From: Ben Hutchings <ben@decadent.org.uk>
To: linux-kernel@vger.kernel.org, stable@vger.kernel.org
Cc: akpm@linux-foundation.org, "Borislav Petkov" <bp@alien8.de>,
"Thomas Gleixner" <tglx@linutronix.de>,
"Chuck Ebbert" <cebbert.lkml@gmail.com>,
"Richard W.M. Jones" <rjones@redhat.com>
Subject: [PATCH 3.2 051/104] x86/alternatives: Make optimize_nops() interrupt safe and synced
Date: Mon, 12 Mar 2018 03:03:34 +0000 [thread overview]
Message-ID: <lsq.1520823814.326036003@decadent.org.uk> (raw)
In-Reply-To: <lsq.1520823814.606620518@decadent.org.uk>
3.2.101-rc1 review patch. If anyone has any objections, please let me know.
------------------
From: Thomas Gleixner <tglx@linutronix.de>
commit 66c117d7fa2ae429911e60d84bf31a90b2b96189 upstream.
Richard reported the following crash:
[ 0.036000] BUG: unable to handle kernel paging request at 55501e06
[ 0.036000] IP: [<c0aae48b>] common_interrupt+0xb/0x38
[ 0.036000] Call Trace:
[ 0.036000] [<c0409c80>] ? add_nops+0x90/0xa0
[ 0.036000] [<c040a054>] apply_alternatives+0x274/0x630
Chuck decoded:
" 0: 8d 90 90 83 04 24 lea 0x24048390(%eax),%edx
6: 80 fc 0f cmp $0xf,%ah
9: a8 0f test $0xf,%al
>> b: a0 06 1e 50 55 mov 0x55501e06,%al
10: 57 push %edi
11: 56 push %esi
Interrupt 0x30 occurred while the alternatives code was replacing the
initial 0x90,0x90,0x90 NOPs (from the ASM_CLAC macro) with the
optimized version, 0x8d,0x76,0x00. Only the first byte has been
replaced so far, and it makes a mess out of the insn decoding."
optimize_nops() is buggy in two aspects:
- It's not disabling interrupts across the modification
- It's lacking a sync_core() call
Add both.
Fixes: 4fd4b6e5537c 'x86/alternatives: Use optimized NOPs for padding'
Reported-and-tested-by: "Richard W.M. Jones" <rjones@redhat.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Richard W.M. Jones <rjones@redhat.com>
Cc: Chuck Ebbert <cebbert.lkml@gmail.com>
Cc: Borislav Petkov <bp@alien8.de>
Link: http://lkml.kernel.org/r/alpine.DEB.2.11.1509031232340.15006@nanos
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
---
arch/x86/kernel/alternative.c | 5 +++++
1 file changed, 5 insertions(+)
--- a/arch/x86/kernel/alternative.c
+++ b/arch/x86/kernel/alternative.c
@@ -323,10 +323,15 @@ done:
static void __init_or_module optimize_nops(struct alt_instr *a, u8 *instr)
{
+ unsigned long flags;
+
if (instr[0] != 0x90)
return;
+ local_irq_save(flags);
add_nops(instr + (a->instrlen - a->padlen), a->padlen);
+ sync_core();
+ local_irq_restore(flags);
DUMP_BYTES(instr, a->instrlen, "%p: [%d:%d) optimized NOPs: ",
instr, a->instrlen - a->padlen, a->padlen);
next prev parent reply other threads:[~2018-03-12 3:47 UTC|newest]
Thread overview: 106+ messages / expand[flat|nested] mbox.gz Atom feed top
2018-03-12 3:03 [PATCH 3.2 000/104] 3.2.101-rc1 review Ben Hutchings
2018-03-12 3:03 ` [PATCH 3.2 017/104] SELinux: security_load_policy: Silence frame-larger-than warning Ben Hutchings
2018-03-12 3:03 ` [PATCH 3.2 044/104] x86/cpufeatures: Add X86_BUG_SPECTRE_V[12] Ben Hutchings
2018-03-12 3:03 ` [PATCH 3.2 033/104] x86, asm: Extend definitions of _ASM_* with a raw format Ben Hutchings
2018-03-12 3:03 ` [PATCH 3.2 036/104] x86/alternatives: Add missing '\n' at end of ALTERNATIVE inline asm Ben Hutchings
2018-03-12 3:03 ` [PATCH 3.2 073/104] x86/retpoline: Optimize inline assembler for vmexit_fill_RSB Ben Hutchings
2018-03-12 3:03 ` [PATCH 3.2 007/104] rtlwifi: rtl8192c: Fix W=1 warning Ben Hutchings
