diff options
author | Mark Rutland <mark.rutland@arm.com> | 2022-10-19 17:41:18 +0300 |
---|---|---|
committer | Will Deacon <will@kernel.org> | 2022-11-15 16:46:18 +0300 |
commit | dbfbd87efa79575491af0ba1a87bf567eaea6cae (patch) | |
tree | ac619dcf5414baf11ea7d1dd5036f492760cc082 /arch/arm64/kernel/traps.c | |
parent | bff8f413c71ffc3cb679dbd9a5632b33af563f9f (diff) | |
download | linux-dbfbd87efa79575491af0ba1a87bf567eaea6cae.tar.xz |
arm64: factor insn read out of call_undef_hook()
Subsequent patches will rework EL0 UNDEF handling, removing the need for
struct undef_hook and call_undef_hook. In preparation for those changes,
this patch factors the logic for reading user instructions out of
call_undef_hook() and into a new user_insn_read() helper, matching the
style of the existing aarch64_insn_read() helper used for reading kernel
instructions.
There should be no functional change as a result of this patch.
Signed-off-by: Mark Rutland <mark.rutland@arm.com>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: James Morse <james.morse@arm.com>
Cc: Joey Gouly <joey.gouly@arm.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Will Deacon <will@kernel.org>
Link: https://lore.kernel.org/r/20221019144123.612388-5-mark.rutland@arm.com
Signed-off-by: Will Deacon <will@kernel.org>
Diffstat (limited to 'arch/arm64/kernel/traps.c')
-rw-r--r-- | arch/arm64/kernel/traps.c | 31 |
1 files changed, 22 insertions, 9 deletions
diff --git a/arch/arm64/kernel/traps.c b/arch/arm64/kernel/traps.c index ccd7d773e5cd..4d51afd010e1 100644 --- a/arch/arm64/kernel/traps.c +++ b/arch/arm64/kernel/traps.c @@ -394,25 +394,22 @@ void unregister_undef_hook(struct undef_hook *hook) raw_spin_unlock_irqrestore(&undef_lock, flags); } -static int call_undef_hook(struct pt_regs *regs) +static int user_insn_read(struct pt_regs *regs, u32 *insnp) { - struct undef_hook *hook; - unsigned long flags; u32 instr; - int (*fn)(struct pt_regs *regs, u32 instr) = NULL; unsigned long pc = instruction_pointer(regs); if (compat_thumb_mode(regs)) { /* 16-bit Thumb instruction */ __le16 instr_le; if (get_user(instr_le, (__le16 __user *)pc)) - goto exit; + return -EFAULT; instr = le16_to_cpu(instr_le); if (aarch32_insn_is_wide(instr)) { u32 instr2; if (get_user(instr_le, (__le16 __user *)(pc + 2))) - goto exit; + return -EFAULT; instr2 = le16_to_cpu(instr_le); instr = (instr << 16) | instr2; } @@ -420,10 +417,20 @@ static int call_undef_hook(struct pt_regs *regs) /* 32-bit ARM instruction */ __le32 instr_le; if (get_user(instr_le, (__le32 __user *)pc)) - goto exit; + return -EFAULT; instr = le32_to_cpu(instr_le); } + *insnp = instr; + return 0; +} + +static int call_undef_hook(struct pt_regs *regs, u32 instr) +{ + struct undef_hook *hook; + unsigned long flags; + int (*fn)(struct pt_regs *regs, u32 instr) = NULL; + raw_spin_lock_irqsave(&undef_lock, flags); list_for_each_entry(hook, &undef_hook, node) if ((instr & hook->instr_mask) == hook->instr_val && @@ -431,7 +438,7 @@ static int call_undef_hook(struct pt_regs *regs) fn = hook->fn; raw_spin_unlock_irqrestore(&undef_lock, flags); -exit: + return fn ? fn(regs, instr) : 1; } @@ -483,13 +490,19 @@ void arm64_notify_segfault(unsigned long addr) void do_el0_undef(struct pt_regs *regs, unsigned long esr) { + u32 insn; + /* check for AArch32 breakpoint instructions */ if (!aarch32_break_handler(regs)) return; - if (call_undef_hook(regs) == 0) + if (user_insn_read(regs, &insn)) + goto out_err; + + if (call_undef_hook(regs, insn) == 0) return; +out_err: force_signal_inject(SIGILL, ILL_ILLOPC, regs->pc, 0); } |