From: Andy Lutomirski <luto@kernel.org>
To: x86@kernel.org
Cc: LKML <linux-kernel@vger.kernel.org>,
Yu-cheng Yu <yu-cheng.yu@intel.com>,
Dave Hansen <dave.hansen@linux.intel.com>,
Peter Zijlstra <peterz@infradead.org>,
Borislav Petkov <bp@alien8.de>, Andy Lutomirski <luto@kernel.org>
Subject: [PATCH 11/13] x86/oops: Show the correct CS value in show_regs()
Date: Mon, 19 Nov 2018 14:45:35 -0800 [thread overview]
Message-ID: <19b4052cdb692eb66ef48b078ac3197b6787564a.1542667307.git.luto@kernel.org> (raw)
In-Reply-To: <cover.1542667307.git.luto@kernel.org>
In-Reply-To: <cover.1542667307.git.luto@kernel.org>
show_regs() shows the CS in the CPU register instead of the value in
regs. This means that we'll probably print "CS: 0010" almost all
the time regardless of what was actually in CS when the kernel
malfunctioned. This gives a particularly confusing result if we
OOPSed due to an implicit supervisor access from user mode.
Signed-off-by: Andy Lutomirski <luto@kernel.org>
---
arch/x86/kernel/process_64.c | 5 ++---
1 file changed, 2 insertions(+), 3 deletions(-)
diff --git a/arch/x86/kernel/process_64.c b/arch/x86/kernel/process_64.c
index 0e0b4288a4b2..2b8e6324fa20 100644
--- a/arch/x86/kernel/process_64.c
+++ b/arch/x86/kernel/process_64.c
@@ -66,7 +66,7 @@ void __show_regs(struct pt_regs *regs, enum show_regs_mode mode)
unsigned long cr0 = 0L, cr2 = 0L, cr3 = 0L, cr4 = 0L, fs, gs, shadowgs;
unsigned long d0, d1, d2, d3, d6, d7;
unsigned int fsindex, gsindex;
- unsigned int ds, cs, es;
+ unsigned int ds, es;
show_iret_regs(regs);
@@ -98,7 +98,6 @@ void __show_regs(struct pt_regs *regs, enum show_regs_mode mode)
}
asm("movl %%ds,%0" : "=r" (ds));
- asm("movl %%cs,%0" : "=r" (cs));
asm("movl %%es,%0" : "=r" (es));
asm("movl %%fs,%0" : "=r" (fsindex));
asm("movl %%gs,%0" : "=r" (gsindex));
@@ -114,7 +113,7 @@ void __show_regs(struct pt_regs *regs, enum show_regs_mode mode)
printk(KERN_DEFAULT "FS: %016lx(%04x) GS:%016lx(%04x) knlGS:%016lx\n",
fs, fsindex, gs, gsindex, shadowgs);
- printk(KERN_DEFAULT "CS: %04x DS: %04x ES: %04x CR0: %016lx\n", cs, ds,
+ printk(KERN_DEFAULT "CS: %04lx DS: %04x ES: %04x CR0: %016lx\n", regs->cs, ds,
es, cr0);
printk(KERN_DEFAULT "CR2: %016lx CR3: %016lx CR4: %016lx\n", cr2, cr3,
cr4);
--
2.17.2
next prev parent reply other threads:[~2018-11-19 22:46 UTC|newest]
Thread overview: 25+ messages / expand[flat|nested] mbox.gz Atom feed top
2018-11-19 22:45 [PATCH 00/13] x86/fault: #PF improvements, mostly related to USER bit Andy Lutomirski
2018-11-19 22:45 ` [PATCH 01/13] x86/fault: Check user_mode(regs) when avoiding an mmap_sem deadlock Andy Lutomirski
2018-11-20 8:14 ` [tip:x86/mm] " tip-bot for Andy Lutomirski
2018-11-20 8:15 ` [PATCH 01/13] " Peter Zijlstra
2018-11-19 22:45 ` [PATCH 02/13] x86/fault: Check user_mode(regs) when validating a stack extension Andy Lutomirski
2018-11-20 7:39 ` Ingo Molnar
2018-11-20 8:13 ` Ingo Molnar
2018-11-19 22:45 ` [PATCH 03/13] x86/cpufeatures, x86/fault: Mark SMAP as disabled when configured out Andy Lutomirski
2018-11-20 8:15 ` [tip:x86/mm] " tip-bot for Andy Lutomirski
2018-11-19 22:45 ` [PATCH 04/13] x86/fault: Fold smap_violation() into do_user_addr_fault() Andy Lutomirski
2018-11-20 8:15 ` [tip:x86/mm] " tip-bot for Andy Lutomirski
2018-11-19 22:45 ` [PATCH 05/13] x86/fault: Fix SMAP #PF handling buglet for implicit supervisor accesses Andy Lutomirski
2018-11-20 8:16 ` [tip:x86/mm] " tip-bot for Andy Lutomirski
2018-11-19 22:45 ` [PATCH 06/13] x86/fault: Improve the condition for signalling vs OOPSing Andy Lutomirski
2018-11-20 8:16 ` [tip:x86/mm] " tip-bot for Andy Lutomirski
2018-11-19 22:45 ` [PATCH 07/13] x86/fault: Make error_code sanitization more robust Andy Lutomirski
2018-11-20 8:17 ` [tip:x86/mm] " tip-bot for Andy Lutomirski
2018-11-19 22:45 ` [PATCH 08/13] x86/fault: Don't set thread.cr2, etc before OOPSing Andy Lutomirski
2018-11-20 8:17 ` [tip:x86/mm] " tip-bot for Andy Lutomirski
2018-11-19 22:45 ` [PATCH 09/13] x86/fault: Remove sw_error_code Andy Lutomirski
2018-11-19 22:45 ` [PATCH 10/13] x86/fault: Don't try to recover from an implicit supervisor access Andy Lutomirski
2018-11-19 22:45 ` Andy Lutomirski [this message]
2018-11-19 22:45 ` [PATCH 12/13] x86/fault: Decode page fault OOPSes better Andy Lutomirski
2018-11-27 14:46 ` Sean Christopherson
2018-11-19 22:45 ` [PATCH 13/13] x86/vsyscall/64: Use X86_PF constants in the simulated #PF error code Andy Lutomirski
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