2018-03-12 3:03 ` [PATCH 3.2 016/104] gcov: compile specific gcov implementation based on gcc version Ben Hutchings
2018-03-12 3:03 ` [PATCH 3.2 047/104] x86/cpu: Implement CPU vulnerabilites sysfs functions Ben Hutchings
2018-03-12 3:03 ` [PATCH 3.2 046/104] sysfs/cpu: Add vulnerability folder Ben Hutchings
2018-03-12 3:03 ` [PATCH 3.2 072/104] x86/pti: Document fix wrong index Ben Hutchings
2018-03-12 3:03 ` [PATCH 3.2 025/104] atp: remove set_rx_mode_8012() Ben Hutchings
2018-03-12 3:03 ` [PATCH 3.2 041/104] x86/cpufeatures: Add X86_BUG_CPU_INSECURE Ben Hutchings
2018-03-12 3:03 ` [PATCH 3.2 001/104] brcmfmac: work-around gcc 4.7 build issue Ben Hutchings
2018-03-12 3:03 ` [PATCH 3.2 042/104] x86/cpu, x86/pti: Do not enable PTI on AMD processors Ben Hutchings
2018-03-12 3:03 ` [PATCH 3.2 052/104] x86/alternatives: Fix optimize_nops() checking Ben Hutchings
2018-03-12 3:03 ` [PATCH 3.2 056/104] kconfig.h: use __is_defined() to check if MODULE is defined Ben Hutchings
2018-03-12 3:03 ` [PATCH 3.2 085/104] x86: Introduce barrier_nospec Ben Hutchings
2018-03-12 3:03 ` [PATCH 3.2 088/104] vfs, fdtable: Prevent bounds-check bypass via speculative execution Ben Hutchings
2018-03-12 3:03 ` [PATCH 3.2 003/104] rtlwifi: rtl8192se: Fix gcc 4.7.x warning Ben Hutchings
2018-03-12 3:03 ` [PATCH 3.2 068/104] x86/retpoline: Add LFENCE to the retpoline/RSB filling RSB macros Ben Hutchings
2018-03-12 3:03 ` [PATCH 3.2 101/104] x86: Introduce __uaccess_begin_nospec() and uaccess_try_nospec Ben Hutchings
2018-03-12 3:03 ` [PATCH 3.2 089/104] x86/spectre: Report get_user mitigation for spectre_v1 Ben Hutchings
2018-03-12 3:03 ` [PATCH 3.2 070/104] kprobes/x86: Blacklist indirect thunk functions for kprobes Ben Hutchings
2018-03-12 3:03 ` [PATCH 3.2 079/104] x86/bugs: Drop one "mitigation" from dmesg Ben Hutchings
2018-03-12 3:03 ` [PATCH 3.2 091/104] x86/paravirt: Remove 'noreplace-paravirt' cmdline option Ben Hutchings
2018-03-12 3:03 ` [PATCH 3.2 008/104] rtlwifi: rtl8192de: Fix W=1 build warnings Ben Hutchings
2018-03-12 3:03 ` [PATCH 3.2 009/104] rtl8192c:dm: Properly initialize local array and set value Ben Hutchings
2018-03-12 3:03 ` [PATCH 3.2 054/104] x86/cpu/AMD: Use LFENCE_RDTSC in preference to MFENCE_RDTSC Ben Hutchings
2018-03-12 3:03 ` [PATCH 3.2 092/104] x86/kvm: Update spectre-v1 mitigation Ben Hutchings
2018-03-12 3:03 ` [PATCH 3.2 076/104] x86/retpoline: Remove the esp/rsp thunk Ben Hutchings
2018-03-12 3:03 ` [PATCH 3.2 075/104] x86/retpoline: Fill RSB on context switch for affected CPUs Ben Hutchings
2018-03-12 3:03 ` [PATCH 3.2 005/104] ath6kl: fix uninitialized variable in ath6kl_sdio_enable_scatter() Ben Hutchings
2018-03-12 3:03 ` [PATCH 3.2 018/104] gcov: add support for GCC 4.9 Ben Hutchings
2018-03-12 3:03 ` [PATCH 3.2 071/104] kprobes/x86: Disable optimizing on the function jumps to indirect thunk Ben Hutchings
2018-03-12 3:03 ` [PATCH 3.2 012/104] usb: renesas_usbhs: fixup __usbhs_for_each_pipe 1st pos Ben Hutchings
2018-03-12 3:03 ` [PATCH 3.2 065/104] x86/retpoline/irq32: Convert assembler indirect jumps Ben Hutchings
2018-03-12 3:03 ` [PATCH 3.2 080/104] x86/cpu/bugs: Make retpoline module warning conditional Ben Hutchings
2018-03-12 3:03 ` [PATCH 3.2 030/104] KVM: VMX: Make use of asm.h Ben Hutchings
2018-03-12 3:03 ` [PATCH 3.2 094/104] x86/spectre: Simplify spectre_v2 command line parsing Ben Hutchings
