| #!/bin/sh |
| |
| # Usage: make-syscalls.sh ../sysdeps/unix/common |
| # Expects $sysdirs in environment. |
| |
| ############################################################################## |
| # |
| # This script is used to process the syscall data encoded in the various |
| # syscalls.list files to produce thin assembly syscall wrappers around the |
| # appropriate OS syscall. See syscall-template.s for more details on the |
| # actual wrapper. |
| # |
| # Syscall Signature Prefixes: |
| # |
| # E: errno and return value are not set by the call |
| # V: errno is not set, but errno or zero (success) is returned from the call |
| # |
| # Syscall Signature Key Letters: |
| # |
| # a: unchecked address (e.g., 1st arg to mmap) |
| # b: non-NULL buffer (e.g., 2nd arg to read; return value from mmap) |
| # B: optionally-NULL buffer (e.g., 4th arg to getsockopt) |
| # f: buffer of 2 ints (e.g., 4th arg to socketpair) |
| # F: 3rd arg to fcntl |
| # i: scalar (any signedness & size: int, long, long long, enum, whatever) |
| # I: 3rd arg to ioctl |
| # n: scalar buffer length (e.g., 3rd arg to read) |
| # N: pointer to value/return scalar buffer length (e.g., 6th arg to recvfrom) |
| # p: non-NULL pointer to typed object (e.g., any non-void* arg) |
| # P: optionally-NULL pointer to typed object (e.g., 2nd argument to gettimeofday) |
| # s: non-NULL string (e.g., 1st arg to open) |
| # S: optionally-NULL string (e.g., 1st arg to acct) |
| # v: vararg scalar (e.g., optional 3rd arg to open) |
| # V: byte-per-page vector (3rd arg to mincore) |
| # W: wait status, optionally-NULL pointer to int (e.g., 2nd arg of wait4) |
| # |
| |
| ############################################################################## |
| |
| thisdir=$1; shift |
| |
| echo '' |
| echo \#### DIRECTORY = $thisdir |
| # Check each sysdep dir with higher priority than this one, |
| # and remove from $calls all the functions found in other dirs. |
| # Punt when we reach the directory defining these syscalls. |
| sysdirs=`for dir in $sysdirs; do |
| test $dir = $thisdir && break; echo $dir; done` |
| echo \#### SYSDIRS = $sysdirs |
| |
| # Get the list of system calls for this directory. |
| calls=`sed 's/#.*$// |
| /^[ ]*$/d' $thisdir/syscalls.list` |
| |
| calls=`echo "$calls" | |
| while read file caller rest; do |
| # Remove each syscall that is implemented by a file in $dir. |
| # If a syscall specified a "caller", then only compile that syscall |
| # if the caller function is also implemented in this directory. |
| srcfile=-; |
| for dir in $sysdirs; do |
| { test -f $dir/$file.c && srcfile=$dir/$file.c; } || |
| { test -f $dir/$file.S && srcfile=$dir/$file.S; } || |
| { test x$caller != x- && |
| { { test -f $dir/$caller.c && srcfile=$dir/$caller.c; } || |
| { test -f $dir/$caller.S && srcfile=$dir/$caller.S; }; }; } && break; |
| done; |
| echo $file $srcfile $caller $rest; |
| done` |
| |
| # Any calls left? |
| test -n "$calls" || exit 0 |
| |
| # This uses variables $weak, $strong, and $any_versioned. |
| emit_weak_aliases() |
| { |
| # A shortcoming in the current gas is that it will only allow one |
| # version-alias per symbol. So we create new strong aliases as needed. |
| vcount="" |
| |
| # We use the <shlib-compat.h> macros to generate the versioned aliases |
| # so that the version sets can be mapped to the configuration's |
| # minimum version set as per shlib-versions DEFAULT lines. If an |
