Y2038

y2038@lists.linaro.org

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1142 discussions

[PATCH 0/2] microblaze: Unify the system call scripts

by Firoz Khan

System call table generation support is provided for alpha, ia64, m68k, microblaze, mips, parisc, powerpc, sh, sparc and xtensa architectures. The implementat- ions are almost similar across all the above archte- ctures. In order to reduce the source code across all the above architectures, create common ".sh" files and keep it in the common directory, script/. This will be a generic scripts which can use for all the above architectures. This patch depends on; https://lore.kernel.org/lkml/1546439331-18646-1-git-send-email-firoz.khan@l… Firoz Khan (2): microblaze: remove nargs from __SYSCALL microblaze: generate uapi header and system call table files arch/microblaze/kernel/syscall_table.S | 2 +- arch/microblaze/kernel/syscalls/Makefile | 11 ++++++-- arch/microblaze/kernel/syscalls/syscallhdr.sh | 36 --------------------------- arch/microblaze/kernel/syscalls/syscalltbl.sh | 32 ------------------------ 4 files changed, 10 insertions(+), 71 deletions(-) delete mode 100644 arch/microblaze/kernel/syscalls/syscallhdr.sh delete mode 100644 arch/microblaze/kernel/syscalls/syscalltbl.sh -- 1.9.1

7 years

[PATCH 0/2] alpha: Unify the system call scripts

by Firoz Khan

System call table generation support is provided for alpha, ia64, m68k, microblaze, mips, parisc, powerpc, sh, sparc and xtensa architectures. The implementat- ions are almost similar across all the above archte- ctures. In order to reduce the source code across all the above architectures, create common ".sh" files and keep it in the common directory, script/. This will be a generic scripts which can use for all the above architectures. This patch depends on; https://lore.kernel.org/lkml/1546439331-18646-1-git-send-email-firoz.khan@l… Firoz Khan (2): alpha: remove nargs from __SYSCALL alpha: generate uapi header and syscall table header files arch/alpha/kernel/syscalls/Makefile | 11 ++++++++-- arch/alpha/kernel/syscalls/syscallhdr.sh | 36 -------------------------------- arch/alpha/kernel/syscalls/syscalltbl.sh | 32 ---------------------------- arch/alpha/kernel/systbls.S | 2 +- 4 files changed, 10 insertions(+), 71 deletions(-) delete mode 100644 arch/alpha/kernel/syscalls/syscallhdr.sh delete mode 100644 arch/alpha/kernel/syscalls/syscalltbl.sh -- 1.9.1

