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From: Vineet Gupta <Vineet.Gupta1@synopsys.com>
To: <linux-arch@vger.kernel.org>, <linux-kernel@vger.kernel.org>
Cc: <arnd@arndb.de>, <arc-linux-dev@synopsys.com>,
	Vineet Gupta <Vineet.Gupta1@synopsys.com>
Subject: [PATCH 04/28] ARCv2: STAR 9000808988: signals involving Delay Slot
Date: Tue, 9 Jun 2015 17:18:04 +0530	[thread overview]
Message-ID: <1433850508-26317-5-git-send-email-vgupta@synopsys.com> (raw)
In-Reply-To: <1433850508-26317-1-git-send-email-vgupta@synopsys.com>

Reported by Anton as LTP:munmap01 failing with Illegal Instruction
Exception.

   --------------------->8--------------------------------------
   mmap2(NULL, 24576, PROT_READ|PROT_WRITE, MAP_SHARED, 3, 0) = 0x200d2000
   munmap(0x200d2000, 24576)               = 0
   --- SIGSEGV {si_signo=SIGSEGV, si_code=SEGV_MAPERR, si_addr=0x200d2000}
   ---
   potentially unexpected fatal signal 4.
   Path: /munmap01
   CPU: 0 PID: 61 Comm: munmap01 Not tainted 3.13.0-g5d5c46d9a556 #8
   task: 9f1a8000 ti: 9f154000 task.ti: 9f154000

   [ECR   ]: 0x00020100 => Illegal Insn
   [EFA   ]: 0x0001354c
   [BLINK ]: 0x200515d4
   [ERET  ]: 0x1354c
       @off 0x1354c in [/munmap01]
       VMA: 0x00010000 to 0x00018000
   [STAT32]: 0x800802c0
   ...
   --------------------->8--------------------------------------

The issue was
1. munmap01 accessed unmapped memory (on purpose) with signal handler
   installed for SIGSEGV

2. The faulting instruction happened to be in Delay Slot
   00011864 <main>:
      11908:	bl.d       13284 <tst_resm>
      1190c:	stb        r16,[r2]

3. kernel sets up the reg file for signal handler and correctly clears
   the DE bit in pt_regs->status32 placeholder

4. However RESTORE_CALLEE_SAVED_USER macro is not adjusted for ARCv2,
   and it over-writes the above with orig/stale value of status32

5. After RTIE, userspace signal handler executes a non branch
   instruction with DE bit set, triggering Illegal Instruction Exception.

Reported-by: Anton Kolesov <akolesov@synopsys.com>
Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
---
 arch/arc/include/asm/entry.h  | 17 ++++++++++-------
 arch/arc/kernel/asm-offsets.c |  2 ++
 2 files changed, 12 insertions(+), 7 deletions(-)

diff --git a/arch/arc/include/asm/entry.h b/arch/arc/include/asm/entry.h
index 29d0ab6e10f5..ad7860c5ce15 100644
--- a/arch/arc/include/asm/entry.h
+++ b/arch/arc/include/asm/entry.h
@@ -125,8 +125,6 @@
 	POP	r13
 .endm
 
-#define OFF_USER_R25_FROM_R24	(SZ_CALLEE_REGS + SZ_PT_REGS - 8)/4
-
 /*--------------------------------------------------------------
  * Collect User Mode callee regs as struct callee_regs - needed by
  * fork/do_signal/unaligned-access-emulation.
@@ -139,12 +137,13 @@
  *-------------------------------------------------------------*/
 .macro SAVE_CALLEE_SAVED_USER
 
+	mov	r12, sp		; save SP as ref to pt_regs
 	SAVE_R13_TO_R24
 
 #ifdef CONFIG_ARC_CURR_IN_REG
-	; Retrieve orig r25 and save it on stack
-	ld.as   r12, [sp, OFF_USER_R25_FROM_R24]
-	st.a    r12, [sp, -4]
+	; Retrieve orig r25 and save it with rest of callee_regs
+	ld.as   r12, [r12, PT_user_r25]
+	PUSH	r12
 #else
 	PUSH	r25
 #endif
@@ -191,12 +190,16 @@
 .macro RESTORE_CALLEE_SAVED_USER
 