| # entry point is specified in the form NAME@VERSION:OBSOLETED, a |
| # SHLIB_COMPAT conditional is generated. |
| if [ $any_versioned = t ]; then |
| echo " echo '#include <shlib-compat.h>'; \\" |
| fi |
| |
| for name in $weak; do |
| case $name in |
| *@@*) |
| base=`echo $name | sed 's/@@.*//'` |
| ver=`echo $name | sed 's/.*@@//;s/\./_/g'` |
| echo " echo '#if IS_IN (libc)'; \\" |
| if test -z "$vcount" ; then |
| source=$strong |
| vcount=1 |
| else |
| source="${strong}_${vcount}" |
| vcount=`expr $vcount + 1` |
| echo " echo 'strong_alias ($strong, $source)'; \\" |
| fi |
| echo " echo 'versioned_symbol (libc, $source, $base, $ver)'; \\" |
| echo " echo '#else'; \\" |
| echo " echo 'strong_alias ($strong, $base)'; \\" |
| echo " echo '#endif'; \\" |
| ;; |
| *@*) |
| base=`echo $name | sed 's/@.*//'` |
| ver=`echo $name | sed 's/.*@//;s/\./_/g'` |
| case $ver in |
| *:*) |
| compat_ver=${ver#*:} |
| ver=${ver%%:*} |
| compat_cond=" && SHLIB_COMPAT (libc, $ver, $compat_ver)" |
| ;; |
| *) |
| compat_cond= |
| ;; |
| esac |
| echo " echo '#if defined SHARED && IS_IN (libc)$compat_cond'; \\" |
| if test -z "$vcount" ; then |
| source=$strong |
| vcount=1 |
| else |
| source="${strong}_${vcount}" |
| vcount=`expr $vcount + 1` |
| echo " echo 'strong_alias ($strong, $source)'; \\" |
| fi |
| echo " echo 'compat_symbol (libc, $source, $base, $ver)'; \\" |
| echo " echo '#endif'; \\" |
| ;; |
| !*) |
| name=`echo $name | sed 's/.//'` |
| echo " echo 'strong_alias ($strong, $name)'; \\" |
| echo " echo 'hidden_def ($name)'; \\" |
| ;; |
| *) |
| echo " echo 'weak_alias ($strong, $name)'; \\" |
| echo " echo 'hidden_weak ($name)'; \\" |
| ;; |
| esac |
| done |
| } |
| |
| |
| # Emit rules to compile the syscalls remaining in $calls. |
| echo "$calls" | |
| while read file srcfile caller syscall args strong weak; do |
| |
| vdso_syscall= |
| case x"$syscall" in |
| *:*@*) |
| vdso_syscall="${syscall#*:}" |
| syscall="${syscall%:*}" |
| ;; |
| esac |
| |
| case x"$syscall" in |
| x-) callnum=_ ;; |
| *) |
| # Figure out if $syscall is defined with a number in syscall.h. |
| callnum=- |
| eval `{ echo "#include <sysdep.h>"; |
| echo "callnum=SYS_ify ($syscall)"; } | |
| $asm_CPP -D__OPTIMIZE__ - | |
| sed -n -e "/^callnum=.*$syscall/d" \ |
| -e "/^\(callnum=\)[ ]*\(.*\)/s//\1'\2'/p"` |
| ;; |
| esac |
| |
| noerrno=0 |
| errval=0 |
| case $args in |
| E*) noerrno=1; args=`echo $args | sed 's/E:\?//'`;; |
| V*) errval=1; args=`echo $args | sed 's/V:\?//'`;; |
| esac |
| |
| # Derive the number of arguments from the argument signature |
| case $args in |
| [0-9]) nargs=$args;; |
| ?:) nargs=0;; |
| ?:?) nargs=1;; |
| ?:??) nargs=2;; |
| ?:???) nargs=3;; |
| ?:????) nargs=4;; |
| ?:?????) nargs=5;; |
| ?:??????) nargs=6;; |
| ?:???????) nargs=7;; |
| ?:????????) nargs=8;; |
| ?:?????????) nargs=9;; |
| esac |
| |
| # Make sure only the first syscall rule is used, if multiple dirs |
| # define the same syscall. |
| echo '' |
| echo "#### CALL=$file NUMBER=$callnum ARGS=$args SOURCE=$srcfile" |
| |
| # If there are versioned aliases the entry is only generated for the |
| # shared library, unless it is a default version. |
| any_versioned=f |
| shared_only=f |
| case $weak in |
| *@@*) any_versioned=t ;; |
| *@*) any_versioned=t shared_only=t ;; |
| esac |
| |
| case x$srcfile"$callnum" in |
| x--) |
| # Undefined callnum for an extra syscall. |
| if [ x$caller != x- ]; then |
| if [ $noerrno != 0 ]; then |
