From: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
To: linux-kernel@vger.kernel.org
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
stable@vger.kernel.org, Andy Lutomirski <luto@kernel.org>,
Linus Torvalds <torvalds@linux-foundation.org>,
Thomas Gleixner <tglx@linutronix.de>
Subject: [PATCH 4.4 38/43] x86/entry/64: Dont use IST entry for #BP stack
Date: Tue, 27 Mar 2018 18:27:42 +0200 [thread overview]
Message-ID: <20180327162718.547354643@linuxfoundation.org> (raw)
In-Reply-To: <20180327162716.407986916@linuxfoundation.org>
4.4-stable review patch. If anyone has any objections, please let me know.
------------------
From: Andy Lutomirski <luto@kernel.org>
commit d8ba61ba58c88d5207c1ba2f7d9a2280e7d03be9 upstream.
There's nothing IST-worthy about #BP/int3. We don't allow kprobes
in the small handful of places in the kernel that run at CPL0 with
an invalid stack, and 32-bit kernels have used normal interrupt
gates for #BP forever.
Furthermore, we don't allow kprobes in places that have usergs while
in kernel mode, so "paranoid" is also unnecessary.
Signed-off-by: Andy Lutomirski <luto@kernel.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: stable@vger.kernel.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
arch/x86/entry/entry_64.S | 2 +-
arch/x86/kernel/traps.c | 24 +++++++++++-------------
2 files changed, 12 insertions(+), 14 deletions(-)
--- a/arch/x86/entry/entry_64.S
+++ b/arch/x86/entry/entry_64.S
@@ -1018,7 +1018,7 @@ apicinterrupt3 HYPERVISOR_CALLBACK_VECTO
#endif /* CONFIG_HYPERV */
idtentry debug do_debug has_error_code=0 paranoid=1 shift_ist=DEBUG_STACK
-idtentry int3 do_int3 has_error_code=0 paranoid=1 shift_ist=DEBUG_STACK
+idtentry int3 do_int3 has_error_code=0
idtentry stack_segment do_stack_segment has_error_code=1
#ifdef CONFIG_XEN
--- a/arch/x86/kernel/traps.c
+++ b/arch/x86/kernel/traps.c
@@ -480,7 +480,6 @@ do_general_protection(struct pt_regs *re
}
NOKPROBE_SYMBOL(do_general_protection);
-/* May run on IST stack. */
dotraplinkage void notrace do_int3(struct pt_regs *regs, long error_code)
{
#ifdef CONFIG_DYNAMIC_FTRACE
@@ -495,7 +494,15 @@ dotraplinkage void notrace do_int3(struc
if (poke_int3_handler(regs))
return;
+ /*
+ * Use ist_enter despite the fact that we don't use an IST stack.
+ * We can be called from a kprobe in non-CONTEXT_KERNEL kernel
+ * mode or even during context tracking state changes.
+ *
+ * This means that we can't schedule. That's okay.
+ */
ist_enter(regs);
+
RCU_LOCKDEP_WARN(!rcu_is_watching(), "entry code didn't wake RCU");
#ifdef CONFIG_KGDB_LOW_LEVEL_TRAP
if (kgdb_ll_trap(DIE_INT3, "int3", regs, error_code, X86_TRAP_BP,
@@ -512,15 +519,9 @@ dotraplinkage void notrace do_int3(struc
SIGTRAP) == NOTIFY_STOP)
goto exit;
- /*
- * Let others (NMI) know that the debug stack is in use
- * as we may switch to the interrupt stack.
- */
- debug_stack_usage_inc();
preempt_conditional_sti(regs);
do_trap(X86_TRAP_BP, SIGTRAP, "int3", regs, error_code, NULL);
preempt_conditional_cli(regs);
- debug_stack_usage_dec();
exit:
ist_exit(regs);
}
@@ -886,19 +887,16 @@ void __init trap_init(void)
cpu_init();
/*
- * X86_TRAP_DB and X86_TRAP_BP have been set
- * in early_trap_init(). However, ITS works only after
- * cpu_init() loads TSS. See comments in early_trap_init().
+ * X86_TRAP_DB was installed in early_trap_init(). However,
+ * IST works only after cpu_init() loads TSS. See comments
+ * in early_trap_init().
