aboutsummaryrefslogtreecommitdiff
path: root/arch/um/os-Linux/skas/process.c
diff options
context:
space:
mode:
Diffstat (limited to 'arch/um/os-Linux/skas/process.c')
-rw-r--r--arch/um/os-Linux/skas/process.c281
1 files changed, 186 insertions, 95 deletions
diff --git a/arch/um/os-Linux/skas/process.c b/arch/um/os-Linux/skas/process.c
index e8b7a97e83d..d36c89c24a4 100644
--- a/arch/um/os-Linux/skas/process.c
+++ b/arch/um/os-Linux/skas/process.c
@@ -15,6 +15,7 @@
#include "as-layout.h"
#include "chan_user.h"
#include "kern_constants.h"
+#include "kern_util.h"
#include "mem.h"
#include "os.h"
#include "process.h"
@@ -37,27 +38,27 @@ int is_skas_winch(int pid, int fd, void *data)
static int ptrace_dump_regs(int pid)
{
- unsigned long regs[MAX_REG_NR];
- int i;
+ unsigned long regs[MAX_REG_NR];
+ int i;
- if (ptrace(PTRACE_GETREGS, pid, 0, regs) < 0)
- return -errno;
+ if (ptrace(PTRACE_GETREGS, pid, 0, regs) < 0)
+ return -errno;
printk(UM_KERN_ERR "Stub registers -\n");
for (i = 0; i < ARRAY_SIZE(regs); i++)
printk(UM_KERN_ERR "\t%d - %lx\n", i, regs[i]);
- return 0;
+ return 0;
}
/*
* Signals that are OK to receive in the stub - we'll just continue it.
* SIGWINCH will happen when UML is inside a detached screen.
*/
-#define STUB_SIG_MASK ((1 << SIGVTALRM) | (1 << SIGWINCH))
+#define STUB_SIG_MASK (1 << SIGVTALRM)
/* Signals that the stub will finish with - anything else is an error */
-#define STUB_DONE_MASK ((1 << SIGUSR1) | (1 << SIGTRAP))
+#define STUB_DONE_MASK (1 << SIGTRAP)
void wait_stub_done(int pid)
{
@@ -72,9 +73,11 @@ void wait_stub_done(int pid)
break;
err = ptrace(PTRACE_CONT, pid, 0, 0);
- if (err)
- panic("wait_stub_done : continue failed, errno = %d\n",
- errno);
+ if (err) {
+ printk(UM_KERN_ERR "wait_stub_done : continue failed, "
+ "errno = %d\n", errno);
+ fatal_sigsegv();
+ }
}
if (((1 << WSTOPSIG(status)) & STUB_DONE_MASK) != 0)
@@ -85,8 +88,10 @@ bad_wait:
if (err)
printk(UM_KERN_ERR "Failed to get registers from stub, "
"errno = %d\n", -err);
- panic("wait_stub_done : failed to wait for SIGUSR1/SIGTRAP, pid = %d, "
- "n = %d, errno = %d, status = 0x%x\n", pid, n, errno, status);
+ 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);
+ fatal_sigsegv();
}
extern unsigned long current_stub_stack(void);
@@ -97,9 +102,11 @@ void get_skas_faultinfo(int pid, struct faultinfo * fi)
if (ptrace_faultinfo) {
err = ptrace(PTRACE_FAULTINFO, pid, 0, fi);
- if (err)
- panic("get_skas_faultinfo - PTRACE_FAULTINFO failed, "
- "errno = %d\n", errno);
+ if (err) {
+ printk(UM_KERN_ERR "get_skas_faultinfo - "
+ "PTRACE_FAULTINFO failed, errno = %d\n", errno);
+ fatal_sigsegv();
+ }
/* Special handling for i386, which has different structs */
if (sizeof(struct ptrace_faultinfo) < sizeof(struct faultinfo))
@@ -109,9 +116,11 @@ void get_skas_faultinfo(int pid, struct faultinfo * fi)
}
else {
err = ptrace(PTRACE_CONT, pid, 0, SIGSEGV);
- if (err)
- panic("Failed to continue stub, pid = %d, errno = %d\n",
- pid, errno);
+ if (err) {
+ printk(UM_KERN_ERR "Failed to continue stub, pid = %d, "
+ "errno = %d\n", pid, errno);
+ fatal_sigsegv();
+ }
wait_stub_done(pid);
/*
@@ -137,6 +146,9 @@ 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();
+
/* Mark this as a syscall */
UPT_SYSCALL_NR(regs) = PT_SYSCALL_NR(regs->gp);
@@ -144,25 +156,31 @@ static void handle_trap(int pid, struct uml_pt_regs *regs,
