powerpc/32: Enter exceptions with MSR_EE unset

All exceptions handlers know when to reenable interrupts, so it is safer to enter all of them with MSR_EE unset, except for syscalls. Suggested-by: Benjamin Herrenschmidt <benh@kernel.crashing.org> [splited out from benh RFC patch] Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
mariux64 · May 2, 2019 · 642770d · 642770d
1 parent f97dec2
commit 642770d
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Showing 7 changed files with 90 additions and 106 deletions.
diff --git a/arch/powerpc/kernel/head_32.S b/arch/powerpc/kernel/head_32.S
@@ -341,7 +341,7 @@ Alignment:
 	mfspr	r5,SPRN_DSISR
 	stw	r5,_DSISR(r11)
 	addi	r3,r1,STACK_FRAME_OVERHEAD
-	EXC_XFER_EE(0x600, alignment_exception)
+	EXC_XFER_STD(0x600, alignment_exception)
 
 /* Program check exception */
 	EXCEPTION(0x700, ProgramCheck, program_check_exception, EXC_XFER_STD)
@@ -362,13 +362,13 @@ END_FTR_SECTION_IFSET(CPU_FTR_FPU_UNAVAILABLE)
 	bl	load_up_fpu		/* if from user, just load it up */
 	b	fast_exception_return
 1:	addi	r3,r1,STACK_FRAME_OVERHEAD
-	EXC_XFER_EE_LITE(0x800, kernel_fp_unavailable_exception)
+	EXC_XFER_LITE(0x800, kernel_fp_unavailable_exception)
 
 /* Decrementer */
 	EXCEPTION(0x900, Decrementer, timer_interrupt, EXC_XFER_LITE)
 
-	EXCEPTION(0xa00, Trap_0a, unknown_exception, EXC_XFER_EE)
-	EXCEPTION(0xb00, Trap_0b, unknown_exception, EXC_XFER_EE)
+	EXCEPTION(0xa00, Trap_0a, unknown_exception, EXC_XFER_STD)
+	EXCEPTION(0xb00, Trap_0b, unknown_exception, EXC_XFER_STD)
 
 /* System call */
 	. = 0xc00
@@ -379,7 +379,7 @@ SystemCall:
 
 /* Single step - not used on 601 */
 	EXCEPTION(0xd00, SingleStep, single_step_exception, EXC_XFER_STD)
-	EXCEPTION(0xe00, Trap_0e, unknown_exception, EXC_XFER_EE)
+	EXCEPTION(0xe00, Trap_0e, unknown_exception, EXC_XFER_STD)
 
 /*
  * The Altivec unavailable trap is at 0x0f20.  Foo.
@@ -611,35 +611,35 @@ END_MMU_FTR_SECTION_IFSET(MMU_FTR_NEED_DTLB_SW_LRU)
 #define altivec_assist_exception	unknown_exception
 #endif
 