*/
set_intr_gate_ist(X86_TRAP_DB, &debug, DEBUG_STACK);
- /* int3 can be called from all */
- set_system_intr_gate_ist(X86_TRAP_BP, &int3, DEBUG_STACK);
x86_init.irqs.trap_init();
#ifdef CONFIG_X86_64
memcpy(&debug_idt_table, &idt_table, IDT_ENTRIES * 16);
set_nmi_gate(X86_TRAP_DB, &debug);
- set_nmi_gate(X86_TRAP_BP, &int3);
#endif
}
next prev parent reply other threads:[~2018-03-27 16:30 UTC|newest]
Thread overview: 64+ messages / expand[flat|nested] mbox.gz Atom feed top
2018-03-27 16:27 [PATCH 4.4 00/43] 4.4.125-stable review Greg Kroah-Hartman
2018-03-27 16:27 ` [PATCH 4.4 01/43] MIPS: ralink: Remove ralink_halt() Greg Kroah-Hartman
2018-03-27 16:27 ` [PATCH 4.4 02/43] iio: st_pressure: st_accel: pass correct platform data to init Greg Kroah-Hartman
2018-03-27 16:27 ` [PATCH 4.4 03/43] ALSA: usb-audio: Fix parsing descriptor of UAC2 processing unit Greg Kroah-Hartman
2018-03-27 16:27 ` [PATCH 4.4 04/43] ALSA: aloop: Sync stale timer before release Greg Kroah-Hartman
2018-03-27 16:27 ` [PATCH 4.4 05/43] ALSA: aloop: Fix access to not-yet-ready substream via cable Greg Kroah-Hartman
2018-03-27 16:27 ` [PATCH 4.4 06/43] ALSA: hda/realtek - Always immediately update mute LED with pin VREF Greg Kroah-Hartman
2018-03-27 16:27 ` [PATCH 4.4 07/43] mmc: dw_mmc: fix falling from idmac to PIO mode when dw_mci_reset occurs Greg Kroah-Hartman
2018-03-27 16:27 ` [PATCH 4.4 08/43] PCI: Add function 1 DMA alias quirk for Highpoint RocketRAID 644L Greg Kroah-Hartman
2018-03-27 16:27 ` [PATCH 4.4 09/43] ahci: Add PCI-id for the Highpoint Rocketraid 644L card Greg Kroah-Hartman
2018-03-27 16:27 ` [PATCH 4.4 10/43] clk: bcm2835: Protect sections updating shared registers Greg Kroah-Hartman
2018-03-27 16:27 ` [PATCH 4.4 11/43] Bluetooth: btusb: Fix quirk for Atheros 1525/QCA6174 Greg Kroah-Hartman
2018-03-27 16:27 ` [PATCH 4.4 12/43] libata: fix length validation of ATAPI-relayed SCSI commands Greg Kroah-Hartman
2018-03-27 16:27 ` [PATCH 4.4 13/43] libata: remove WARN() for DMA or PIO command without data Greg Kroah-Hartman
2018-03-27 16:27 ` [PATCH 4.4 14/43] libata: Apply NOLPM quirk to Crucial MX100 512GB SSDs Greg Kroah-Hartman
2018-03-27 16:27 ` [PATCH 4.4 15/43] libata: disable LPM for Crucial BX100 SSD 500GB drive Greg Kroah-Hartman
2018-03-27 16:27 ` [PATCH 4.4 16/43] libata: Enable queued TRIM for Samsung SSD 860 Greg Kroah-Hartman
2018-03-27 16:27 ` [PATCH 4.4 17/43] libata: Apply NOLPM quirk to Crucial M500 480 and 960GB SSDs Greg Kroah-Hartman
2018-03-27 16:27 ` [PATCH 4.4 18/43] libata: Make Crucial BX100 500GB LPM quirk apply to all firmware versions Greg Kroah-Hartman
2018-03-27 16:27 ` [PATCH 4.4 19/43] libata: Modify quirks for MX100 to limit NCQ_TRIM quirk to MU01 version Greg Kroah-Hartman
2018-03-27 16:27 ` [PATCH 4.4 20/43] mm/vmalloc: add interfaces to free unmapped page table Greg Kroah-Hartman
2018-03-27 20:17 ` Dan Rue
2018-03-27 20:27 ` Kani, Toshi
2018-03-27 20:31 ` Nathan Chancellor
2018-03-27 20:40 ` Kani, Toshi
