On 12/11/09 7:23 PM, Maxim Kuvyrkov wrote:
On 12/11/09 5:01 PM, Geert Uytterhoeven wrote:
On Mon, Dec 7, 2009 at 09:38, Maxim Kuvyrkov<ma...@codesourcery.com>
wrote:
...
BTW, other architectures seem to call these __NR_[gs]et_thread_area
instead of __NR_{read,write}_tp?
Shouldn't we follow for consistency?
Yes, we may. As long as the syscall numbers stay the same. I'll send the
updated patch once the memory handling issue is resolved.
Here is the updated patch. I renamed {read,write}_tp syscalls to
[gs]et_thread_area. Regarding the memory access issue in cmpxchg
syscall, I looked through the mm/ files and it seems that checking for
!pte_write() is the right way to fix the problem; so the patch fixes
that too.
As I understand, this patch fixes all outstanding issues and is ready
for merge.
Regards,
--
Maxim Kuvyrkov
CodeSourcery
ma...@codesourcery.com
(650) 331-3385 x724
From f1e2bdaa191f08d33938bd42cf090f3d9466866e Mon Sep 17 00:00:00 2001
From: Maxim Kuvyrkov <ma...@codesourcery.com>
Date: Mon, 7 Dec 2009 00:24:27 -0800
Subject: [PATCH 1/2] Add NPTL support for m68k
This patch adds several syscalls, that provide necessary
functionality to support NPTL on m68k/ColdFire.
The syscalls are get_thread_area, set_thread_area, atomic_cmpxchg_32 and
atomic_barrier.
The cmpxchg syscall is required for ColdFire as it doesn't support 'cas'
instruction.
Also a ptrace call PTRACE_GET_THREAD_AREA is added to allow debugger to
inspect the TLS storage.
Signed-off-by: Maxim Kuvyrkov <ma...@codesourcery.com>
---
arch/m68k/include/asm/ptrace.h | 2 +
arch/m68k/include/asm/swab.h | 2 +-
arch/m68k/include/asm/thread_info_mm.h | 1 +
arch/m68k/include/asm/unistd.h | 6 ++-
arch/m68k/kernel/entry.S | 4 ++
arch/m68k/kernel/process.c | 4 ++
arch/m68k/kernel/ptrace.c | 5 ++
arch/m68k/kernel/sys_m68k.c | 81 ++++++++++++++++++++++++++++++++
8 files changed, 103 insertions(+), 2 deletions(-)
diff --git a/arch/m68k/include/asm/ptrace.h b/arch/m68k/include/asm/ptrace.h
index a6ab663..43ab86a 100644
--- a/arch/m68k/include/asm/ptrace.h
+++ b/arch/m68k/include/asm/ptrace.h
@@ -71,6 +71,8 @@ struct switch_stack {
#define PTRACE_GETFPREGS 14
#define PTRACE_SETFPREGS 15
+#define PTRACE_GET_THREAD_AREA 25
+
#define PTRACE_SINGLEBLOCK 33 /* resume execution until next branch */
#ifdef __KERNEL__
diff --git a/arch/m68k/include/asm/swab.h b/arch/m68k/include/asm/swab.h
index 5b754aa..b7b37a4 100644
--- a/arch/m68k/include/asm/thread_info_mm.h
+++ b/arch/m68k/include/asm/thread_info_mm.h
@@ -16,6 +16,7 @@ struct thread_info {
struct exec_domain *exec_domain; /* execution domain */
int preempt_count; /* 0 => preemptable, <0 => BUG
*/
__u32 cpu; /* should always be 0 on m68k */
+ unsigned long tp_value; /* thread pointer */
struct restart_block restart_block;
};
#endif /* __ASSEMBLY__ */
diff --git a/arch/m68k/include/asm/unistd.h b/arch/m68k/include/asm/unistd.h
index 48b87f5..d72a71d 100644
--- a/arch/m68k/include/asm/unistd.h
+++ b/arch/m68k/include/asm/unistd.h
@@ -336,10 +336,14 @@
#define __NR_pwritev 330
#define __NR_rt_tgsigqueueinfo 331
#define __NR_perf_event_open 332
+#define __NR_get_thread_area 333
+#define __NR_set_thread_area 334
+#define __NR_atomic_cmpxchg_32 335
+#define __NR_atomic_barrier 336
#ifdef __KERNEL__
-#define NR_syscalls 333
+#define NR_syscalls 337
#define __ARCH_WANT_IPC_PARSE_VERSION
#define __ARCH_WANT_OLD_READDIR
diff --git a/arch/m68k/kernel/entry.S b/arch/m68k/kernel/entry.S
index 77fc7c1..e136b8c 100644
--- a/arch/m68k/kernel/entry.S
+++ b/arch/m68k/kernel/entry.S
@@ -761,4 +761,8 @@ sys_call_table:
.long sys_pwritev /* 330 */
.long sys_rt_tgsigqueueinfo
.long sys_perf_event_open
+ .long sys_get_thread_area
+ .long sys_set_thread_area
+ .long sys_atomic_cmpxchg_32 /* 335 */
+ .long sys_atomic_barrier
diff --git a/arch/m68k/kernel/process.c b/arch/m68k/kernel/process.c