7 years

[PATCH v3] sock: Make sock->sk_stamp thread-safe

by Deepa Dinamani

Al Viro mentioned (Message-ID <20170626041334.GZ10672(a)ZenIV.linux.org.uk>) that there is probably a race condition lurking in accesses of sk_stamp on 32-bit machines. sock->sk_stamp is of type ktime_t which is always an s64. On a 32 bit architecture, we might run into situations of unsafe access as the access to the field becomes non atomic. Use seqlocks for synchronization. This allows us to avoid using spinlocks for readers as readers do not need mutual exclusion. Another approach to solve this is to require sk_lock for all modifications of the timestamps. The current approach allows for timestamps to have their own lock: sk_stamp_lock. This allows for the patch to not compete with already existing critical sections, and side effects are limited to the paths in the patch. The addition of the new field maintains the data locality optimizations from commit 9115e8cd2a0c ("net: reorganize struct sock for better data locality") Note that all the instances of the sk_stamp accesses are either through the ioctl or the syscall recvmsg. Signed-off-by: Deepa Dinamani <deepa.kernel(a)gmail.com> --- Changes since v2: * added ifdef as per eric's request Changes since v1: * fixed sunrpc sk_stamp update include/net/sock.h | 38 +++++++++++++++++++++++++++++++++++--- net/compat.c | 15 +++++++++------ net/core/sock.c | 15 ++++++++++----- net/sunrpc/svcsock.c | 2 +- 4 files changed, 55 insertions(+), 15 deletions(-) diff --git a/include/net/sock.h b/include/net/sock.h index f665d74ae509..e144c071c93f 100644 --- a/include/net/sock.h +++ b/include/net/sock.h @@ -298,6 +298,7 @@ struct sock_common { * @sk_filter: socket filtering instructions * @sk_timer: sock cleanup timer * @sk_stamp: time stamp of last packet received + * @sk_stamp_seq: lock for accessing sk_stamp on 32 bit architectures only * @sk_tsflags: SO_TIMESTAMPING socket options * @sk_tskey: counter to disambiguate concurrent tstamp requests * @sk_zckey: counter to order MSG_ZEROCOPY notifications @@ -474,6 +475,9 @@ struct sock { const struct cred *sk_peer_cred; long sk_rcvtimeo; ktime_t sk_stamp; +#if BITS_PER_LONG==32 + seqlock_t sk_stamp_seq; +#endif u16 sk_tsflags; u8 sk_shutdown; u32 sk_tskey; @@ -2287,6 +2291,34 @@ static inline void sk_drops_add(struct sock *sk, const struct sk_buff *skb) atomic_add(segs, &sk->sk_drops); } +static inline ktime_t sock_read_timestamp(struct sock *sk) +{ +#if BITS_PER_LONG==32 + unsigned int seq; + ktime_t kt; + + do { + seq = read_seqbegin(&sk->sk_stamp_seq); + kt = sk->sk_stamp; + } while (read_seqretry(&sk->sk_stamp_seq, seq)); + + return kt; +#else + return sk->sk_stamp; +#endif +} + +static inline void sock_write_timestamp(struct sock *sk, ktime_t kt) +{ +#if BITS_PER_LONG==32 + write_seqlock(&sk->sk_stamp_seq); + sk->sk_stamp = kt; + write_sequnlock(&sk->sk_stamp_seq); +#else + sk->sk_stamp = kt; +#endif +} + void __sock_recv_timestamp(struct msghdr *msg, struct sock *sk, struct sk_buff *skb); void __sock_recv_wifi_status(struct msghdr *msg, struct sock *sk, @@ -2311,7 +2343,7 @@ sock_recv_timestamp(struct msghdr *msg, struct sock *sk, struct sk_buff *skb) (sk->sk_tsflags & SOF_TIMESTAMPING_RAW_HARDWARE))) __sock_recv_timestamp(msg, sk, skb); else - sk->sk_stamp = kt; + sock_write_timestamp(sk, kt); if (sock_flag(sk, SOCK_WIFI_STATUS) && skb->wifi_acked_valid) __sock_recv_wifi_status(msg, sk, skb); @@ -2332,9 +2364,9 @@ static inline void sock_recv_ts_and_drops(struct msghdr *msg, struct sock *sk, if (sk->sk_flags & FLAGS_TS_OR_DROPS || sk->sk_tsflags & TSFLAGS_ANY) __sock_recv_ts_and_drops(msg, sk, skb); else if (unlikely(sock_flag(sk, SOCK_TIMESTAMP))) - sk->sk_stamp = skb->tstamp; + sock_write_timestamp(sk, skb->tstamp); else if (unlikely(sk->sk_stamp == SK_DEFAULT_STAMP)) - sk->sk_stamp = 0; + sock_write_timestamp(sk, 0); } void __sock_tx_timestamp(__u16 tsflags, __u8 *tx_flags); diff --git a/net/compat.c b/net/compat.c index 47a614b370cd..d1f3a8a0b3ef 100644 --- a/net/compat.c +++ b/net/compat.c @@ -467,12 +467,14 @@ int compat_sock_get_timestamp(struct sock *sk, struct timeval __user *userstamp) ctv = (struct compat_timeval __user *) userstamp; err = -ENOENT; sock_enable_timestamp(sk, SOCK_TIMESTAMP); - tv = ktime_to_timeval(sk->sk_stamp); + tv = ktime_to_timeval(sock_read_timestamp(sk)); + if (tv.tv_sec == -1) return err; if (tv.tv_sec == 0) { - sk->sk_stamp = ktime_get_real(); - tv = ktime_to_timeval(sk->sk_stamp); + ktime_t kt = ktime_get_real(); + sock_write_timestamp(sk, kt); + tv = ktime_to_timeval(kt); } err = 0; if (put_user(tv.tv_sec, &ctv->tv_sec) || @@ -494,12 +496,13 @@ int compat_sock_get_timestampns(struct sock *sk, struct timespec __user *usersta ctv = (struct compat_timespec __user *) userstamp; err = -ENOENT; sock_enable_timestamp(sk, SOCK_TIMESTAMP); - ts = ktime_to_timespec(sk->sk_stamp); + ts = ktime_to_timespec(sock_read_timestamp(sk)); if (ts.tv_sec == -1) return err; if (ts.tv_sec == 0) { - sk->sk_stamp = ktime_get_real(); - ts = ktime_to_timespec(sk->sk_stamp); + ktime_t kt = ktime_get_real(); + sock_write_timestamp(sk, kt); + ts = ktime_to_timespec(kt); } err = 0; if (put_user(ts.tv_sec, &ctv->tv_sec) || diff --git a/net/core/sock.c b/net/core/sock.c index 6d7e189e3cd9..8236b28611c5 100644 --- a/net/core/sock.c +++ b/net/core/sock.c @@ -2747,6 +2747,9 @@ void sock_init_data(struct socket *sock, struct sock *sk) sk->sk_sndtimeo = MAX_SCHEDULE_TIMEOUT; sk->sk_stamp = SK_DEFAULT_STAMP; +#if BITS_PER_LONG==32 + seqlock_init(&sk->sk_stamp_seq); +#endif atomic_set(&sk->sk_zckey, 0); #ifdef CONFIG_NET_RX_BUSY_POLL @@ -2846,12 +2849,13 @@ int sock_get_timestamp(struct sock *sk, struct timeval __user *userstamp) struct timeval tv; sock_enable_timestamp(sk, SOCK_TIMESTAMP); - tv = ktime_to_timeval(sk->sk_stamp); + tv = ktime_to_timeval(sock_read_timestamp(sk)); if (tv.tv_sec == -1) return -ENOENT; if (tv.tv_sec == 0) { - sk->sk_stamp = ktime_get_real(); - tv = ktime_to_timeval(sk->sk_stamp); + ktime_t kt = ktime_get_real(); + sock_write_timestamp(sk, kt); + tv = ktime_to_timeval(kt); } return copy_to_user(userstamp, &tv, sizeof(tv)) ? -EFAULT : 0; } @@ -2862,11 +2866,12 @@ int sock_get_timestampns(struct sock *sk, struct timespec __user *userstamp) struct timespec ts; sock_enable_timestamp(sk, SOCK_TIMESTAMP); - ts = ktime_to_timespec(sk->sk_stamp); + ts = ktime_to_timespec(sock_read_timestamp(sk)); if (ts.tv_sec == -1) return -ENOENT; if (ts.tv_sec == 0) { - sk->sk_stamp = ktime_get_real(); + ktime_t kt = ktime_get_real(); + sock_write_timestamp(sk, kt); ts = ktime_to_timespec(sk->sk_stamp); } return copy_to_user(userstamp, &ts, sizeof(ts)) ? -EFAULT : 0; diff --git a/net/sunrpc/svcsock.c b/net/sunrpc/svcsock.c index 986f3ed7d1a2..b7e67310ec37 100644 --- a/net/sunrpc/svcsock.c +++ b/net/sunrpc/svcsock.c @@ -549,7 +549,7 @@ static int svc_udp_recvfrom(struct svc_rqst *rqstp) /* Don't enable netstamp, sunrpc doesn't need that much accuracy */ } - svsk->sk_sk->sk_stamp = skb->tstamp; + sock_write_timestamp(svsk->sk_sk, skb->tstamp); set_bit(XPT_DATA, &svsk->sk_xprt.xpt_flags); /* there may be more data... */ len = skb->len; -- 2.17.1

