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| author | Helge Deller <deller@gmx.de> | 2016-03-30 14:14:31 +0200 |
|---|---|---|
| committer | Helge Deller <deller@gmx.de> | 2016-03-31 12:28:38 +0200 |
| commit | 910cd32e552ea09caa89cdbe328e468979b030dd (patch) | |
| tree | 02cc8c1d9d0202d76f988ae242ccbc328a8e43cd /arch/parisc | |
| parent | 4f4acc9472e54ce702f1d85fc9e6d57767dec91f (diff) | |
| download | lwn-910cd32e552ea09caa89cdbe328e468979b030dd.tar.gz lwn-910cd32e552ea09caa89cdbe328e468979b030dd.zip | |
parisc: Fix and enable seccomp filter support
The seccomp filter support requires careful handling of task registers. This
includes reloading of the return value (%r28) and proper syscall exit if
secure_computing() returned -1.
Additionally we need to sign-extend the syscall number from signed 32bit to
signed 64bit in do_syscall_trace_enter() since the ptrace interface only allows
storing 32bit values in compat mode.
Signed-off-by: Helge Deller <deller@gmx.de>
Cc: stable@vger.kernel.org # v4.5
Diffstat (limited to 'arch/parisc')
| -rw-r--r-- | arch/parisc/Kconfig | 1 | ||||
| -rw-r--r-- | arch/parisc/include/asm/syscall.h | 13 | ||||
| -rw-r--r-- | arch/parisc/kernel/ptrace.c | 9 | ||||
| -rw-r--r-- | arch/parisc/kernel/syscall.S | 2 |
4 files changed, 23 insertions, 2 deletions
diff --git a/arch/parisc/Kconfig b/arch/parisc/Kconfig index 14f655cf542e..86ed37671ef5 100644 --- a/arch/parisc/Kconfig +++ b/arch/parisc/Kconfig @@ -29,6 +29,7 @@ config PARISC select TTY # Needed for pdc_cons.c select HAVE_DEBUG_STACKOVERFLOW select HAVE_ARCH_AUDITSYSCALL + select HAVE_ARCH_SECCOMP_FILTER select ARCH_NO_COHERENT_DMA_MMAP help diff --git a/arch/parisc/include/asm/syscall.h b/arch/parisc/include/asm/syscall.h index a5eba95d87fe..637ce8d6f375 100644 --- a/arch/parisc/include/asm/syscall.h +++ b/arch/parisc/include/asm/syscall.h @@ -39,6 +39,19 @@ static inline void syscall_get_arguments(struct task_struct *tsk, } } +static inline void syscall_set_return_value(struct task_struct *task, + struct pt_regs *regs, + int error, long val) +{ + regs->gr[28] = error ? error : val; +} + +static inline void syscall_rollback(struct task_struct *task, + struct pt_regs *regs) +{ + /* do nothing */ +} + static inline int syscall_get_arch(void) { int arch = AUDIT_ARCH_PARISC; diff --git a/arch/parisc/kernel/ptrace.c b/arch/parisc/kernel/ptrace.c index ce0b2b4075c7..8fb81a391599 100644 --- a/arch/parisc/kernel/ptrace.c +++ b/arch/parisc/kernel/ptrace.c @@ -270,7 +270,8 @@ long compat_arch_ptrace(struct task_struct *child, compat_long_t request, long do_syscall_trace_enter(struct pt_regs *regs) { /* Do the secure computing check first. */ - secure_computing_strict(regs->gr[20]); + if (secure_computing() == -1) + return -1; if (test_thread_flag(TIF_SYSCALL_TRACE) && tracehook_report_syscall_entry(regs)) { @@ -296,7 +297,11 @@ long do_syscall_trace_enter(struct pt_regs *regs) regs->gr[23] & 0xffffffff); out: - return regs->gr[20]; + /* + * Sign extend the syscall number to 64bit since it may have been + * modified by a compat ptrace call + */ + return (int) ((u32) regs->gr[20]); } void do_syscall_trace_exit(struct pt_regs *regs) diff --git a/arch/parisc/kernel/syscall.S b/arch/parisc/kernel/syscall.S index fbafa0d0e2bf..c976ebfe2269 100644 --- a/arch/parisc/kernel/syscall.S +++ b/arch/parisc/kernel/syscall.S @@ -329,6 +329,7 @@ tracesys_next: ldo -THREAD_SZ_ALGN-FRAME_SIZE(%r30),%r1 /* get task ptr */ LDREG TI_TASK(%r1), %r1 + LDREG TASK_PT_GR28(%r1), %r28 /* Restore return value */ LDREG TASK_PT_GR26(%r1), %r26 /* Restore the users args */ LDREG TASK_PT_GR25(%r1), %r25 LDREG TASK_PT_GR24(%r1), %r24 @@ -342,6 +343,7 @@ tracesys_next: stw %r21, -56(%r30) /* 6th argument */ #endif + cmpib,COND(=),n -1,%r20,tracesys_exit /* seccomp may have returned -1 */ comiclr,>>= __NR_Linux_syscalls, %r20, %r0 b,n .Ltracesys_nosys |