[PATCHv2] arm: Preserve TPIDRURW on context switch
From: André Hentschel
Date: Fri Apr 19 2013 - 11:55:28 EST
From: =?UTF-8?q?Andr=C3=A9=20Hentschel?= <nerv@xxxxxxxxxxx>
There are more and more applications coming to WinRT, Wine could support them,
but mostly they expect to have the thread environment block (TEB) in TPIDRURW.
This register must be preserved per thread instead of being cleared.
Signed-off-by: André Hentschel <nerv@xxxxxxxxxxx>
---
This patch is against a86d52667d8eda5de39393ce737794403bdce1eb
I could only test it with kernel 3.4.6
arch/arm/include/asm/thread_info.h | 2 +-
arch/arm/include/asm/tls.h | 32 +++++++++++++++++++-------------
arch/arm/kernel/entry-armv.S | 9 ++++-----
arch/arm/kernel/process.c | 2 +-
arch/arm/kernel/ptrace.c | 2 +-
arch/arm/kernel/traps.c | 4 ++--
6 files changed, 28 insertions(+), 23 deletions(-)
diff --git a/arch/arm/include/asm/thread_info.h b/arch/arm/include/asm/thread_info.h
index cddda1f..bb5b48d 100644
--- a/arch/arm/include/asm/thread_info.h
+++ b/arch/arm/include/asm/thread_info.h
@@ -58,7 +58,7 @@ struct thread_info {
struct cpu_context_save cpu_context; /* cpu context */
__u32 syscall; /* syscall number */
__u8 used_cp[16]; /* thread used copro */
- unsigned long tp_value;
+ unsigned long tp_value[2];
#ifdef CONFIG_CRUNCH
struct crunch_state crunchstate;
#endif
diff --git a/arch/arm/include/asm/tls.h b/arch/arm/include/asm/tls.h
index 73409e6..ea0189e 100644
--- a/arch/arm/include/asm/tls.h
+++ b/arch/arm/include/asm/tls.h
@@ -2,29 +2,35 @@
#define __ASMARM_TLS_H
#ifdef __ASSEMBLY__
- .macro set_tls_none, tp, tmp1, tmp2
+ .macro set_tls_none, ntp, ptp, tmp1, tmp2
.endm
- .macro set_tls_v6k, tp, tmp1, tmp2
- mcr p15, 0, \tp, c13, c0, 3 @ set TLS register
- mov \tmp1, #0
- mcr p15, 0, \tmp1, c13, c0, 2 @ clear user r/w TLS register
+ .macro set_tls_v6k, ntp, ptp, tmp1, tmp2
+ mrc p15, 0, \tmp2, c13, c0, 2 @ get user r/w TLS register
+ str \tmp2, [\ptp, #4]
+ ldrd \tmp1, \tmp2, [\ntp]
+ mcr p15, 0, \tmp1, c13, c0, 3 @ set user r/o TLS register
+ mcr p15, 0, \tmp2, c13, c0, 2 @ set user r/w TLS register
.endm
- .macro set_tls_v6, tp, tmp1, tmp2
+ .macro set_tls_v6, ntp, ptp, tmp1, tmp2
ldr \tmp1, =elf_hwcap
ldr \tmp1, [\tmp1, #0]
mov \tmp2, #0xffff0fff
tst \tmp1, #HWCAP_TLS @ hardware TLS available?