7 years

[GIT PULL] y2038: more syscalls and cleanups

by Arnd Bergmann

Hi Linus and Thomas, I realized that the merge window is now imminent, but I had not sent a pull request to Thomas for the current y2038 stuff. These patches have been around for a while though, and were in linux-next through my tree. I got one bug report on Monday and incorporated a simple fix, which changed the commit date for the second half of the series, in case you are wondering. Thomas, is it ok for you to just provide an Ack for this branch and have Linus merge it directly? Arnd The following changes since commit 651022382c7f8da46cb4872a545ee1da6d097d2a: Linux 4.20-rc1 (2018-11-04 15:37:52 -0800) are available in the Git repository at: https://git.kernel.org:/pub/scm/linux/kernel/git/arnd/playground.git tags/y2038-for-4.21 for you to fetch changes up to e4b92b108c6cd6b311e4b6e85d6a87a34599a6e3: timekeeping: remove obsolete time accessors (2018-12-18 16:13:05 +0100) ---------------------------------------------------------------- y2038: more syscalls and cleanups This concludes the main part of the system call rework for 64-bit time_t, which has spread over most of year 2018, the last six system calls being - ppoll - pselect6 - io_pgetevents - recvmmsg - futex - rt_sigtimedwait As before, nothing changes for 64-bit architectures, while 32-bit architectures gain another entry point that differs only in the layout of the timespec structure. Hopefully in the next release we can wire up all 22 of those system calls on all 32-bit architectures, which gives us a baseline version for glibc to start using them. This does not include the clock_adjtime, getrusage/waitid, and getitimer/setitimer system calls. I still plan to have new versions of those as well, but they are not required for correct operation of the C library since they can be emulated using the old 32-bit time_t based system calls. Aside from the system calls, there are also a few cleanups here, removing old kernel internal interfaces that have become unused after all references got removed. The arch/sh cleanups are part of this, there were posted several times over the past year without a reaction from the maintainers, while the corresponding changes made it into all other architectures. ---------------------------------------------------------------- Arnd Bergmann (13): y2038: futex: Move compat implementation into futex.c y2038: futex: Add support for __kernel_timespec y2038: socket: Add compat_sys_recvmmsg_time64 y2038: signal: Add sys_rt_sigtimedwait_time32 y2038: signal: Add compat_sys_rt_sigtimedwait_time64 sh: dreamcast: rtc: push down rtc class ops into driver sh: sh03: rtc: push down rtc class ops into driver sh: remove unused rtc_sh_get/set_time infrastructure sh: remove board_time_init() callback timekeeping: remove unused {read,update}_persistent_clock timekeeping: remove timespec_add/timespec_del vfs: replace current_kernel_time64 with ktime equivalent timekeeping: remove obsolete time accessors Deepa Dinamani (5): signal: Add set_user_sigmask() signal: Add restore_user_sigmask() ppoll: use __kernel_timespec pselect6: use __kernel_timespec io_pgetevents: use __kernel_timespec Documentation/sh/new-machine.txt | 8 -- arch/sh/boards/mach-dreamcast/Makefile | 4 +- arch/sh/boards/mach-dreamcast/rtc.c | 45 +++++++--- arch/sh/boards/mach-dreamcast/setup.c | 1 - arch/sh/boards/mach-sh03/Makefile | 3 +- arch/sh/boards/mach-sh03/rtc.c | 51 ++++++----- arch/sh/boards/mach-sh03/setup.c | 9 -- arch/sh/boards/of-generic.c | 8 -- arch/sh/configs/dreamcast_defconfig | 2 + arch/sh/configs/sh03_defconfig | 2 + arch/sh/include/asm/rtc.h | 3 - arch/sh/include/mach-dreamcast/mach/sysasic.h | 1 - arch/sh/kernel/time.c | 74 +--------------- fs/aio.c | 134 ++++++++++++++++++++--------- fs/eventpoll.c | 52 ++---------- fs/inode.c | 4 +- fs/select.c | 360 +++++++++++++++++++++++++++++++++++++++++++++--------------------------------- include/linux/compat.h | 26 ++++++ include/linux/futex.h | 8 -- include/linux/signal.h | 4 + include/linux/socket.h | 9 +- include/linux/syscalls.h | 29 +++++-- include/linux/time32.h | 25 ------ include/linux/timekeeping.h | 14 --- include/linux/timekeeping32.h | 15 ---- kernel/Makefile | 3 - kernel/futex.c | 207 +++++++++++++++++++++++++++++++++++++++++++-- kernel/futex_compat.c | 202 -------------------------------------------- kernel/signal.c | 143 +++++++++++++++++++++++++++++++ kernel/sys_ni.c | 2 + kernel/time/ntp.c | 10 +-- kernel/time/time.c | 36 -------- kernel/time/timekeeping.c | 12 +-- net/compat.c | 34 +++----- net/socket.c | 62 ++++++++++---- 35 files changed, 847 insertions(+), 755 deletions(-) delete mode 100644 kernel/futex_compat.c

7 years

[GIT PULL] asm-generic: syscall table script for arch/sh

by Arnd Bergmann

The following changes since commit 2e6e902d185027f8e3cb8b7305238f7e35d6a436: Linux 4.20-rc4 (2018-11-25 14:19:31 -0800) are available in the Git repository at: git://git.kernel.org/pub/scm/linux/kernel/git/arnd/asm-generic.git tags/asm-generic-4.21 for you to fetch changes up to 2b3c5a99d5f314960e00950c1782eac9361de30f: sh: generate uapi header and syscall table header files (2018-12-19 17:54:40 +0100) ---------------------------------------------------------------- asm-generic: syscall table script for arch/sh I worked with Firoz Khan to change all architectures to have their system call tables (syscall.S and asm/unistd.h) generated by a script from a more readable input file the same way that we already had on x86, s390 and arm. I offered to take those conversions through the asm-generic tree that did not get picked up by the architecture maintainers, and fortunately all but one have now been accepted into arch maintainer trees, so this branch only contains the conversion for arch/sh/, with permission from Rich. The conversion does not include the old 64-bit sh5 architecture, which has never shipped and not even compiled in a long time. The table in include/uapi/asm/unistd.h is also not included here, as Firoz is still working on that one. It will have to wait for the next following merge window, hopefully together with the addition of the 64-bit time_t system calls for the y2038 work that led to the system call table rework. Acked-by: Rich Felker <dalias(a)libc.org> Signed-off-by: Arnd Bergmann <arnd(a)arndb.de> ---------------------------------------------------------------- Firoz Khan (3): sh: add __NR_syscalls along with NR_syscalls sh: add system call table generation support sh: generate uapi header and syscall table header files arch/sh/Makefile | 3 + arch/sh/include/asm/Kbuild | 1 + arch/sh/include/asm/unistd.h | 2 + arch/sh/include/uapi/asm/Kbuild | 1 + arch/sh/include/uapi/asm/unistd_32.h | 4 +- arch/sh/include/uapi/asm/unistd_64.h | 4 +- arch/sh/kernel/syscalls/Makefile | 38 +++++++++ arch/sh/kernel/syscalls/syscall.tbl | 392 ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ arch/sh/kernel/syscalls/syscallhdr.sh | 36 ++++++++ arch/sh/kernel/syscalls/syscalltbl.sh | 32 +++++++ arch/sh/kernel/syscalls_32.S | 387 +----------------------------------------------------------------------------------- 11 files changed, 514 insertions(+), 386 deletions(-) create mode 100644 arch/sh/kernel/syscalls/Makefile create mode 100644 arch/sh/kernel/syscalls/syscall.tbl create mode 100644 arch/sh/kernel/syscalls/syscallhdr.sh create mode 100644 arch/sh/kernel/syscalls/syscalltbl.sh