2018-03-12 3:03 ` [PATCH 3.2 069/104] retpoline: Introduce start/end markers of indirect thunk Ben Hutchings
2018-03-12 3:03 ` [PATCH 3.2 050/104] x86/alternatives: Fix ALTERNATIVE_2 padding generation properly Ben Hutchings
2018-03-12 3:03 ` [PATCH 3.2 082/104] Documentation: Document array_index_nospec Ben Hutchings
2018-03-12 3:03 ` [PATCH 3.2 100/104] nospec: Include <asm/barrier.h> dependency Ben Hutchings
2018-03-12 3:03 ` [PATCH 3.2 035/104] x86: Add another set of MSR accessor functions Ben Hutchings
2018-03-12 3:03 ` [PATCH 3.2 062/104] x86/retpoline/hyperv: Convert assembler indirect jumps Ben Hutchings
2018-03-12 3:03 ` [PATCH 3.2 095/104] x86/speculation: Fix typo IBRS_ATT, which should be IBRS_ALL Ben Hutchings
2018-03-12 3:03 ` [PATCH 3.2 038/104] x86/Documentation: Add PTI description Ben Hutchings
2018-03-12 3:03 ` [PATCH 3.2 049/104] x86/alternatives: Guard NOPs optimization Ben Hutchings
2018-03-12 3:03 ` [PATCH 3.2 034/104] bitops: Introduce BIT_ULL Ben Hutchings
2018-03-12 3:03 ` [PATCH 3.2 097/104] x86/spectre: Fix an error message Ben Hutchings
2018-03-12 3:03 ` [PATCH 3.2 074/104] x86/cpu/intel: Introduce macros for Intel family numbers Ben Hutchings
2018-03-12 3:03 ` [PATCH 3.2 090/104] x86/spectre: Fix spelling mistake: "vunerable"-> "vulnerable" Ben Hutchings
2018-03-12 3:03 ` [PATCH 3.2 077/104] module/retpoline: Warn about missing retpoline in module Ben Hutchings
2018-03-12 3:03 ` [PATCH 3.2 048/104] sysfs/cpu: Fix typos in vulnerability documentation Ben Hutchings
2018-03-12 3:03 ` [PATCH 3.2 087/104] x86/syscall: Sanitize syscall table de-references under speculation Ben Hutchings
2018-03-12 3:03 ` [PATCH 3.2 102/104] x86/uaccess: Use __uaccess_begin_nospec() and uaccess_try_nospec Ben Hutchings
2018-03-12 3:03 ` [PATCH 3.2 024/104] [media] budget-av: only use t_state if initialized Ben Hutchings
2018-03-12 3:03 ` Ben Hutchings [this message]
2018-03-12 3:03 ` [PATCH 3.2 015/104] gcov: add support for gcc 4.7 gcov format Ben Hutchings
2018-03-12 3:03 ` [PATCH 3.2 032/104] x86, cpu: Expand cpufeature facility to include cpu bugs Ben Hutchings
2018-03-12 3:03 ` [PATCH 3.2 014/104] gcov: move gcov structs definitions to a gcc version specific file Ben Hutchings
2018-03-12 3:03 ` [PATCH 3.2 098/104] nospec: Move array_index_nospec() parameter checking into separate macro Ben Hutchings
2018-03-12 3:03 ` [PATCH 3.2 026/104] staging/wlan-ng: Fix 'Branch condition evaluates to a garbage value' in p80211netdev.c Ben Hutchings
2018-03-12 3:03 ` [PATCH 3.2 028/104] x86/bitops: Move BIT_64() for a wider use Ben Hutchings
2018-03-12 3:03 ` [PATCH 3.2 060/104] x86/retpoline/entry: Convert entry assembler indirect jumps Ben Hutchings
2018-03-12 3:03 ` [PATCH 3.2 099/104] nospec: Kill array_index_nospec_mask_check() Ben Hutchings
2018-03-12 3:03 ` [PATCH 3.2 020/104] modpost: reduce visibility of symbols and constify r/o arrays Ben Hutchings
2018-03-12 3:03 ` [PATCH 3.2 031/104] KVM: SVM: Make use of asm.h Ben Hutchings
2018-03-12 3:03 ` [PATCH 3.2 063/104] x86/retpoline/xen: Convert Xen hypercall indirect jumps Ben Hutchings
2018-03-12 3:03 ` [PATCH 3.2 064/104] x86/retpoline/checksum32: Convert assembler " Ben Hutchings
2018-03-12 3:03 ` [PATCH 3.2 040/104] x86/cpufeatures: Make CPU bugs sticky Ben Hutchings
2018-03-12 3:03 ` [PATCH 3.2 022/104] fs: namespace: suppress 'may be used uninitialized' warnings Ben Hutchings