 #ifdef CONFIG_ARC_CURR_IN_REG
-	ld.ab   r12, [sp, 4]
-	st.as   r12, [sp, OFF_USER_R25_FROM_R24]
+	POP	r12
 #else
 	POP	r25
 #endif
 	RESTORE_R24_TO_R13
+
+	; SP is back to start of pt_regs
+#ifdef CONFIG_ARC_CURR_IN_REG
+	st.as   r12, [sp, PT_user_r25]
+#endif
 .endm
 
 /*--------------------------------------------------------------
diff --git a/arch/arc/kernel/asm-offsets.c b/arch/arc/kernel/asm-offsets.c
index b9cf23313273..605281f5b301 100644
--- a/arch/arc/kernel/asm-offsets.c
+++ b/arch/arc/kernel/asm-offsets.c
@@ -60,5 +60,7 @@ int main(void)
 
 	DEFINE(SZ_CALLEE_REGS, sizeof(struct callee_regs));
 	DEFINE(SZ_PT_REGS, sizeof(struct pt_regs));
+	DEFINE(PT_user_r25, offsetof(struct pt_regs, user_r25));
+
 	return 0;
 }
-- 
1.9.1


WARNING: multiple messages have this Message-ID (diff)
From: Vineet Gupta <Vineet.Gupta1@synopsys.com>
To: linux-arch@vger.kernel.org, linux-kernel@vger.kernel.org
Cc: arnd@arndb.de, arc-linux-dev@synopsys.com,
	Vineet Gupta <Vineet.Gupta1@synopsys.com>
Subject: [PATCH 04/28] ARCv2: STAR 9000808988: signals involving Delay Slot
Date: Tue, 9 Jun 2015 17:18:04 +0530	[thread overview]
Message-ID: <1433850508-26317-5-git-send-email-vgupta@synopsys.com> (raw)
In-Reply-To: <1433850508-26317-1-git-send-email-vgupta@synopsys.com>

Reported by Anton as LTP:munmap01 failing with Illegal Instruction
Exception.

   --------------------->8--------------------------------------
   mmap2(NULL, 24576, PROT_READ|PROT_WRITE, MAP_SHARED, 3, 0) = 0x200d2000
   munmap(0x200d2000, 24576)               = 0
   --- SIGSEGV {si_signo=SIGSEGV, si_code=SEGV_MAPERR, si_addr=0x200d2000}
   ---
   potentially unexpected fatal signal 4.
   Path: /munmap01
   CPU: 0 PID: 61 Comm: munmap01 Not tainted 3.13.0-g5d5c46d9a556 #8
   task: 9f1a8000 ti: 9f154000 task.ti: 9f154000

   [ECR   ]: 0x00020100 => Illegal Insn
   [EFA   ]: 0x0001354c
   [BLINK ]: 0x200515d4
   [ERET  ]: 0x1354c
       @off 0x1354c in [/munmap01]
       VMA: 0x00010000 to 0x00018000
   [STAT32]: 0x800802c0
   ...
   --------------------->8--------------------------------------

The issue was
1. munmap01 accessed unmapped memory (on purpose) with signal handler
   installed for SIGSEGV

2. The faulting instruction happened to be in Delay Slot
   00011864 <main>:
      11908:	bl.d       13284 <tst_resm>
      1190c:	stb        r16,[r2]

3. kernel sets up the reg file for signal handler and correctly clears
   the DE bit in pt_regs->status32 placeholder

4. However RESTORE_CALLEE_SAVED_USER macro is not adjusted for ARCv2,
   and it over-writes the above with orig/stale value of status32

5. After RTIE, userspace signal handler executes a non branch
   instruction with DE bit set, triggering Illegal Instruction Exception.

