arch/tile: eliminate pt_regs trampolines for syscalls

Using the new current_pt_regs() model, we can remove some trampolines
from assembly code and call directly to the C syscall implementations.
rt_sigreturn() and clone() still need some assembly wrapping, but no
longer are passed a pt_regs pointer.  sigaltstack() and the
tilepro-specific cmpxchg_badaddr() syscalls are now just straight C.

Signed-off-by: Chris Metcalf <cmetcalf@tilera.com>

diff --git a/arch/tile/include/asm/compat.h b/arch/tile/include/asm/compat.h
index 3bcf1b94b5632ffca23aee6b39ee386973fec02c..ca61fb4296b34d835e1e147d40cbc9c84a385a9d 100644 (file)
--- a/arch/tile/include/asm/compat.h
+++ b/arch/tile/include/asm/compat.h
@@ -280,10 +280,9 @@ long compat_sys_rt_sigaction(int sig, struct compat_sigaction __user *act,
                             size_t sigsetsize);
 long compat_sys_rt_sigqueueinfo(int pid, int sig,
                                struct compat_siginfo __user *uinfo);
-long compat_sys_rt_sigreturn(struct pt_regs *);
+long compat_sys_rt_sigreturn(void);
 long compat_sys_sigaltstack(const struct compat_sigaltstack __user *uss_ptr,
-                           struct compat_sigaltstack __user *uoss_ptr,
-                           struct pt_regs *);
+                           struct compat_sigaltstack __user *uoss_ptr);
 long compat_sys_truncate64(char __user *filename, u32 dummy, u32 low, u32 high);
 long compat_sys_ftruncate64(unsigned int fd, u32 dummy, u32 low, u32 high);
 long compat_sys_pread64(unsigned int fd, char __user *ubuf, size_t count,
@@ -300,9 +299,7 @@ long compat_sys_fallocate(int fd, int mode,
 long compat_sys_sched_rr_get_interval(compat_pid_t pid,
                                      struct compat_timespec __user *interval);
 
-/* These are the intvec_64.S trampolines. */
-long _compat_sys_sigaltstack(const struct compat_sigaltstack __user *uss_ptr,
-                           struct compat_sigaltstack __user *uoss_ptr);
+/* Assembly trampoline to avoid clobbering r0. */
 long _compat_sys_rt_sigreturn(void);
 
 #endif /* _ASM_TILE_COMPAT_H */

diff --git a/arch/tile/include/asm/syscalls.h b/arch/tile/include/asm/syscalls.h
index 0d52992f8e05e7aac85df02f3073d25d433a1a44..369696d63e7b833fe6f01758a0d95c1bf8b1fe4f 100644 (file)
--- a/arch/tile/include/asm/syscalls.h
+++ b/arch/tile/include/asm/syscalls.h
@@ -51,8 +51,7 @@ long sys_cacheflush(unsigned long addr, unsigned long len,
 
 #ifndef __tilegx__
 /* mm/fault.c */
-long sys_cmpxchg_badaddr(unsigned long address, struct pt_regs *);
-long _sys_cmpxchg_badaddr(unsigned long address);
+long sys_cmpxchg_badaddr(unsigned long address);
 #endif
 
 #ifdef CONFIG_COMPAT
@@ -63,15 +62,23 @@ long sys_truncate64(const char __user *path, loff_t length);
 long sys_ftruncate64(unsigned int fd, loff_t length);
 #endif
 
-/* These are the intvec*.S trampolines. */
-long _sys_sigaltstack(const stack_t __user *, stack_t __user *);
-long _sys_rt_sigreturn(void);
-long _sys_clone(unsigned long clone_flags, unsigned long newsp,
+/* Provide versions of standard syscalls that use current_pt_regs(). */
+long sys_clone(unsigned long clone_flags, unsigned long newsp,
                void __user *parent_tid, void __user *child_tid);
 long sys_execve(const char __user *filename,
                 const char __user *const __user *argv,
                 const char __user *const __user *envp);
+long sys_rt_sigreturn(void);
+long sys_sigaltstack(const stack_t __user *, stack_t __user *);
+#define sys_clone sys_clone
 #define sys_execve sys_execve
+#define sys_rt_sigreturn sys_rt_sigreturn
+#define sys_sigaltstack sys_sigaltstack
+
+/* These are the intvec*.S trampolines. */
+long _sys_rt_sigreturn(void);
+long _sys_clone(unsigned long clone_flags, unsigned long newsp,
+               void __user *parent_tid, void __user *child_tid);
 