index 0529659..17c3f32 100644
--- a/arch/m68k/kernel/process.c
+++ b/arch/m68k/kernel/process.c
@@ -251,6 +251,10 @@ int copy_thread(unsigned long clone_flags, unsigned long
usp,
p->thread.usp = usp;
p->thread.ksp = (unsigned long)childstack;
+
+ if (clone_flags & CLONE_SETTLS)
+ task_thread_info(p)->tp_value = regs->d5;
+
/*
* Must save the current SFC/DFC value, NOT the value when
* the parent was last descheduled - RGH 10-08-96
diff --git a/arch/m68k/kernel/ptrace.c b/arch/m68k/kernel/ptrace.c
index 1fc217e..616e597 100644
--- a/arch/m68k/kernel/ptrace.c
+++ b/arch/m68k/kernel/ptrace.c
@@ -245,6 +245,11 @@ long arch_ptrace(struct task_struct *child, long request,
long addr, long data)
ret = -EFAULT;
break;
+ case PTRACE_GET_THREAD_AREA:
+ ret = put_user(task_thread_info(child)->tp_value,
+ (unsigned long __user *)data);
+ break;
+
default:
ret = ptrace_request(child, request, addr, data);
break;
diff --git a/arch/m68k/kernel/sys_m68k.c b/arch/m68k/kernel/sys_m68k.c
index 7deb402..1f0db88 100644
--- a/arch/m68k/kernel/sys_m68k.c
+++ b/arch/m68k/kernel/sys_m68k.c
@@ -28,6 +28,11 @@
#include <asm/traps.h>
#include <asm/page.h>
#include <asm/unistd.h>
+#include <linux/elf.h>
+#include <asm/tlb.h>
+
+asmlinkage int do_page_fault(struct pt_regs *regs, unsigned long address,
+ unsigned long error_code);
/* common code for old and new mmaps */
static inline long do_mmap2(
@@ -662,3 +667,79 @@ int kernel_execve(const char *filename, char *const
argv[], char *const envp[])
: "d" (__a), "d" (__b), "d" (__c));
return __res;
}
+
+asmlinkage unsigned long sys_get_thread_area(void)
+{
+ return current_thread_info()->tp_value;
+}
+
+asmlinkage int sys_set_thread_area(unsigned long tp)
+{
+ current_thread_info()->tp_value = tp;
+ return 0;
+}
+
+/* This syscall gets its arguments in A0 (mem), D2 (oldval) and
+ D1 (newval). */
+asmlinkage int
+sys_atomic_cmpxchg_32(unsigned long newval, int oldval, int d3, int d4, int d5,
+ unsigned long __user * mem)
+{
+ /* This was borrowed from ARM's implementation. */
+ for (;;) {
+ struct mm_struct *mm = current->mm;
+ pgd_t *pgd;
+ pmd_t *pmd;
+ pte_t *pte;
+ spinlock_t *ptl;
+ unsigned long mem_value;
+
+ down_read(&mm->mmap_sem);
+ pgd = pgd_offset(mm, (unsigned long)mem);
+ if (!pgd_present(*pgd))
+ goto bad_access;
+ pmd = pmd_offset(pgd, (unsigned long)mem);
+ if (!pmd_present(*pmd))
+ goto bad_access;
+ pte = pte_offset_map_lock(mm, pmd, (unsigned long)mem, &ptl);
+ if (!pte_present(*pte) || !pte_dirty(*pte)
+ || !pte_write(*pte)) {
+ pte_unmap_unlock(pte, ptl);
+ goto bad_access;
+ }
+
+ mem_value = *mem;
+ if (mem_value == oldval)
+ *mem = newval;
+
+ pte_unmap_unlock(pte, ptl);
+ up_read(&mm->mmap_sem);
+ return mem_value;
+
+ bad_access:
+ up_read(&mm->mmap_sem);
+ /* This is not necessarily a bad access, we can get here if
+ a memory we're trying to write to should be copied-on-write.
+ Make the kernel do the necessary page stuff, then re-iterate.
+ Simulate a write access fault to do that. */
+ {
+ /* The first argument of the function corresponds to
+ D1, which is the first field of struct pt_regs. */
+ struct pt_regs *fp = (struct pt_regs *)&newval;
+
+ /* '3' is an RMW flag. */
+ if (do_page_fault(fp, (unsigned long)mem, 3))
+ /* If the do_page_fault() failed, we don't
+ have anything meaningful to return.
+ There should be a SIGSEGV pending for
+ the process. */
+ return 0xdeadbeef;
+ }
+ }
+}
+
+asmlinkage int sys_atomic_barrier(void)
+{
+ /* no code needed for uniprocs */
+ return 0;
+}
--
1.6.2.4
_______________________________________________
uClinux-dev mailing list
uClinux-dev@uclinux.org
http://mailman.uclinux.org/mailman/listinfo/uclinux-dev
This message was resent by uclinux-dev@uclinux.org
To unsubscribe see:
http://mailman.uclinux.org/mailman/options/uclinux-dev
