diff options
Diffstat (limited to 'arch/powerpc/include/asm/syscall.h')
| -rw-r--r-- | arch/powerpc/include/asm/syscall.h | 54 |
1 files changed, 33 insertions, 21 deletions
diff --git a/arch/powerpc/include/asm/syscall.h b/arch/powerpc/include/asm/syscall.h index ff21b7a2f0cc..ab9f3f0a8637 100644 --- a/arch/powerpc/include/asm/syscall.h +++ b/arch/powerpc/include/asm/syscall.h @@ -22,10 +22,15 @@ extern const unsigned long sys_call_table[]; #endif /* CONFIG_FTRACE_SYSCALLS */ -static inline long syscall_get_nr(struct task_struct *task, - struct pt_regs *regs) +static inline int syscall_get_nr(struct task_struct *task, struct pt_regs *regs) { - return TRAP(regs) == 0xc00 ? regs->gpr[0] : -1L; + /* + * Note that we are returning an int here. That means 0xffffffff, ie. + * 32-bit negative 1, will be interpreted as -1 on a 64-bit kernel. + * This is important for seccomp so that compat tasks can set r0 = -1 + * to reject the syscall. + */ + return TRAP(regs) == 0xc00 ? regs->gpr[0] : -1; } static inline void syscall_rollback(struct task_struct *task, @@ -34,12 +39,6 @@ static inline void syscall_rollback(struct task_struct *task, regs->gpr[3] = regs->orig_gpr3; } -static inline long syscall_get_error(struct task_struct *task, - struct pt_regs *regs) -{ - return (regs->ccr & 0x10000000) ? -regs->gpr[3] : 0; -} - static inline long syscall_get_return_value(struct task_struct *task, struct pt_regs *regs) { @@ -50,9 +49,15 @@ static inline void syscall_set_return_value(struct task_struct *task, struct pt_regs *regs, int error, long val) { + /* + * In the general case it's not obvious that we must deal with CCR + * here, as the syscall exit path will also do that for us. However + * there are some places, eg. the signal code, which check ccr to + * decide if the value in r3 is actually an error. + */ if (error) { regs->ccr |= 0x10000000L; - regs->gpr[3] = -error; + regs->gpr[3] = error; } else { regs->ccr &= ~0x10000000L; regs->gpr[3] = val; @@ -64,19 +69,22 @@ static inline void syscall_get_arguments(struct task_struct *task, unsigned int i, unsigned int n, unsigned long *args) { + unsigned long val, mask = -1UL; + BUG_ON(i + n > 6); -#ifdef CONFIG_PPC64 - if (test_tsk_thread_flag(task, TIF_32BIT)) { - /* - * Zero-extend 32-bit argument values. The high bits are - * garbage ignored by the actual syscall dispatch. - */ - while (n-- > 0) - args[n] = (u32) regs->gpr[3 + i + n]; - return; - } + +#ifdef CONFIG_COMPAT + if (test_tsk_thread_flag(task, TIF_32BIT)) + mask = 0xffffffff; #endif - memcpy(args, ®s->gpr[3 + i], n * sizeof(args[0])); + while (n--) { + if (n == 0 && i == 0) + val = regs->orig_gpr3; + else + val = regs->gpr[3 + i + n]; + + args[n] = val & mask; + } } static inline void syscall_set_arguments(struct task_struct *task, @@ -86,6 +94,10 @@ static inline void syscall_set_arguments(struct task_struct *task, { BUG_ON(i + n > 6); memcpy(®s->gpr[3 + i], args, n * sizeof(args[0])); + + /* Also copy the first argument into orig_gpr3 */ + if (i == 0 && n > 0) + regs->orig_gpr3 = args[0]; } static inline int syscall_get_arch(void) |