| echo >&2 "$0: no number for $fileno, no-error syscall ($strong $weak)" |
| exit 2 |
| fi |
| echo "unix-stub-syscalls += $strong $weak" |
| fi |
| ;; |
| x*-) ;; ### Do nothing for undefined callnum |
| x-*) |
| echo "ifeq (,\$(filter $file,\$(unix-syscalls)))" |
| |
| if test $shared_only = t; then |
| # The versioned symbols are only in the shared library. |
| echo "ifneq (,\$(filter .os,\$(object-suffixes)))" |
| fi |
| # Accumulate the list of syscall files for this directory. |
| echo "unix-syscalls += $file" |
| test x$caller = x- || echo "unix-extra-syscalls += $file" |
| |
| # Emit a compilation rule for this syscall. |
| if test $shared_only = t; then |
| # The versioned symbols are only in the shared library. |
| echo "shared-only-routines += $file" |
| test -n "$vdso_syscall" || echo "\$(objpfx)${file}.os: \\" |
| else |
| object_suffixes='$(object-suffixes)' |
| test -z "$vdso_syscall" || object_suffixes='$(object-suffixes-noshared)' |
| echo "\ |
| \$(foreach p,\$(sysd-rules-targets),\ |
| \$(foreach o,${object_suffixes},\$(objpfx)\$(patsubst %,\$p,$file)\$o)): \\" |
| fi |
| |
| echo " \$(..)sysdeps/unix/make-syscalls.sh" |
| case x"$callnum" in |
| x_) |
| echo "\ |
| \$(make-target-directory) |
| (echo '/* Dummy module requested by syscalls.list */'; \\" |
| ;; |
| x*) |
| echo "\ |
| \$(make-target-directory) |
| (echo '#define SYSCALL_NAME $syscall'; \\ |
| echo '#define SYSCALL_NARGS $nargs'; \\ |
| echo '#define SYSCALL_SYMBOL $strong'; \\ |
| echo '#define SYSCALL_NOERRNO $noerrno'; \\ |
| echo '#define SYSCALL_ERRVAL $errval'; \\ |
| echo '#include <syscall-template.S>'; \\" |
| ;; |
| esac |
| |
| # Append any weak aliases or versions defined for this syscall function. |
| emit_weak_aliases |
| |
| # And finally, pipe this all into the compiler. |
| echo ' ) | $(compile-syscall) '"\ |
| \$(foreach p,\$(patsubst %$file,%,\$(basename \$(@F))),\$(\$(p)CPPFLAGS))" |
| |
| if test -n "$vdso_syscall"; then |
| # In the shared library, we're going to emit an IFUNC using a vDSO function. |
| # $vdso_syscall looks like "name@KERNEL_X.Y" where "name" is the symbol |
| # name in the vDSO and KERNEL_X.Y is its symbol version. |
| vdso_symbol="${vdso_syscall%@*}" |
| vdso_symver="${vdso_syscall#*@}" |
| vdso_symver=`echo "$vdso_symver" | sed 's/\./_/g'` |
| cat <<EOF |
| |
| \$(foreach p,\$(sysd-rules-targets),\$(objpfx)\$(patsubst %,\$p,$file).os): \\ |
| \$(..)sysdeps/unix/make-syscalls.sh |
| \$(make-target-directory) |
| (echo '#define ${strong} __redirect_${strong}'; \\ |
| echo '#include <dl-vdso.h>'; \\ |
| echo '#undef ${strong}'; \\ |
| echo '#define vdso_ifunc_init() \\'; \\ |
| echo ' PREPARE_VERSION_KNOWN (symver, ${vdso_symver})'; \\ |
| echo '__ifunc (__redirect_${strong}, ${strong},'; \\ |
| echo ' _dl_vdso_vsym ("${vdso_symbol}", &symver), void,'; \\ |
| echo ' vdso_ifunc_init)'; \\ |
| EOF |
| # This is doing "hidden_def (${strong})", but the compiler |
| # doesn't know that we've defined ${strong} in the same file, so |
| # we can't do it the normal way. |
| cat <<EOF |
| echo 'asm (".globl __GI_${strong}");'; \\ |
| echo 'asm ("__GI_${strong} = ${strong}");'; \\ |
| EOF |
| emit_weak_aliases |
| cat <<EOF |
| ) | \$(compile-stdin.c) \ |
| \$(foreach p,\$(patsubst %$file,%,\$(basename \$(@F))),\$(\$(p)CPPFLAGS)) |
| EOF |
| fi |
| |
| if test $shared_only = t; then |
| # The versioned symbols are only in the shared library. |
| echo endif |
| fi |
| |
| echo endif |
| ;; |
| esac |
| |
| done |