-	EXCEPTION(0x1300, Trap_13, instruction_breakpoint_exception, EXC_XFER_EE)
-	EXCEPTION(0x1400, SMI, SMIException, EXC_XFER_EE)
-	EXCEPTION(0x1500, Trap_15, unknown_exception, EXC_XFER_EE)
-	EXCEPTION(0x1600, Trap_16, altivec_assist_exception, EXC_XFER_EE)
+	EXCEPTION(0x1300, Trap_13, instruction_breakpoint_exception, EXC_XFER_STD)
+	EXCEPTION(0x1400, SMI, SMIException, EXC_XFER_STD)
+	EXCEPTION(0x1500, Trap_15, unknown_exception, EXC_XFER_STD)
+	EXCEPTION(0x1600, Trap_16, altivec_assist_exception, EXC_XFER_STD)
 	EXCEPTION(0x1700, Trap_17, TAUException, EXC_XFER_STD)
-	EXCEPTION(0x1800, Trap_18, unknown_exception, EXC_XFER_EE)
-	EXCEPTION(0x1900, Trap_19, unknown_exception, EXC_XFER_EE)
-	EXCEPTION(0x1a00, Trap_1a, unknown_exception, EXC_XFER_EE)
-	EXCEPTION(0x1b00, Trap_1b, unknown_exception, EXC_XFER_EE)
-	EXCEPTION(0x1c00, Trap_1c, unknown_exception, EXC_XFER_EE)
-	EXCEPTION(0x1d00, Trap_1d, unknown_exception, EXC_XFER_EE)
-	EXCEPTION(0x1e00, Trap_1e, unknown_exception, EXC_XFER_EE)
-	EXCEPTION(0x1f00, Trap_1f, unknown_exception, EXC_XFER_EE)
-	EXCEPTION(0x2000, RunMode, RunModeException, EXC_XFER_EE)
-	EXCEPTION(0x2100, Trap_21, unknown_exception, EXC_XFER_EE)
-	EXCEPTION(0x2200, Trap_22, unknown_exception, EXC_XFER_EE)
-	EXCEPTION(0x2300, Trap_23, unknown_exception, EXC_XFER_EE)
-	EXCEPTION(0x2400, Trap_24, unknown_exception, EXC_XFER_EE)
-	EXCEPTION(0x2500, Trap_25, unknown_exception, EXC_XFER_EE)
-	EXCEPTION(0x2600, Trap_26, unknown_exception, EXC_XFER_EE)
-	EXCEPTION(0x2700, Trap_27, unknown_exception, EXC_XFER_EE)
-	EXCEPTION(0x2800, Trap_28, unknown_exception, EXC_XFER_EE)
-	EXCEPTION(0x2900, Trap_29, unknown_exception, EXC_XFER_EE)
-	EXCEPTION(0x2a00, Trap_2a, unknown_exception, EXC_XFER_EE)
-	EXCEPTION(0x2b00, Trap_2b, unknown_exception, EXC_XFER_EE)
-	EXCEPTION(0x2c00, Trap_2c, unknown_exception, EXC_XFER_EE)
-	EXCEPTION(0x2d00, Trap_2d, unknown_exception, EXC_XFER_EE)
-	EXCEPTION(0x2e00, Trap_2e, unknown_exception, EXC_XFER_EE)
-	EXCEPTION(0x2f00, Trap_2f, unknown_exception, EXC_XFER_EE)
+	EXCEPTION(0x1800, Trap_18, unknown_exception, EXC_XFER_STD)
+	EXCEPTION(0x1900, Trap_19, unknown_exception, EXC_XFER_STD)
+	EXCEPTION(0x1a00, Trap_1a, unknown_exception, EXC_XFER_STD)
+	EXCEPTION(0x1b00, Trap_1b, unknown_exception, EXC_XFER_STD)
+	EXCEPTION(0x1c00, Trap_1c, unknown_exception, EXC_XFER_STD)
+	EXCEPTION(0x1d00, Trap_1d, unknown_exception, EXC_XFER_STD)
+	EXCEPTION(0x1e00, Trap_1e, unknown_exception, EXC_XFER_STD)
+	EXCEPTION(0x1f00, Trap_1f, unknown_exception, EXC_XFER_STD)
+	EXCEPTION(0x2000, RunMode, RunModeException, EXC_XFER_STD)
+	EXCEPTION(0x2100, Trap_21, unknown_exception, EXC_XFER_STD)
+	EXCEPTION(0x2200, Trap_22, unknown_exception, EXC_XFER_STD)
+	EXCEPTION(0x2300, Trap_23, unknown_exception, EXC_XFER_STD)
+	EXCEPTION(0x2400, Trap_24, unknown_exception, EXC_XFER_STD)
+	EXCEPTION(0x2500, Trap_25, unknown_exception, EXC_XFER_STD)
+	EXCEPTION(0x2600, Trap_26, unknown_exception, EXC_XFER_STD)
+	EXCEPTION(0x2700, Trap_27, unknown_exception, EXC_XFER_STD)
+	EXCEPTION(0x2800, Trap_28, unknown_exception, EXC_XFER_STD)
+	EXCEPTION(0x2900, Trap_29, unknown_exception, EXC_XFER_STD)
+	EXCEPTION(0x2a00, Trap_2a, unknown_exception, EXC_XFER_STD)
+	EXCEPTION(0x2b00, Trap_2b, unknown_exception, EXC_XFER_STD)
+	EXCEPTION(0x2c00, Trap_2c, unknown_exception, EXC_XFER_STD)
+	EXCEPTION(0x2d00, Trap_2d, unknown_exception, EXC_XFER_STD)
+	EXCEPTION(0x2e00, Trap_2e, unknown_exception, EXC_XFER_STD)
+	EXCEPTION(0x2f00, Trap_2f, unknown_exception, EXC_XFER_STD)
 
