| Message ID | 20200409201154.3365671-1-alistair.francis@wdc.com |
|---|---|
| State | New |
| Headers | show |
| Series | [v3,1/2] linux: wait4: Fix incorrect return value comparison | expand |
On 09/04/2020 17:11, Alistair Francis via Libc-alpha wrote: > Patch 600f00b "linux: Use long time_t for wait4/getrusage" introduced > two bugs: > - The usage32 struct was set if the wait4 syscall had an error. > - For 32-bit systems the usage struct was set even if it was specified > as NULL. > > This patch fixes the two issues. Ok with the changes below. > --- > sysdeps/unix/sysv/linux/wait4.c | 32 ++++++++++++++++++++------------ > 1 file changed, 20 insertions(+), 12 deletions(-) > > diff --git a/sysdeps/unix/sysv/linux/wait4.c b/sysdeps/unix/sysv/linux/wait4.c > index d14bd4da27..21eb154b72 100644 > --- a/sysdeps/unix/sysv/linux/wait4.c > +++ b/sysdeps/unix/sysv/linux/wait4.c > @@ -29,14 +29,18 @@ __wait4_time64 (pid_t pid, int *stat_loc, int options, struct __rusage64 *usage) > # if __KERNEL_OLD_TIMEVAL_MATCHES_TIMEVAL64 > return SYSCALL_CANCEL (wait4, pid, stat_loc, options, usage); > # else > - struct __rusage32 usage32; > - pid_t ret = SYSCALL_CANCEL (wait4, pid, stat_loc, options, &usage32); > - > - if (ret != 0) > - return ret; > + pid_t ret; > > if (usage != NULL) > - rusage32_to_rusage64 (&usage32, usage); > + { > + struct __rusage32 usage32; > + ret = SYSCALL_CANCEL (wait4, pid, stat_loc, options, &usage32); Indentation seems off. > + > + if (ret > 0) > + rusage32_to_rusage64 (&usage32, usage);> + } > + else > + ret = SYSCALL_CANCEL (wait4, pid, stat_loc, options, NULL); I think there is no much gain in optimizing stack usage here, I would prefer to simplify to just: struct __rusage32 usage32; ret = SYSCALL_CANCEL (wait4, pid, stat_loc, options, usage != NULL ? &usage32 : NULL); if (ret > 0 && usage != NULL) rusage32_to_rusage64 (&usage32, usage); > > return ret; > # endif > @@ -114,15 +118,19 @@ libc_hidden_def (__wait4_time64) > pid_t > __wait4 (pid_t pid, int *stat_loc, int options, struct rusage *usage) > { > - pid_t ret ; > - struct __rusage64 usage64; > + pid_t ret; > > - ret = __wait4_time64 (pid, stat_loc, options, &usage64); > + if (usage != NULL) > + { > + struct __rusage64 usage64; > > - if (ret != 0) > - return ret; > + ret = __wait4_time64 (pid, stat_loc, options, &usage64); > > - rusage64_to_rusage (&usage64, usage); > + if (ret > 0) > + rusage64_to_rusage (&usage64, usage); > + } > + else > + ret = __wait4_time64 (pid, stat_loc, options, NULL); > > return ret; > } > Same as before: struct __rusage64 usage64; ret = __wait4_time64 (pid, stat_loc, options, usage != NULL ? &usage64 : NULL); if (ret > 0 && usage != 0) rusage64_to_rusage (&usage64, usage);
diff --git a/sysdeps/unix/sysv/linux/wait4.c b/sysdeps/unix/sysv/linux/wait4.c index d14bd4da27..21eb154b72 100644 --- a/sysdeps/unix/sysv/linux/wait4.c +++ b/sysdeps/unix/sysv/linux/wait4.c @@ -29,14 +29,18 @@ __wait4_time64 (pid_t pid, int *stat_loc, int options, struct __rusage64 *usage) # if __KERNEL_OLD_TIMEVAL_MATCHES_TIMEVAL64 return SYSCALL_CANCEL (wait4, pid, stat_loc, options, usage); # else - struct __rusage32 usage32; - pid_t ret = SYSCALL_CANCEL (wait4, pid, stat_loc, options, &usage32); - - if (ret != 0) - return ret; + pid_t ret; if (usage != NULL) - rusage32_to_rusage64 (&usage32, usage); + { + struct __rusage32 usage32; + ret = SYSCALL_CANCEL (wait4, pid, stat_loc, options, &usage32); + + if (ret > 0) + rusage32_to_rusage64 (&usage32, usage); + } + else + ret = SYSCALL_CANCEL (wait4, pid, stat_loc, options, NULL); return ret; # endif @@ -114,15 +118,19 @@ libc_hidden_def (__wait4_time64) pid_t __wait4 (pid_t pid, int *stat_loc, int options, struct rusage *usage) { - pid_t ret ; - struct __rusage64 usage64; + pid_t ret; - ret = __wait4_time64 (pid, stat_loc, options, &usage64); + if (usage != NULL) + { + struct __rusage64 usage64; - if (ret != 0) - return ret; + ret = __wait4_time64 (pid, stat_loc, options, &usage64); - rusage64_to_rusage (&usage64, usage); + if (ret > 0) + rusage64_to_rusage (&usage64, usage); + } + else + ret = __wait4_time64 (pid, stat_loc, options, NULL); return ret; }