From: Peter Zijlstra <peterz@infradead.org>
To: Mark Rutland <mark.rutland@arm.com>
Cc: Kees Cook <keescook@chromium.org>,
"Reshetova, Elena" <elena.reshetova@intel.com>,
Greg KH <gregkh@linuxfoundation.org>,
Arnd Bergmann <arnd@arndb.de>,
Thomas Gleixner <tglx@linutronix.de>,
Ingo Molnar <mingo@kernel.org>,
"H. Peter Anvin" <h.peter.anvin@intel.com>,
Will Deacon <will.deacon@arm.com>,
David Windsor <dwindsor@gmail.com>,
Hans Liljestrand <ishkamiel@gmail.com>,
David Howells <dhowells@redhat.com>,
LKML <linux-kernel@vger.kernel.org>,
"kernel-hardening@lists.openwall.com"
<kernel-hardening@lists.openwall.com>
Subject: Re: [kernel-hardening] Re: [PATCH 4/4] refcount: Report failures through CHECK_DATA_CORRUPTION
Date: Wed, 8 Feb 2017 10:43:13 +0100 [thread overview]
Message-ID: <20170208094313.GI6536@twins.programming.kicks-ass.net> (raw)
In-Reply-To: <20170208091250.GT6515@twins.programming.kicks-ass.net>
On Wed, Feb 08, 2017 at 10:12:50AM +0100, Peter Zijlstra wrote:
> Something like:
>
> #define EX_REG_HANDLER(_reg) \
> bool ex_handler_value_##_reg(const struct exception_table_entry *fixup, \
> struct pt_regs *regs, int trapnr) \
> { \
> void (*handler)(unsigned long) = \
> (void *)((unsigned long)&fixup->to + fixup->to); \
> \
> if (trapnr != X86_TRAP_UD) \
> return false; \
> \
> regs->ip += 2; /* size of UD2 instruction */ \
> handler(regs->_reg); \
> return true; \
> }
>
> EX_REG_HANDLER(bx);
> EX_REG_HANDLER(cx);
> ...
> EX_REG_HANDLER(ss);
>
>
> asm (
> " .macro reg_to_handler r\n"
> " .irp rs,bx,cx,...,ss\n"
> " .ifc \\r, %\\rs\n"
> " ex_handler_value_\\rs\n"
> " .endif\n"
" .ifc \\r, %e\\rs\n"
" ex_handler_value_\\rs\n"
" .endif\n"
" .ifc \\r, %r\\rs\n"
" ex_handler_value_\\rs\n"
" .endif\n"
> " .endr\n"
> " .endm\n"
> );
to match the 16, 32 and 64 bit names of the same registers. The byte
registers will need additional magic :/
> #define EXCEPTION_VALUE(val, handler) \
> asm volatile ("1: ud2" \
> _ASM_EXTABLE_HANDLE(1b, handler, \
> reg_to_handler %0) \
> : : "r" (val))
>
>
> Where the generic version can simply be:
>
> #define EXCEPTION_VALUE(val, handler) handler((unsigned long)val)
>
>
> Makes sense?
next prev parent reply other threads:[~2017-02-08 9:44 UTC|newest]
Thread overview: 24+ messages / expand[flat|nested] mbox.gz Atom feed top
2017-02-03 23:26 [PATCH 0/4] refcount_t followups Kees Cook
2017-02-03 23:26 ` [PATCH 1/4] refcount_t: fix Kconfig help Kees Cook
2017-02-03 23:26 ` [PATCH 2/4] lkdtm: convert to refcount_t testing Kees Cook
2017-02-10 8:32 ` [tip:locking/core] lkdtm: Convert " tip-bot for Kees Cook
2017-02-03 23:26 ` [PATCH 3/4] bug: Switch data corruption check to __must_check Kees Cook
2017-02-03 23:26 ` [PATCH 4/4] refcount: Report failures through CHECK_DATA_CORRUPTION Kees Cook
2017-02-05 15:40 ` Peter Zijlstra
2017-02-05 23:33 ` Kees Cook
2017-02-06 8:57 ` Peter Zijlstra
2017-02-06 16:54 ` Kees Cook
2017-02-07 8:34 ` Peter Zijlstra
2017-02-07 11:10 ` [kernel-hardening] " Mark Rutland
2017-02-07 12:36 ` Peter Zijlstra
2017-02-07 13:50 ` Mark Rutland
2017-02-07 15:07 ` Peter Zijlstra
2017-02-07 16:03 ` Mark Rutland
2017-02-07 17:30 ` Peter Zijlstra
2017-02-07 17:55 ` Mark Rutland
2017-02-08 9:12 ` Peter Zijlstra
2017-02-08 9:43 ` Peter Zijlstra [this message]
2017-02-08 14:10 ` Mark Rutland
2017-02-08 21:20 ` Kees Cook
2017-02-09 10:27 ` Peter Zijlstra
2017-02-10 23:39 ` Kees Cook
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