2018-03-27 20:47 ` Nathan Chancellor
2018-03-28 6:32 ` gregkh
2018-03-28 6:47 ` Nathan Chancellor
2018-03-28 9:58 ` gregkh
2018-03-28 15:06 ` Kani, Toshi
2018-03-28 16:16 ` gregkh
2018-03-27 16:27 ` [PATCH 4.4 21/43] x86/mm: implement free pmd/pte page interfaces Greg Kroah-Hartman
2018-03-27 16:27 ` [PATCH 4.4 22/43] drm/vmwgfx: Fix a destoy-while-held mutex problem Greg Kroah-Hartman
2018-03-27 16:27 ` [PATCH 4.4 23/43] drm/radeon: Dont turn off DP sink when disconnected Greg Kroah-Hartman
2018-03-27 16:27 ` [PATCH 4.4 24/43] drm: udl: Properly check framebuffer mmap offsets Greg Kroah-Hartman
2018-03-27 16:27 ` [PATCH 4.4 25/43] acpi, numa: fix pxm to online numa node associations Greg Kroah-Hartman
2018-03-27 16:27 ` [PATCH 4.4 26/43] brcmfmac: fix P2P_DEVICE ethernet address generation Greg Kroah-Hartman
2018-03-27 16:27 ` [PATCH 4.4 27/43] rtlwifi: rtl8723be: Fix loss of signal Greg Kroah-Hartman
2018-03-27 16:27 ` [PATCH 4.4 28/43] tracing: probeevent: Fix to support minus offset from symbol Greg Kroah-Hartman
2018-03-27 16:27 ` [PATCH 4.4 29/43] mtd: nand: fsl_ifc: Fix nand waitfunc return value Greg Kroah-Hartman
2018-03-27 16:27 ` [PATCH 4.4 30/43] staging: ncpfs: memory corruption in ncp_read_kernel() Greg Kroah-Hartman
2018-03-27 16:27 ` [PATCH 4.4 31/43] can: cc770: Fix stalls on rt-linux, remove redundant IRQ ack Greg Kroah-Hartman
2018-03-27 16:27 ` [PATCH 4.4 32/43] can: cc770: Fix queue stall & dropped RTR reply Greg Kroah-Hartman
2018-03-27 16:27 ` [PATCH 4.4 33/43] can: cc770: Fix use after free in cc770_tx_interrupt() Greg Kroah-Hartman
2018-03-27 16:27 ` [PATCH 4.4 34/43] tty: vt: fix up tabstops properly Greg Kroah-Hartman
2018-03-27 16:27 ` [PATCH 4.4 35/43] kvm/x86: fix icebp instruction handling Greg Kroah-Hartman
2018-03-27 16:27 ` [PATCH 4.4 36/43] x86/build/64: Force the linker to use 2MB page size Greg Kroah-Hartman
2018-03-27 16:27 ` [PATCH 4.4 37/43] x86/boot/64: Verify alignment of the LOAD segment Greg Kroah-Hartman
2018-03-27 16:27 ` Greg Kroah-Hartman [this message]
2018-03-27 16:27 ` [PATCH 4.4 39/43] perf/x86/intel: Dont accidentally clear high bits in bdw_limit_period() Greg Kroah-Hartman
2018-03-27 16:27 ` [PATCH 4.4 40/43] staging: lustre: ptlrpc: kfree used instead of kvfree Greg Kroah-Hartman
2018-03-27 16:27 ` [PATCH 4.4 41/43] kbuild: disable clangs default use of -fmerge-all-constants Greg Kroah-Hartman
2018-03-27 16:27 ` [PATCH 4.4 42/43] bpf: skip unnecessary capability check Greg Kroah-Hartman
2018-03-27 16:27 ` [PATCH 4.4 43/43] bpf, x64: increase number of passes Greg Kroah-Hartman
2018-03-27 18:24 ` [PATCH 4.4 00/43] 4.4.125-stable review Nathan Chancellor
2018-03-28 10:04 ` Greg Kroah-Hartman
2018-03-27 20:21 ` Dan Rue
2018-03-28 10:03 ` Greg Kroah-Hartman
2018-03-27 22:59 ` Shuah Khan
2018-03-28 0:21 ` kernelci.org bot
2018-03-30 23:56 ` Kevin Hilman
2018-03-28 9:58 ` Greg Kroah-Hartman
2018-03-28 15:42 ` Dan Rue
2018-03-28 13:38 ` Guenter Roeck
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