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authorRichard Weinberger <richard@nod.at>2015-03-18 21:31:27 +0100
committerRichard Weinberger <richard@nod.at>2015-04-13 21:00:53 +0200
commitd0b5e15f0c0fdd759dd3dd48dc2dc2e7199e0da0 (patch)
tree7b833b85c0e2eabf6b38d8b94875b430554afae7 /arch/um/os-Linux
parentaaeac66b1a02d399ec8ee63e8d617c1d601ea353 (diff)
um: Remove SKAS3/4 support
Before we had SKAS0 UML had two modes of operation TT (tracing thread) and SKAS3/4 (separated kernel address space). TT was known to be insecure and got removed a long time ago. SKAS3/4 required a few (3 or 4) patches on the host side which never went mainline. The last host patch is 10 years old. With SKAS0 mode (separated kernel address space using 0 host patches), default since 2005, SKAS3/4 is obsolete and can be removed. Signed-off-by: Richard Weinberger <richard@nod.at>
Diffstat (limited to 'arch/um/os-Linux')
-rw-r--r--arch/um/os-Linux/process.c16
-rw-r--r--arch/um/os-Linux/skas/mem.c100
-rw-r--r--arch/um/os-Linux/skas/process.c200
-rw-r--r--arch/um/os-Linux/start_up.c154
4 files changed, 62 insertions, 408 deletions
diff --git a/arch/um/os-Linux/process.c b/arch/um/os-Linux/process.c
index 33496fe2bb52..8408aba915b2 100644
--- a/arch/um/os-Linux/process.c
+++ b/arch/um/os-Linux/process.c
@@ -16,7 +16,6 @@
#include <init.h>
#include <longjmp.h>
#include <os.h>
-#include <skas_ptrace.h>
#define ARBITRARY_ADDR -1
#define FAILURE_PID -1
@@ -102,21 +101,6 @@ void os_kill_process(int pid, int reap_child)
CATCH_EINTR(waitpid(pid, NULL, __WALL));
}
-/* This is here uniquely to have access to the userspace errno, i.e. the one
- * used by ptrace in case of error.
- */
-
-long os_ptrace_ldt(long pid, long addr, long data)
-{
- int ret;
-
- ret = ptrace(PTRACE_LDT, pid, addr, data);
-
- if (ret < 0)
- return -errno;
- return ret;
-}
-
/* Kill off a ptraced child by all means available. kill it normally first,
* then PTRACE_KILL it, then PTRACE_CONT it in case it's in a run state from
* which it can't exit directly.
diff --git a/arch/um/os-Linux/skas/mem.c b/arch/um/os-Linux/skas/mem.c
index 689b18db798f..e7f8c945a573 100644
--- a/arch/um/os-Linux/skas/mem.c
+++ b/arch/um/os-Linux/skas/mem.c
@@ -12,7 +12,6 @@
#include <as-layout.h>
#include <mm_id.h>
#include <os.h>
-#include <proc_mm.h>
#include <ptrace_user.h>
#include <registers.h>
#include <skas.h>
@@ -46,8 +45,6 @@ static int __init init_syscall_regs(void)
__initcall(init_syscall_regs);
-extern int proc_mm;
-
static inline long do_syscall_stub(struct mm_id * mm_idp, void **addr)
{
int n, i;
@@ -56,10 +53,6 @@ static inline long do_syscall_stub(struct mm_id * mm_idp, void **addr)
unsigned long * syscall;
int err, pid = mm_idp->u.pid;
- if (proc_mm)
- /* FIXME: Need to look up userspace_pid by cpu */
- pid = userspace_pid[0];
-
n = ptrace_setregs(pid, syscall_regs);
if (n < 0) {
printk(UM_KERN_ERR "Registers - \n");
@@ -178,38 +171,12 @@ int map(struct mm_id * mm_idp, unsigned long virt, unsigned long len, int prot,
int phys_fd, unsigned long long offset, int done, void **data)
{
int ret;
+ unsigned long args[] = { virt, len, prot,
+ MAP_SHARED | MAP_FIXED, phys_fd,
+ MMAP_OFFSET(offset) };
- if (proc_mm) {
- struct proc_mm_op map;
- int fd = mm_idp->u.mm_fd;
