Commit 9674cdc7 authored by Maxim Kuvyrkov's avatar Maxim Kuvyrkov Committed by Geert Uytterhoeven

m68k: Add NPTL support

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: default avatarMaxim Kuvyrkov <maxim@codesourcery.com>
Signed-off-by: default avatarGeert Uytterhoeven <geert@linux-m68k.org>
parent f54bcdc2
......@@ -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__
......
......@@ -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__ */
......
......@@ -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
......
......@@ -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
......@@ -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
......
......@@ -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;
......
......@@ -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);
asmlinkage long sys_mmap2(unsigned long addr, unsigned long len,
unsigned long prot, unsigned long flags,
......@@ -595,3 +600,79 @@ 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;
}
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