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Merge branch 'x86-pti-for-linus' of git://git.kernel.org/pub/scm/linu…
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…x/kernel/git/tip/tip

Pull x86/pti updates from Thomas Gleixner:
 "Yet another pile of melted spectrum related updates:

   - Drop native vsyscall support finally as it causes more trouble than
     benefit.

   - Make microcode loading more robust. There were a few issues
     especially related to late loading which are now surfacing because
     late loading of the IB* microcodes addressing spectre issues has
     become more widely used.

   - Simplify and robustify the syscall handling in the entry code

   - Prevent kprobes on the entry trampoline code which lead to kernel
     crashes when the probe hits before CR3 is updated

   - Don't check microcode versions when running on hypervisors as they
     are considered as lying anyway.

   - Fix the 32bit objtool build and a coment typo"

* 'x86-pti-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  x86/kprobes: Fix kernel crash when probing .entry_trampoline code
  x86/pti: Fix a comment typo
  x86/microcode: Synchronize late microcode loading
  x86/microcode: Request microcode on the BSP
  x86/microcode/intel: Look into the patch cache first
  x86/microcode: Do not upload microcode if CPUs are offline
  x86/microcode/intel: Writeback and invalidate caches before updating microcode
  x86/microcode/intel: Check microcode revision before updating sibling threads
  x86/microcode: Get rid of struct apply_microcode_ctx
  x86/spectre_v2: Don't check microcode versions when running under hypervisors
  x86/vsyscall/64: Drop "native" vsyscalls
  x86/entry/64/compat: Save one instruction in entry_INT80_compat()
  x86/entry: Do not special-case clone(2) in compat entry
  x86/syscalls: Use COMPAT_SYSCALL_DEFINEx() macros for x86-only compat syscalls
  x86/syscalls: Use proper syscall definition for sys_ioperm()
  x86/entry: Remove stale syscall prototype
  x86/syscalls/32: Simplify $entry == $compat entries
  objtool: Fix 32-bit build
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Linus Torvalds committed Mar 11, 2018
2 parents 1ad5daa + c07a8f8 commit ed58d66
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Showing 17 changed files with 291 additions and 182 deletions.
11 changes: 1 addition & 10 deletions arch/x86/Kconfig
Original file line number Diff line number Diff line change
Expand Up @@ -2307,23 +2307,14 @@ choice
it can be used to assist security vulnerability exploitation.

This setting can be changed at boot time via the kernel command
line parameter vsyscall=[native|emulate|none].
line parameter vsyscall=[emulate|none].

On a system with recent enough glibc (2.14 or newer) and no
static binaries, you can say None without a performance penalty
to improve security.

If unsure, select "Emulate".

config LEGACY_VSYSCALL_NATIVE
bool "Native"
help
Actual executable code is located in the fixed vsyscall
address mapping, implementing time() efficiently. Since
this makes the mapping executable, it can be used during
security vulnerability exploitation (traditionally as
ROP gadgets). This configuration is not recommended.

config LEGACY_VSYSCALL_EMULATE
bool "Emulate"
help
Expand Down
16 changes: 1 addition & 15 deletions arch/x86/entry/entry_64_compat.S
Original file line number Diff line number Diff line change
Expand Up @@ -363,9 +363,7 @@ ENTRY(entry_INT80_compat)
pushq 2*8(%rdi) /* regs->ip */
pushq 1*8(%rdi) /* regs->orig_ax */

movq (%rdi), %rdi /* restore %rdi */

pushq %rdi /* pt_regs->di */
pushq (%rdi) /* pt_regs->di */
pushq %rsi /* pt_regs->si */
pushq %rdx /* pt_regs->dx */
pushq %rcx /* pt_regs->cx */
Expand Down Expand Up @@ -406,15 +404,3 @@ ENTRY(entry_INT80_compat)
TRACE_IRQS_ON
jmp swapgs_restore_regs_and_return_to_usermode
END(entry_INT80_compat)