-
- map = ((struct proc_mm_op) { .op = MM_MMAP,
- .u =
- { .mmap =
- { .addr = virt,
- .len = len,
- .prot = prot,
- .flags = MAP_SHARED |
- MAP_FIXED,
- .fd = phys_fd,
- .offset= offset
- } } } );
- CATCH_EINTR(ret = write(fd, &map, sizeof(map)));
- if (ret != sizeof(map)) {
- ret = -errno;
- printk(UM_KERN_ERR "map : /proc/mm map failed, "
- "err = %d\n", -ret);
- }
- else ret = 0;
- }
- else {
- unsigned long args[] = { virt, len, prot,
- MAP_SHARED | MAP_FIXED, phys_fd,
- MMAP_OFFSET(offset) };
-
- ret = run_syscall_stub(mm_idp, STUB_MMAP_NR, args, virt,
- data, done);
- }
+ ret = run_syscall_stub(mm_idp, STUB_MMAP_NR, args, virt,
+ data, done);
return ret;
}
@@ -218,32 +185,11 @@ int unmap(struct mm_id * mm_idp, unsigned long addr, unsigned long len,
int done, void **data)
{
int ret;
+ unsigned long args[] = { (unsigned long) addr, len, 0, 0, 0,
+ 0 };
- if (proc_mm) {
- struct proc_mm_op unmap;
- int fd = mm_idp->u.mm_fd;
-
- unmap = ((struct proc_mm_op) { .op = MM_MUNMAP,
- .u =
- { .munmap =
- { .addr =
- (unsigned long) addr,
- .len = len } } } );
- CATCH_EINTR(ret = write(fd, &unmap, sizeof(unmap)));
- if (ret != sizeof(unmap)) {
- ret = -errno;
- printk(UM_KERN_ERR "unmap - proc_mm write returned "
- "%d\n", ret);
- }
- else ret = 0;
- }
- else {
- unsigned long args[] = { (unsigned long) addr, len, 0, 0, 0,
- 0 };
-
- ret = run_syscall_stub(mm_idp, __NR_munmap, args, 0,
- data, done);
- }
+ ret = run_syscall_stub(mm_idp, __NR_munmap, args, 0,
+ data, done);
return ret;
}
@@ -251,33 +197,11 @@ int unmap(struct mm_id * mm_idp, unsigned long addr, unsigned long len,
int protect(struct mm_id * mm_idp, unsigned long addr, unsigned long len,
unsigned int prot, int done, void **data)
{
- struct proc_mm_op protect;
int ret;
+ unsigned long args[] = { addr, len, prot, 0, 0, 0 };
- if (proc_mm) {
- int fd = mm_idp->u.mm_fd;
-
- protect = ((struct proc_mm_op) { .op = MM_MPROTECT,
- .u =
- { .mprotect =
- { .addr =
- (unsigned long) addr,
- .len = len,
- .prot = prot } } } );
-
- CATCH_EINTR(ret = write(fd, &protect, sizeof(protect)));
- if (ret != sizeof(protect)) {
- ret = -errno;
- printk(UM_KERN_ERR "protect failed, err = %d", -ret);
- }
- else ret = 0;
- }
- else {
- unsigned long args[] = { addr, len, prot, 0, 0, 0 };
-
- ret = run_syscall_stub(mm_idp, __NR_mprotect, args, 0,
- data, done);
- }
+ ret = run_syscall_stub(mm_idp, __NR_mprotect, args, 0,
+ data, done);
return ret;
}
diff --git a/arch/um/os-Linux/skas/process.c b/arch/um/os-Linux/skas/process.c
index 908579f2b0ab..50ebeae5cbb3 100644
--- a/arch/um/os-Linux/skas/process.c
+++ b/arch/um/os-Linux/skas/process.c
@@ -16,11 +16,9 @@
#include <kern_util.h>
#include <mem.h>
#include <os.h>
-#include <proc_mm.h>
#include <ptrace_user.h>
#include <registers.h>
#include <skas.h>
-#include <skas_ptrace.h>
#include <sysdep/stub.h>
int is_skas_winch(int pid, int fd, void *data)
@@ -91,50 +89,33 @@ extern unsigned long current_stub_stack(void);
static void get_skas_faultinfo(int pid, struct faultinfo *fi)
{
int err;
+ unsigned long fpregs[FP_SIZE];
- if (ptrace_faultinfo) {
- err = ptrace(PTRACE_FAULTINFO, pid, 0, fi);
- 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))
- memset((char *)fi + sizeof(struct ptrace_faultinfo), 0,