{
err = ptrace(PTRACE_POKEUSR, pid, PT_SYSCALL_NR_OFFSET,
__NR_getpid);
- if (err < 0)
- panic("handle_trap - nullifying syscall failed, "
- "errno = %d\n", errno);
+ 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)
- panic("handle_trap - continuing to end of syscall "
- "failed, errno = %d\n", errno);
+ 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 "
+ (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);
- panic("handle_trap - failed to wait at end of syscall, "
- "errno = %d, status = %d\n", errno, status);
- }
+ 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);
@@ -178,10 +196,13 @@ static int userspace_tramp(void *stack)
ptrace(PTRACE_TRACEME, 0, 0, 0);
signal(SIGTERM, SIG_DFL);
+ signal(SIGWINCH, SIG_IGN);
err = set_interval();
- if (err)
- panic("userspace_tramp - setting timer failed, errno = %d\n",
- err);
+ if (err) {
+ printk(UM_KERN_ERR "userspace_tramp - setting timer failed, "
+ "errno = %d\n", err);
+ exit(1);
+ }
if (!proc_mm) {
/*
@@ -221,16 +242,14 @@ static int userspace_tramp(void *stack)
set_sigstack((void *) STUB_DATA, UM_KERN_PAGE_SIZE);
sigemptyset(&sa.sa_mask);
- sigaddset(&sa.sa_mask, SIGIO);
- sigaddset(&sa.sa_mask, SIGWINCH);
- sigaddset(&sa.sa_mask, SIGVTALRM);
- sigaddset(&sa.sa_mask, SIGUSR1);
- sa.sa_flags = SA_ONSTACK;
+ sa.sa_flags = SA_ONSTACK | SA_NODEFER;
sa.sa_handler = (void *) v;
sa.sa_restorer = NULL;
- if (sigaction(SIGSEGV, &sa, NULL) < 0)
- panic("userspace_tramp - setting SIGSEGV handler "
- "failed - errno = %d\n", errno);
+ if (sigaction(SIGSEGV, &sa, NULL) < 0) {
+ printk(UM_KERN_ERR "userspace_tramp - setting SIGSEGV "
+ "handler failed - errno = %d\n", errno);
+ exit(1);
+ }
}
kill(os_getpid(), SIGSTOP);
@@ -246,13 +265,18 @@ int start_userspace(unsigned long stub_stack)
{
void *stack;
unsigned long sp;
- int pid, status, n, flags;
+ int pid, status, n, flags, err;
stack = mmap(NULL, UM_KERN_PAGE_SIZE,
PROT_READ | PROT_WRITE | PROT_EXEC,
MAP_PRIVATE | MAP_ANONYMOUS, -1, 0);
- if (stack == MAP_FAILED)
- panic("start_userspace : mmap failed, errno = %d", errno);
+ if (stack == MAP_FAILED) {
+ err = -errno;
+ printk(UM_KERN_ERR "start_userspace : mmap failed, "
+ "errno = %d\n", errno);
+ return err;
+ }
+
sp = (unsigned long) stack + UM_KERN_PAGE_SIZE - sizeof(void *);
flags = CLONE_FILES;
@@ -262,29 +286,50 @@ int start_userspace(unsigned long stub_stack)
flags |= SIGCHLD;
pid = clone(userspace_tramp, (void *) sp, flags, (void *) stub_stack);
- if (pid < 0)
- panic("start_userspace : clone failed, errno = %d", errno);
+ if (pid < 0) {
+ err = -errno;
+ printk(UM_KERN_ERR "start_userspace : clone failed, "
+ "errno = %d\n", errno);
+ return err;
+ }
do {
CATCH_EINTR(n = waitpid(pid, &status, WUNTRACED | __WALL));
- if (n < 0)
- panic("start_userspace : wait failed, errno = %d",
- errno);
+ if (n < 0) {
+ err = -errno;
+ printk(UM_KERN_ERR "start_userspace : wait failed, "
+ "errno = %d\n", errno);
+ goto out_kill;
+ }
} while (WIFSTOPPED(status) && (WSTOPSIG(status) == SIGVTALRM));
- if (!WIFSTOPPED(status) || (WSTOPSIG(status) != SIGSTOP))
- panic("start_userspace : expected SIGSTOP, got status = %d",
- status);
+ if (!WIFSTOPPED(status) || (WSTOPSIG(status) != SIGSTOP)) {
+ err = -EINVAL;
+ printk(UM_KERN_ERR "start_userspace : expected SIGSTOP, got "
+ "status = %d\n", status);
+ goto out_kill;
+ }