Reported-by: Anton Kolesov <akolesov@synopsys.com>
Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
---
 arch/arc/include/asm/entry.h  | 17 ++++++++++-------
 arch/arc/kernel/asm-offsets.c |  2 ++
 2 files changed, 12 insertions(+), 7 deletions(-)

diff --git a/arch/arc/include/asm/entry.h b/arch/arc/include/asm/entry.h
index 29d0ab6e10f5..ad7860c5ce15 100644
--- a/arch/arc/include/asm/entry.h
+++ b/arch/arc/include/asm/entry.h
@@ -125,8 +125,6 @@
 	POP	r13
 .endm
 
-#define OFF_USER_R25_FROM_R24	(SZ_CALLEE_REGS + SZ_PT_REGS - 8)/4
-
 /*--------------------------------------------------------------
  * Collect User Mode callee regs as struct callee_regs - needed by
  * fork/do_signal/unaligned-access-emulation.
@@ -139,12 +137,13 @@
  *-------------------------------------------------------------*/
 .macro SAVE_CALLEE_SAVED_USER
 
+	mov	r12, sp		; save SP as ref to pt_regs
 	SAVE_R13_TO_R24
 
 #ifdef CONFIG_ARC_CURR_IN_REG
-	; Retrieve orig r25 and save it on stack
-	ld.as   r12, [sp, OFF_USER_R25_FROM_R24]
-	st.a    r12, [sp, -4]
+	; Retrieve orig r25 and save it with rest of callee_regs
+	ld.as   r12, [r12, PT_user_r25]
+	PUSH	r12
 #else
 	PUSH	r25
 #endif
@@ -191,12 +190,16 @@
 .macro RESTORE_CALLEE_SAVED_USER
 
 #ifdef CONFIG_ARC_CURR_IN_REG
-	ld.ab   r12, [sp, 4]
-	st.as   r12, [sp, OFF_USER_R25_FROM_R24]
+	POP	r12
 #else
 	POP	r25
 #endif
 	RESTORE_R24_TO_R13
+
+	; SP is back to start of pt_regs
+#ifdef CONFIG_ARC_CURR_IN_REG
+	st.as   r12, [sp, PT_user_r25]
+#endif
 .endm
 
 /*--------------------------------------------------------------
diff --git a/arch/arc/kernel/asm-offsets.c b/arch/arc/kernel/asm-offsets.c
index b9cf23313273..605281f5b301 100644
--- a/arch/arc/kernel/asm-offsets.c
+++ b/arch/arc/kernel/asm-offsets.c
@@ -60,5 +60,7 @@ int main(void)
 
 	DEFINE(SZ_CALLEE_REGS, sizeof(struct callee_regs));
 	DEFINE(SZ_PT_REGS, sizeof(struct pt_regs));
+	DEFINE(PT_user_r25, offsetof(struct pt_regs, user_r25));
+
 	return 0;
 }
-- 
1.9.1

  parent reply	other threads:[~2015-06-09 11:58 UTC|newest]

