linux-yocto/arch/riscv/kernel/sys_riscv.c
Jessica Liu 316b60b984 riscv: mmap(): use unsigned offset type in riscv_sys_mmap
The variable type of offset should be consistent with the relevant
interfaces of mmap which described in commit 295f10061a ("syscalls:
mmap(): use unsigned offset type consistently"). Otherwise, a user input
with the top bit set would result in a negative page offset rather than a
large one.

Signed-off-by: Jessica Liu <liu.xuemei1@zte.com.cn>
Tested-by: Han Gao <rabenda.cn@gmail.com>
Reviewed-by: Alexandre Ghiti <alexghiti@rivosinc.com>
Reviewed-by: Nutty Liu <liujingqi@lanxincomputing.com>
Link: https://lore.kernel.org/r/20250801104948133AaMr5S6E382PbNNhoJgHA@zte.com.cn
[pjw@kernel.org: hand-applied mangled patch; fixed checkpatch error]
Signed-off-by: Paul Walmsley <pjw@kernel.org>
2025-09-18 08:19:47 -06:00

76 lines
2.4 KiB
C

// SPDX-License-Identifier: GPL-2.0-only
/*
* Copyright (C) 2012 Regents of the University of California
* Copyright (C) 2014 Darius Rad <darius@bluespec.com>
* Copyright (C) 2017 SiFive
*/
#include <linux/syscalls.h>
#include <asm/cacheflush.h>
static long riscv_sys_mmap(unsigned long addr, unsigned long len,
unsigned long prot, unsigned long flags,
unsigned long fd, unsigned long offset,
unsigned long page_shift_offset)
{
if (unlikely(offset & (~PAGE_MASK >> page_shift_offset)))
return -EINVAL;
return ksys_mmap_pgoff(addr, len, prot, flags, fd,
offset >> (PAGE_SHIFT - page_shift_offset));
}
#ifdef CONFIG_64BIT
SYSCALL_DEFINE6(mmap, unsigned long, addr, unsigned long, len,
unsigned long, prot, unsigned long, flags,
unsigned long, fd, unsigned long, offset)
{
return riscv_sys_mmap(addr, len, prot, flags, fd, offset, 0);
}
#endif
#if defined(CONFIG_32BIT) || defined(CONFIG_COMPAT)
SYSCALL_DEFINE6(mmap2, unsigned long, addr, unsigned long, len,
unsigned long, prot, unsigned long, flags,
unsigned long, fd, unsigned long, offset)
{
/*
* Note that the shift for mmap2 is constant (12),
* regardless of PAGE_SIZE
*/
return riscv_sys_mmap(addr, len, prot, flags, fd, offset, 12);
}
#endif
/*
* Allows the instruction cache to be flushed from userspace. Despite RISC-V
* having a direct 'fence.i' instruction available to userspace (which we
* can't trap!), that's not actually viable when running on Linux because the
* kernel might schedule a process on another hart. There is no way for
* userspace to handle this without invoking the kernel (as it doesn't know the
* thread->hart mappings), so we've defined a RISC-V specific system call to
* flush the instruction cache.
*
* sys_riscv_flush_icache() is defined to flush the instruction cache over an
* address range, with the flush applying to either all threads or just the
* caller. We don't currently do anything with the address range, that's just
* in there for forwards compatibility.
*/
SYSCALL_DEFINE3(riscv_flush_icache, uintptr_t, start, uintptr_t, end,
uintptr_t, flags)
{
/* Check the reserved flags. */
if (unlikely(flags & ~SYS_RISCV_FLUSH_ICACHE_ALL))
return -EINVAL;
flush_icache_mm(current->mm, flags & SYS_RISCV_FLUSH_ICACHE_LOCAL);
return 0;
}
/* Not defined using SYSCALL_DEFINE0 to avoid error injection */
asmlinkage long __riscv_sys_ni_syscall(const struct pt_regs *__unused)
{
return -ENOSYS;
}