if (ptrace(PTRACE_OLDSETOPTIONS, pid, NULL,
- (void *) PTRACE_O_TRACESYSGOOD) < 0)
- panic("start_userspace : PTRACE_OLDSETOPTIONS failed, "
- "errno = %d\n", errno);
+ (void *) PTRACE_O_TRACESYSGOOD) < 0) {
+ err = -errno;
+ printk(UM_KERN_ERR "start_userspace : PTRACE_OLDSETOPTIONS "
+ "failed, errno = %d\n", errno);
+ goto out_kill;
+ }
- if (munmap(stack, UM_KERN_PAGE_SIZE) < 0)
- panic("start_userspace : munmap failed, errno = %d\n", errno);
+ if (munmap(stack, UM_KERN_PAGE_SIZE) < 0) {
+ err = -errno;
+ printk(UM_KERN_ERR "start_userspace : munmap failed, "
+ "errno = %d\n", errno);
+ goto out_kill;
+ }
return pid;
+
+ out_kill:
+ os_kill_ptraced_process(pid, 1);
+ return err;
}
void userspace(struct uml_pt_regs *regs)
@@ -302,7 +347,16 @@ void userspace(struct uml_pt_regs *regs)
nsecs += os_nsecs();
while (1) {
- restore_registers(pid, regs);
+ /*
+ * This can legitimately fail if the process loads a
+ * bogus value into a segment register. It will
+ * segfault and PTRACE_GETREGS will read that value
+ * out of the process. However, PTRACE_SETREGS will
+ * fail. In this case, there is nothing to do but
+ * just kill the process.
+ */
+ if (ptrace(PTRACE_SETREGS, pid, 0, regs->gp))
+ fatal_sigsegv();
/* Now we set local_using_sysemu to be used for one loop */
local_using_sysemu = get_using_sysemu();
@@ -310,19 +364,26 @@ void userspace(struct uml_pt_regs *regs)
op = SELECT_PTRACE_OPERATION(local_using_sysemu,
singlestepping(NULL));
- err = ptrace(op, pid, 0, 0);
- if (err)
- panic("userspace - could not resume userspace process, "
- "pid=%d, ptrace operation = %d, errno = %d\n",
- pid, op, errno);
+ if (ptrace(op, pid, 0, 0)) {
+ printk(UM_KERN_ERR "userspace - ptrace continue "
+ "failed, op = %d, errno = %d\n", op, errno);
+ fatal_sigsegv();
+ }
CATCH_EINTR(err = waitpid(pid, &status, WUNTRACED | __WALL));
- if (err < 0)
- panic("userspace - waitpid failed, errno = %d\n",
- errno);
+ if (err < 0) {
+ printk(UM_KERN_ERR "userspace - wait failed, "
+ "errno = %d\n", errno);
+ fatal_sigsegv();
+ }
regs->is_user = 1;
- save_registers(pid, regs);
+ if (ptrace(PTRACE_GETREGS, pid, 0, regs->gp)) {
+ printk(UM_KERN_ERR "userspace - PTRACE_GETREGS failed, "
+ "errno = %d\n", errno);
+ fatal_sigsegv();
+ }
+
UPT_SYSCALL_NR(regs) = -1; /* Assume: It's not a syscall */
if (WIFSTOPPED(status)) {
@@ -345,7 +406,7 @@ void userspace(struct uml_pt_regs *regs)
break;
case SIGVTALRM:
now = os_nsecs();
- if(now < nsecs)
+ if (now < nsecs)
break;
block_signals();
(*sig_info[sig])(sig, regs);
@@ -368,6 +429,7 @@ void userspace(struct uml_pt_regs *regs)
default:
printk(UM_KERN_ERR "userspace - child stopped "
"with signal %d\n", sig);
+ fatal_sigsegv();
}
pid = userspace_pid[0];
interrupt_end();
@@ -419,9 +481,12 @@ int copy_context_skas0(unsigned long new_stack, int pid)
.it_interval = tv }) });
err = ptrace_setregs(pid, thread_regs);
- if (err < 0)
- panic("copy_context_skas0 : PTRACE_SETREGS failed, "
- "pid = %d, errno = %d\n", pid, -err);
+ if (err < 0) {
+ err = -errno;
+ printk(UM_KERN_ERR "copy_context_skas0 : PTRACE_SETREGS "
+ "failed, pid = %d, errno = %d\n", pid, -err);
+ return err;
+ }
/* set a well known return code for detection of child write failure */
child_data->err = 12345678;
@@ -431,31 +496,47 @@ int copy_context_skas0(unsigned long new_stack, int pid)
* parent's stack, and check, if bad result.