- mcrne p15, 0, \tp, c13, c0, 3 @ yes, set TLS register
- movne \tmp1, #0
- mcrne p15, 0, \tmp1, c13, c0, 2 @ clear user r/w TLS register
- streq \tp, [\tmp2, #-15] @ set TLS value at 0xffff0ff0
+ mrcne p15, 0, \tmp2, c13, c0, 2 @ get user r/w TLS register
+ strne \tmp2, [\ptp, #4]
+ ldrdne \tmp1, \tmp2, [\ntp]
+ ldreq \tmp1, [\ntp]
+ mcrne p15, 0, \tmp1, c13, c0, 3 @ yes, set user r/o TLS register
+ mcrne p15, 0, \tmp2, c13, c0, 2 @ set user r/w TLS register
+ streq \tmp1, [\tmp2, #-15] @ set TLS value at 0xffff0ff0
.endm
- .macro set_tls_software, tp, tmp1, tmp2
- mov \tmp1, #0xffff0fff
- str \tp, [\tmp1, #-15] @ set TLS value at 0xffff0ff0
+ .macro set_tls_software, ntp, ptp, tmp1, tmp2
+ ldr \tmp1, [\ntp]
+ mov \tmp2, #0xffff0fff
+ str \tmp1, [\tmp2, #-15] @ set TLS value at 0xffff0ff0
.endm
#endif
diff --git a/arch/arm/kernel/entry-armv.S b/arch/arm/kernel/entry-armv.S
index 0f82098..78ce1c6 100644
--- a/arch/arm/kernel/entry-armv.S
+++ b/arch/arm/kernel/entry-armv.S
@@ -728,21 +728,20 @@ ENTRY(__switch_to)
UNWIND(.fnstart )
UNWIND(.cantunwind )
add ip, r1, #TI_CPU_SAVE
- ldr r3, [r2, #TI_TP_VALUE]
ARM( stmia ip!, {r4 - sl, fp, sp, lr} ) @ Store most regs on stack
THUMB( stmia ip!, {r4 - sl, fp} ) @ Store most regs on stack
THUMB( str sp, [ip], #4 )
THUMB( str lr, [ip], #4 )
-#ifdef CONFIG_CPU_USE_DOMAINS
- ldr r6, [r2, #TI_CPU_DOMAIN]
-#endif
- set_tls r3, r4, r5
+ add r3, r2, #TI_TP_VALUE
+ add r4, r1, #TI_TP_VALUE
+ set_tls r3, r4, r6, r7
#if defined(CONFIG_CC_STACKPROTECTOR) && !defined(CONFIG_SMP)
ldr r7, [r2, #TI_TASK]
ldr r8, =__stack_chk_guard
ldr r7, [r7, #TSK_STACK_CANARY]
#endif
#ifdef CONFIG_CPU_USE_DOMAINS
+ ldr r6, [r2, #TI_CPU_DOMAIN]
mcr p15, 0, r6, c3, c0, 0 @ Set domain register
#endif
mov r5, r0
diff --git a/arch/arm/kernel/process.c b/arch/arm/kernel/process.c
index 047d3e4..b3171c4 100644
--- a/arch/arm/kernel/process.c
+++ b/arch/arm/kernel/process.c
@@ -395,7 +395,7 @@ copy_thread(unsigned long clone_flags, unsigned long stack_start,
clear_ptrace_hw_breakpoint(p);
if (clone_flags & CLONE_SETTLS)
- thread->tp_value = childregs->ARM_r3;
+ thread->tp_value[0] = childregs->ARM_r3;
thread_notify(THREAD_NOTIFY_COPY, thread);
diff --git a/arch/arm/kernel/ptrace.c b/arch/arm/kernel/ptrace.c
index 03deeff..2bc1514 100644
--- a/arch/arm/kernel/ptrace.c
+++ b/arch/arm/kernel/ptrace.c
@@ -849,7 +849,7 @@ long arch_ptrace(struct task_struct *child, long request,
#endif
case PTRACE_GET_THREAD_AREA:
- ret = put_user(task_thread_info(child)->tp_value,
+ ret = put_user(task_thread_info(child)->tp_value[0],
datap);
break;
diff --git a/arch/arm/kernel/traps.c b/arch/arm/kernel/traps.c
index 1c08911..f9d6259 100644
--- a/arch/arm/kernel/traps.c
+++ b/arch/arm/kernel/traps.c
@@ -588,7 +588,7 @@ asmlinkage int arm_syscall(int no, struct pt_regs *regs)
return regs->ARM_r0;
case NR(set_tls):
- thread->tp_value = regs->ARM_r0;
+ thread->tp_value[0] = regs->ARM_r0;
if (tls_emu)
return 0;
if (has_tls_reg) {
@@ -706,7 +706,7 @@ static int get_tp_trap(struct pt_regs *regs, unsigned int instr)
int reg = (instr >> 12) & 15;
if (reg == 15)
return 1;
- regs->uregs[reg] = current_thread_info()->tp_value;
+ regs->uregs[reg] = current_thread_info()->tp_value[0];
regs->ARM_pc += 4;
return 0;
}
--
1.7.10.4
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