Thread overview: 109+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2015-06-09 11:48 [PATCH 00/28] ARCv2 port to Linux - (B) ISA / Core / platform support Vineet Gupta
2015-06-09 11:48 ` Vineet Gupta
2015-06-09 11:48 ` [PATCH 01/28] ARCv2: [intc] HS38 core interrupt controller Vineet Gupta
2015-06-09 11:48   ` Vineet Gupta
2015-06-09 11:48 ` [PATCH 02/28] ARCv2: Support for ARCv2 ISA and HS38x cores Vineet Gupta
2015-06-09 11:48   ` Vineet Gupta
2015-06-09 11:48 ` [PATCH 03/28] ARCv2: STAR 9000793984: Handle return from intr to Delay Slot Vineet Gupta
2015-06-09 11:48   ` Vineet Gupta
2015-06-09 11:48 ` Vineet Gupta [this message]
2015-06-09 11:48   ` [PATCH 04/28] ARCv2: STAR 9000808988: signals involving " Vineet Gupta
2015-06-09 11:48 ` [PATCH 05/28] ARCv2: STAR 9000814690: Really Re-enable interrupts to avoid deadlocks Vineet Gupta
2015-06-09 11:48   ` Vineet Gupta
2015-06-09 11:48 ` [PATCH 06/28] ARCv2: MMUv4: TLB programming Model changes Vineet Gupta
2015-06-09 11:48   ` Vineet Gupta
2015-06-09 11:48 ` [PATCH 07/28] ARCv2: MMUv4: cache programming model changes Vineet Gupta
2015-06-09 11:48   ` Vineet Gupta
2015-06-09 11:48 ` [PATCH 08/28] ARCv2: MMUv4: support aliasing icache config Vineet Gupta
2015-06-09 11:48   ` Vineet Gupta
2015-06-09 11:48 ` [PATCH 09/28] ARCv2: optimised string/mem lib routines Vineet Gupta
2015-06-09 11:48   ` Vineet Gupta
2015-06-09 11:48 ` [PATCH 10/28] ARCv2: Adhere to Zero Delay loop restriction Vineet Gupta
2015-06-09 11:48   ` Vineet Gupta
2015-06-09 11:48 ` [PATCH 11/28] ARCv2: extable: Enable sorting at build time Vineet Gupta
2015-06-09 11:48   ` Vineet Gupta
2015-06-24  5:51   ` Vineet Gupta
2015-06-24  5:51     ` Vineet Gupta
2015-06-29 20:38     ` David Daney
2015-06-30  4:41       ` Vineet Gupta
2015-06-30  4:41         ` Vineet Gupta
2015-06-09 11:48 ` [PATCH 12/28] ARCv2: clocksource: Introduce 64bit local RTC counter Vineet Gupta
2015-06-09 11:48   ` Vineet Gupta
2015-06-09 11:48 ` [PATCH 13/28] ARC: make plat_smp_ops weak to allow over-rides Vineet Gupta
2015-06-09 11:48   ` Vineet Gupta
2015-06-09 11:48 ` [PATCH 14/28] ARCv2: SMP: ARConnect debug/robustness Vineet Gupta
2015-06-09 11:48   ` Vineet Gupta
2015-06-09 11:48 ` [PATCH 15/28] ARCv2: SMP: clocksource: Enable Global Real Time counter Vineet Gupta
2015-06-09 11:48   ` Vineet Gupta
2015-06-09 11:48 ` [PATCH 16/28] ARCv2: SMP: intc: IDU 2nd level intc for dynamic IRQ distribution Vineet Gupta
2015-06-09 11:48   ` Vineet Gupta
2015-06-09 11:48 ` [PATCH 17/28] ARC: add compiler barrier to LLSC based cmpxchg Vineet Gupta
2015-06-09 11:48   ` Vineet Gupta
2015-06-09 12:23   ` Peter Zijlstra
2015-06-09 11:48 ` [PATCH 18/28] ARC: add smp barriers around atomics per memory-barrriers.txt Vineet Gupta
2015-06-09 11:48   ` Vineet Gupta
2015-06-09 12:30   ` Peter Zijlstra
2015-06-10  9:17     ` Vineet Gupta
2015-06-10 10:53       ` Peter Zijlstra
2015-06-11 13:03         ` Vineet Gupta
2015-06-12 12:15   ` [PATCH v2] ARC: add smp barriers around atomics per Documentation/atomic_ops.txt Vineet Gupta
2015-06-12 12:15     ` Vineet Gupta
2015-06-12 13:04     ` Peter Zijlstra