 	. = 0x3000
 
@@ -651,7 +651,7 @@ AltiVecUnavailable:
 	b	fast_exception_return
 #endif /* CONFIG_ALTIVEC */
 1:	addi	r3,r1,STACK_FRAME_OVERHEAD
-	EXC_XFER_EE_LITE(0xf20, altivec_unavailable_exception)
+	EXC_XFER_LITE(0xf20, altivec_unavailable_exception)
 
 PerformanceMonitor:
 	EXCEPTION_PROLOG

diff --git a/arch/powerpc/kernel/head_32.h b/arch/powerpc/kernel/head_32.h
@@ -127,12 +127,4 @@
 	EXC_XFER_TEMPLATE(hdlr, n+1, MSR_KERNEL | MSR_EE, NOCOPY, transfer_to_handler, \
 			  ret_from_except)
 
-#define EXC_XFER_EE(n, hdlr)		\
-	EXC_XFER_TEMPLATE(hdlr, n, MSR_KERNEL, COPY_EE, transfer_to_handler_full, \
-			  ret_from_except_full)
-
-#define EXC_XFER_EE_LITE(n, hdlr)	\
-	EXC_XFER_TEMPLATE(hdlr, n+1, MSR_KERNEL, COPY_EE, transfer_to_handler, \
-			  ret_from_except)
-
 #endif /* __HEAD_32_H__ */
diff --git a/arch/powerpc/kernel/head_40x.S b/arch/powerpc/kernel/head_40x.S
@@ -332,7 +332,7 @@ _ENTRY(saved_ksp_limit)
 	mfspr	r4,SPRN_DEAR		/* Grab the DEAR and save it */
 	stw	r4,_DEAR(r11)
 	addi	r3,r1,STACK_FRAME_OVERHEAD
-	EXC_XFER_EE(0x600, alignment_exception)
+	EXC_XFER_STD(0x600, alignment_exception)
 
 /* 0x0700 - Program Exception */
 	START_EXCEPTION(0x0700, ProgramCheck)
@@ -342,19 +342,19 @@ _ENTRY(saved_ksp_limit)
 	addi	r3,r1,STACK_FRAME_OVERHEAD
 	EXC_XFER_STD(0x700, program_check_exception)
 
-	EXCEPTION(0x0800, Trap_08, unknown_exception, EXC_XFER_EE)
-	EXCEPTION(0x0900, Trap_09, unknown_exception, EXC_XFER_EE)
-	EXCEPTION(0x0A00, Trap_0A, unknown_exception, EXC_XFER_EE)
-	EXCEPTION(0x0B00, Trap_0B, unknown_exception, EXC_XFER_EE)
+	EXCEPTION(0x0800, Trap_08, unknown_exception, EXC_XFER_STD)
+	EXCEPTION(0x0900, Trap_09, unknown_exception, EXC_XFER_STD)
+	EXCEPTION(0x0A00, Trap_0A, unknown_exception, EXC_XFER_STD)
+	EXCEPTION(0x0B00, Trap_0B, unknown_exception, EXC_XFER_STD)
 
 /* 0x0C00 - System Call Exception */
 	START_EXCEPTION(0x0C00,	SystemCall)
 	EXCEPTION_PROLOG
 	EXC_XFER_SYS(0xc00, DoSyscall)
 
-	EXCEPTION(0x0D00, Trap_0D, unknown_exception, EXC_XFER_EE)
-	EXCEPTION(0x0E00, Trap_0E, unknown_exception, EXC_XFER_EE)
-	EXCEPTION(0x0F00, Trap_0F, unknown_exception, EXC_XFER_EE)
+	EXCEPTION(0x0D00, Trap_0D, unknown_exception, EXC_XFER_STD)
+	EXCEPTION(0x0E00, Trap_0E, unknown_exception, EXC_XFER_STD)
+	EXCEPTION(0x0F00, Trap_0F, unknown_exception, EXC_XFER_STD)
 
