "copy_context_skas0 - stub-child %d reports "
-		       "error %ld\n", pid, data->child_err);
+		printk(UM_KERN_ERR "%s - stub-child %d reports error %ld\n",
+		       __func__, pid, data->child_err);
 		err = data->child_err;
 		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 "copy_context_skas0 : PTRACE_OLDSETOPTIONS "
-		       "failed, errno = %d\n", errno);
+		printk(UM_KERN_ERR "%s : PTRACE_SETOPTIONS failed, errno = %d\n",
+		       __func__, errno);
 		goto out_kill;
 	}
 
@@ -671,8 +624,8 @@ int start_idle_thread(void *stack, jmp_buf *switch_buf)
 		kmalloc_ok = 0;
 		return 1;
 	default:
-		printk(UM_KERN_ERR "Bad sigsetjmp return in "
-		       "start_idle_thread - %d\n", n);
+		printk(UM_KERN_ERR "Bad sigsetjmp return in %s - %d\n",
+		       __func__, n);
 		fatal_sigsegv();
 	}
 	longjmp(*switch_buf, 1);
@@ -707,10 +660,24 @@ void halt_skas(void)
 	UML_LONGJMP(&initial_jmpbuf, INIT_JMP_HALT);
 }
 
+static bool noreboot;
+
+static int __init noreboot_cmd_param(char *str, int *add)
+{
+	noreboot = true;
+	return 0;
+}
+
+__uml_setup("noreboot", noreboot_cmd_param,
+"noreboot\n"
+"    Rather than rebooting, exit always, akin to QEMU's -no-reboot option.\n"
+"    This is useful if you're using CONFIG_PANIC_TIMEOUT in order to catch\n"
+"    crashes in CI\n");
+
 void reboot_skas(void)
 {
 	block_signals_trace();
-	UML_LONGJMP(&initial_jmpbuf, INIT_JMP_REBOOT);
+	UML_LONGJMP(&initial_jmpbuf, noreboot ? INIT_JMP_HALT : INIT_JMP_REBOOT);
 }
 
 void __switch_mm(struct mm_id *mm_idp)