From 90303b102353302e84758f245906368907e6a23b Mon Sep 17 00:00:00 2001 From: Catalin Marinas Date: Thu, 12 Jan 2006 16:53:51 +0000 Subject: [ARM] 3256/1: Make the function-returning ldm's use sp as the base register Patch from Catalin Marinas If the low interrupt latency mode is enabled for the CPU (from ARMv6 onwards), the ldm/stm instructions are no longer atomic. An ldm instruction restoring the sp and pc registers can be interrupted immediately after sp was updated but before the pc. If this happens, the CPU restores the base register to the value before the ldm instruction but if the base register is not sp, the interrupt routine will corrupt the stack and the restarted ldm instruction will load garbage. Note that future ARM cores might always run in the low interrupt latency mode. Signed-off-by: Catalin Marinas Signed-off-by: Russell King --- arch/arm/kernel/fiq.c | 4 ++-- arch/arm/lib/csumpartialcopy.S | 6 ++++-- arch/arm/lib/csumpartialcopygeneric.S | 6 ++---- arch/arm/lib/csumpartialcopyuser.S | 8 +++++--- 4 files changed, 13 insertions(+), 11 deletions(-) (limited to 'arch') diff --git a/arch/arm/kernel/fiq.c b/arch/arm/kernel/fiq.c index 9299dfc2569..1ec3f7faa25 100644 --- a/arch/arm/kernel/fiq.c +++ b/arch/arm/kernel/fiq.c @@ -101,7 +101,7 @@ void __attribute__((naked)) set_fiq_regs(struct pt_regs *regs) ldmia %1, {r8 - r14}\n\ msr cpsr_c, %0 @ return to SVC mode\n\ mov r0, r0\n\ - ldmea fp, {fp, sp, pc}" + ldmfd sp, {fp, sp, pc}" : "=&r" (tmp) : "r" (®s->ARM_r8), "I" (PSR_I_BIT | PSR_F_BIT | FIQ_MODE)); } @@ -119,7 +119,7 @@ void __attribute__((naked)) get_fiq_regs(struct pt_regs *regs) stmia %1, {r8 - r14}\n\ msr cpsr_c, %0 @ return to SVC mode\n\ mov r0, r0\n\ - ldmea fp, {fp, sp, pc}" + ldmfd sp, {fp, sp, pc}" : "=&r" (tmp) : "r" (®s->ARM_r8), "I" (PSR_I_BIT | PSR_F_BIT | FIQ_MODE)); } diff --git a/arch/arm/lib/csumpartialcopy.S b/arch/arm/lib/csumpartialcopy.S index 990ee63b246..21effe0dbf9 100644 --- a/arch/arm/lib/csumpartialcopy.S +++ b/arch/arm/lib/csumpartialcopy.S @@ -18,11 +18,13 @@ */ .macro save_regs + mov ip, sp stmfd sp!, {r1, r4 - r8, fp, ip, lr, pc} + sub fp, ip, #4 .endm - .macro load_regs,flags - LOADREGS(\flags,fp,{r1, r4 - r8, fp, sp, pc}) + .macro load_regs + ldmfd sp, {r1, r4 - r8, fp, sp, pc} .endm .macro load1b, reg1 diff --git a/arch/arm/lib/csumpartialcopygeneric.S b/arch/arm/lib/csumpartialcopygeneric.S index 4a4609c1909..c50e8f5285d 100644 --- a/arch/arm/lib/csumpartialcopygeneric.S +++ b/arch/arm/lib/csumpartialcopygeneric.S @@ -23,7 +23,7 @@ len .req r2 sum .req r3 .Lzero: mov r0, sum - load_regs ea + load_regs /* * Align an unaligned destination pointer. We know that @@ -87,9 +87,7 @@ sum .req r3 b .Ldone FN_ENTRY - mov ip, sp save_regs - sub fp, ip, #4 cmp len, #8 @ Ensure that we have at least blo .Lless8 @ 8 bytes to copy. @@ -163,7 +161,7 @@ FN_ENTRY ldr sum, [sp, #0] @ dst tst sum, #1 movne r0, r0, ror #8 - load_regs ea + load_regs .Lsrc_not_aligned: adc sum, sum, #0 @ include C from dst alignment diff --git a/arch/arm/lib/csumpartialcopyuser.S b/arch/arm/lib/csumpartialcopyuser.S index 333bca292de..c3b93e22ea2 100644 --- a/arch/arm/lib/csumpartialcopyuser.S +++ b/arch/arm/lib/csumpartialcopyuser.S @@ -18,11 +18,13 @@ .text .macro save_regs + mov ip, sp stmfd sp!, {r1 - r2, r4 - r8, fp, ip, lr, pc} + sub fp, ip, #4 .endm - .macro load_regs,flags - ldm\flags fp, {r1, r2, r4-r8, fp, sp, pc} + .macro load_regs + ldmfd sp, {r1, r2, r4-r8, fp, sp, pc} .endm .macro load1b, reg1 @@ -100,5 +102,5 @@ 6002: teq r2, r1 strneb r0, [r1], #1 bne 6002b - load_regs ea + load_regs .previous -- cgit v1.2.3