 /* 0x1000 - Programmable Interval Timer (PIT) Exception */
 	. = 0x1000
@@ -571,25 +571,25 @@ _ENTRY(saved_ksp_limit)
 	mfspr	r10, SPRN_SPRG_SCRATCH0
 	b	InstructionAccess
 
-	EXCEPTION(0x1300, Trap_13, unknown_exception, EXC_XFER_EE)
-	EXCEPTION(0x1400, Trap_14, unknown_exception, EXC_XFER_EE)
-	EXCEPTION(0x1500, Trap_15, unknown_exception, EXC_XFER_EE)
-	EXCEPTION(0x1600, Trap_16, unknown_exception, EXC_XFER_EE)
+	EXCEPTION(0x1300, Trap_13, unknown_exception, EXC_XFER_STD)
+	EXCEPTION(0x1400, Trap_14, unknown_exception, EXC_XFER_STD)
+	EXCEPTION(0x1500, Trap_15, unknown_exception, EXC_XFER_STD)
+	EXCEPTION(0x1600, Trap_16, unknown_exception, EXC_XFER_STD)
 #ifdef CONFIG_IBM405_ERR51
 	/* 405GP errata 51 */
 	START_EXCEPTION(0x1700, Trap_17)
 	b DTLBMiss
 #else
-	EXCEPTION(0x1700, Trap_17, unknown_exception, EXC_XFER_EE)
+	EXCEPTION(0x1700, Trap_17, unknown_exception, EXC_XFER_STD)
 #endif
-	EXCEPTION(0x1800, Trap_18, unknown_exception, EXC_XFER_EE)
-	EXCEPTION(0x1900, Trap_19, unknown_exception, EXC_XFER_EE)
-	EXCEPTION(0x1A00, Trap_1A, unknown_exception, EXC_XFER_EE)
-	EXCEPTION(0x1B00, Trap_1B, unknown_exception, EXC_XFER_EE)
-	EXCEPTION(0x1C00, Trap_1C, unknown_exception, EXC_XFER_EE)
-	EXCEPTION(0x1D00, Trap_1D, unknown_exception, EXC_XFER_EE)
-	EXCEPTION(0x1E00, Trap_1E, unknown_exception, EXC_XFER_EE)
-	EXCEPTION(0x1F00, Trap_1F, unknown_exception, EXC_XFER_EE)
+	EXCEPTION(0x1800, Trap_18, unknown_exception, EXC_XFER_STD)
+	EXCEPTION(0x1900, Trap_19, unknown_exception, EXC_XFER_STD)
+	EXCEPTION(0x1A00, Trap_1A, unknown_exception, EXC_XFER_STD)
+	EXCEPTION(0x1B00, Trap_1B, unknown_exception, EXC_XFER_STD)
+	EXCEPTION(0x1C00, Trap_1C, unknown_exception, EXC_XFER_STD)
+	EXCEPTION(0x1D00, Trap_1D, unknown_exception, EXC_XFER_STD)
+	EXCEPTION(0x1E00, Trap_1E, unknown_exception, EXC_XFER_STD)
+	EXCEPTION(0x1F00, Trap_1F, unknown_exception, EXC_XFER_STD)
 
 /* Check for a single step debug exception while in an exception
  * handler before state has been saved.  This is to catch the case
@@ -665,7 +665,7 @@ Decrementer:
 FITException:
 	EXCEPTION_PROLOG
 	addi	r3,r1,STACK_FRAME_OVERHEAD;
-	EXC_XFER_EE(0x1010, unknown_exception)
+	EXC_XFER_STD(0x1010, unknown_exception)
 
 	/* Watchdog Timer (WDT) Exception. (from 0x1020) */
 WDTException:

diff --git a/arch/powerpc/kernel/head_44x.S b/arch/powerpc/kernel/head_44x.S
@@ -281,7 +281,7 @@ interrupt_base:
 	FP_UNAVAILABLE_EXCEPTION
 #else
 	EXCEPTION(0x2010, BOOKE_INTERRUPT_FP_UNAVAIL, \
-		  FloatingPointUnavailable, unknown_exception, EXC_XFER_EE)
+		  FloatingPointUnavailable, unknown_exception, EXC_XFER_STD)
 #endif
 	/* System Call Interrupt */
 	START_EXCEPTION(SystemCall)
@@ -290,15 +290,15 @@ interrupt_base:
 
