diff options
Diffstat (limited to 'arch/parisc')
| -rw-r--r-- | arch/parisc/Kconfig | 16 | ||||
| -rw-r--r-- | arch/parisc/hpux/sys_hpux.c | 2 | ||||
| -rw-r--r-- | arch/parisc/include/asm/seccomp.h | 16 | ||||
| -rw-r--r-- | arch/parisc/include/asm/thread_info.h | 5 | ||||
| -rw-r--r-- | arch/parisc/include/uapi/asm/unistd.h | 5 | ||||
| -rw-r--r-- | arch/parisc/kernel/ptrace.c | 6 | ||||
| -rw-r--r-- | arch/parisc/kernel/syscall.S | 233 | ||||
| -rw-r--r-- | arch/parisc/kernel/syscall_table.S | 3 |
8 files changed, 279 insertions, 7 deletions
diff --git a/arch/parisc/Kconfig b/arch/parisc/Kconfig index 6e75e20..1554a6f 100644 --- a/arch/parisc/Kconfig +++ b/arch/parisc/Kconfig @@ -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" diff --git a/arch/parisc/hpux/sys_hpux.c b/arch/parisc/hpux/sys_hpux.c index d9dc6cd..e5c4da0 100644 --- a/arch/parisc/hpux/sys_hpux.c +++ b/arch/parisc/hpux/sys_hpux.c @@ -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") ) { diff --git a/arch/parisc/include/asm/seccomp.h b/arch/parisc/include/asm/seccomp.h new file mode 100644 index 0000000..015f788 --- /dev/null +++ b/arch/parisc/include/asm/seccomp.h @@ -0,0 +1,16 @@ +#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 */ diff --git a/arch/parisc/include/asm/thread_info.h b/arch/parisc/include/asm/thread_info.h index 4b9b10c..a846118 100644 --- a/arch/parisc/include/asm/thread_info.h +++ b/arch/parisc/include/asm/thread_info.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 diff --git a/arch/parisc/include/uapi/asm/unistd.h b/arch/parisc/include/uapi/asm/unistd.h index 47e0e21..8667f18 100644 --- a/arch/parisc/include/uapi/asm/unistd.h +++ b/arch/parisc/include/uapi/asm/unistd.h @@ -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 */ diff --git a/arch/parisc/kernel/ptrace.c b/arch/parisc/kernel/ptrace.c index e842ee2..3bab724 100644 --- a/arch/parisc/kernel/ptrace.c +++ b/arch/parisc/kernel/ptrace.c @@ -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; diff --git a/arch/parisc/kernel/syscall.S b/arch/parisc/kernel/syscall.S index 8387860..7ef22e3 100644 --- a/arch/parisc/kernel/syscall.S +++ b/arch/parisc/kernel/syscall.S @@ -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 */ diff --git a/arch/parisc/kernel/syscall_table.S b/arch/parisc/kernel/syscall_table.S index 84c5d3a..b563d9c 100644 --- a/arch/parisc/kernel/syscall_table.S +++ b/arch/parisc/kernel/syscall_table.S @@ -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 */ |
