This is a note to let you know that I've just added the patch titled
arm64: factor insn read out of call_undef_hook()
to the 5.10-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
arm64-factor-insn-read-out-of-call_undef_hook.patch
and it can be found in the queue-5.10 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
>From ruanjinjie@xxxxxxxxxx Wed Oct 11 12:06:37 2023
From: Jinjie Ruan <ruanjinjie@xxxxxxxxxx>
Date: Wed, 11 Oct 2023 10:05:39 +0000
Subject: arm64: factor insn read out of call_undef_hook()
To: <catalin.marinas@xxxxxxx>, <will@xxxxxxxxxx>, <yuzenghui@xxxxxxxxxx>, <anshuman.khandual@xxxxxxx>, <gregkh@xxxxxxxxxxxxxxxxxxx>, <mark.rutland@xxxxxxx>, <broonie@xxxxxxxxxx>, <youngmin.nam@xxxxxxxxxxx>, <ardb@xxxxxxxxxx>, <f.fainelli@xxxxxxxxx>, <james.morse@xxxxxxx>, <sashal@xxxxxxxxxx>, <scott@xxxxxxxxxxxxxxxxxxxxxx>, <ebiederm@xxxxxxxxxxxx>, <haibinzhang@xxxxxxxxxxx>, <hewenliang4@xxxxxxxxxx>, <linux-arm-kernel@xxxxxxxxxxxxxxxxxxx>, <linux-kernel@xxxxxxxxxxxxxxx>, <stable@xxxxxxxxxx>
Cc: <ruanjinjie@xxxxxxxxxx>
Message-ID: <20231011100545.979577-10-ruanjinjie@xxxxxxxxxx>
From: Mark Rutland <mark.rutland@xxxxxxx>
commit dbfbd87efa79575491af0ba1a87bf567eaea6cae upstream.
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@xxxxxxx>
Cc: Catalin Marinas <catalin.marinas@xxxxxxx>
Cc: James Morse <james.morse@xxxxxxx>
Cc: Joey Gouly <joey.gouly@xxxxxxx>
Cc: Peter Zijlstra <peterz@xxxxxxxxxxxxx>
Cc: Will Deacon <will@xxxxxxxxxx>
Link: https://lore.kernel.org/r/20221019144123.612388-5-mark.rutland@xxxxxxx
Signed-off-by: Will Deacon <will@xxxxxxxxxx>
Signed-off-by: Jinjie Ruan <ruanjinjie@xxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
arch/arm64/kernel/traps.c | 31 ++++++++++++++++++++++---------
1 file changed, 22 insertions(+), 9 deletions(-)
--- a/arch/arm64/kernel/traps.c
+++ b/arch/arm64/kernel/traps.c
@@ -303,25 +303,22 @@ void unregister_undef_hook(struct undef_
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;
void __user *pc = (void __user *)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;
}
@@ -329,10 +326,20 @@ static int call_undef_hook(struct pt_reg
/* 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 &&
@@ -340,7 +347,7 @@ static int call_undef_hook(struct pt_reg
fn = hook->fn;
raw_spin_unlock_irqrestore(&undef_lock, flags);
-exit:
+
return fn ? fn(regs, instr) : 1;
}
@@ -392,13 +399,19 @@ void arm64_notify_segfault(unsigned long
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);
}
Patches currently in stable-queue which might be from ruanjinjie@xxxxxxxxxx are
queue-5.10/arm64-factor-insn-read-out-of-call_undef_hook.patch
queue-5.10/arm64-rework-el0-mrs-emulation.patch
queue-5.10/arm64-die-pass-err-as-long.patch
queue-5.10/arm64-armv8_deprecated-rework-deprected-instruction-handling.patch
queue-5.10/arm64-armv8_deprecated-fix-unused-function-error.patch
queue-5.10/arm64-armv8_deprecated-move-aarch32-helper-earlier.patch
queue-5.10/arm64-consistently-pass-esr_elx-to-die.patch
queue-5.10/arm64-factor-out-el1-ssbs-emulation-hook.patch
queue-5.10/arm64-report-el1-undefs-better.patch
queue-5.10/arm64-armv8_deprecated-fold-ops-into-insn_emulation.patch
queue-5.10/arm64-rework-bti-exception-handling.patch
queue-5.10/arm64-rework-fpac-exception-handling.patch
queue-5.10/arm64-split-el0-el1-undef-handlers.patch
queue-5.10/arm64-allow-kprobes-on-el0-handlers.patch
queue-5.10/arm64-armv8_deprecated-move-emulation-functions.patch
