Commit 5910cfdc authored by Linus Torvalds's avatar Linus Torvalds
Browse files

Merge branch 'parisc-3.17-1' of git://git.kernel.org/pub/scm/linux/kernel/git/deller/parisc-linux

Pull parisc updates from Helge Deller:
 "The most important patch is a new Light Weigth Syscall (LWS) for 8,
  16, 32 and 64 bit atomic CAS operations which is required in order to
  be able to implement the atomic gcc builtins on our platform.

  Other than that, we wire up the seccomp, getrandom and memfd_create
  syscalls, fixes a minor off-by-one bug and a wrong printk string"

* 'parisc-3.17-1' of git://git.kernel.org/pub/scm/linux/kernel/git/deller/parisc-linux:
  parisc: Implement new LWS CAS supporting 64 bit operations.
  parisc: Wire up seccomp, getrandom and memfd_create syscalls
  parisc: dino: fix %d confusingly prefixed with 0x in format string
  parisc: sys_hpux: NUL terminator is one past the end
parents 02c1be3d 89206491
......@@ -321,6 +321,22 @@ source "fs/Kconfig"
source "arch/parisc/Kconfig.debug"
config SECCOMP
def_bool y
prompt "Enable seccomp to safely compute untrusted bytecode"
---help---
This kernel feature is useful for number crunching applications
that may need to compute untrusted bytecode during their
execution. By using pipes or other transports made available to
the process as file descriptors supporting the read/write
syscalls, it's possible to isolate those applications in
their own address space using seccomp. Once seccomp is
enabled via prctl(PR_SET_SECCOMP), it cannot be disabled
and the task is only allowed to execute a few safe syscalls
defined by each seccomp mode.
If unsure, say Y. Only embedded should say N here.
source "security/Kconfig"
source "crypto/Kconfig"
......
......@@ -456,7 +456,7 @@ int hpux_sysfs(int opcode, unsigned long arg1, unsigned long arg2)
}
/* String could be altered by userspace after strlen_user() */
fsname[len] = '\0';
fsname[len - 1] = '\0';
printk(KERN_DEBUG "that is '%s' as (char *)\n", fsname);
if ( !strcmp(fsname, "hfs") ) {
......
#ifndef _ASM_PARISC_SECCOMP_H
#define _ASM_PARISC_SECCOMP_H
#include <linux/unistd.h>
#define __NR_seccomp_read __NR_read
#define __NR_seccomp_write __NR_write
#define __NR_seccomp_exit __NR_exit
#define __NR_seccomp_sigreturn __NR_rt_sigreturn
#define __NR_seccomp_read_32 __NR_read
#define __NR_seccomp_write_32 __NR_write
#define __NR_seccomp_exit_32 __NR_exit
#define __NR_seccomp_sigreturn_32 __NR_rt_sigreturn
#endif /* _ASM_PARISC_SECCOMP_H */
......@@ -60,6 +60,7 @@ struct thread_info {
#define TIF_NOTIFY_RESUME 8 /* callback before returning to user */
#define TIF_SINGLESTEP 9 /* single stepping? */
#define TIF_BLOCKSTEP 10 /* branch stepping? */
#define TIF_SECCOMP 11 /* secure computing */
#define _TIF_SYSCALL_TRACE (1 << TIF_SYSCALL_TRACE)
#define _TIF_SIGPENDING (1 << TIF_SIGPENDING)
......@@ -70,11 +71,13 @@ struct thread_info {
#define _TIF_NOTIFY_RESUME (1 << TIF_NOTIFY_RESUME)
#define _TIF_SINGLESTEP (1 << TIF_SINGLESTEP)
#define _TIF_BLOCKSTEP (1 << TIF_BLOCKSTEP)
#define _TIF_SECCOMP (1 << TIF_SECCOMP)
#define _TIF_USER_WORK_MASK (_TIF_SIGPENDING | _TIF_NOTIFY_RESUME | \
_TIF_NEED_RESCHED)
#define _TIF_SYSCALL_TRACE_MASK (_TIF_SYSCALL_TRACE | _TIF_SINGLESTEP | \
_TIF_BLOCKSTEP | _TIF_SYSCALL_AUDIT)
_TIF_BLOCKSTEP | _TIF_SYSCALL_AUDIT | \
_TIF_SECCOMP)
#ifdef CONFIG_64BIT
# ifdef CONFIG_COMPAT
......