2018-03-12 3:03 ` [PATCH 3.2 019/104] ath6kl: fix struct hif_scatter_req list handling Ben Hutchings
2018-03-12 3:03 ` [PATCH 3.2 086/104] x86/get_user: Use pointer masking to limit speculation Ben Hutchings
2018-03-12 3:03 ` [PATCH 3.2 002/104] Bluetooth: Remove unused hci_le_ltk_reply() Ben Hutchings
2018-03-12 3:03 ` [PATCH 3.2 061/104] x86/retpoline/ftrace: Convert ftrace assembler indirect jumps Ben Hutchings
2018-03-12 3:03 ` [PATCH 3.2 006/104] Turn off -Wmaybe-uninitialized when building with -Os Ben Hutchings
2018-03-12 3:03 ` [PATCH 3.2 039/104] x86/cpu: Factor out application of forced CPU caps Ben Hutchings
2018-03-12 3:03 ` [PATCH 3.2 011/104] Removed unused typedef to avoid "unused local typedef" warnings Ben Hutchings
2018-03-12 3:03 ` [PATCH 3.2 103/104] x86: fix build warnign with 32-bit PAE Ben Hutchings
2018-03-12 3:03 ` [PATCH 3.2 053/104] x86/cpu/AMD: Make LFENCE a serializing instruction Ben Hutchings
2018-03-12 3:03 ` [PATCH 3.2 027/104] kconfig: fix IS_ENABLED to not require all options to be defined Ben Hutchings
2018-03-12 3:03 ` [PATCH 3.2 021/104] modpost: don't emit section mismatch warnings for compiler optimizations Ben Hutchings
2018-03-12 3:03 ` [PATCH 3.2 078/104] x86/nospec: Fix header guards names Ben Hutchings
2018-03-12 3:03 ` [PATCH 3.2 055/104] x86/asm: Make asm/alternative.h safe from assembly Ben Hutchings
2018-03-12 3:03 ` [PATCH 3.2 045/104] x86/cpu: Merge bugs.c and bugs_64.c Ben Hutchings
2018-03-12 3:03 ` [PATCH 3.2 023/104] [media] max2165: trival fix for some -Wuninitialized warning Ben Hutchings
2018-03-12 3:03 ` [PATCH 3.2 029/104] x86, alternative: Add header guards to <asm/alternative-asm.h> Ben Hutchings
2018-03-12 3:03 ` [PATCH 3.2 067/104] x86/retpoline: Remove compile time warning Ben Hutchings
2018-03-12 3:03 ` [PATCH 3.2 083/104] array_index_nospec: Sanitize speculative array de-references Ben Hutchings
2018-03-12 3:03 ` [PATCH 3.2 043/104] x86/pti: Rename BUG_CPU_INSECURE to BUG_CPU_MELTDOWN Ben Hutchings
2018-03-12 3:03 ` [PATCH 3.2 096/104] x86/cpufeatures: Clean up Spectre v2 related CPUID flags Ben Hutchings
2018-03-12 3:03 ` [PATCH 3.2 058/104] x86/retpoline: Add initial retpoline support Ben Hutchings
2018-03-12 3:03 ` [PATCH 3.2 013/104] usb: renesas_usbhs: tidyup original usbhsx_for_each_xxx macro Ben Hutchings
2018-03-12 3:03 ` [PATCH 3.2 059/104] x86/spectre: Add boot time option to select Spectre v2 mitigation Ben Hutchings
2018-03-12 3:03 ` [PATCH 3.2 057/104] x86/asm: Use register variable to get stack pointer value Ben Hutchings
2018-03-12 3:03 ` [PATCH 3.2 084/104] x86: Implement array_index_mask_nospec Ben Hutchings
2018-03-12 3:03 ` [PATCH 3.2 004/104] brcm80211: Remove bogus memcpy in ai_detach Ben Hutchings
2018-03-12 3:03 ` [PATCH 3.2 104/104] cris: Remove old legacy "-traditional" flag from arch-v10/lib/Makefile Ben Hutchings
2018-03-12 3:03 ` [PATCH 3.2 093/104] x86/retpoline: Avoid retpolines for built-in __init functions Ben Hutchings
2018-03-12 3:03 ` [PATCH 3.2 037/104] kvm: vmx: Scrub hardware GPRs at VM-exit Ben Hutchings
2018-03-12 3:03 ` [PATCH 3.2 066/104] x86/retpoline: Fill return stack buffer on vmexit Ben Hutchings
2018-03-12 3:03 ` [PATCH 3.2 010/104] rtlwifi: initialize local array and set value Ben Hutchings
2018-03-12 14:54 ` [PATCH 3.2 000/104] 3.2.101-rc1 review Guenter Roeck
2018-03-12 19:53 ` Ben Hutchings
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