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author | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-05-06 01:02:30 +0000 |
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committer | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-05-06 01:02:30 +0000 |
commit | 76cb841cb886eef6b3bee341a2266c76578724ad (patch) | |
tree | f5892e5ba6cc11949952a6ce4ecbe6d516d6ce58 /arch/arm64/kernel/sys_compat.c | |
parent | Initial commit. (diff) | |
download | linux-76cb841cb886eef6b3bee341a2266c76578724ad.tar.xz linux-76cb841cb886eef6b3bee341a2266c76578724ad.zip |
Adding upstream version 4.19.249.upstream/4.19.249
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to 'arch/arm64/kernel/sys_compat.c')
-rw-r--r-- | arch/arm64/kernel/sys_compat.c | 134 |
1 files changed, 134 insertions, 0 deletions
diff --git a/arch/arm64/kernel/sys_compat.c b/arch/arm64/kernel/sys_compat.c new file mode 100644 index 000000000..3ef9d0a3a --- /dev/null +++ b/arch/arm64/kernel/sys_compat.c @@ -0,0 +1,134 @@ +/* + * Based on arch/arm/kernel/sys_arm.c + * + * Copyright (C) People who wrote linux/arch/i386/kernel/sys_i386.c + * Copyright (C) 1995, 1996 Russell King. + * Copyright (C) 2012 ARM Ltd. + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License version 2 as + * published by the Free Software Foundation. + * + * This program is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + * GNU General Public License for more details. + * + * You should have received a copy of the GNU General Public License + * along with this program. If not, see <http://www.gnu.org/licenses/>. + */ + +#include <linux/compat.h> +#include <linux/cpufeature.h> +#include <linux/personality.h> +#include <linux/sched.h> +#include <linux/sched/signal.h> +#include <linux/slab.h> +#include <linux/syscalls.h> +#include <linux/uaccess.h> + +#include <asm/cacheflush.h> +#include <asm/system_misc.h> +#include <asm/tlbflush.h> +#include <asm/unistd.h> + +static long +__do_compat_cache_op(unsigned long start, unsigned long end) +{ + long ret; + + do { + unsigned long chunk = min(PAGE_SIZE, end - start); + + if (fatal_signal_pending(current)) + return 0; + + if (cpus_have_const_cap(ARM64_WORKAROUND_1542419)) { + /* + * The workaround requires an inner-shareable tlbi. + * We pick the reserved-ASID to minimise the impact. + */ + __tlbi(aside1is, __TLBI_VADDR(0, 0)); + dsb(ish); + } + + ret = __flush_cache_user_range(start, start + chunk); + if (ret) + return ret; + + cond_resched(); + start += chunk; + } while (start < end); + + return 0; +} + +static inline long +do_compat_cache_op(unsigned long start, unsigned long end, int flags) +{ + if (end < start || flags) + return -EINVAL; + + if (!access_ok(VERIFY_READ, (const void __user *)start, end - start)) + return -EFAULT; + + return __do_compat_cache_op(start, end); +} +/* + * Handle all unrecognised system calls. + */ +long compat_arm_syscall(struct pt_regs *regs, int scno) +{ + siginfo_t info; + + switch (scno) { + /* + * Flush a region from virtual address 'r0' to virtual address 'r1' + * _exclusive_. There is no alignment requirement on either address; + * user space does not need to know the hardware cache layout. + * + * r2 contains flags. It should ALWAYS be passed as ZERO until it + * is defined to be something else. For now we ignore it, but may + * the fires of hell burn in your belly if you break this rule. ;) + * + * (at a later date, we may want to allow this call to not flush + * various aspects of the cache. Passing '0' will guarantee that + * everything necessary gets flushed to maintain consistency in + * the specified region). + */ + case __ARM_NR_compat_cacheflush: + return do_compat_cache_op(regs->regs[0], regs->regs[1], regs->regs[2]); + + case __ARM_NR_compat_set_tls: + current->thread.uw.tp_value = regs->regs[0]; + + /* + * Protect against register corruption from context switch. + * See comment in tls_thread_flush. + */ + barrier(); + write_sysreg(regs->regs[0], tpidrro_el0); + return 0; + + default: + /* + * Calls 0xf0xxx..0xf07ff are defined to return -ENOSYS + * if not implemented, rather than raising SIGILL. This + * way the calling program can gracefully determine whether + * a feature is supported. + */ + if (scno < __ARM_NR_COMPAT_END) + return -ENOSYS; + break; + } + + clear_siginfo(&info); + info.si_signo = SIGILL; + info.si_errno = 0; + info.si_code = ILL_ILLTRP; + info.si_addr = (void __user *)instruction_pointer(regs) - + (compat_thumb_mode(regs) ? 2 : 4); + + arm64_notify_die("Oops - bad compat syscall(2)", regs, &info, scno); + return 0; +} |