Commit 6b14e419 authored by Chris Metcalf's avatar Chris Metcalf Committed by Al Viro
Browse files

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: default avatarChris Metcalf <cmetcalf@tilera.com>
parent 53055065

arch/tile/include/asm/compat.h

+3 −6
Original line number Diff line number Diff line
@@ -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 */

arch/tile/include/asm/syscalls.h

+13 −6
Original line number Diff line number Diff line
@@ -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>

arch/tile/kernel/compat.c

+2 −2
Original line number Diff line number Diff line
@@ -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



/*

arch/tile/kernel/compat_signal.c

+5 −5
Original line number Diff line number Diff line
@@ -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;

arch/tile/kernel/intvec_32.S

+1 −12
Original line number Diff line number Diff line
@@ -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

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