*/
err = ptrace(PTRACE_CONT, pid, 0, 0);
- if (err)
- panic("Failed to continue new process, pid = %d, "
- "errno = %d\n", pid, errno);
+ if (err) {
+ err = -errno;
+ printk(UM_KERN_ERR "Failed to continue new process, pid = %d, "
+ "errno = %d\n", pid, errno);
+ return err;
+ }
+
wait_stub_done(pid);
pid = data->err;
- if (pid < 0)
- panic("copy_context_skas0 - stub-parent reports error %d\n",
- -pid);
+ if (pid < 0) {
+ printk(UM_KERN_ERR "copy_context_skas0 - stub-parent reports "
+ "error %d\n", -pid);
+ return pid;
+ }
/*
* Wait, until child has finished too: read child's result from
* child's stack and check it.
*/
wait_stub_done(pid);
- if (child_data->err != STUB_DATA)
- panic("copy_context_skas0 - stub-child reports error %ld\n",
- child_data->err);
+ if (child_data->err != STUB_DATA) {
+ printk(UM_KERN_ERR "copy_context_skas0 - stub-child reports "
+ "error %ld\n", child_data->err);
+ err = child_data->err;
+ goto out_kill;
+ }
if (ptrace(PTRACE_OLDSETOPTIONS, pid, NULL,
- (void *)PTRACE_O_TRACESYSGOOD) < 0)
- panic("copy_context_skas0 : PTRACE_OLDSETOPTIONS failed, "
- "errno = %d\n", errno);
+ (void *)PTRACE_O_TRACESYSGOOD) < 0) {
+ err = -errno;
+ printk(UM_KERN_ERR "copy_context_skas0 : PTRACE_OLDSETOPTIONS "
+ "failed, errno = %d\n", errno);
+ goto out_kill;
+ }
return pid;
+
+ out_kill:
+ os_kill_ptraced_process(pid, 1);
+ return err;
}
/*
@@ -463,8 +544,8 @@ int copy_context_skas0(unsigned long new_stack, int pid)
* available. Opening /proc/mm creates a new mm_context, which lacks
* the stub-pages. Thus, we map them using /proc/mm-fd
*/
-void map_stub_pages(int fd, unsigned long code,
- unsigned long data, unsigned long stack)
+int map_stub_pages(int fd, unsigned long code, unsigned long data,
+ unsigned long stack)
{
struct proc_mm_op mmop;
int n;
@@ -488,8 +569,9 @@ void map_stub_pages(int fd, unsigned long code,
printk(UM_KERN_ERR "mmap args - addr = 0x%lx, fd = %d, "
"offset = %llx\n", code, code_fd,
(unsigned long long) code_offset);
- panic("map_stub_pages : /proc/mm map for code failed, "
- "err = %d\n", n);
+ printk(UM_KERN_ERR "map_stub_pages : /proc/mm map for code "
+ "failed, err = %d\n", n);
+ return -n;
}
if (stack) {
@@ -507,10 +589,15 @@ void map_stub_pages(int fd, unsigned long code,
.offset = map_offset
} } });
CATCH_EINTR(n = write(fd, &mmop, sizeof(mmop)));
- if (n != sizeof(mmop))
- panic("map_stub_pages : /proc/mm map for data failed, "
- "err = %d\n", errno);
+ if (n != sizeof(mmop)) {
+ n = errno;
+ printk(UM_KERN_ERR "map_stub_pages : /proc/mm map for "
+ "data failed, err = %d\n", n);
+ return -n;
+ }
}
+
+ return 0;
}
void new_thread(void *stack, jmp_buf *buf, void (*handler)(void))
@@ -571,7 +658,9 @@ int start_idle_thread(void *stack, jmp_buf *switch_buf)
kmalloc_ok = 0;
return 1;
default:
- panic("Bad sigsetjmp return in start_idle_thread - %d\n", n);
+ printk(UM_KERN_ERR "Bad sigsetjmp return in "
+ "start_idle_thread - %d\n", n);
+ fatal_sigsegv();
}
longjmp(*switch_buf, 1);
}
@@ -614,9 +703,11 @@ void __switch_mm(struct mm_id *mm_idp)
if (proc_mm) {
err = ptrace(PTRACE_SWITCH_MM, userspace_pid[0], 0,
mm_idp->u.mm_fd);
- if (err)
- panic("__switch_mm - PTRACE_SWITCH_MM failed, "
- "errno = %d\n", errno);
+ if (err) {
+ printk(UM_KERN_ERR "__switch_mm - PTRACE_SWITCH_MM "
+ "failed, errno = %d\n", errno);
+ fatal_sigsegv();
+ }
}
else userspace_pid[0] = mm_idp->u.pid;
}