7 years

[PATCH v5 0/7] mips: system call table generation support

by Firoz Khan

The purpose of this patch series is, we can easily add/modify/delete system call table support by cha- nging entry in syscall.tbl file instead of manually changing many files. The other goal is to unify the system call table generation support implementation across all the architectures. The system call tables are in different format in all architecture. It will be difficult to manually add, modify or delete the system calls in the resp- ective files manually. To make it easy by keeping a script and which'll generate uapi header file and syscall table file. syscall.tbl contains the list of available system calls along with system call number and correspond- ing entry point. Add a new system call in this arch- itecture will be possible by adding new entry in the syscall.tbl file. Adding a new table entry consisting of: - System call number. - ABI. - System call name. - Entry point name. - Compat entry name, if required. ARM, s390 and x86 architecuture does exist the sim- ilar support. I leverage their implementation to come up with a generic solution. I have done the same support for work for alpha, ia64, m68k, microblaze, parisc, powerpc, sh, sparc, and xtensa. Below mentioned git repository contains more details about the workflow. https://github.com/frzkhn/system_call_table_generator/ Finally, this is the ground work to solve the Y2038 issue. We need to add two dozen of system calls to solve Y2038 issue. So this patch series will help to add new system calls easily by adding new entry in the syscall.tbl. Changes since v4: - _MIPS_SIM_ABIN64 (suppose to be _MIPS_SIM_NABI64) macro rename back to _MIPS_SIM_ABI64 to avoid toolchain issue. Changes since v3: - rearranged the patches for '64' to 'n64' conver- sion. - moved the unistd_nr_*.h files to asm/unistd.h - modified the *.sh files. Changes since v2: - fixed __NR_syscalls assign issue. Changes since v1: - optimized/updated the syscall table generation scripts. - fixed all mixed indentation issues in syscall.tbl. - added "comments" in syscall_*.tbl. - changed from generic-y to generated-y in Kbuild. Firoz Khan (7): mips: add __NR_syscalls along with __NR_Linux_syscalls mips: remove unused macros mips: rename macros and files from '64' to 'n64' mips: add +1 to __NR_syscalls in uapi header mips: remove syscall table entries mips: add system call table generation support mips: generate uapi header and system call table files arch/mips/Makefile | 3 + arch/mips/include/asm/Kbuild | 4 + arch/mips/include/asm/unistd.h | 11 +- arch/mips/include/uapi/asm/Kbuild | 6 + arch/mips/include/uapi/asm/unistd.h | 1074 +---------------------------- arch/mips/kernel/Makefile | 2 +- arch/mips/kernel/ftrace.c | 8 +- arch/mips/kernel/scall32-o32.S | 391 +---------- arch/mips/kernel/scall64-64.S | 444 ------------ arch/mips/kernel/scall64-n32.S | 341 +-------- arch/mips/kernel/scall64-n64.S | 117 ++++ arch/mips/kernel/scall64-o32.S | 379 +--------- arch/mips/kernel/syscalls/Makefile | 96 +++ arch/mips/kernel/syscalls/syscall_n32.tbl | 343 +++++++++ arch/mips/kernel/syscalls/syscall_n64.tbl | 339 +++++++++ arch/mips/kernel/syscalls/syscall_o32.tbl | 382 ++++++++++ arch/mips/kernel/syscalls/syscallhdr.sh | 37 + arch/mips/kernel/syscalls/syscallnr.sh | 28 + arch/mips/kernel/syscalls/syscalltbl.sh | 36 + 19 files changed, 1427 insertions(+), 2614 deletions(-) delete mode 100644 arch/mips/kernel/scall64-64.S create mode 100644 arch/mips/kernel/scall64-n64.S create mode 100644 arch/mips/kernel/syscalls/Makefile create mode 100644 arch/mips/kernel/syscalls/syscall_n32.tbl create mode 100644 arch/mips/kernel/syscalls/syscall_n64.tbl create mode 100644 arch/mips/kernel/syscalls/syscall_o32.tbl create mode 100644 arch/mips/kernel/syscalls/syscallhdr.sh create mode 100644 arch/mips/kernel/syscalls/syscallnr.sh create mode 100644 arch/mips/kernel/syscalls/syscalltbl.sh -- 1.9.1

