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From: Adhemerval Zanella <azanella@sourceware.org> To: glibc-cvs@sourceware.org Subject: [glibc/azanella/clang] linux: Avoid shifting a negative signed on POSIX timer interface Date: Fri, 11 Mar 2022 17:22:10 +0000 (GMT) [thread overview] Message-ID: <20220311172210.E34C7385783A@sourceware.org> (raw) https://sourceware.org/git/gitweb.cgi?p=glibc.git;h=b19d7b655ca8b9cc7abdddb1c89855ed5de2aeb2 commit b19d7b655ca8b9cc7abdddb1c89855ed5de2aeb2 Author: Adhemerval Zanella <adhemerval.zanella@linaro.org> Date: Wed Mar 9 17:12:03 2022 -0300 linux: Avoid shifting a negative signed on POSIX timer interface The current macros uses pid as signed value, which triggers a compiler warning for process and thread timers. Replace MAKE_PROCESS_CPUCLOCK with static inline function that expects the pid as unsigned. These are similar to what Linux does internally. Checked on x86_64-linux-gnu. Diff: --- nptl/pthread_getcpuclockid.c | 2 +- sysdeps/unix/sysv/linux/clock_getcpuclockid.c | 2 +- sysdeps/unix/sysv/linux/clock_nanosleep.c | 2 +- sysdeps/unix/sysv/linux/kernel-posix-cpu-timers.h | 30 ++++++++++++++++++----- sysdeps/unix/sysv/linux/timer_create.c | 4 +-- 5 files changed, 29 insertions(+), 11 deletions(-) diff --git a/nptl/pthread_getcpuclockid.c b/nptl/pthread_getcpuclockid.c index 344bd6560e..b8bf09f550 100644 --- a/nptl/pthread_getcpuclockid.c +++ b/nptl/pthread_getcpuclockid.c @@ -35,7 +35,7 @@ __pthread_getcpuclockid (pthread_t threadid, clockid_t *clockid) /* The clockid_t value is a simple computation from the TID. */ - const clockid_t tidclock = MAKE_THREAD_CPUCLOCK (pd->tid, CPUCLOCK_SCHED); + const clockid_t tidclock = make_thread_cpuclock (pd->tid, CPUCLOCK_SCHED); *clockid = tidclock; return 0; diff --git a/sysdeps/unix/sysv/linux/clock_getcpuclockid.c b/sysdeps/unix/sysv/linux/clock_getcpuclockid.c index 5534127ed7..355d3c86af 100644 --- a/sysdeps/unix/sysv/linux/clock_getcpuclockid.c +++ b/sysdeps/unix/sysv/linux/clock_getcpuclockid.c @@ -29,7 +29,7 @@ __clock_getcpuclockid (pid_t pid, clockid_t *clock_id) /* The clockid_t value is a simple computation from the PID. But we do a clock_getres call to validate it. */ - const clockid_t pidclock = MAKE_PROCESS_CPUCLOCK (pid, CPUCLOCK_SCHED); + const clockid_t pidclock = make_process_cpuclock (pid, CPUCLOCK_SCHED); #ifndef __NR_clock_getres_time64 # define __NR_clock_getres_time64 __NR_clock_getres diff --git a/sysdeps/unix/sysv/linux/clock_nanosleep.c b/sysdeps/unix/sysv/linux/clock_nanosleep.c index befe6ecb8c..e610fd4e8d 100644 --- a/sysdeps/unix/sysv/linux/clock_nanosleep.c +++ b/sysdeps/unix/sysv/linux/clock_nanosleep.c @@ -34,7 +34,7 @@ __clock_nanosleep_time64 (clockid_t clock_id, int flags, if (clock_id == CLOCK_THREAD_CPUTIME_ID) return EINVAL; if (clock_id == CLOCK_PROCESS_CPUTIME_ID) - clock_id = MAKE_PROCESS_CPUCLOCK (0, CPUCLOCK_SCHED); + clock_id = PROCESS_CLOCK; /* If the call is interrupted by a signal handler or encounters an error, it returns a positive value similar to errno. */ diff --git a/sysdeps/unix/sysv/linux/kernel-posix-cpu-timers.h