ENTRY(stub32_clone)
/*
* The 32-bit clone ABI is: clone(..., int tls_val, int *child_tidptr).
* The 64-bit clone ABI is: clone(..., int *child_tidptr, int tls_val).
*
* The native 64-bit kernel's sys_clone() implements the latter,
* so we need to swap arguments here before calling it:
*/
xchg %r8, %rcx
jmp sys_clone
ENDPROC(stub32_clone)
38 changes: 19 additions & 19 deletions arch/x86/entry/syscalls/syscall_32.tbl
Original file line number Diff line number Diff line change
Expand Up @@ -8,12 +8,12 @@
#
0 i386 restart_syscall sys_restart_syscall
1 i386 exit sys_exit
2 i386 fork sys_fork sys_fork
2 i386 fork sys_fork
3 i386 read sys_read
4 i386 write sys_write
5 i386 open sys_open compat_sys_open
6 i386 close sys_close
7 i386 waitpid sys_waitpid sys32_waitpid
7 i386 waitpid sys_waitpid compat_sys_x86_waitpid
8 i386 creat sys_creat
9 i386 link sys_link
10 i386 unlink sys_unlink
Expand Down Expand Up @@ -78,7 +78,7 @@
69 i386 ssetmask sys_ssetmask
70 i386 setreuid sys_setreuid16
71 i386 setregid sys_setregid16
72 i386 sigsuspend sys_sigsuspend sys_sigsuspend
72 i386 sigsuspend sys_sigsuspend
73 i386 sigpending sys_sigpending compat_sys_sigpending
74 i386 sethostname sys_sethostname
75 i386 setrlimit sys_setrlimit compat_sys_setrlimit
Expand All @@ -96,7 +96,7 @@
87 i386 swapon sys_swapon
88 i386 reboot sys_reboot
89 i386 readdir sys_old_readdir compat_sys_old_readdir
90 i386 mmap sys_old_mmap sys32_mmap
90 i386 mmap sys_old_mmap compat_sys_x86_mmap
91 i386 munmap sys_munmap
92 i386 truncate sys_truncate compat_sys_truncate
93 i386 ftruncate sys_ftruncate compat_sys_ftruncate
Expand Down Expand Up @@ -126,7 +126,7 @@
117 i386 ipc sys_ipc compat_sys_ipc
118 i386 fsync sys_fsync
119 i386 sigreturn sys_sigreturn sys32_sigreturn
120 i386 clone sys_clone stub32_clone
120 i386 clone sys_clone compat_sys_x86_clone
121 i386 setdomainname sys_setdomainname
122 i386 uname sys_newuname
123 i386 modify_ldt sys_modify_ldt
Expand Down Expand Up @@ -186,8 +186,8 @@
177 i386 rt_sigtimedwait sys_rt_sigtimedwait compat_sys_rt_sigtimedwait
178 i386 rt_sigqueueinfo sys_rt_sigqueueinfo compat_sys_rt_sigqueueinfo
179 i386 rt_sigsuspend sys_rt_sigsuspend
180 i386 pread64 sys_pread64 sys32_pread
181 i386 pwrite64 sys_pwrite64 sys32_pwrite
180 i386 pread64 sys_pread64 compat_sys_x86_pread
181 i386 pwrite64 sys_pwrite64 compat_sys_x86_pwrite
182 i386 chown sys_chown16
183 i386 getcwd sys_getcwd
184 i386 capget sys_capget
Expand All @@ -196,14 +196,14 @@
187 i386 sendfile sys_sendfile compat_sys_sendfile
188 i386 getpmsg
189 i386 putpmsg
190 i386 vfork sys_vfork sys_vfork
190 i386 vfork sys_vfork
191 i386 ugetrlimit sys_getrlimit compat_sys_getrlimit
192 i386 mmap2 sys_mmap_pgoff
193 i386 truncate64 sys_truncate64 sys32_truncate64
194 i386 ftruncate64 sys_ftruncate64 sys32_ftruncate64
195 i386 stat64 sys_stat64 sys32_stat64
196 i386 lstat64 sys_lstat64 sys32_lstat64
197 i386 fstat64 sys_fstat64 sys32_fstat64
193 i386 truncate64 sys_truncate64 compat_sys_x86_truncate64