- sizeof(struct faultinfo) -
- sizeof(struct ptrace_faultinfo));
+ err = get_fp_registers(pid, fpregs);
+ if (err < 0) {
+ printk(UM_KERN_ERR "save_fp_registers returned %d\n",
+ err);
+ fatal_sigsegv();
}
- else {
- unsigned long fpregs[FP_SIZE];
-
- err = get_fp_registers(pid, fpregs);
- if (err < 0) {
- printk(UM_KERN_ERR "save_fp_registers returned %d\n",
- err);
- fatal_sigsegv();
- }
- err = ptrace(PTRACE_CONT, pid, 0, SIGSEGV);
- if (err) {
- printk(UM_KERN_ERR "Failed to continue stub, pid = %d, "
- "errno = %d\n", pid, errno);
- fatal_sigsegv();
- }
- wait_stub_done(pid);
+ err = ptrace(PTRACE_CONT, pid, 0, SIGSEGV);
+ if (err) {
+ printk(UM_KERN_ERR "Failed to continue stub, pid = %d, "
+ "errno = %d\n", pid, errno);
+ fatal_sigsegv();
+ }
+ wait_stub_done(pid);
- /*
- * faultinfo is prepared by the stub-segv-handler at start of
- * the stub stack page. We just have to copy it.
- */
- memcpy(fi, (void *)current_stub_stack(), sizeof(*fi));
+ /*
+ * faultinfo is prepared by the stub-segv-handler at start of
+ * the stub stack page. We just have to copy it.
+ */
+ memcpy(fi, (void *)current_stub_stack(), sizeof(*fi));
- err = put_fp_registers(pid, fpregs);
- if (err < 0) {
- printk(UM_KERN_ERR "put_fp_registers returned %d\n",
- err);
- fatal_sigsegv();
- }
+ err = put_fp_registers(pid, fpregs);
+ if (err < 0) {
+ printk(UM_KERN_ERR "put_fp_registers returned %d\n",
+ err);
+ fatal_sigsegv();
}
}
@@ -198,7 +179,8 @@ extern int __syscall_stub_start;
static int userspace_tramp(void *stack)
{
void *addr;
- int err;
+ int err, fd;
+ unsigned long long offset;
ptrace(PTRACE_TRACEME, 0, 0, 0);
@@ -211,36 +193,32 @@ static int userspace_tramp(void *stack)
exit(1);
}
- if (!proc_mm) {
- /*
- * This has a pte, but it can't be mapped in with the usual
- * tlb_flush mechanism because this is part of that mechanism
- */
- int fd;
- unsigned long long offset;
- fd = phys_mapping(to_phys(&__syscall_stub_start), &offset);
- addr = mmap64((void *) STUB_CODE, UM_KERN_PAGE_SIZE,
- PROT_EXEC, MAP_FIXED | MAP_PRIVATE, fd, offset);
+ /*
+ * This has a pte, but it can't be mapped in with the usual
+ * tlb_flush mechanism because this is part of that mechanism
+ */
+ fd = phys_mapping(to_phys(&__syscall_stub_start), &offset);
+ 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);
+ exit(1);
+ }
+
+ if (stack != NULL) {
+ fd = phys_mapping(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 mmap stub at 0x%lx failed, "
- "errno = %d\n", STUB_CODE, errno);
+ printk(UM_KERN_ERR "mapping segfault stack "
+ "at 0x%lx failed, errno = %d\n",
+ STUB_DATA, errno);
exit(1);
}
-
- if (stack != NULL) {
- fd = phys_mapping(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);
- }
- }
}
- if (!ptrace_faultinfo && (stack != NULL)) {
+ if (stack != NULL) {
struct sigaction sa;
unsigned long v = STUB_CODE +
@@ -286,11 +264,7 @@ int start_userspace(unsigned long stub_stack)
sp = (unsigned long) stack + UM_KERN_PAGE_SIZE - sizeof(void *);
- flags = CLONE_FILES;
- if (proc_mm)
- flags |= CLONE_VM;
- else
- flags |= SIGCHLD;
+ flags = CLONE_FILES | SIGCHLD;
pid = clone(userspace_tramp, (void *) sp, flags, (void *) stub_stack);
if (pid < 0) {
@@ -413,8 +387,7 @@ void userspace(struct uml_pt_regs *regs)