7 years

[PATCH v6 0/5] powerpc: system call table generation support

by Firoz Khan

The purpose of this patch series is, we can easily add/modify/delete system call table support by cha- nging entry in syscall.tbl file instead of manually changing many files. The other goal is to unify the system call table generation support implementation across all the architectures. The system call tables are in different format in all architecture. It will be difficult to manually add, modify or delete the system calls in the resp- ective files manually. To make it easy by keeping a script and which'll generate uapi header file and syscall table file. syscall.tbl contains the list of available system calls along with system call number and correspond- ing entry point. Add a new system call in this arch- itecture will be possible by adding new entry in the syscall.tbl file. Adding a new table entry consisting of: - System call number. - ABI. - System call name. - Entry point name. - Compat entry name, if required. - spu entry name, if required. ARM, s390 and x86 architecuture does exist the sim- ilar support. I leverage their implementation to come up with a generic solution. I have done the same support for work for alpha, ia64, m68k, microblaze, mips, parisc, sh, sparc, and xtensa. Below mentioned git repository contains more details about the workflow. https://github.com/frzkhn/system_call_table_generator/ Finally, this is the ground work to solve the Y2038 issue. We need to add two dozen of system calls to solve Y2038 issue. So this patch series will help to add new system calls easily by adding new entry in the syscall.tbl. Changes since v5: - rebased with 4.20-rc7. Changes since v4: - DOTSYM macro removed for ppc32, which was causing the compilation error. Changes since v3: - split compat syscall table out from native table. - modified the script to add new line in the generated file. Changes since v2: - modified/optimized the syscall.tbl to avoid duplicate for the spu entries. - updated the syscalltbl.sh to meet the above point. Changes since v1: - optimized/updated the syscall table generation scripts. - fixed all mixed indentation issues in syscall.tbl. - added "comments" in syscall_*.tbl. - changed from generic-y to generated-y in Kbuild. Firoz Khan (5): powerpc: add __NR_syscalls along with NR_syscalls powerpc: move macro definition from asm/systbl.h powerpc: add system call table generation support powerpc: split compat syscall table out from native table powerpc: generate uapi header and system call table files arch/powerpc/Makefile | 3 + arch/powerpc/include/asm/Kbuild | 4 + arch/powerpc/include/asm/syscall.h | 3 +- arch/powerpc/include/asm/systbl.h | 396 -------------------------- arch/powerpc/include/asm/unistd.h | 3 +- arch/powerpc/include/uapi/asm/Kbuild | 2 + arch/powerpc/include/uapi/asm/unistd.h | 389 +------------------------ arch/powerpc/kernel/Makefile | 10 - arch/powerpc/kernel/entry_64.S | 7 +- arch/powerpc/kernel/syscalls/Makefile | 63 ++++ arch/powerpc/kernel/syscalls/syscall.tbl | 427 ++++++++++++++++++++++++++++ arch/powerpc/kernel/syscalls/syscallhdr.sh | 37 +++ arch/powerpc/kernel/syscalls/syscalltbl.sh | 36 +++ arch/powerpc/kernel/systbl.S | 40 ++- arch/powerpc/kernel/systbl_chk.c | 60 ---- arch/powerpc/kernel/vdso.c | 7 +- arch/powerpc/platforms/cell/spu_callbacks.c | 17 +- 17 files changed, 606 insertions(+), 898 deletions(-) delete mode 100644 arch/powerpc/include/asm/systbl.h create mode 100644 arch/powerpc/kernel/syscalls/Makefile create mode 100644 arch/powerpc/kernel/syscalls/syscall.tbl create mode 100644 arch/powerpc/kernel/syscalls/syscallhdr.sh create mode 100644 arch/powerpc/kernel/syscalls/syscalltbl.sh delete mode 100644 arch/powerpc/kernel/systbl_chk.c -- 1.9.1

