Skip to content

Commit

Permalink
x86/entry/32: Use IA32-specific wrappers for syscalls taking 64-bit a…
Browse files Browse the repository at this point in the history 
…rguments

For the 32-bit syscall interface, 64-bit arguments (loff_t) are passed via
a pair of 32-bit registers.  These register pairs end up in consecutive stack
slots, which matches the C ABI for 64-bit arguments.  But when accessing the
registers directly from pt_regs, the wrapper needs to manually reassemble the
64-bit value.  These wrappers already exist for 32-bit compat, so make them
available to 32-bit native in preparation for enabling pt_regs-based syscalls.

Signed-off-by: Brian Gerst <brgerst@gmail.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Dominik Brodowski <linux@dominikbrodowski.net>
Link: https://lkml.kernel.org/r/20200313195144.164260-16-brgerst@gmail.com
  • Loading branch information
@KAGA-KOKO
Brian Gerst authored and KAGA-KOKO committed Mar 21, 2020
1 parent 866128a commit 121b32a
Show file tree
Hide file tree
Showing 5 changed files with 79 additions and 75 deletions.
18 changes: 9 additions & 9 deletions arch/x86/entry/syscalls/syscall_32.tbl
View file
Original file line number Diff line number Diff line change
Expand Up @@ -191,8 +191,8 @@
177 i386 rt_sigtimedwait sys_rt_sigtimedwait_time32 compat_sys_rt_sigtimedwait_time32
178 i386 rt_sigqueueinfo sys_rt_sigqueueinfo compat_sys_rt_sigqueueinfo
179 i386 rt_sigsuspend sys_rt_sigsuspend compat_sys_rt_sigsuspend
180 i386 pread64 sys_pread64 compat_sys_ia32_pread64
181 i386 pwrite64 sys_pwrite64 compat_sys_ia32_pwrite64
180 i386 pread64 sys_ia32_pread64
181 i386 pwrite64 sys_ia32_pwrite64
182 i386 chown sys_chown16
183 i386 getcwd sys_getcwd
184 i386 capget sys_capget
Expand All @@ -204,8 +204,8 @@
190 i386 vfork sys_vfork
191 i386 ugetrlimit sys_getrlimit compat_sys_getrlimit
192 i386 mmap2 sys_mmap_pgoff
193 i386 truncate64 sys_truncate64 compat_sys_ia32_truncate64
194 i386 ftruncate64 sys_ftruncate64 compat_sys_ia32_ftruncate64
193 i386 truncate64 sys_ia32_truncate64
194 i386 ftruncate64 sys_ia32_ftruncate64
195 i386 stat64 sys_stat64 compat_sys_ia32_stat64
196 i386 lstat64 sys_lstat64 compat_sys_ia32_lstat64
197 i386 fstat64 sys_fstat64 compat_sys_ia32_fstat64
Expand Down Expand Up @@ -236,7 +236,7 @@
# 222 is unused
# 223 is unused
224 i386 gettid sys_gettid
225 i386 readahead sys_readahead compat_sys_ia32_readahead
225 i386 readahead sys_ia32_readahead
226 i386 setxattr sys_setxattr
227 i386 lsetxattr sys_lsetxattr
228 i386 fsetxattr sys_fsetxattr
Expand All @@ -261,7 +261,7 @@
247 i386 io_getevents sys_io_getevents_time32
248 i386 io_submit sys_io_submit compat_sys_io_submit
249 i386 io_cancel sys_io_cancel
250 i386 fadvise64 sys_fadvise64 compat_sys_ia32_fadvise64
250 i386 fadvise64 sys_ia32_fadvise64
# 251 is available for reuse (was briefly sys_set_zone_reclaim)
252 i386 exit_group sys_exit_group
253 i386 lookup_dcookie sys_lookup_dcookie compat_sys_lookup_dcookie
Expand All @@ -283,7 +283,7 @@
269 i386 fstatfs64 sys_fstatfs64 compat_sys_fstatfs64
270 i386 tgkill sys_tgkill
271 i386 utimes sys_utimes_time32
272 i386 fadvise64_64 sys_fadvise64_64 compat_sys_ia32_fadvise64_64
272 i386 fadvise64_64 sys_ia32_fadvise64_64
273 i386 vserver
274 i386 mbind sys_mbind
275 i386 get_mempolicy sys_get_mempolicy compat_sys_get_mempolicy
Expand Down Expand Up @@ -325,7 +325,7 @@
311 i386 set_robust_list sys_set_robust_list compat_sys_set_robust_list
312 i386 get_robust_list sys_get_robust_list compat_sys_get_robust_list
313 i386 splice sys_splice
314 i386 sync_file_range sys_sync_file_range compat_sys_ia32_sync_file_range
314 i386 sync_file_range sys_ia32_sync_file_range
315 i386 tee sys_tee
316 i386 vmsplice sys_vmsplice compat_sys_vmsplice
317 i386 move_pages sys_move_pages compat_sys_move_pages
Expand All @@ -335,7 +335,7 @@
321 i386 signalfd sys_signalfd compat_sys_signalfd
322 i386 timerfd_create sys_timerfd_create
323 i386 eventfd sys_eventfd
324 i386 fallocate sys_fallocate compat_sys_ia32_fallocate
324 i386 fallocate sys_ia32_fallocate
325 i386 timerfd_settime sys_timerfd_settime32
326 i386 timerfd_gettime sys_timerfd_gettime32
327 i386 signalfd4 sys_signalfd4 compat_sys_signalfd4
Expand Down
2 changes: 1 addition & 1 deletion arch/x86/ia32/Makefile
View file
Original file line number Diff line number Diff line change
Expand Up @@ -3,7 +3,7 @@
# Makefile for the ia32 kernel emulation subsystem.
#