switch (sig) {
case SIGSEGV:
- if (PTRACE_FULL_FAULTINFO ||
- !ptrace_faultinfo) {
+ if (PTRACE_FULL_FAULTINFO) {
get_skas_faultinfo(pid,
&regs->faultinfo);
(*sig_info[SIGSEGV])(SIGSEGV, (struct siginfo *)&si,
@@ -571,67 +544,6 @@ int copy_context_skas0(unsigned long new_stack, int pid)
return err;
}
-/*
- * This is used only, if stub pages are needed, while proc_mm is
- * available. Opening /proc/mm creates a new mm_context, which lacks
- * the stub-pages. Thus, we map them using /proc/mm-fd
- */
-int map_stub_pages(int fd, unsigned long code, unsigned long data,
- unsigned long stack)
-{
- struct proc_mm_op mmop;
- int n;
- unsigned long long code_offset;
- int code_fd = phys_mapping(to_phys((void *) &__syscall_stub_start),
- &code_offset);
-
- mmop = ((struct proc_mm_op) { .op = MM_MMAP,
- .u =
- { .mmap =
- { .addr = code,
- .len = UM_KERN_PAGE_SIZE,
- .prot = PROT_EXEC,
- .flags = MAP_FIXED | MAP_PRIVATE,
- .fd = code_fd,
- .offset = code_offset
- } } });
- CATCH_EINTR(n = write(fd, &mmop, sizeof(mmop)));
- if (n != sizeof(mmop)) {
- n = errno;
- printk(UM_KERN_ERR "mmap args - addr = 0x%lx, fd = %d, "
- "offset = %llx\n", code, code_fd,
- (unsigned long long) code_offset);
- printk(UM_KERN_ERR "map_stub_pages : /proc/mm map for code "
- "failed, err = %d\n", n);
- return -n;
- }
-
- if (stack) {
- unsigned long long map_offset;
- int map_fd = phys_mapping(to_phys((void *)stack), &map_offset);
- mmop = ((struct proc_mm_op)
- { .op = MM_MMAP,
- .u =
- { .mmap =
- { .addr = data,
- .len = UM_KERN_PAGE_SIZE,
- .prot = PROT_READ | PROT_WRITE,
- .flags = MAP_FIXED | MAP_SHARED,
- .fd = map_fd,
- .offset = map_offset
- } } });
- CATCH_EINTR(n = write(fd, &mmop, sizeof(mmop)));
- 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))
{
(*buf)[0].JB_IP = (unsigned long) handler;
@@ -728,17 +640,5 @@ void reboot_skas(void)
void __switch_mm(struct mm_id *mm_idp)
{
- int err;
-
- /* FIXME: need cpu pid in __switch_mm */
- if (proc_mm) {
- err = ptrace(PTRACE_SWITCH_MM, userspace_pid[0], 0,
- mm_idp->u.mm_fd);
- 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;
+ userspace_pid[0] = mm_idp->u.pid;
}
diff --git a/arch/um/os-Linux/start_up.c b/arch/um/os-Linux/start_up.c
index 337518c5042a..47f1ff056a54 100644
--- a/arch/um/os-Linux/start_up.c
+++ b/arch/um/os-Linux/start_up.c
@@ -24,7 +24,6 @@
#include <ptrace_user.h>
#include <registers.h>
#include <skas.h>
-#include <skas_ptrace.h>
static void ptrace_child(void)
{
@@ -143,44 +142,6 @@ static int stop_ptraced_child(int pid, int exitcode, int mustexit)
}
/* Changed only during early boot */
-int ptrace_faultinfo;
-static int disable_ptrace_faultinfo;
-
-int ptrace_ldt;
-static int disable_ptrace_ldt;
-
-int proc_mm;
-static int disable_proc_mm;
-
-int have_switch_mm;
-static int disable_switch_mm;
-
-int skas_needs_stub;
-
-static int __init skas0_cmd_param(char *str, int* add)
-{
- disable_ptrace_faultinfo = 1;
- disable_ptrace_ldt = 1;
- disable_proc_mm = 1;
- disable_switch_mm = 1;
-
- return 0;
-}
-
-/* The two __uml_setup would conflict, without this stupid alias. */
-
-static int __init mode_skas0_cmd_param(char *str, int* add)
- __attribute__((alias("skas0_cmd_param")));
-
-__uml_setup("skas0", skas0_cmd_param,
