lists.openwall.net   lists  /  announce  owl-users  owl-dev  john-users  john-dev  passwdqc-users  yescrypt  popa3d-users  /  oss-security  kernel-hardening  musl  sabotage  tlsify  passwords  /  crypt-dev  xvendor  /  Bugtraq  Full-Disclosure  linux-kernel  linux-netdev  linux-ext4  linux-hardening  linux-cve-announce  PHC 
Open Source and information security mailing list archives
 
Hash Suite: Windows password security audit tool. GUI, reports in PDF.
[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]
Message-ID: <20241028160917.1380714-14-alexander.shishkin@linux.intel.com>
Date: Mon, 28 Oct 2024 18:08:01 +0200
From: Alexander Shishkin <alexander.shishkin@...ux.intel.com>
To: Andy Lutomirski <luto@...nel.org>,
	Thomas Gleixner <tglx@...utronix.de>,
	Ingo Molnar <mingo@...hat.com>,
	Borislav Petkov <bp@...en8.de>,
	Dave Hansen <dave.hansen@...ux.intel.com>,
	x86@...nel.org,
	"H. Peter Anvin" <hpa@...or.com>,
	Peter Zijlstra <peterz@...radead.org>,
	Ard Biesheuvel <ardb@...nel.org>,
	"Paul E. McKenney" <paulmck@...nel.org>,
	Josh Poimboeuf <jpoimboe@...nel.org>,
	Xiongwei Song <xiongwei.song@...driver.com>,
	Xin Li <xin3.li@...el.com>,
	"Mike Rapoport (IBM)" <rppt@...nel.org>,
	Brijesh Singh <brijesh.singh@....com>,
	Michael Roth <michael.roth@....com>,
	Tony Luck <tony.luck@...el.com>,
	"Kirill A. Shutemov" <kirill.shutemov@...ux.intel.com>,
	Alexey Kardashevskiy <aik@....com>
Cc: Jonathan Corbet <corbet@....net>,
	Alexander Shishkin <alexander.shishkin@...ux.intel.com>,
	Sohil Mehta <sohil.mehta@...el.com>,
	Ingo Molnar <mingo@...nel.org>,
	Pawan Gupta <pawan.kumar.gupta@...ux.intel.com>,
	Daniel Sneddon <daniel.sneddon@...ux.intel.com>,
	Kai Huang <kai.huang@...el.com>,
	Sandipan Das <sandipan.das@....com>,
	Breno Leitao <leitao@...ian.org>,
	Rick Edgecombe <rick.p.edgecombe@...el.com>,
	Alexei Starovoitov <ast@...nel.org>,
	Hou Tao <houtao1@...wei.com>,
	Juergen Gross <jgross@...e.com>,
	Vegard Nossum <vegard.nossum@...cle.com>,
	Kees Cook <kees@...nel.org>,
	Eric Biggers <ebiggers@...gle.com>,
	Jason Gunthorpe <jgg@...pe.ca>,
	"Masami Hiramatsu (Google)" <mhiramat@...nel.org>,
	Andrew Morton <akpm@...ux-foundation.org>,
	Luis Chamberlain <mcgrof@...nel.org>,
	Yuntao Wang <ytcoode@...il.com>,
	Rasmus Villemoes <linux@...musvillemoes.dk>,
	Christophe Leroy <christophe.leroy@...roup.eu>,
	Tejun Heo <tj@...nel.org>,
	Changbin Du <changbin.du@...wei.com>,
	Huang Shijie <shijie@...amperecomputing.com>,
	Geert Uytterhoeven <geert+renesas@...der.be>,
	Namhyung Kim <namhyung@...nel.org>,
	Arnaldo Carvalho de Melo <acme@...hat.com>,
	linux-doc@...r.kernel.org,
	linux-kernel@...r.kernel.org,
	linux-efi@...r.kernel.org
Subject: [PATCH v5 13/16] x86/traps: Communicate a LASS violation in #GP message

Provide a more helpful message on #GP when a kernel side LASS violation
is detected.

Signed-off-by: Alexander Shishkin <alexander.shishkin@...ux.intel.com>
---
 arch/x86/kernel/traps.c | 14 ++++++++++----
 1 file changed, 10 insertions(+), 4 deletions(-)

diff --git a/arch/x86/kernel/traps.c b/arch/x86/kernel/traps.c
index bae635cc6971..89e35ab8dbd9 100644
--- a/arch/x86/kernel/traps.c
+++ b/arch/x86/kernel/traps.c
@@ -537,7 +537,8 @@ DEFINE_IDTENTRY(exc_bounds)
 enum kernel_gp_hint {
 	GP_NO_HINT,
 	GP_NON_CANONICAL,
-	GP_CANONICAL
+	GP_CANONICAL,
+	GP_LASS_VIOLATION
 };
 
 /*
@@ -573,6 +574,8 @@ static enum kernel_gp_hint get_kernel_gp_address(struct pt_regs *regs,
 	if (*addr < ~__VIRTUAL_MASK &&
 	    *addr + insn.opnd_bytes - 1 > __VIRTUAL_MASK)
 		return GP_NON_CANONICAL;
+	else if (*addr < ~__VIRTUAL_MASK && cpu_feature_enabled(X86_FEATURE_LASS))
+		return GP_LASS_VIOLATION;
 #endif
 
 	return GP_CANONICAL;
@@ -696,6 +699,11 @@ DEFINE_IDTENTRY_ERRORCODE(exc_general_protection)
 	char desc[sizeof(GPFSTR) + 50 + 2*sizeof(unsigned long) + 1] = GPFSTR;
 	enum kernel_gp_hint hint = GP_NO_HINT;
 	unsigned long gp_addr;
+	static char *help[] = {
+		[GP_NON_CANONICAL]	= "probably for non-canonical address",
+		[GP_CANONICAL]		= "maybe for address",
+		[GP_LASS_VIOLATION]	= "LASS prevented access to address"
+	};
 
 	if (user_mode(regs) && try_fixup_enqcmd_gp())
 		return;
@@ -735,9 +743,7 @@ DEFINE_IDTENTRY_ERRORCODE(exc_general_protection)
 		hint = get_kernel_gp_address(regs, &gp_addr);
 
 	if (hint != GP_NO_HINT)
-		snprintf(desc, sizeof(desc), GPFSTR ", %s 0x%lx",
-			 (hint == GP_NON_CANONICAL) ? "probably for non-canonical address"
-						    : "maybe for address",
+		snprintf(desc, sizeof(desc), GPFSTR ", %s 0x%lx", help[hint],
 			 gp_addr);
 
 	/*
-- 
2.45.2


Powered by blists - more mailing lists

Powered by Openwall GNU/*/Linux Powered by OpenVZ