 	/* Auxiliary Processor Unavailable Interrupt */
 	EXCEPTION(0x2020, BOOKE_INTERRUPT_AP_UNAVAIL, \
-		  AuxillaryProcessorUnavailable, unknown_exception, EXC_XFER_EE)
+		  AuxillaryProcessorUnavailable, unknown_exception, EXC_XFER_STD)
 
 	/* Decrementer Interrupt */
 	DECREMENTER_EXCEPTION
 
 	/* Fixed Internal Timer Interrupt */
 	/* TODO: Add FIT support */
 	EXCEPTION(0x1010, BOOKE_INTERRUPT_FIT, FixedIntervalTimer, \
-		  unknown_exception, EXC_XFER_EE)
+		  unknown_exception, EXC_XFER_STD)
 
 	/* Watchdog Timer Interrupt */
 	/* TODO: Add watchdog support */

diff --git a/arch/powerpc/kernel/head_8xx.S b/arch/powerpc/kernel/head_8xx.S
@@ -167,7 +167,7 @@ Alignment:
 	mfspr	r5,SPRN_DSISR
 	stw	r5,_DSISR(r11)
 	addi	r3,r1,STACK_FRAME_OVERHEAD
-	EXC_XFER_EE(0x600, alignment_exception)
+	EXC_XFER_STD(0x600, alignment_exception)
 
 /* Program check exception */
 	EXCEPTION(0x700, ProgramCheck, program_check_exception, EXC_XFER_STD)
@@ -179,8 +179,8 @@ Alignment:
 /* Decrementer */
 	EXCEPTION(0x900, Decrementer, timer_interrupt, EXC_XFER_LITE)
 
-	EXCEPTION(0xa00, Trap_0a, unknown_exception, EXC_XFER_EE)
-	EXCEPTION(0xb00, Trap_0b, unknown_exception, EXC_XFER_EE)
+	EXCEPTION(0xa00, Trap_0a, unknown_exception, EXC_XFER_STD)
+	EXCEPTION(0xb00, Trap_0b, unknown_exception, EXC_XFER_STD)
 
 /* System call */
 	. = 0xc00
@@ -190,8 +190,8 @@ SystemCall:
 
 /* Single step - not used on 601 */
 	EXCEPTION(0xd00, SingleStep, single_step_exception, EXC_XFER_STD)
-	EXCEPTION(0xe00, Trap_0e, unknown_exception, EXC_XFER_EE)
-	EXCEPTION(0xf00, Trap_0f, unknown_exception, EXC_XFER_EE)
+	EXCEPTION(0xe00, Trap_0e, unknown_exception, EXC_XFER_STD)
+	EXCEPTION(0xf00, Trap_0f, unknown_exception, EXC_XFER_STD)
 
 /* On the MPC8xx, this is a software emulation interrupt.  It occurs
  * for all unimplemented and illegal instructions.
@@ -521,13 +521,13 @@ DARFixed:/* Return from dcbx instruction bug workaround */
 	/* 0x300 is DataAccess exception, needed by bad_page_fault() */
 	EXC_XFER_LITE(0x300, handle_page_fault)
 
-	EXCEPTION(0x1500, Trap_15, unknown_exception, EXC_XFER_EE)
-	EXCEPTION(0x1600, Trap_16, unknown_exception, EXC_XFER_EE)
-	EXCEPTION(0x1700, Trap_17, unknown_exception, EXC_XFER_EE)
-	EXCEPTION(0x1800, Trap_18, unknown_exception, EXC_XFER_EE)
-	EXCEPTION(0x1900, Trap_19, unknown_exception, EXC_XFER_EE)
-	EXCEPTION(0x1a00, Trap_1a, unknown_exception, EXC_XFER_EE)
-	EXCEPTION(0x1b00, Trap_1b, unknown_exception, EXC_XFER_EE)
+	EXCEPTION(0x1500, Trap_15, unknown_exception, EXC_XFER_STD)
+	EXCEPTION(0x1600, Trap_16, unknown_exception, EXC_XFER_STD)
+	EXCEPTION(0x1700, Trap_17, unknown_exception, EXC_XFER_STD)
+	EXCEPTION(0x1800, Trap_18, unknown_exception, EXC_XFER_STD)
+	EXCEPTION(0x1900, Trap_19, unknown_exception, EXC_XFER_STD)
+	EXCEPTION(0x1a00, Trap_1a, unknown_exception, EXC_XFER_STD)
+	EXCEPTION(0x1b00, Trap_1b, unknown_exception, EXC_XFER_STD)
 