 #include <asm-generic/syscalls.h>
 

diff --git a/arch/tile/kernel/compat.c b/arch/tile/kernel/compat.c
index a8e5a847037c4850329d446a144444dc07f2987b..a2e805569d5d4cbad881b12faa620a2c5578ce23 100644 (file)
--- a/arch/tile/kernel/compat.c
+++ b/arch/tile/kernel/compat.c
@@ -102,9 +102,9 @@ long compat_sys_sched_rr_get_interval(compat_pid_t pid,
 #define compat_sys_fadvise64_64 sys32_fadvise64_64
 #define compat_sys_readahead sys32_readahead
 
-/* Call the trampolines to manage pt_regs where necessary. */
-#define compat_sys_sigaltstack _compat_sys_sigaltstack
+/* Call the assembly trampolines where necessary. */
 #define compat_sys_rt_sigreturn _compat_sys_rt_sigreturn
+#undef sys_clone
 #define sys_clone _sys_clone
 
 /*

diff --git a/arch/tile/kernel/compat_signal.c b/arch/tile/kernel/compat_signal.c
index 08b4fe1717bb975aa6edff118fa79f641e77b237..210a9bbae96322b8b530b8e3aa2bafafeabbc021 100644 (file)
--- a/arch/tile/kernel/compat_signal.c
+++ b/arch/tile/kernel/compat_signal.c
@@ -197,8 +197,7 @@ int copy_siginfo_from_user32(siginfo_t *to, struct compat_siginfo __user *from)
 }
 
 long compat_sys_sigaltstack(const struct compat_sigaltstack __user *uss_ptr,
-                           struct compat_sigaltstack __user *uoss_ptr,
-                           struct pt_regs *regs)
+                           struct compat_sigaltstack __user *uoss_ptr)
 {
        stack_t uss, uoss;
        int ret;
@@ -219,7 +218,7 @@ long compat_sys_sigaltstack(const struct compat_sigaltstack __user *uss_ptr,
        set_fs(KERNEL_DS);
        ret = do_sigaltstack(uss_ptr ? (stack_t __user __force *)&uss : NULL,
                             (stack_t __user __force *)&uoss,
-                            (unsigned long)compat_ptr(regs->sp));
+                            (unsigned long)compat_ptr(current_pt_regs()->sp));
        set_fs(seg);
        if (ret >= 0 && uoss_ptr)  {
                if (!access_ok(VERIFY_WRITE, uoss_ptr, sizeof(*uoss_ptr)) ||
@@ -232,8 +231,9 @@ long compat_sys_sigaltstack(const struct compat_sigaltstack __user *uss_ptr,
 }
 
 /* The assembly shim for this function arranges to ignore the return value. */
-long compat_sys_rt_sigreturn(struct pt_regs *regs)
+long compat_sys_rt_sigreturn(void)
 {
+       struct pt_regs *regs = current_pt_regs();
        struct compat_rt_sigframe __user *frame =
                (struct compat_rt_sigframe __user *) compat_ptr(regs->sp);
        sigset_t set;
@@ -248,7 +248,7 @@ long compat_sys_rt_sigreturn(struct pt_regs *regs)
        if (restore_sigcontext(regs, &frame->uc.uc_mcontext))
                goto badframe;
 