194 i386 ftruncate64 sys_ftruncate64 compat_sys_x86_ftruncate64
195 i386 stat64 sys_stat64 compat_sys_x86_stat64
196 i386 lstat64 sys_lstat64 compat_sys_x86_lstat64
197 i386 fstat64 sys_fstat64 compat_sys_x86_fstat64
198 i386 lchown32 sys_lchown
199 i386 getuid32 sys_getuid
200 i386 getgid32 sys_getgid
Expand Down Expand Up @@ -231,7 +231,7 @@
# 222 is unused
# 223 is unused
224 i386 gettid sys_gettid
225 i386 readahead sys_readahead sys32_readahead
225 i386 readahead sys_readahead compat_sys_x86_readahead
226 i386 setxattr sys_setxattr
227 i386 lsetxattr sys_lsetxattr
228 i386 fsetxattr sys_fsetxattr
Expand All @@ -256,7 +256,7 @@
247 i386 io_getevents sys_io_getevents compat_sys_io_getevents
248 i386 io_submit sys_io_submit compat_sys_io_submit
249 i386 io_cancel sys_io_cancel
250 i386 fadvise64 sys_fadvise64 sys32_fadvise64
250 i386 fadvise64 sys_fadvise64 compat_sys_x86_fadvise64
# 251 is available for reuse (was briefly sys_set_zone_reclaim)
252 i386 exit_group sys_exit_group
253 i386 lookup_dcookie sys_lookup_dcookie compat_sys_lookup_dcookie
Expand All @@ -278,7 +278,7 @@
269 i386 fstatfs64 sys_fstatfs64 compat_sys_fstatfs64
270 i386 tgkill sys_tgkill
271 i386 utimes sys_utimes compat_sys_utimes
272 i386 fadvise64_64 sys_fadvise64_64 sys32_fadvise64_64
272 i386 fadvise64_64 sys_fadvise64_64 compat_sys_x86_fadvise64_64
273 i386 vserver
274 i386 mbind sys_mbind
275 i386 get_mempolicy sys_get_mempolicy compat_sys_get_mempolicy
Expand Down Expand Up @@ -306,7 +306,7 @@
297 i386 mknodat sys_mknodat
298 i386 fchownat sys_fchownat
299 i386 futimesat sys_futimesat compat_sys_futimesat
300 i386 fstatat64 sys_fstatat64 sys32_fstatat
300 i386 fstatat64 sys_fstatat64 compat_sys_x86_fstatat
301 i386 unlinkat sys_unlinkat
302 i386 renameat sys_renameat
303 i386 linkat sys_linkat
Expand All @@ -320,7 +320,7 @@
311 i386 set_robust_list sys_set_robust_list compat_sys_set_robust_list
312 i386 get_robust_list sys_get_robust_list compat_sys_get_robust_list
313 i386 splice sys_splice
314 i386 sync_file_range sys_sync_file_range sys32_sync_file_range
314 i386 sync_file_range sys_sync_file_range compat_sys_x86_sync_file_range
315 i386 tee sys_tee
316 i386 vmsplice sys_vmsplice compat_sys_vmsplice
317 i386 move_pages sys_move_pages compat_sys_move_pages
Expand All @@ -330,7 +330,7 @@
321 i386 signalfd sys_signalfd compat_sys_signalfd
322 i386 timerfd_create sys_timerfd_create
323 i386 eventfd sys_eventfd
324 i386 fallocate sys_fallocate sys32_fallocate
324 i386 fallocate sys_fallocate compat_sys_x86_fallocate
325 i386 timerfd_settime sys_timerfd_settime compat_sys_timerfd_settime
326 i386 timerfd_gettime sys_timerfd_gettime compat_sys_timerfd_gettime
327 i386 signalfd4 sys_signalfd4 compat_sys_signalfd4
Expand Down
16 changes: 3 additions & 13 deletions arch/x86/entry/vsyscall/vsyscall_64.c
Original file line number Diff line number Diff line change
Expand Up @@ -42,10 +42,8 @@
#define CREATE_TRACE_POINTS
#include "vsyscall_trace.h"