......@@ -830,8 +830,11 @@
#define __NR_sched_getattr (__NR_Linux + 335)
#define __NR_utimes (__NR_Linux + 336)
#define __NR_renameat2 (__NR_Linux + 337)
#define __NR_seccomp (__NR_Linux + 338)
#define __NR_getrandom (__NR_Linux + 339)
#define __NR_memfd_create (__NR_Linux + 340)
#define __NR_Linux_syscalls (__NR_renameat2 + 1)
#define __NR_Linux_syscalls (__NR_memfd_create + 1)
#define __IGNORE_select /* newselect */
......
......@@ -270,6 +270,12 @@ long do_syscall_trace_enter(struct pt_regs *regs)
{
long ret = 0;
/* Do the secure computing check first. */
if (secure_computing(regs->gr[20])) {
/* seccomp failures shouldn't expose any additional code. */
return -1;
}
if (test_thread_flag(TIF_SYSCALL_TRACE) &&
tracehook_report_syscall_entry(regs))
ret = -1L;
......
......@@ -74,7 +74,7 @@ ENTRY(linux_gateway_page)
/* ADDRESS 0xb0 to 0xb8, lws uses two insns for entry */
/* Light-weight-syscall entry must always be located at 0xb0 */
/* WARNING: Keep this number updated with table size changes */
#define __NR_lws_entries (2)
#define __NR_lws_entries (3)
lws_entry:
gate lws_start, %r0 /* increase privilege */
......@@ -502,7 +502,7 @@ lws_exit:
/***************************************************
Implementing CAS as an atomic operation:
Implementing 32bit CAS as an atomic operation:
%r26 - Address to examine
%r25 - Old value to check (old)
......@@ -659,6 +659,230 @@ cas_action:
ASM_EXCEPTIONTABLE_ENTRY(2b-linux_gateway_page, 3b-linux_gateway_page)
/***************************************************
New CAS implementation which uses pointers and variable size
information. The value pointed by old and new MUST NOT change
while performing CAS. The lock only protect the value at %r26.
%r26 - Address to examine
%r25 - Pointer to the value to check (old)
%r24 - Pointer to the value to set (new)
%r23 - Size of the variable (0/1/2/3 for 8/16/32/64 bit)
%r28 - Return non-zero on failure
%r21 - Kernel error code
%r21 has the following meanings:
EAGAIN - CAS is busy, ldcw failed, try again.
EFAULT - Read or write failed.
Scratch: r20, r22, r28, r29, r1, fr4 (32bit for 64bit CAS only)
****************************************************/
/* ELF32 Process entry path */
lws_compare_and_swap_2:
#ifdef CONFIG_64BIT
/* Clip the input registers */
depdi 0, 31, 32, %r26
depdi 0, 31, 32, %r25
depdi 0, 31, 32, %r24
depdi 0, 31, 32, %r23
#endif
/* Check the validity of the size pointer */
subi,>>= 4, %r23, %r0
b,n lws_exit_nosys
/* Jump to the functions which will load the old and new values into
registers depending on the their size */
shlw %r23, 2, %r29
blr %r29, %r0
nop
/* 8bit load */
4: ldb 0(%sr3,%r25), %r25
b cas2_lock_start
5: ldb 0(%sr3,%r24), %r24
nop
nop
nop
nop
nop
/* 16bit load */
6: ldh 0(%sr3,%r25), %r25
b cas2_lock_start
7: ldh 0(%sr3,%r24), %r24
nop
nop
