On [Sat, 23.02.2008 09:25], Kirill A. Shutemov wrote: > On [Sat, 23.02.2008 12:00], Takashi Yoshii wrote: > > getgroups() and getgroups32() returns NGROUPS_MAX when both its two args are > > zero. But because we pass a ptr to allocated space as 2nd arg, this function > > are interfered. The patch attached fixed it. > > /yoshii > > --- > > linux-user/syscall.c: fix getgroups{,32} when both args are zero. > > > > My version of patch to fix same problem: > > getgroups: return total number of supplementary group IDs for the > process if size == 0 > > diff --git a/linux-user/syscall.c b/linux-user/syscall.c > index ad97871..96a11a9 100644 > --- a/linux-user/syscall.c > +++ b/linux-user/syscall.c > @@ -5029,6 +5029,8 @@ abi_long do_syscall(void *cpu_env, int num, abi_long > arg1, > > grouplist = alloca(gidsetsize * sizeof(gid_t)); > ret = get_errno(getgroups(gidsetsize, grouplist)); > + if (gidsetsize == 0) > + break; > if (!is_error(ret)) { > target_grouplist = lock_user(VERIFY_WRITE, arg2, gidsetsize > * 2, 0); > if (!target_grouplist) > @@ -5179,6 +5181,8 @@ abi_long do_syscall(void *cpu_env, int num, abi_long > arg1, > > grouplist = alloca(gidsetsize * sizeof(gid_t)); > ret = get_errno(getgroups(gidsetsize, grouplist)); > + if (gidsetsize == 0) > + break; > if (!is_error(ret)) { > target_grouplist = lock_user(VERIFY_WRITE, arg2, gidsetsize > * 4, 0); > if (!target_grouplist) { > > Another patch for getgroups: > > Trivial optimization of getgroups syscall implementation: > swap only returned groups, not all group in list. > > diff --git a/linux-user/syscall.c b/linux-user/syscall.c > index 6f2872f..ad97871 100644 > --- a/linux-user/syscall.c > +++ b/linux-user/syscall.c > @@ -5033,7 +5033,7 @@ abi_long do_syscall(void *cpu_env, int num, abi_long > arg1, > target_grouplist = lock_user(VERIFY_WRITE, arg2, gidsetsize > * 2, 0); > if (!target_grouplist) > goto efault; > - for(i = 0;i < gidsetsize; i++) > + for(i = 0;i < ret; i++) > target_grouplist[i] = tswap16(grouplist[i]); > unlock_user(target_grouplist, arg2, gidsetsize * 2); > } > @@ -5185,7 +5185,7 @@ abi_long do_syscall(void *cpu_env, int num, abi_long > arg1, > ret = -TARGET_EFAULT; > goto fail; > } > - for(i = 0;i < gidsetsize; i++) > + for(i = 0;i < ret; i++) > target_grouplist[i] = tswap32(grouplist[i]); > unlock_user(target_grouplist, arg2, gidsetsize * 4); > } > > It makes getgroups much faster in some cases.
Can anybody commit it? -- Regards, Kirill A. Shutemov + Belarus, Minsk + Velesys Ltd, http://www.velesys.com/ + ALT Linux Team, http://www.altlinux.com/
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