7 years

[PATCH] sock: Make sock->sk_tstamp thread-safe

by Deepa Dinamani

Al Viro mentioned that there is probably a race condition lurking in accesses of sk_tstamp on 32-bit machines. sock->sk_tstamp is of type ktime_t which is always an s64. On a 32 bit architecture, we might run into situations of unsafe access as the access to the field becomes non atomic. Use seqlocks for synchronization. This allows us to avoid using spinlocks for readers as readers do not need mutual exclusion. Another approach to solve this is to require sk_lock for all modifications of the timestamps. The current approach allows for timestamps to have their own lock: sk_tstamp_lock. This allows for the patch to not compete with already existing critical sections, and side effects are limited to the paths in the patch. The addition of the new field maintains the data locality optimizations from commit 9115e8cd2a0c ("net: reorganize struct sock for better data locality") Note that all the instances of the sk_tstamp accesses are either through the ioctl or the syscall recvmsg. Signed-off-by: Deepa Dinamani <deepa.kernel(a)gmail.com> --- include/net/sock.h | 16 +++++++++++++--- net/compat.c | 30 +++++++++++++++++++++++++----- net/core/sock.c | 34 +++++++++++++++++++++++++++++----- 3 files changed, 67 insertions(+), 13 deletions(-) diff --git a/include/net/sock.h b/include/net/sock.h index fe58aec00d09..2cb641606533 100644 --- a/include/net/sock.h +++ b/include/net/sock.h @@ -298,6 +298,7 @@ struct sock_common { * @sk_filter: socket filtering instructions * @sk_timer: sock cleanup timer * @sk_stamp: time stamp of last packet received + * @sk_stamp_seq: lock for accessing sk_stamp * @sk_tsflags: SO_TIMESTAMPING socket options * @sk_tskey: counter to disambiguate concurrent tstamp requests * @sk_zckey: counter to order MSG_ZEROCOPY notifications @@ -474,6 +475,7 @@ struct sock { const struct cred *sk_peer_cred; long sk_rcvtimeo; ktime_t sk_stamp; + seqlock_t sk_stamp_seq; u16 sk_tsflags; u8 sk_shutdown; u32 sk_tskey; @@ -2311,8 +2313,11 @@ sock_recv_timestamp(struct msghdr *msg, struct sock *sk, struct sk_buff *skb) (hwtstamps->hwtstamp && (sk->sk_tsflags & SOF_TIMESTAMPING_RAW_HARDWARE))) __sock_recv_timestamp(msg, sk, skb); - else + else { + write_seqlock(&sk->sk_stamp_seq); sk->sk_stamp = kt; + write_sequnlock(&sk->sk_stamp_seq); + } if (sock_flag(sk, SOCK_WIFI_STATUS) && skb->wifi_acked_valid) __sock_recv_wifi_status(msg, sk, skb); @@ -2332,10 +2337,15 @@ static inline void sock_recv_ts_and_drops(struct msghdr *msg, struct sock *sk, if (sk->sk_flags & FLAGS_TS_OR_DROPS || sk->sk_tsflags & TSFLAGS_ANY) __sock_recv_ts_and_drops(msg, sk, skb); - else if (unlikely(sock_flag(sk, SOCK_TIMESTAMP))) + else if (unlikely(sock_flag(sk, SOCK_TIMESTAMP))) { + write_seqlock(&sk->sk_stamp_seq); sk->sk_stamp = skb->tstamp; - else if (unlikely(sk->sk_stamp == SK_DEFAULT_STAMP)) + write_sequnlock(&sk->sk_stamp_seq); + } else if (unlikely(sk->sk_stamp == SK_DEFAULT_STAMP)) { + write_seqlock(&sk->sk_stamp_seq); sk->sk_stamp = 0; + write_sequnlock(&sk->sk_stamp_seq); + } } void __sock_tx_timestamp(__u16 tsflags, __u8 *tx_flags); diff --git a/net/compat.c b/net/compat.c index 6c9fceeefac0..3022f4941687 100644 --- a/net/compat.c +++ b/net/compat.c @@ -459,6 +459,7 @@ int compat_sock_get_timestamp(struct sock *sk, struct timeval __user *userstamp) { struct compat_timeval __user *ctv; int err; + unsigned int seq; struct timeval tv; if (COMPAT_USE_64BIT_TIME) @@ -467,11 +468,20 @@ int compat_sock_get_timestamp(struct sock *sk, struct timeval __user *userstamp) ctv = (struct compat_timeval __user *) userstamp; err = -ENOENT; sock_enable_timestamp(sk, SOCK_TIMESTAMP); - tv = ktime_to_timeval(sk->sk_stamp); + + do { + seq = read_seqbegin(&sk->sk_stamp_seq); + tv = ktime_to_timeval(sk->sk_stamp); + } while (read_seqretry(&sk->sk_stamp_seq, seq)); + if (tv.tv_sec == -1) return err; if (tv.tv_sec == 0) { - sk->sk_stamp = ktime_get_real(); + ktime_t kt = ktime_get_real(); + + write_seqlock(&sk->sk_stamp_seq); + sk->sk_stamp = kt; + write_sequnlock(&sk->sk_stamp_seq); tv = ktime_to_timeval(sk->sk_stamp); } err = 0; @@ -486,6 +496,7 @@ int compat_sock_get_timestampns(struct sock *sk, struct timespec __user *usersta { struct compat_timespec __user *ctv; int err; + unsigned int seq; struct timespec ts; if (COMPAT_USE_64BIT_TIME) @@ -494,12 +505,21 @@ int compat_sock_get_timestampns(struct sock *sk, struct timespec __user *usersta ctv = (struct compat_timespec __user *) userstamp; err = -ENOENT; sock_enable_timestamp(sk, SOCK_TIMESTAMP); - ts = ktime_to_timespec(sk->sk_stamp); + + do { + seq = read_seqbegin(&sk->sk_stamp_seq); + ts = ktime_to_timespec(sk->sk_stamp); + } while (read_seqretry(&sk->sk_stamp_seq, seq)); + if (ts.tv_sec == -1) return err; if (ts.tv_sec == 0) { - sk->sk_stamp = ktime_get_real(); - ts = ktime_to_timespec(sk->sk_stamp); + ktime_t kt = ktime_get_real(); + + write_seqlock(&sk->sk_stamp_seq); + sk->sk_stamp = kt; + write_sequnlock(&sk->sk_stamp_seq); + ts = ktime_to_timespec(kt); } err = 0; if (put_user(ts.tv_sec, &ctv->tv_sec) || diff --git a/net/core/sock.c b/net/core/sock.c index f0e0e12b2e0d..a9a99af24a95 100644 --- a/net/core/sock.c +++ b/net/core/sock.c @@ -2783,6 +2783,7 @@ void sock_init_data(struct socket *sock, struct sock *sk) sk->sk_sndtimeo = MAX_SCHEDULE_TIMEOUT; sk->sk_stamp = SK_DEFAULT_STAMP; + seqlock_init(&sk->sk_stamp_seq); atomic_set(&sk->sk_zckey, 0); #ifdef CONFIG_NET_RX_BUSY_POLL @@ -2880,15 +2881,27 @@ EXPORT_SYMBOL(lock_sock_fast); int sock_get_timestamp(struct sock *sk, struct timeval __user *userstamp) { struct timeval tv; + unsigned int seq; sock_enable_timestamp(sk, SOCK_TIMESTAMP); - tv = ktime_to_timeval(sk->sk_stamp); + + do { + seq = read_seqbegin(&sk->sk_stamp_seq); + tv = ktime_to_timeval(sk->sk_stamp); + } while (read_seqretry(&sk->sk_stamp_seq, seq)); + if (tv.tv_sec == -1) return -ENOENT; if (tv.tv_sec == 0) { - sk->sk_stamp = ktime_get_real(); - tv = ktime_to_timeval(sk->sk_stamp); + ktime_t kt = ktime_get_real(); + + write_seqlock(&sk->sk_stamp_seq); + sk->sk_stamp = kt; + write_sequnlock(&sk->sk_stamp_seq); + + tv = ktime_to_timeval(kt); } + return copy_to_user(userstamp, &tv, sizeof(tv)) ? -EFAULT : 0; } EXPORT_SYMBOL(sock_get_timestamp); @@ -2896,13 +2909,24 @@ EXPORT_SYMBOL(sock_get_timestamp); int sock_get_timestampns(struct sock *sk, struct timespec __user *userstamp) { struct timespec ts; + unsigned int seq; sock_enable_timestamp(sk, SOCK_TIMESTAMP); - ts = ktime_to_timespec(sk->sk_stamp); + + do { + seq = read_seqbegin(&sk->sk_stamp_seq); + ts = ktime_to_timespec(sk->sk_stamp); + } while (read_seqretry(&sk->sk_stamp_seq, seq)); + if (ts.tv_sec == -1) return -ENOENT; if (ts.tv_sec == 0) { - sk->sk_stamp = ktime_get_real(); + ktime_t kt = ktime_get_real(); + + write_seqlock(&sk->sk_stamp_seq); + sk->sk_stamp = kt; + write_sequnlock(&sk->sk_stamp_seq); + ts = ktime_to_timespec(sk->sk_stamp); } return copy_to_user(userstamp, &ts, sizeof(ts)) ? -EFAULT : 0; -- 2.17.1