-       if (compat_sys_sigaltstack(&frame->uc.uc_stack, NULL, regs) != 0)
+       if (compat_sys_sigaltstack(&frame->uc.uc_stack, NULL) != 0)
                goto badframe;
 
        return 0;

diff --git a/arch/tile/kernel/intvec_32.S b/arch/tile/kernel/intvec_32.S
index 174b837ef9265deed933f1a12ae668c8715cbf14..f212bf7cea86693c0649d56d1b9b46cc3ea0417c 100644 (file)
--- a/arch/tile/kernel/intvec_32.S
+++ b/arch/tile/kernel/intvec_32.S
@@ -1452,15 +1452,6 @@ STD_ENTRY_LOCAL(bad_intr)
        panic   "Unhandled interrupt %#x: PC %#lx"
        STD_ENDPROC(bad_intr)
 
-/* Put address of pt_regs in reg and jump. */
-#define PTREGS_SYSCALL(x, reg)                          \
-       STD_ENTRY(_##x);                                \
-       {                                               \
-        PTREGS_PTR(reg, PTREGS_OFFSET_BASE);           \
-        j      x                                       \
-       };                                              \
-       STD_ENDPROC(_##x)
-
 /*
  * Special-case sigreturn to not write r0 to the stack on return.
  * This is technically more efficient, but it also avoids difficulties
@@ -1476,11 +1467,9 @@ STD_ENTRY_LOCAL(bad_intr)
        };                                              \
        STD_ENDPROC(_##x)
 
-PTREGS_SYSCALL(sys_sigaltstack, r2)
 PTREGS_SYSCALL_SIGRETURN(sys_rt_sigreturn, r0)
-PTREGS_SYSCALL(sys_cmpxchg_badaddr, r1)
 
-/* Save additional callee-saves to pt_regs, put address in r4 and jump. */
+/* Save additional callee-saves to pt_regs and jump to standard function. */
 STD_ENTRY(_sys_clone)
        push_extra_callee_saves r4
        j       sys_clone

diff --git a/arch/tile/kernel/intvec_64.S b/arch/tile/kernel/intvec_64.S
index 283efedf67d6feb5c0635b8a0367742445ba011c..54bc9a6678e8d6b03c319d56b7b5b234f502fb6e 100644 (file)
--- a/arch/tile/kernel/intvec_64.S
+++ b/arch/tile/kernel/intvec_64.S
@@ -1181,15 +1181,6 @@ STD_ENTRY_LOCAL(bad_intr)
        panic   "Unhandled interrupt %#x: PC %#lx"
        STD_ENDPROC(bad_intr)
 
-/* Put address of pt_regs in reg and jump. */
-#define PTREGS_SYSCALL(x, reg)                          \
-       STD_ENTRY(_##x);                                \
-       {                                               \
-        PTREGS_PTR(reg, PTREGS_OFFSET_BASE);           \
-        j      x                                       \
-       };                                              \
-       STD_ENDPROC(_##x)
-
 /*
  * Special-case sigreturn to not write r0 to the stack on return.
  * This is technically more efficient, but it also avoids difficulties
@@ -1205,14 +1196,12 @@ STD_ENTRY_LOCAL(bad_intr)
        };                                              \
        STD_ENDPROC(_##x)
 
-PTREGS_SYSCALL(sys_sigaltstack, r2)
 PTREGS_SYSCALL_SIGRETURN(sys_rt_sigreturn, r0)
 #ifdef CONFIG_COMPAT
-PTREGS_SYSCALL(compat_sys_sigaltstack, r2)
 PTREGS_SYSCALL_SIGRETURN(compat_sys_rt_sigreturn, r0)
 #endif
 
-/* Save additional callee-saves to pt_regs, put address in r4 and jump. */
+/* Save additional callee-saves to pt_regs and jump to standard function. */
 STD_ENTRY(_sys_clone)
        push_extra_callee_saves r4
        j       sys_clone

diff --git a/arch/tile/kernel/process.c b/arch/tile/kernel/process.c
index 58f8fd1f0bc2f2a67ca5e9289f43af50a4968d0c..6e7fb4e41f1c26a991ef2a88cb84225275ab61c8 100644 (file)
--- a/arch/tile/kernel/process.c
+++ b/arch/tile/kernel/process.c
@@ -584,10 +584,10 @@ int do_work_pending(struct pt_regs *regs, u32 thread_info_flags)
 }
 
