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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>
This commit is contained in:
Chris Metcalf 2012-10-23 13:30:54 -04:00 committed by Al Viro
parent 530550651f
commit 6b14e4198c
10 changed files with 39 additions and 57 deletions
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9
arch/tile/include/asm/compat.h
View File

@ -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 */

19
arch/tile/include/asm/syscalls.h
View File

@ -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>

4
arch/tile/kernel/compat.c
View File

@ -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
/*

10
arch/tile/kernel/compat_signal.c
View File

@ -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;

13
arch/tile/kernel/intvec_32.S
View File

@ -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

13
arch/tile/kernel/intvec_64.S
View File

@ -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

6
arch/tile/kernel/process.c
View File

@ -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,

9
arch/tile/kernel/signal.c
View File

@ -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;

8
arch/tile/kernel/sys.c
View File

@ -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

5
arch/tile/mm/fault.c
View File

@ -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);