2015-06-12 13:16       ` Vineet Gupta
2015-06-09 11:48 ` [PATCH 19/28] arch: conditionally define smp_{mb,rmb,wmb} Vineet Gupta
2015-06-09 11:48   ` Vineet Gupta
2015-06-09 12:32   ` Peter Zijlstra
2015-06-09 11:48 ` [PATCH 20/28] ARCv2: barriers Vineet Gupta
2015-06-09 11:48   ` Vineet Gupta
2015-06-09 12:40   ` Peter Zijlstra
2015-06-10  9:34     ` Vineet Gupta
2015-06-10 10:58       ` Peter Zijlstra
2015-06-10 13:01         ` Will Deacon
2015-06-11 12:13           ` Vineet Gupta
2015-06-11 13:39             ` Will Deacon
2015-06-19 13:13               ` Vineet Gupta
2015-06-19 13:13                 ` Vineet Gupta
2015-06-19 13:13                 ` Vineet Gupta
2015-06-22 13:36                 ` Will Deacon
2015-06-22 13:36                   ` Will Deacon
2015-06-22 13:36                   ` Will Deacon
2015-06-23  7:58                   ` [PATCH v2 " Vineet Gupta
2015-06-23  7:58                     ` Vineet Gupta
2015-06-23  8:49                     ` Will Deacon
2015-06-23  9:03                       ` Vineet Gupta
2015-06-23  9:26                         ` Will Deacon
2015-06-23  9:52                           ` [PATCH v3 22/28] " Vineet Gupta
2015-06-23  9:52                             ` Vineet Gupta
2015-06-23 16:28                             ` Will Deacon
2015-06-23  9:25                     ` [PATCH v2 20/28] " Peter Zijlstra
2015-06-23  8:02                   ` [PATCH " Vineet Gupta
2015-06-09 11:48 ` [PATCH 21/28] ARC: Reduce bitops lines of code using macros Vineet Gupta
2015-06-09 11:48   ` Vineet Gupta
2015-06-12 12:20   ` [PATCH v2] " Vineet Gupta
2015-06-12 12:20     ` Vineet Gupta
2015-06-12 13:05     ` Peter Zijlstra
2015-06-09 11:48 ` [PATCH 22/28] ARCv2: STAR 9000837815 workaround hardware exclusive transactions livelock Vineet Gupta
2015-06-09 11:48   ` Vineet Gupta
2015-06-09 12:35   ` Peter Zijlstra
2015-06-10 10:01     ` Vineet Gupta
2015-06-10 11:02       ` Peter Zijlstra
2015-06-19  9:55         ` [PATCH v2 " Vineet Gupta
2015-06-19  9:55           ` Vineet Gupta
2015-06-19  9:59           ` Will Deacon
2015-06-19 10:09             ` Vineet Gupta
2015-06-23  7:59             ` Vineet Gupta
2015-06-23  7:59               ` Vineet Gupta
2015-06-09 11:48 ` [PATCH 23/28] ARCv2: SLC: Handle explcit flush for DMA ops (w/o IO-coherency) Vineet Gupta
2015-06-09 11:48   ` Vineet Gupta
2015-06-09 11:48 ` [PATCH 24/28] ARCv2: All bits in place, allow ARCv2 builds Vineet Gupta
2015-06-09 11:48   ` Vineet Gupta
2015-06-09 11:48 ` [PATCH 25/28] ARCv2: [nsim*hs*] Support simulation platforms for HS38x cores Vineet Gupta
2015-06-09 11:48   ` Vineet Gupta
2015-06-09 11:48   ` Vineet Gupta
2015-06-09 11:48 ` [PATCH 26/28] ARC: [axs101] Prepare for AXS103 Vineet Gupta
2015-06-09 11:48   ` Vineet Gupta
2015-06-09 11:48 ` [PATCH 27/28] ARCv2: [axs103] Support ARC SDP FPGA platform for HS38x cores Vineet Gupta
2015-06-09 11:48   ` Vineet Gupta
2015-06-09 11:48   ` Vineet Gupta
2015-06-09 11:48 ` [PATCH 28/28] ARCv2: [vdk] dts files and defconfig for HS38 VDK Vineet Gupta
2015-06-09 11:48   ` Vineet Gupta

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