obj-$(CONFIG_IA32_EMULATION) := sys_ia32.o ia32_signal.o
obj-$(CONFIG_IA32_EMULATION) := ia32_signal.o

obj-$(CONFIG_IA32_AOUT) += ia32_aout.o

Expand Down
2 changes: 2 additions & 0 deletions arch/x86/kernel/Makefile
View file
Original file line number Diff line number Diff line change
Expand Up @@ -53,6 +53,8 @@ obj-y += setup.o x86_init.o i8259.o irqinit.o
obj-$(CONFIG_JUMP_LABEL) += jump_label.o
obj-$(CONFIG_IRQ_WORK) += irq_work.o
obj-y += probe_roms.o
obj-$(CONFIG_X86_32) += sys_ia32.o
obj-$(CONFIG_IA32_EMULATION) += sys_ia32.o
obj-$(CONFIG_X86_64) += sys_x86_64.o
obj-$(CONFIG_X86_ESPFIX64) += espfix_64.o
obj-$(CONFIG_SYSFS) += ksysfs.o
Expand Down
131 changes: 66 additions & 65 deletions arch/x86/ia32/sys_ia32.c → arch/x86/kernel/sys_ia32.c
View file
Original file line number Diff line number Diff line change
Expand Up @@ -51,20 +51,80 @@

#define AA(__x) ((unsigned long)(__x))


COMPAT_SYSCALL_DEFINE3(ia32_truncate64, const char __user *, filename,
unsigned long, offset_low, unsigned long, offset_high)
SYSCALL_DEFINE3(ia32_truncate64, const char __user *, filename,
unsigned long, offset_low, unsigned long, offset_high)
{
return ksys_truncate(filename,
((loff_t) offset_high << 32) | offset_low);
}

COMPAT_SYSCALL_DEFINE3(ia32_ftruncate64, unsigned int, fd,
unsigned long, offset_low, unsigned long, offset_high)
SYSCALL_DEFINE3(ia32_ftruncate64, unsigned int, fd,
unsigned long, offset_low, unsigned long, offset_high)
{
return ksys_ftruncate(fd, ((loff_t) offset_high << 32) | offset_low);
}

/* warning: next two assume little endian */
SYSCALL_DEFINE5(ia32_pread64, unsigned int, fd, char __user *, ubuf,
u32, count, u32, poslo, u32, poshi)
{
return ksys_pread64(fd, ubuf, count,
((loff_t)AA(poshi) << 32) | AA(poslo));
}

SYSCALL_DEFINE5(ia32_pwrite64, unsigned int, fd, const char __user *, ubuf,
u32, count, u32, poslo, u32, poshi)
{
return ksys_pwrite64(fd, ubuf, count,
((loff_t)AA(poshi) << 32) | AA(poslo));
}


/*
* Some system calls that need sign extended arguments. This could be
* done by a generic wrapper.
*/
SYSCALL_DEFINE6(ia32_fadvise64_64, int, fd, __u32, offset_low,
__u32, offset_high, __u32, len_low, __u32, len_high,
int, advice)
{
return ksys_fadvise64_64(fd,
(((u64)offset_high)<<32) | offset_low,
(((u64)len_high)<<32) | len_low,
advice);
}

SYSCALL_DEFINE4(ia32_readahead, int, fd, unsigned int, off_lo,
unsigned int, off_hi, size_t, count)
{
return ksys_readahead(fd, ((u64)off_hi << 32) | off_lo, count);
}

