linux-stable/arch/arm64/kernel/sys_compat.c
Fuad Tabba fade9c2c6e arm64: Rename arm64-internal cache maintenance functions
Although naming across the codebase isn't that consistent, it
tends to follow certain patterns. Moreover, the term "flush"
isn't defined in the Arm Architecture reference manual, and might
be interpreted to mean clean, invalidate, or both for a cache.

Rename arm64-internal functions to make the naming internally
consistent, as well as making it consistent with the Arm ARM, by
specifying whether it applies to the instruction, data, or both
caches, whether the operation is a clean, invalidate, or both.
Also specify which point the operation applies to, i.e., to the
point of unification (PoU), coherency (PoC), or persistence
(PoP).

This commit applies the following sed transformation to all files
under arch/arm64:

"s/\b__flush_cache_range\b/caches_clean_inval_pou_macro/g;"\
"s/\b__flush_icache_range\b/caches_clean_inval_pou/g;"\
"s/\binvalidate_icache_range\b/icache_inval_pou/g;"\
"s/\b__flush_dcache_area\b/dcache_clean_inval_poc/g;"\
"s/\b__inval_dcache_area\b/dcache_inval_poc/g;"\
"s/__clean_dcache_area_poc\b/dcache_clean_poc/g;"\
"s/\b__clean_dcache_area_pop\b/dcache_clean_pop/g;"\
"s/\b__clean_dcache_area_pou\b/dcache_clean_pou/g;"\
"s/\b__flush_cache_user_range\b/caches_clean_inval_user_pou/g;"\
"s/\b__flush_icache_all\b/icache_inval_all_pou/g;"

Note that __clean_dcache_area_poc is deliberately missing a word
boundary check at the beginning in order to match the efistub
symbols in image-vars.h.

Also note that, despite its name, __flush_icache_range operates
on both instruction and data caches. The name change here
reflects that.

No functional change intended.

Acked-by: Mark Rutland <mark.rutland@arm.com>
Signed-off-by: Fuad Tabba <tabba@google.com>
Reviewed-by: Ard Biesheuvel <ardb@kernel.org>
Link: https://lore.kernel.org/r/20210524083001.2586635-19-tabba@google.com
Signed-off-by: Will Deacon <will@kernel.org>
2021-05-25 19:27:49 +01:00

119 lines
3 KiB
C

// SPDX-License-Identifier: GPL-2.0-only
/*
* 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.
*/
#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 = caches_clean_inval_user_pou(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((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)
{
unsigned long addr;
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;
}
addr = instruction_pointer(regs) - (compat_thumb_mode(regs) ? 2 : 4);
arm64_notify_die("Oops - bad compat syscall(2)", regs,
SIGILL, ILL_ILLTRP, addr, scno);
return 0;
}