diff options
| author | Robin Murphy <robin.murphy@arm.com> | 2018-02-19 14:38:00 +0100 |
|---|---|---|
| committer | Catalin Marinas <catalin.marinas@arm.com> | 2018-02-19 14:59:58 +0100 |
| commit | 9085b34d0e8361595a7d19034c550d5d15044556 (patch) | |
| tree | 1c93d515a8c65e8ce5f8a2afd46c8adc5832a226 /arch/arm64/kernel/armv8_deprecated.c | |
| parent | arm64: Fix compilation error while accessing MPIDR_HWID_BITMASK from .S files (diff) | |
| download | linux-9085b34d0e8361595a7d19034c550d5d15044556.tar.xz linux-9085b34d0e8361595a7d19034c550d5d15044556.zip | |
arm64: uaccess: Formalise types for access_ok()
In converting __range_ok() into a static inline, I inadvertently made
it more type-safe, but without considering the ordering of the relevant
conversions. This leads to quite a lot of Sparse noise about the fact
that we use __chk_user_ptr() after addr has already been converted from
a user pointer to an unsigned long.
Rather than just adding another cast for the sake of shutting Sparse up,
it seems reasonable to rework the types to make logical sense (although
the resulting codegen for __range_ok() remains identical). The only
callers this affects directly are our compat traps where the inferred
"user-pointer-ness" of a register value now warrants explicit casting.
Signed-off-by: Robin Murphy <robin.murphy@arm.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
Diffstat (limited to 'arch/arm64/kernel/armv8_deprecated.c')
| -rw-r--r-- | arch/arm64/kernel/armv8_deprecated.c | 4 |
1 files changed, 3 insertions, 1 deletions
diff --git a/arch/arm64/kernel/armv8_deprecated.c b/arch/arm64/kernel/armv8_deprecated.c index c33b5e4010ab..68450e954d47 100644 --- a/arch/arm64/kernel/armv8_deprecated.c +++ b/arch/arm64/kernel/armv8_deprecated.c @@ -370,6 +370,7 @@ static unsigned int __kprobes aarch32_check_condition(u32 opcode, u32 psr) static int swp_handler(struct pt_regs *regs, u32 instr) { u32 destreg, data, type, address = 0; + const void __user *user_ptr; int rn, rt2, res = 0; perf_sw_event(PERF_COUNT_SW_EMULATION_FAULTS, 1, regs, regs->pc); @@ -401,7 +402,8 @@ static int swp_handler(struct pt_regs *regs, u32 instr) aarch32_insn_extract_reg_num(instr, A32_RT2_OFFSET), data); /* Check access in reasonable access range for both SWP and SWPB */ - if (!access_ok(VERIFY_WRITE, (address & ~3), 4)) { + user_ptr = (const void __user *)(unsigned long)(address & ~3); + if (!access_ok(VERIFY_WRITE, user_ptr, 4)) { pr_debug("SWP{B} emulation: access to 0x%08x not allowed!\n", address); goto fault; |