SYSCALL_DEFINE6(ia32_sync_file_range, int, fd, unsigned int, off_low,
unsigned int, off_hi, unsigned int, n_low,
unsigned int, n_hi, int, flags)
{
return ksys_sync_file_range(fd,
((u64)off_hi << 32) | off_low,
((u64)n_hi << 32) | n_low, flags);
}

SYSCALL_DEFINE5(ia32_fadvise64, int, fd, unsigned int, offset_lo,
unsigned int, offset_hi, size_t, len, int, advice)
{
return ksys_fadvise64_64(fd, ((u64)offset_hi << 32) | offset_lo,
len, advice);
}

SYSCALL_DEFINE6(ia32_fallocate, int, fd, int, mode,
unsigned int, offset_lo, unsigned int, offset_hi,
unsigned int, len_lo, unsigned int, len_hi)
{
return ksys_fallocate(fd, mode, ((u64)offset_hi << 32) | offset_lo,
((u64)len_hi << 32) | len_lo);
}

#ifdef CONFIG_IA32_EMULATION
/*
* Another set for IA32/LFS -- x86_64 struct stat is different due to
* support for 64bit inode numbers.
Expand Down Expand Up @@ -170,66 +230,6 @@ COMPAT_SYSCALL_DEFINE1(ia32_mmap, struct mmap_arg_struct32 __user *, arg)
a.offset>>PAGE_SHIFT);
}

/* warning: next two assume little endian */
COMPAT_SYSCALL_DEFINE5(ia32_pread64, unsigned int, fd, char __user *, ubuf,
u32, count, u32, poslo, u32, poshi)
{
return ksys_pread64(fd, ubuf, count,
((loff_t)AA(poshi) << 32) | AA(poslo));
}

COMPAT_SYSCALL_DEFINE5(ia32_pwrite64, unsigned int, fd, const char __user *, ubuf,
u32, count, u32, poslo, u32, poshi)
{
return ksys_pwrite64(fd, ubuf, count,
((loff_t)AA(poshi) << 32) | AA(poslo));
}


/*
* Some system calls that need sign extended arguments. This could be
* done by a generic wrapper.
*/
COMPAT_SYSCALL_DEFINE6(ia32_fadvise64_64, int, fd, __u32, offset_low,
__u32, offset_high, __u32, len_low, __u32, len_high,
int, advice)
{
return ksys_fadvise64_64(fd,
(((u64)offset_high)<<32) | offset_low,
(((u64)len_high)<<32) | len_low,
advice);
}

COMPAT_SYSCALL_DEFINE4(ia32_readahead, int, fd, unsigned int, off_lo,
unsigned int, off_hi, size_t, count)
{
return ksys_readahead(fd, ((u64)off_hi << 32) | off_lo, count);
}

COMPAT_SYSCALL_DEFINE6(ia32_sync_file_range, int, fd, unsigned int, off_low,
unsigned int, off_hi, unsigned int, n_low,
unsigned int, n_hi, int, flags)
{
return ksys_sync_file_range(fd,
((u64)off_hi << 32) | off_low,
((u64)n_hi << 32) | n_low, flags);
}

COMPAT_SYSCALL_DEFINE5(ia32_fadvise64, int, fd, unsigned int, offset_lo,
unsigned int, offset_hi, size_t, len, int, advice)
{
return ksys_fadvise64_64(fd, ((u64)offset_hi << 32) | offset_lo,
len, advice);
}

COMPAT_SYSCALL_DEFINE6(ia32_fallocate, int, fd, int, mode,
unsigned int, offset_lo, unsigned int, offset_hi,
unsigned int, len_lo, unsigned int, len_hi)
{
return ksys_fallocate(fd, mode, ((u64)offset_hi << 32) | offset_lo,
((u64)len_hi << 32) | len_lo);
}

/*
* The 32-bit clone ABI is CONFIG_CLONE_BACKWARDS
*/
Expand All @@ -252,3 +252,4 @@ COMPAT_SYSCALL_DEFINE5(ia32_clone, unsigned long, clone_flags,

return _do_fork(&args);
}
#endif /* CONFIG_IA32_EMULATION */
1 change: 1 addition & 0 deletions arch/x86/um/Makefile
View file
Original file line number Diff line number Diff line change
Expand Up @@ -21,6 +21,7 @@ obj-y += checksum_32.o syscalls_32.o
obj-$(CONFIG_ELF_CORE) += elfcore.o

subarch-y = ../lib/string_32.o ../lib/atomic64_32.o ../lib/atomic64_cx8_32.o
subarch-y += ../kernel/sys_ia32.o

else

Expand Down

0 comments on commit 121b32a

Please sign in to comment.