 /* On the MPC8xx, these next four traps are used for development
  * support of breakpoints and such.  Someday I will get around to
@@ -549,7 +549,7 @@ DataBreakpoint:
 	mfspr	r4,SPRN_BAR
 	stw	r4,_DAR(r11)
 	mfspr	r5,SPRN_DSISR
-	EXC_XFER_EE(0x1c00, do_break)
+	EXC_XFER_STD(0x1c00, do_break)
 11:
 	mtcr	r10
 	mfspr	r10, SPRN_SPRG_SCRATCH0
@@ -569,10 +569,10 @@ InstructionBreakpoint:
 	mfspr	r10, SPRN_SPRG_SCRATCH0
 	rfi
 #else
-	EXCEPTION(0x1d00, Trap_1d, unknown_exception, EXC_XFER_EE)
+	EXCEPTION(0x1d00, Trap_1d, unknown_exception, EXC_XFER_STD)
 #endif
-	EXCEPTION(0x1e00, Trap_1e, unknown_exception, EXC_XFER_EE)
-	EXCEPTION(0x1f00, Trap_1f, unknown_exception, EXC_XFER_EE)
+	EXCEPTION(0x1e00, Trap_1e, unknown_exception, EXC_XFER_STD)
+	EXCEPTION(0x1f00, Trap_1f, unknown_exception, EXC_XFER_STD)
 
 	. = 0x2000
 

diff --git a/arch/powerpc/kernel/head_booke.h b/arch/powerpc/kernel/head_booke.h
@@ -255,14 +255,6 @@ END_BTB_FLUSH_SECTION
 	EXC_XFER_TEMPLATE(hdlr, n+1, MSR_KERNEL | MSR_EE, NOCOPY, transfer_to_handler, \
 			  ret_from_except)
 
-#define EXC_XFER_EE(n, hdlr)		\
-	EXC_XFER_TEMPLATE(hdlr, n, MSR_KERNEL, COPY_EE, transfer_to_handler_full, \
-			  ret_from_except_full)
-
-#define EXC_XFER_EE_LITE(n, hdlr)	\
-	EXC_XFER_TEMPLATE(hdlr, n+1, MSR_KERNEL, COPY_EE, transfer_to_handler, \
-			  ret_from_except)
-
 /* Check for a single step debug exception while in an exception
  * handler before state has been saved.  This is to catch the case
  * where an instruction that we are trying to single step causes
@@ -405,7 +397,7 @@ END_BTB_FLUSH_SECTION
 	mfspr   r4,SPRN_DEAR;           /* Grab the DEAR and save it */	      \
 	stw     r4,_DEAR(r11);						      \
 	addi    r3,r1,STACK_FRAME_OVERHEAD;				      \
-	EXC_XFER_EE(0x0600, alignment_exception)
+	EXC_XFER_STD(0x0600, alignment_exception)
 
 #define PROGRAM_EXCEPTION						      \
 	START_EXCEPTION(Program)					      \
@@ -430,7 +422,7 @@ END_BTB_FLUSH_SECTION
 	bl	load_up_fpu;		/* if from user, just load it up */   \
 	b	fast_exception_return;					      \
 1:	addi	r3,r1,STACK_FRAME_OVERHEAD;				      \
-	EXC_XFER_EE_LITE(0x800, kernel_fp_unavailable_exception)
+	EXC_XFER_STD(0x800, kernel_fp_unavailable_exception)
 
 #ifndef __ASSEMBLY__
 struct exception_regs {