 /* Note there is an implicit fifth argument if (clone_flags & CLONE_SETTLS). */
-SYSCALL_DEFINE5(clone, unsigned long, clone_flags, unsigned long, newsp,
-               void __user *, parent_tidptr, void __user *, child_tidptr,
-               struct pt_regs *, regs)
+SYSCALL_DEFINE4(clone, unsigned long, clone_flags, unsigned long, newsp,
+               void __user *, parent_tidptr, void __user *, child_tidptr)
 {
+       struct pt_regs *regs = current_pt_regs();
        if (!newsp)
                newsp = regs->sp;
        return do_fork(clone_flags, newsp, regs, 0,

diff --git a/arch/tile/kernel/signal.c b/arch/tile/kernel/signal.c
index 67efb656d10451946baa827066811948dc45b2d6..657a7ace4ab4638e6b32701e0f59a2a3a0650556 100644 (file)
--- a/arch/tile/kernel/signal.c
+++ b/arch/tile/kernel/signal.c
@@ -37,10 +37,10 @@
 
 #define DEBUG_SIG 0
 
-SYSCALL_DEFINE3(sigaltstack, const stack_t __user *, uss,
-               stack_t __user *, uoss, struct pt_regs *, regs)
+SYSCALL_DEFINE2(sigaltstack, const stack_t __user *, uss,
+               stack_t __user *, uoss)
 {
-       return do_sigaltstack(uss, uoss, regs->sp);
+       return do_sigaltstack(uss, uoss, current_pt_regs()->sp);
 }
 
 
@@ -83,8 +83,9 @@ void signal_fault(const char *type, struct pt_regs *regs,
 }
 
 /* The assembly shim for this function arranges to ignore the return value. */
-SYSCALL_DEFINE1(rt_sigreturn, struct pt_regs *, regs)
+SYSCALL_DEFINE0(rt_sigreturn)
 {
+       struct pt_regs *regs = current_pt_regs();
        struct rt_sigframe __user *frame =
                (struct rt_sigframe __user *)(regs->sp);
        sigset_t set;

diff --git a/arch/tile/kernel/sys.c b/arch/tile/kernel/sys.c
index 359e76f68838583c06ed8369e62cabaf1c8bda55..02ff5c0ef775091f43589361faa00d7760abe675 100644 (file)
--- a/arch/tile/kernel/sys.c
+++ b/arch/tile/kernel/sys.c
@@ -106,13 +106,11 @@ SYSCALL_DEFINE6(mmap, unsigned long, addr, unsigned long, len,
 #define sys_readahead sys32_readahead
 #endif
 
-/* Call the trampolines to manage pt_regs where necessary. */
-#define sys_sigaltstack _sys_sigaltstack
+/* Call the assembly trampolines where necessary. */
+#undef sys_rt_sigreturn
 #define sys_rt_sigreturn _sys_rt_sigreturn
+#undef sys_clone
 #define sys_clone _sys_clone
-#ifndef __tilegx__
-#define sys_cmpxchg_badaddr _sys_cmpxchg_badaddr
-#endif
 
 /*
  * Note that we can't include <linux/unistd.h> here since the header

diff --git a/arch/tile/mm/fault.c b/arch/tile/mm/fault.c
index fe811fa5f1b96f682633e2c54f6be6bbdd525095..3d2b81c163a6aac89e0e32d862bd603021eec917 100644 (file)
--- a/arch/tile/mm/fault.c
+++ b/arch/tile/mm/fault.c
@@ -70,9 +70,10 @@ static noinline void force_sig_info_fault(const char *type, int si_signo,
  * Synthesize the fault a PL0 process would get by doing a word-load of
  * an unaligned address or a high kernel address.
  */
-SYSCALL_DEFINE2(cmpxchg_badaddr, unsigned long, address,
-               struct pt_regs *, regs)
+SYSCALL_DEFINE1(cmpxchg_badaddr, unsigned long, address)
 {
+       struct pt_regs *regs = current_pt_regs();
+
        if (address >= PAGE_OFFSET)
                force_sig_info_fault("atomic segfault", SIGSEGV, SEGV_MAPERR,
                                     address, INT_DTLB_MISS, current, regs);