linux-stable/arch/powerpc/platforms/cell/spu_callbacks.c
Rohan McLure 8640de0dee powerpc: Use common syscall handler type
Cause syscall handlers to be typed as follows when called indirectly
throughout the kernel. This is to allow for better type checking.

typedef long (*syscall_fn)(unsigned long, unsigned long, unsigned long,
                           unsigned long, unsigned long, unsigned long);

Since both 32 and 64-bit abis allow for at least the first six
machine-word length parameters to a function to be passed by registers,
even handlers which admit fewer than six parameters may be viewed as
having the above type.

Coercing syscalls to syscall_fn requires a cast to void* to avoid
-Wcast-function-type.

Fixup comparisons in VDSO to avoid pointer-integer comparison. Introduce
explicit cast on systems with SPUs.

Signed-off-by: Rohan McLure <rmclure@linux.ibm.com>
Reviewed-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20220921065605.1051927-19-rmclure@linux.ibm.com
2022-09-28 19:22:09 +10:00

64 lines
1.8 KiB
C

// SPDX-License-Identifier: GPL-2.0-only
/*
* System call callback functions for SPUs
*/
#undef DEBUG
#include <linux/kallsyms.h>
#include <linux/export.h>
#include <linux/syscalls.h>
#include <asm/spu.h>
#include <asm/syscalls.h>
#include <asm/unistd.h>
/*
* This table defines the system calls that an SPU can call.
* It is currently a subset of the 64 bit powerpc system calls,
* with the exact semantics.
*
* The reasons for disabling some of the system calls are:
* 1. They interact with the way SPU syscalls are handled
* and we can't let them execute ever:
* restart_syscall, exit, for, execve, ptrace, ...
* 2. They are deprecated and replaced by other means:
* uselib, pciconfig_*, sysfs, ...
* 3. They are somewhat interacting with the system in a way
* we don't want an SPU to:
* reboot, init_module, mount, kexec_load
* 4. They are optional and we can't rely on them being
* linked into the kernel. Unfortunately, the cond_syscall
* helper does not work here as it does not add the necessary
* opd symbols:
* mbind, mq_open, ipc, ...
*/
static const syscall_fn spu_syscall_table[] = {
#define __SYSCALL_WITH_COMPAT(nr, entry, compat) __SYSCALL(nr, entry)
#define __SYSCALL(nr, entry) [nr] = (void *) entry,
#include <asm/syscall_table_spu.h>
};
long spu_sys_callback(struct spu_syscall_block *s)
{
syscall_fn syscall;
if (s->nr_ret >= ARRAY_SIZE(spu_syscall_table)) {
pr_debug("%s: invalid syscall #%lld", __func__, s->nr_ret);
return -ENOSYS;
}
syscall = spu_syscall_table[s->nr_ret];
pr_debug("SPU-syscall "
"%pSR:syscall%lld(%llx, %llx, %llx, %llx, %llx, %llx)\n",
syscall,
s->nr_ret,
s->parm[0], s->parm[1], s->parm[2],
s->parm[3], s->parm[4], s->parm[5]);
return syscall(s->parm[0], s->parm[1], s->parm[2],
s->parm[3], s->parm[4], s->parm[5]);
}
EXPORT_SYMBOL_GPL(spu_sys_callback);