nop
nop
nop
/* 32bit load */
8: ldw 0(%sr3,%r25), %r25
b cas2_lock_start
9: ldw 0(%sr3,%r24), %r24
nop
nop
nop
nop
nop
/* 64bit load */
#ifdef CONFIG_64BIT
10: ldd 0(%sr3,%r25), %r25
11: ldd 0(%sr3,%r24), %r24
#else
/* Load new value into r22/r23 - high/low */
10: ldw 0(%sr3,%r25), %r22
11: ldw 4(%sr3,%r25), %r23
/* Load new value into fr4 for atomic store later */
12: flddx 0(%sr3,%r24), %fr4
#endif
cas2_lock_start:
/* Load start of lock table */
ldil L%lws_lock_start, %r20
ldo R%lws_lock_start(%r20), %r28
/* Extract four bits from r26 and hash lock (Bits 4-7) */
extru %r26, 27, 4, %r20
/* Find lock to use, the hash is either one of 0 to
15, multiplied by 16 (keep it 16-byte aligned)
and add to the lock table offset. */
shlw %r20, 4, %r20
add %r20, %r28, %r20
rsm PSW_SM_I, %r0 /* Disable interrupts */
/* COW breaks can cause contention on UP systems */
LDCW 0(%sr2,%r20), %r28 /* Try to acquire the lock */
cmpb,<>,n %r0, %r28, cas2_action /* Did we get it? */
cas2_wouldblock:
ldo 2(%r0), %r28 /* 2nd case */
ssm PSW_SM_I, %r0
b lws_exit /* Contended... */
ldo -EAGAIN(%r0), %r21 /* Spin in userspace */
/*
prev = *addr;
if ( prev == old )
*addr = new;
return prev;
*/
/* NOTES:
This all works becuse intr_do_signal
and schedule both check the return iasq
and see that we are on the kernel page
so this process is never scheduled off
or is ever sent any signal of any sort,
thus it is wholly atomic from usrspaces
perspective
*/
cas2_action:
/* Jump to the correct function */
blr %r29, %r0
/* Set %r28 as non-zero for now */
ldo 1(%r0),%r28
/* 8bit CAS */
13: ldb,ma 0(%sr3,%r26), %r29
sub,= %r29, %r25, %r0
b,n cas2_end
14: stb,ma %r24, 0(%sr3,%r26)
b cas2_end
copy %r0, %r28
nop
nop
/* 16bit CAS */
15: ldh,ma 0(%sr3,%r26), %r29
sub,= %r29, %r25, %r0
b,n cas2_end
16: sth,ma %r24, 0(%sr3,%r26)
b cas2_end
copy %r0, %r28
nop
nop
/* 32bit CAS */
17: ldw,ma 0(%sr3,%r26), %r29
sub,= %r29, %r25, %r0
b,n cas2_end
18: stw,ma %r24, 0(%sr3,%r26)
b cas2_end
copy %r0, %r28
nop
nop
/* 64bit CAS */
#ifdef CONFIG_64BIT
19: ldd,ma 0(%sr3,%r26), %r29
sub,= %r29, %r25, %r0
b,n cas2_end
20: std,ma %r24, 0(%sr3,%r26)
copy %r0, %r28
#else
/* Compare first word */
19: ldw,ma 0(%sr3,%r26), %r29
sub,= %r29, %r22, %r0
b,n cas2_end
/* Compare second word */
20: ldw,ma 4(%sr3,%r26), %r29
sub,= %r29, %r23, %r0
b,n cas2_end
/* Perform the store */
21: fstdx %fr4, 0(%sr3,%r26)
copy %r0, %r28
#endif
cas2_end:
/* Free lock */
stw,ma %r20, 0(%sr2,%r20)
/* Enable interrupts */
ssm PSW_SM_I, %r0
/* Return to userspace, set no error */
b lws_exit
copy %r0, %r21
22:
/* Error occurred on load or store */
/* Free lock */
stw %r20, 0(%sr2,%r20)
ssm PSW_SM_I, %r0
ldo 1(%r0),%r28
b lws_exit
ldo -EFAULT(%r0),%r21 /* set errno */
nop
nop
nop
/* Exception table entries, for the load and store, return EFAULT.
