3eb0f5193b
Call clear_siginfo to ensure every stack allocated siginfo is properly initialized before being passed to the signal sending functions. Note: It is not safe to depend on C initializers to initialize struct siginfo on the stack because C is allowed to skip holes when initializing a structure. The initialization of struct siginfo in tracehook_report_syscall_exit was moved from the helper user_single_step_siginfo into tracehook_report_syscall_exit itself, to make it clear that the local variable siginfo gets fully initialized. In a few cases the scope of struct siginfo has been reduced to make it clear that siginfo siginfo is not used on other paths in the function in which it is declared. Instances of using memset to initialize siginfo have been replaced with calls clear_siginfo for clarity. Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
125 lines
3.3 KiB
C
125 lines
3.3 KiB
C
/*
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* Based on arch/arm/kernel/sys_arm.c
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*
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* Copyright (C) People who wrote linux/arch/i386/kernel/sys_i386.c
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* Copyright (C) 1995, 1996 Russell King.
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* Copyright (C) 2012 ARM Ltd.
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*
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* This program is free software; you can redistribute it and/or modify
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* it under the terms of the GNU General Public License version 2 as
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* published by the Free Software Foundation.
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*
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* This program is distributed in the hope that it will be useful,
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* but WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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* GNU General Public License for more details.
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*
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* You should have received a copy of the GNU General Public License
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* along with this program. If not, see <http://www.gnu.org/licenses/>.
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*/
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#include <linux/compat.h>
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#include <linux/personality.h>
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#include <linux/sched.h>
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#include <linux/sched/signal.h>
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#include <linux/slab.h>
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#include <linux/syscalls.h>
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#include <linux/uaccess.h>
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#include <asm/cacheflush.h>
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#include <asm/system_misc.h>
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#include <asm/unistd.h>
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static long
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__do_compat_cache_op(unsigned long start, unsigned long end)
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{
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long ret;
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do {
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unsigned long chunk = min(PAGE_SIZE, end - start);
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if (fatal_signal_pending(current))
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return 0;
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ret = __flush_cache_user_range(start, start + chunk);
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if (ret)
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return ret;
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cond_resched();
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start += chunk;
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} while (start < end);
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return 0;
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}
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static inline long
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do_compat_cache_op(unsigned long start, unsigned long end, int flags)
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{
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if (end < start || flags)
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return -EINVAL;
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if (!access_ok(VERIFY_READ, (const void __user *)start, end - start))
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return -EFAULT;
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return __do_compat_cache_op(start, end);
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}
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/*
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* Handle all unrecognised system calls.
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*/
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long compat_arm_syscall(struct pt_regs *regs)
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{
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siginfo_t info;
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unsigned int no = regs->regs[7];
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switch (no) {
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/*
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* Flush a region from virtual address 'r0' to virtual address 'r1'
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* _exclusive_. There is no alignment requirement on either address;
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* user space does not need to know the hardware cache layout.
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*
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* r2 contains flags. It should ALWAYS be passed as ZERO until it
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* is defined to be something else. For now we ignore it, but may
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* the fires of hell burn in your belly if you break this rule. ;)
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*
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* (at a later date, we may want to allow this call to not flush
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* various aspects of the cache. Passing '0' will guarantee that
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* everything necessary gets flushed to maintain consistency in
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* the specified region).
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*/
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case __ARM_NR_compat_cacheflush:
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return do_compat_cache_op(regs->regs[0], regs->regs[1], regs->regs[2]);
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case __ARM_NR_compat_set_tls:
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current->thread.uw.tp_value = regs->regs[0];
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/*
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* Protect against register corruption from context switch.
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* See comment in tls_thread_flush.
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*/
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barrier();
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write_sysreg(regs->regs[0], tpidrro_el0);
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return 0;
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default:
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/*
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* Calls 9f00xx..9f07ff are defined to return -ENOSYS
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* if not implemented, rather than raising SIGILL. This
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* way the calling program can gracefully determine whether
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* a feature is supported.
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*/
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if ((no & 0xffff) <= 0x7ff)
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return -ENOSYS;
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break;
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}
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clear_siginfo(&info);
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info.si_signo = SIGILL;
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info.si_errno = 0;
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info.si_code = ILL_ILLTRP;
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info.si_addr = (void __user *)instruction_pointer(regs) -
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(compat_thumb_mode(regs) ? 2 : 4);
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arm64_notify_die("Oops - bad compat syscall(2)", regs, &info, no);
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return 0;
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}
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