b/sysdeps/unix/sysv/linux/kernel-posix-cpu-timers.h index 164a90ddeb..9c74bb1cf5 100644 --- a/sysdeps/unix/sysv/linux/kernel-posix-cpu-timers.h +++ b/sysdeps/unix/sysv/linux/kernel-posix-cpu-timers.h @@ -1,4 +1,12 @@ -/* Parameters for the Linux kernel ABI for CPU clocks. */ +/* + Parameters for the Linux kernel ABI for CPU clocks, the bit fields within + a clockid: + + - The most significant 29 bits hold either a pid or a file descriptor. + - Bit 2 indicates whether a cpu clock refers to a thread or a process. + - Bits 1 and 0 give the type: PROF=0, VIRT=1, SCHED=2, or FD=3. + - A clockid is invalid if bits 2, 1, and 0 are all set. + */ #define CPUCLOCK_PID(clock) ((pid_t) ~((clock) >> 3)) #define CPUCLOCK_PERTHREAD(clock) \ @@ -6,13 +14,23 @@ #define CPUCLOCK_PID_MASK 7 #define CPUCLOCK_PERTHREAD_MASK 4 #define CPUCLOCK_WHICH(clock) ((clock) & (clockid_t) CPUCLOCK_CLOCK_MASK) -#define CPUCLOCK_CLOCK_MASK 3 +#define CPUCLOCK_CLOCK_MASK 3KE_PROCESS_CPUCLOCK #define CPUCLOCK_PROF 0 #define CPUCLOCK_VIRT 1 #define CPUCLOCK_SCHED 2 #define CPUCLOCK_MAX 3 -#define MAKE_PROCESS_CPUCLOCK(pid, clock) \ - ((~(clockid_t) (pid) << 3) | (clockid_t) (clock)) -#define MAKE_THREAD_CPUCLOCK(tid, clock) \ - MAKE_PROCESS_CPUCLOCK((tid), (clock) | CPUCLOCK_PERTHREAD_MASK) +static inline clockid_t +make_process_cpuclock (unsigned int pid, clockid_t clock) +{ + return ((~pid) << 3) | clock; +} + +static inline clockid_t +make_thread_cpuclock (unsigned int tid, clockid_t clock) +{ + return make_process_cpuclock (tid, clock | CPUCLOCK_PERTHREAD_MASK); +} + +#define PROCESS_CLOCK make_process_cpuclock (0, CPUCLOCK_SCHED) +#define THREAD_CLOCK make_thread_cpuclock (0, CPUCLOCK_SCHED) diff --git a/sysdeps/unix/sysv/linux/timer_create.c b/sysdeps/unix/sysv/linux/timer_create.c index a8b2a41d9e..290324a7ea 100644 --- a/sysdeps/unix/sysv/linux/timer_create.c +++ b/sysdeps/unix/sysv/linux/timer_create.c @@ -33,9 +33,9 @@ ___timer_create (clockid_t clock_id, struct sigevent *evp, timer_t *timerid) { { clockid_t syscall_clockid = (clock_id == CLOCK_PROCESS_CPUTIME_ID - ? MAKE_PROCESS_CPUCLOCK (0, CPUCLOCK_SCHED) + ? PROCESS_CLOCK : clock_id == CLOCK_THREAD_CPUTIME_ID - ? MAKE_THREAD_CPUCLOCK (0, CPUCLOCK_SCHED) + ? THREAD_CLOCK : clock_id); /* If the user wants notification via a thread we need to handle
next reply other threads:[~2022-03-11 17:22 UTC|newest] Thread overview: 15+ messages / expand[flat|nested] mbox.gz Atom feed top 2022-03-11 17:22 Adhemerval Zanella [this message] -- strict thread matches above, loose matches on Subject: below -- 2022-10-04 12:55 Adhemerval Zanella 2022-06-09 21:15 Adhemerval Zanella 2022-06-09 13:12 Adhemerval Zanella 2022-06-03 14:01 Adhemerval Zanella 2022-05-13 14:15 Adhemerval Zanella 2022-05-12 19:28 Adhemerval Zanella 2022-05-10 18:19 Adhemerval Zanella 2022-04-29 13:59 Adhemerval Zanella 2022-04-04 12:49 Adhemerval Zanella 2022-03-31 19:01 Adhemerval Zanella 2022-03-29 20:25 Adhemerval Zanella 2022-03-16 18:00 Adhemerval Zanella 2022-03-15 18:38 Adhemerval Zanella 2022-03-10 19:21 Adhemerval Zanella
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