static enum { EMULATE, NATIVE, NONE } vsyscall_mode =
#if defined(CONFIG_LEGACY_VSYSCALL_NATIVE)
NATIVE;
#elif defined(CONFIG_LEGACY_VSYSCALL_NONE)
static enum { EMULATE, NONE } vsyscall_mode =
#ifdef CONFIG_LEGACY_VSYSCALL_NONE
NONE;
#else
EMULATE;
Expand All @@ -56,8 +54,6 @@ static int __init vsyscall_setup(char *str)
if (str) {
if (!strcmp("emulate", str))
vsyscall_mode = EMULATE;
else if (!strcmp("native", str))
vsyscall_mode = NATIVE;
else if (!strcmp("none", str))
vsyscall_mode = NONE;
else
Expand Down Expand Up @@ -139,10 +135,6 @@ bool emulate_vsyscall(struct pt_regs *regs, unsigned long address)

WARN_ON_ONCE(address != regs->ip);

/* This should be unreachable in NATIVE mode. */
if (WARN_ON(vsyscall_mode == NATIVE))
return false;

if (vsyscall_mode == NONE) {
warn_bad_vsyscall(KERN_INFO, regs,
"vsyscall attempted with vsyscall=none");
Expand Down Expand Up @@ -370,9 +362,7 @@ void __init map_vsyscall(void)

if (vsyscall_mode != NONE) {
__set_fixmap(VSYSCALL_PAGE, physaddr_vsyscall,
vsyscall_mode == NATIVE
? PAGE_KERNEL_VSYSCALL
: PAGE_KERNEL_VVAR);
PAGE_KERNEL_VVAR);
set_vsyscall_pgtable_user_bits(swapper_pg_dir);
}

Expand Down
74 changes: 44 additions & 30 deletions arch/x86/ia32/sys_ia32.c
Original file line number Diff line number Diff line change
Expand Up @@ -51,15 +51,14 @@
#define AA(__x) ((unsigned long)(__x))


asmlinkage long sys32_truncate64(const char __user *filename,
unsigned long offset_low,
unsigned long offset_high)
COMPAT_SYSCALL_DEFINE3(x86_truncate64, const char __user *, filename,
unsigned long, offset_low, unsigned long, offset_high)
{
return sys_truncate(filename, ((loff_t) offset_high << 32) | offset_low);
}

asmlinkage long sys32_ftruncate64(unsigned int fd, unsigned long offset_low,
unsigned long offset_high)
COMPAT_SYSCALL_DEFINE3(x86_ftruncate64, unsigned int, fd,
unsigned long, offset_low, unsigned long, offset_high)
{
return sys_ftruncate(fd, ((loff_t) offset_high << 32) | offset_low);
}
Expand Down Expand Up @@ -96,8 +95,8 @@ static int cp_stat64(struct stat64 __user *ubuf, struct kstat *stat)
return 0;
}

asmlinkage long sys32_stat64(const char __user *filename,
struct stat64 __user *statbuf)
COMPAT_SYSCALL_DEFINE2(x86_stat64, const char __user *, filename,
struct stat64 __user *, statbuf)
{
struct kstat stat;
int ret = vfs_stat(filename, &stat);
Expand All @@ -107,8 +106,8 @@ asmlinkage long sys32_stat64(const char __user *filename,
return ret;
}

asmlinkage long sys32_lstat64(const char __user *filename,
struct stat64 __user *statbuf)
COMPAT_SYSCALL_DEFINE2(x86_lstat64, const char __user *, filename,
struct stat64 __user *, statbuf)
{
struct kstat stat;
int ret = vfs_lstat(filename, &stat);
Expand All @@ -117,7 +116,8 @@ asmlinkage long sys32_lstat64(const char __user *filename,
return ret;
}

asmlinkage long sys32_fstat64(unsigned int fd, struct stat64 __user *statbuf)
COMPAT_SYSCALL_DEFINE2(x86_fstat64, unsigned int, fd,
struct stat64 __user *, statbuf)
{
struct kstat stat;
int ret = vfs_fstat(fd, &stat);
Expand All @@ -126,8 +126,9 @@ asmlinkage long sys32_fstat64(unsigned int fd, struct stat64 __user *statbuf)
return ret;
}

asmlinkage long sys32_fstatat(unsigned int dfd, const char __user *filename,
struct stat64 __user *statbuf, int flag)
COMPAT_SYSCALL_DEFINE4(x86_fstatat, unsigned int, dfd,
const char __user *, filename,
struct stat64 __user *, statbuf, int, flag)
{
struct kstat stat;
int error;
Expand All @@ -153,7 +154,7 @@ struct mmap_arg_struct32 {
unsigned int offset;
};

asmlinkage long sys32_mmap(struct mmap_arg_struct32 __user *arg)
COMPAT_SYSCALL_DEFINE1(x86_mmap, struct mmap_arg_struct32 __user *, arg)
{
struct mmap_arg_struct32 a;