7 years

[PATCH v2 1/1] sock: Make sock->sk_stamp thread-safe

by Deepa Dinamani

Al Viro mentioned (Message-ID <20170626041334.GZ10672(a)ZenIV.linux.org.uk>) that there is probably a race condition lurking in accesses of sk_stamp on 32-bit machines. sock->sk_stamp is of type ktime_t which is always an s64. On a 32 bit architecture, we might run into situations of unsafe access as the access to the field becomes non atomic. Use seqlocks for synchronization. This allows us to avoid using spinlocks for readers as readers do not need mutual exclusion. Another approach to solve this is to require sk_lock for all modifications of the timestamps. The current approach allows for timestamps to have their own lock: sk_stamp_lock. This allows for the patch to not compete with already existing critical sections, and side effects are limited to the paths in the patch. The addition of the new field maintains the data locality optimizations from commit 9115e8cd2a0c ("net: reorganize struct sock for better data locality") Note that all the instances of the sk_stamp accesses are either through the ioctl or the syscall recvmsg. Signed-off-by: Deepa Dinamani <deepa.kernel(a)gmail.com> --- Changes since v1: * fixed sunrpc sk_stamp update include/net/sock.h | 16 +++++++++++++--- net/compat.c | 32 ++++++++++++++++++++++++++------ net/core/sock.c | 34 +++++++++++++++++++++++++++++----- net/sunrpc/svcsock.c | 2 ++ 4 files changed, 70 insertions(+), 14 deletions(-) diff --git a/include/net/sock.h b/include/net/sock.h index fe58aec00d09..2cb641606533 100644 --- a/include/net/sock.h +++ b/include/net/sock.h @@ -298,6 +298,7 @@ struct sock_common { * @sk_filter: socket filtering instructions * @sk_timer: sock cleanup timer * @sk_stamp: time stamp of last packet received + * @sk_stamp_seq: lock for accessing sk_stamp * @sk_tsflags: SO_TIMESTAMPING socket options * @sk_tskey: counter to disambiguate concurrent tstamp requests * @sk_zckey: counter to order MSG_ZEROCOPY notifications @@ -474,6 +475,7 @@ struct sock { const struct cred *sk_peer_cred; long sk_rcvtimeo; ktime_t sk_stamp; + seqlock_t sk_stamp_seq; u16 sk_tsflags; u8 sk_shutdown; u32 sk_tskey; @@ -2311,8 +2313,11 @@ sock_recv_timestamp(struct msghdr *msg, struct sock *sk, struct sk_buff *skb) (hwtstamps->hwtstamp && (sk->sk_tsflags & SOF_TIMESTAMPING_RAW_HARDWARE))) __sock_recv_timestamp(msg, sk, skb); - else + else { + write_seqlock(&sk->sk_stamp_seq); sk->sk_stamp = kt; + write_sequnlock(&sk->sk_stamp_seq); + } if (sock_flag(sk, SOCK_WIFI_STATUS) && skb->wifi_acked_valid) __sock_recv_wifi_status(msg, sk, skb); @@ -2332,10 +2337,15 @@ static inline void sock_recv_ts_and_drops(struct msghdr *msg, struct sock *sk, if (sk->sk_flags & FLAGS_TS_OR_DROPS || sk->sk_tsflags & TSFLAGS_ANY) __sock_recv_ts_and_drops(msg, sk, skb); - else if (unlikely(sock_flag(sk, SOCK_TIMESTAMP))) + else if (unlikely(sock_flag(sk, SOCK_TIMESTAMP))) { + write_seqlock(&sk->sk_stamp_seq); sk->sk_stamp = skb->tstamp; - else if (unlikely(sk->sk_stamp == SK_DEFAULT_STAMP)) + write_sequnlock(&sk->sk_stamp_seq); + } else if (unlikely(sk->sk_stamp == SK_DEFAULT_STAMP)) { + write_seqlock(&sk->sk_stamp_seq); sk->sk_stamp = 0; + write_sequnlock(&sk->sk_stamp_seq); + } } void __sock_tx_timestamp(__u16 tsflags, __u8 *tx_flags); diff --git a/net/compat.c b/net/compat.c index 6c9fceeefac0..17da30bd34a9 100644 --- a/net/compat.c +++ b/net/compat.c @@ -459,6 +459,7 @@ int compat_sock_get_timestamp(struct sock *sk, struct timeval __user *userstamp) { struct compat_timeval __user *ctv; int err; + unsigned int seq; struct timeval tv; if (COMPAT_USE_64BIT_TIME) @@ -467,12 +468,21 @@ int compat_sock_get_timestamp(struct sock *sk, struct timeval __user *userstamp) ctv = (struct compat_timeval __user *) userstamp; err = -ENOENT; sock_enable_timestamp(sk, SOCK_TIMESTAMP); - tv = ktime_to_timeval(sk->sk_stamp); + + do { + seq = read_seqbegin(&sk->sk_stamp_seq); + tv = ktime_to_timeval(sk->sk_stamp); + } while (read_seqretry(&sk->sk_stamp_seq, seq)); + if (tv.tv_sec == -1) return err; if (tv.tv_sec == 0) { - sk->sk_stamp = ktime_get_real(); - tv = ktime_to_timeval(sk->sk_stamp); + ktime_t kt = ktime_get_real(); + + write_seqlock(&sk->sk_stamp_seq); + sk->sk_stamp = kt; + write_sequnlock(&sk->sk_stamp_seq); + tv = ktime_to_timeval(kt); } err = 0; if (put_user(tv.tv_sec, &ctv->tv_sec) || @@ -486,6 +496,7 @@ int compat_sock_get_timestampns(struct sock *sk, struct timespec __user *usersta { struct compat_timespec __user *ctv; int err; + unsigned int seq; struct timespec ts; if (COMPAT_USE_64BIT_TIME) @@ -494,12 +505,21 @@ int compat_sock_get_timestampns(struct sock *sk, struct timespec __user *usersta ctv = (struct compat_timespec __user *) userstamp; err = -ENOENT; sock_enable_timestamp(sk, SOCK_TIMESTAMP); - ts = ktime_to_timespec(sk->sk_stamp); + + do { + seq = read_seqbegin(&sk->sk_stamp_seq); + ts = ktime_to_timespec(sk->sk_stamp); + } while (read_seqretry(&sk->sk_stamp_seq, seq)); + if (ts.tv_sec == -1) return err; if (ts.tv_sec == 0) { - sk->sk_stamp = ktime_get_real(); - ts = ktime_to_timespec(sk->sk_stamp); + ktime_t kt = ktime_get_real(); + + write_seqlock(&sk->sk_stamp_seq); + sk->sk_stamp = kt; + write_sequnlock(&sk->sk_stamp_seq); + ts = ktime_to_timespec(kt); } err = 0; if (put_user(ts.tv_sec, &ctv->tv_sec) || diff --git a/net/core/sock.c b/net/core/sock.c index f0e0e12b2e0d..a9a99af24a95 100644 --- a/net/core/sock.c +++ b/net/core/sock.c @@ -2783,6 +2783,7 @@ void sock_init_data(struct socket *sock, struct sock *sk) sk->sk_sndtimeo = MAX_SCHEDULE_TIMEOUT; sk->sk_stamp = SK_DEFAULT_STAMP; + seqlock_init(&sk->sk_stamp_seq); atomic_set(&sk->sk_zckey, 0); #ifdef CONFIG_NET_RX_BUSY_POLL @@ -2880,15 +2881,27 @@ EXPORT_SYMBOL(lock_sock_fast); int sock_get_timestamp(struct sock *sk, struct timeval __user *userstamp) { struct timeval tv; + unsigned int seq; sock_enable_timestamp(sk, SOCK_TIMESTAMP); - tv = ktime_to_timeval(sk->sk_stamp); + + do { + seq = read_seqbegin(&sk->sk_stamp_seq); + tv = ktime_to_timeval(sk->sk_stamp); + } while (read_seqretry(&sk->sk_stamp_seq, seq)); + if (tv.tv_sec == -1) return -ENOENT; if (tv.tv_sec == 0) { - sk->sk_stamp = ktime_get_real(); - tv = ktime_to_timeval(sk->sk_stamp); + ktime_t kt = ktime_get_real(); + + write_seqlock(&sk->sk_stamp_seq); + sk->sk_stamp = kt; + write_sequnlock(&sk->sk_stamp_seq); + + tv = ktime_to_timeval(kt); } + return copy_to_user(userstamp, &tv, sizeof(tv)) ? -EFAULT : 0; } EXPORT_SYMBOL(sock_get_timestamp); @@ -2896,13 +2909,24 @@ EXPORT_SYMBOL(sock_get_timestamp); int sock_get_timestampns(struct sock *sk, struct timespec __user *userstamp) { struct timespec ts; + unsigned int seq; sock_enable_timestamp(sk, SOCK_TIMESTAMP); - ts = ktime_to_timespec(sk->sk_stamp); + + do { + seq = read_seqbegin(&sk->sk_stamp_seq); + ts = ktime_to_timespec(sk->sk_stamp); + } while (read_seqretry(&sk->sk_stamp_seq, seq)); + if (ts.tv_sec == -1) return -ENOENT; if (ts.tv_sec == 0) { - sk->sk_stamp = ktime_get_real(); + ktime_t kt = ktime_get_real(); + + write_seqlock(&sk->sk_stamp_seq); + sk->sk_stamp = kt; + write_sequnlock(&sk->sk_stamp_seq); + ts = ktime_to_timespec(sk->sk_stamp); } return copy_to_user(userstamp, &ts, sizeof(ts)) ? -EFAULT : 0; diff --git a/net/sunrpc/svcsock.c b/net/sunrpc/svcsock.c index 986f3ed7d1a2..cd12177720aa 100644 --- a/net/sunrpc/svcsock.c +++ b/net/sunrpc/svcsock.c @@ -549,7 +549,9 @@ static int svc_udp_recvfrom(struct svc_rqst *rqstp) /* Don't enable netstamp, sunrpc doesn't need that much accuracy */ } + write_seqlock(&svsk->sk_sk->sk_stamp_seq); svsk->sk_sk->sk_stamp = skb->tstamp; + write_sequnlock(&svsk->sk_sk->sk_stamp_seq); set_bit(XPT_DATA, &svsk->sk_xprt.xpt_flags); /* there may be more data... */ len = skb->len; -- 2.17.1