Each of the entries must be relocated. */
ASM_EXCEPTIONTABLE_ENTRY(4b-linux_gateway_page, 22b-linux_gateway_page)
ASM_EXCEPTIONTABLE_ENTRY(5b-linux_gateway_page, 22b-linux_gateway_page)
ASM_EXCEPTIONTABLE_ENTRY(6b-linux_gateway_page, 22b-linux_gateway_page)
ASM_EXCEPTIONTABLE_ENTRY(7b-linux_gateway_page, 22b-linux_gateway_page)
ASM_EXCEPTIONTABLE_ENTRY(8b-linux_gateway_page, 22b-linux_gateway_page)
ASM_EXCEPTIONTABLE_ENTRY(9b-linux_gateway_page, 22b-linux_gateway_page)
ASM_EXCEPTIONTABLE_ENTRY(10b-linux_gateway_page, 22b-linux_gateway_page)
ASM_EXCEPTIONTABLE_ENTRY(11b-linux_gateway_page, 22b-linux_gateway_page)
ASM_EXCEPTIONTABLE_ENTRY(13b-linux_gateway_page, 22b-linux_gateway_page)
ASM_EXCEPTIONTABLE_ENTRY(14b-linux_gateway_page, 22b-linux_gateway_page)
ASM_EXCEPTIONTABLE_ENTRY(15b-linux_gateway_page, 22b-linux_gateway_page)
ASM_EXCEPTIONTABLE_ENTRY(16b-linux_gateway_page, 22b-linux_gateway_page)
ASM_EXCEPTIONTABLE_ENTRY(17b-linux_gateway_page, 22b-linux_gateway_page)
ASM_EXCEPTIONTABLE_ENTRY(18b-linux_gateway_page, 22b-linux_gateway_page)
ASM_EXCEPTIONTABLE_ENTRY(19b-linux_gateway_page, 22b-linux_gateway_page)
ASM_EXCEPTIONTABLE_ENTRY(20b-linux_gateway_page, 22b-linux_gateway_page)
#ifndef CONFIG_64BIT
ASM_EXCEPTIONTABLE_ENTRY(12b-linux_gateway_page, 22b-linux_gateway_page)
ASM_EXCEPTIONTABLE_ENTRY(21b-linux_gateway_page, 22b-linux_gateway_page)
#endif
/* Make sure nothing else is placed on this page */
.align PAGE_SIZE
END(linux_gateway_page)
......@@ -675,8 +899,9 @@ ENTRY(end_linux_gateway_page)
/* Light-weight-syscall table */
/* Start of lws table. */
ENTRY(lws_table)
LWS_ENTRY(compare_and_swap32) /* 0 - ELF32 Atomic compare and swap */
LWS_ENTRY(compare_and_swap64) /* 1 - ELF64 Atomic compare and swap */
LWS_ENTRY(compare_and_swap32) /* 0 - ELF32 Atomic 32bit CAS */
LWS_ENTRY(compare_and_swap64) /* 1 - ELF64 Atomic 32bit CAS */
LWS_ENTRY(compare_and_swap_2) /* 2 - ELF32 Atomic 64bit CAS */
END(lws_table)
/* End of lws table */
......
......@@ -433,6 +433,9 @@
ENTRY_SAME(sched_getattr) /* 335 */
ENTRY_COMP(utimes)
ENTRY_SAME(renameat2)
ENTRY_SAME(seccomp)
ENTRY_SAME(getrandom)
ENTRY_SAME(memfd_create) /* 340 */
/* Nothing yet */
......
......@@ -913,7 +913,7 @@ static int __init dino_probe(struct parisc_device *dev)
printk("%s version %s found at 0x%lx\n", name, version, hpa);
if (!request_mem_region(hpa, PAGE_SIZE, name)) {
printk(KERN_ERR "DINO: Hey! Someone took my MMIO space (0x%ld)!\n",
printk(KERN_ERR "DINO: Hey! Someone took my MMIO space (0x%lx)!\n",
hpa);
return 1;
}
......
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