Expand All @@ -167,22 +168,22 @@ asmlinkage long sys32_mmap(struct mmap_arg_struct32 __user *arg)
a.offset>>PAGE_SHIFT);
}

asmlinkage long sys32_waitpid(compat_pid_t pid, unsigned int __user *stat_addr,
int options)
COMPAT_SYSCALL_DEFINE3(x86_waitpid, compat_pid_t, pid, unsigned int __user *,
stat_addr, int, options)
{
return compat_sys_wait4(pid, stat_addr, options, NULL);
}

/* warning: next two assume little endian */
asmlinkage long sys32_pread(unsigned int fd, char __user *ubuf, u32 count,
u32 poslo, u32 poshi)
COMPAT_SYSCALL_DEFINE5(x86_pread, unsigned int, fd, char __user *, ubuf,
u32, count, u32, poslo, u32, poshi)
{
return sys_pread64(fd, ubuf, count,
((loff_t)AA(poshi) << 32) | AA(poslo));
}

asmlinkage long sys32_pwrite(unsigned int fd, const char __user *ubuf,
u32 count, u32 poslo, u32 poshi)
COMPAT_SYSCALL_DEFINE5(x86_pwrite, unsigned int, fd, const char __user *, ubuf,
u32, count, u32, poslo, u32, poshi)
{
return sys_pwrite64(fd, ubuf, count,
((loff_t)AA(poshi) << 32) | AA(poslo));
Expand All @@ -193,40 +194,53 @@ asmlinkage long sys32_pwrite(unsigned int fd, const char __user *ubuf,
* Some system calls that need sign extended arguments. This could be
* done by a generic wrapper.
*/
long sys32_fadvise64_64(int fd, __u32 offset_low, __u32 offset_high,
__u32 len_low, __u32 len_high, int advice)
COMPAT_SYSCALL_DEFINE6(x86_fadvise64_64, int, fd, __u32, offset_low,
__u32, offset_high, __u32, len_low, __u32, len_high,
int, advice)
{
return sys_fadvise64_64(fd,
(((u64)offset_high)<<32) | offset_low,
(((u64)len_high)<<32) | len_low,
advice);
}

asmlinkage ssize_t sys32_readahead(int fd, unsigned off_lo, unsigned off_hi,
size_t count)
COMPAT_SYSCALL_DEFINE4(x86_readahead, int, fd, unsigned int, off_lo,
unsigned int, off_hi, size_t, count)
{
return sys_readahead(fd, ((u64)off_hi << 32) | off_lo, count);
}

asmlinkage long sys32_sync_file_range(int fd, unsigned off_low, unsigned off_hi,
unsigned n_low, unsigned n_hi, int flags)
COMPAT_SYSCALL_DEFINE6(x86_sync_file_range, int, fd, unsigned int, off_low,
unsigned int, off_hi, unsigned int, n_low,
unsigned int, n_hi, int, flags)
{
return sys_sync_file_range(fd,
((u64)off_hi << 32) | off_low,
((u64)n_hi << 32) | n_low, flags);
}

asmlinkage long sys32_fadvise64(int fd, unsigned offset_lo, unsigned offset_hi,
size_t len, int advice)
COMPAT_SYSCALL_DEFINE5(x86_fadvise64, int, fd, unsigned int, offset_lo,
unsigned int, offset_hi, size_t, len, int, advice)
{
return sys_fadvise64_64(fd, ((u64)offset_hi << 32) | offset_lo,
len, advice);
}

asmlinkage long sys32_fallocate(int fd, int mode, unsigned offset_lo,
unsigned offset_hi, unsigned len_lo,
unsigned len_hi)
COMPAT_SYSCALL_DEFINE6(x86_fallocate, int, fd, int, mode,
unsigned int, offset_lo, unsigned int, offset_hi,
unsigned int, len_lo, unsigned int, len_hi)
{
return sys_fallocate(fd, mode, ((u64)offset_hi << 32) | offset_lo,
((u64)len_hi << 32) | len_lo);
}

/*
* The 32-bit clone ABI is CONFIG_CLONE_BACKWARDS
*/
COMPAT_SYSCALL_DEFINE5(x86_clone, unsigned long, clone_flags,
unsigned long, newsp, int __user *, parent_tidptr,
unsigned long, tls_val, int __user *, child_tidptr)
{
return sys_clone(clone_flags, newsp, parent_tidptr, child_tidptr,
tls_val);
}
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