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From: Sami Tolvanen <samitolvanen@google.com>
To: x86@kernel.org
Cc: Kees Cook <keescook@chromium.org>,
	Josh Poimboeuf <jpoimboe@redhat.com>,
	Peter Zijlstra <peterz@infradead.org>,
	Nathan Chancellor <nathan@kernel.org>,
	Nick Desaulniers <ndesaulniers@google.com>,
	Sedat Dilek <sedat.dilek@gmail.com>,
	linux-hardening@vger.kernel.org, linux-kernel@vger.kernel.org,
	clang-built-linux@googlegroups.com,
	Sami Tolvanen <samitolvanen@google.com>
Subject: [PATCH v2 08/14] x86/extable: Do not mark exception callback as CFI
Date: Mon, 23 Aug 2021 10:13:12 -0700	[thread overview]
Message-ID: <20210823171318.2801096-9-samitolvanen@google.com> (raw)
In-Reply-To: <20210823171318.2801096-1-samitolvanen@google.com>

From: Kees Cook <keescook@chromium.org>

The exception table entries are constructed out of a relative offset
and point to the actual function, not the CFI table entry. For now,
just mark the caller as not checking CFI. The failure is most visible
at boot with CONFIG_DEBUG_RODATA_TEST=y.

Signed-off-by: Kees Cook <keescook@chromium.org>
Signed-off-by: Sami Tolvanen <samitolvanen@google.com>
---
 arch/x86/mm/extable.c | 1 +
 1 file changed, 1 insertion(+)

diff --git a/arch/x86/mm/extable.c b/arch/x86/mm/extable.c
index e1664e9f969c..d150d4d12d53 100644
--- a/arch/x86/mm/extable.c
+++ b/arch/x86/mm/extable.c
@@ -155,6 +155,7 @@ enum handler_type ex_get_fault_handler_type(unsigned long ip)
 		return EX_HANDLER_OTHER;
 }
 
+__nocfi
 int fixup_exception(struct pt_regs *regs, int trapnr, unsigned long error_code,
 		    unsigned long fault_addr)
 {
-- 
2.33.0.rc2.250.ged5fa647cd-goog


  parent reply	other threads:[~2021-08-23 17:13 UTC|newest]

Thread overview: 29+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2021-08-23 17:13 [PATCH v2 00/14] x86: Add support for Clang CFI Sami Tolvanen
2021-08-23 17:13 ` [PATCH v2 01/14] objtool: Add CONFIG_CFI_CLANG support Sami Tolvanen
2021-08-23 17:13 ` [PATCH v2 02/14] objtool: Add ASM_STACK_FRAME_NON_STANDARD Sami Tolvanen
2021-08-23 17:13 ` [PATCH v2 03/14] linkage: Add DECLARE_ASM_FUNC_SYMBOL Sami Tolvanen
2021-08-23 17:13 ` [PATCH v2 04/14] ftrace: Use an opaque type for functions not callable from C Sami Tolvanen
2021-08-23 17:13 ` [PATCH v2 05/14] lkdtm: Disable UNSET_SMEP with CFI Sami Tolvanen
2021-08-23 17:13 ` [PATCH v2 06/14] lkdtm: Use an opaque type for lkdtm_rodata_do_nothing Sami Tolvanen
2021-08-23 17:13 ` [PATCH v2 07/14] x86: Use an opaque type for functions not callable from C Sami Tolvanen
2021-08-26 16:54   ` Andy Lutomirski
2021-08-26 22:11     ` Sami Tolvanen
2021-08-26 23:23       ` Andy Lutomirski
2021-08-26 23:45         ` Sami Tolvanen
2021-08-23 17:13 ` Sami Tolvanen [this message]
2021-08-26 16:56   ` [PATCH v2 08/14] x86/extable: Do not mark exception callback as CFI Andy Lutomirski
2021-08-30 19:57     ` Sami Tolvanen
2021-08-23 17:13 ` [PATCH v2 09/14] x86/purgatory: Disable CFI Sami Tolvanen
2021-08-23 17:13 ` [PATCH v2 10/14] x86, relocs: Ignore __typeid__ relocations Sami Tolvanen
2021-08-23 17:13 ` [PATCH v2 11/14] x86, module: " Sami Tolvanen
2021-08-23 17:13 ` [PATCH v2 12/14] x86, cpu: Use LTO for cpu.c with CFI Sami Tolvanen
2021-08-23 17:13 ` [PATCH v2 13/14] x86, kprobes: Fix optprobe_template_func type mismatch Sami Tolvanen
2021-08-23 17:13 ` [PATCH v2 14/14] x86, build: Allow CONFIG_CFI_CLANG to be selected Sami Tolvanen
2021-08-23 17:16 ` [PATCH v2 00/14] x86: Add support for Clang CFI Tom Stellard
2021-08-23 17:20   ` Sami Tolvanen
2021-08-24 17:26     ` Tom Stellard
2021-08-24 17:30       ` Sami Tolvanen
2021-08-24 19:46 ` Peter Zijlstra
2021-08-25 15:49   ` Sami Tolvanen
2021-08-26 11:43     ` Peter Zijlstra
2021-08-26 21:52       ` Sami Tolvanen

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