7 years

[PATCH v3 0/5] alpha: system call table generation support

by Firoz Khan

The purpose of this patch series is, we can easily add/modify/delete system call table support by cha- nging entry in syscall.tbl file instead of manually changing many files. The other goal is to unify the system call table generation support implementation across all the architectures. The system call tables are in different format in all architecture. It will be difficult to manually add, modify or delete the system calls in the resp- ective files manually. To make it easy by keeping a script and which'll generate uapi header file and syscall table file. syscall.tbl contains the list of available system calls along with system call number and correspond- ing entry point. Add a new system call in this arch- itecture will be possible by adding new entry in the syscall.tbl file. Adding a new table entry consisting of: - System call number. - ABI. - System call name. - Entry point name. ARM, s390 and x86 architecuture does exist the sim- ilar support. I leverage their implementation to come up with a generic solution. I have done the same support for work for ia64, m68k, microblaze, mips, parisc, powerpc, sh, sparc and xtensa. Below mentioned git repository contains more details about the workflow. https://github.com/frzkhn/system_call_table_generator/ Finally, this is the ground work to solve the Y2038 issue. We need to add two dozen of system calls to solve Y2038 issue. So this patch series will help to add new system calls easily by adding new entry in the syscall.tbl. changes since v2: - changed from generic-y to generated-y in Kbuild. - made changes in syscall.tbl for removing entry - alpha_ni_syscall. changes since v1: - optimized/updated the syscall table generation scripts. - fixed all mixed indentation issues in syscall.tbl. - added "comments" in syscall.tbl. - enclosed __NR_sycalls macro with __KERNEL__. - added missing new line. Firoz Khan (5): alpha: move __IGNORE* entries to non uapi header alpha: remove CONFIG_OSF4_COMPAT flag from syscall table alpha: add __NR_syscalls along with NR_SYSCALLS alpha: add system call table generation support alpha: generate uapi header and syscall table header files arch/alpha/Makefile | 3 + arch/alpha/include/asm/Kbuild | 2 +- arch/alpha/include/asm/unistd.h | 23 +- arch/alpha/include/uapi/asm/Kbuild | 1 + arch/alpha/include/uapi/asm/unistd.h | 484 +-------------------------- arch/alpha/kernel/osf_sys.c | 9 +- arch/alpha/kernel/syscalls/Makefile | 38 +++ arch/alpha/kernel/syscalls/syscall.tbl | 453 ++++++++++++++++++++++++++ arch/alpha/kernel/syscalls/syscallhdr.sh | 36 ++ arch/alpha/kernel/syscalls/syscalltbl.sh | 32 ++ arch/alpha/kernel/systbls.S | 542 +------------------------------ 11 files changed, 596 insertions(+), 1027 deletions(-) create mode 100644 arch/alpha/kernel/syscalls/Makefile create mode 100644 arch/alpha/kernel/syscalls/syscall.tbl create mode 100644 arch/alpha/kernel/syscalls/syscallhdr.sh create mode 100644 arch/alpha/kernel/syscalls/syscalltbl.sh -- 1.9.1

7 years

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