-"skas0\n"
-" Disables SKAS3 and SKAS4 usage, so that SKAS0 is used\n\n");
-
-__uml_setup("mode=skas0", mode_skas0_cmd_param,
-"mode=skas0\n"
-" Disables SKAS3 and SKAS4 usage, so that SKAS0 is used.\n\n");
-
-/* Changed only during early boot */
static int force_sysemu_disabled = 0;
static int __init nosysemu_cmd_param(char *str, int* add)
@@ -376,121 +337,6 @@ void __init os_early_checks(void)
stop_ptraced_child(pid, 1, 1);
}
-static int __init noprocmm_cmd_param(char *str, int* add)
-{
- disable_proc_mm = 1;
- return 0;
-}
-
-__uml_setup("noprocmm", noprocmm_cmd_param,
-"noprocmm\n"
-" Turns off usage of /proc/mm, even if host supports it.\n"
-" To support /proc/mm, the host needs to be patched using\n"
-" the current skas3 patch.\n\n");
-
-static int __init noptracefaultinfo_cmd_param(char *str, int* add)
-{
- disable_ptrace_faultinfo = 1;
- return 0;
-}
-
-__uml_setup("noptracefaultinfo", noptracefaultinfo_cmd_param,
-"noptracefaultinfo\n"
-" Turns off usage of PTRACE_FAULTINFO, even if host supports\n"
-" it. To support PTRACE_FAULTINFO, the host needs to be patched\n"
-" using the current skas3 patch.\n\n");
-
-static int __init noptraceldt_cmd_param(char *str, int* add)
-{
- disable_ptrace_ldt = 1;
- return 0;
-}
-
-__uml_setup("noptraceldt", noptraceldt_cmd_param,
-"noptraceldt\n"
-" Turns off usage of PTRACE_LDT, even if host supports it.\n"
-" To support PTRACE_LDT, the host needs to be patched using\n"
-" the current skas3 patch.\n\n");
-
-static inline void check_skas3_ptrace_faultinfo(void)
-{
- struct ptrace_faultinfo fi;
- int pid, n;
-
- non_fatal(" - PTRACE_FAULTINFO...");
- pid = start_ptraced_child();
-
- n = ptrace(PTRACE_FAULTINFO, pid, 0, &fi);
- if (n < 0) {
- if (errno == EIO)
- non_fatal("not found\n");
- else
- perror("not found");
- } else if (disable_ptrace_faultinfo)
- non_fatal("found but disabled on command line\n");
- else {
- ptrace_faultinfo = 1;
- non_fatal("found\n");
- }
-
- stop_ptraced_child(pid, 1, 1);
-}
-
-static inline void check_skas3_ptrace_ldt(void)
-{
-#ifdef PTRACE_LDT
- int pid, n;
- unsigned char ldtbuf[40];
- struct ptrace_ldt ldt_op = (struct ptrace_ldt) {
- .func = 2, /* read default ldt */
- .ptr = ldtbuf,
- .bytecount = sizeof(ldtbuf)};
-
- non_fatal(" - PTRACE_LDT...");
- pid = start_ptraced_child();
-
- n = ptrace(PTRACE_LDT, pid, 0, (unsigned long) &ldt_op);
- if (n < 0) {
- if (errno == EIO)
- non_fatal("not found\n");
- else
- perror("not found");
- } else if (disable_ptrace_ldt)
- non_fatal("found, but use is disabled\n");
- else {
- ptrace_ldt = 1;
- non_fatal("found\n");
- }
-
- stop_ptraced_child(pid, 1, 1);
-#endif
-}
-
-static inline void check_skas3_proc_mm(void)
-{
- non_fatal(" - /proc/mm...");
- if (access("/proc/mm", W_OK) < 0)
- perror("not found");
- else if (disable_proc_mm)
- non_fatal("found but disabled on command line\n");
- else {
- proc_mm = 1;
- non_fatal("found\n");
- }
-}
-
-void can_do_skas(void)
-{
- non_fatal("Checking for the skas3 patch in the host:\n");
-
- check_skas3_proc_mm();
- check_skas3_ptrace_faultinfo();
- check_skas3_ptrace_ldt();
-
- if (!proc_mm || !ptrace_faultinfo || !ptrace_ldt)
- skas_needs_stub = 1;
-}
-
int __init parse_iomem(char *str, int *add)
{
struct iomem_region *new;