| Message ID | 20230210231829.39476-9-imp@bsdimp.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | 2023 Q1 bsd-user upstreaming: bugfixes and sysctl | expand |
On 2/10/23 13:18, Warner Losh wrote: > From: Kyle Evans <kevans@FreeBSD.org> > > do_freebsd_sysctlbyname needs to translate the 'name' back down to a OID > so we can intercept the special ones. Do that and call the common wrapper > do_freebsd_sysctl_oid. > > Signed-off-by: Kyle Evans <kevans@FreeBSD.org> > Signed-off-by: Warner Losh <imp@bsdimp.com> > --- > bsd-user/freebsd/os-sys.c | 58 +++++++++++++++++++++++++++++++++++ > bsd-user/freebsd/os-syscall.c | 4 +++ > 2 files changed, 62 insertions(+) > > diff --git a/bsd-user/freebsd/os-sys.c b/bsd-user/freebsd/os-sys.c > index 13736936e5f..62c729dfe47 100644 > --- a/bsd-user/freebsd/os-sys.c > +++ b/bsd-user/freebsd/os-sys.c > @@ -345,6 +345,64 @@ out: > return ret; > } > > +/* > + * This syscall was created to make sysctlbyname(3) more efficient. > + * Unfortunately, because we have to fake some sysctls, we can't do that. Can't do what? Directly use sysctlbyname? > + if (oldlenp) { > + if (get_user_ual(oldlen, oldlenp)) { > + return -TARGET_EFAULT; > + } Same comment about verifying write early. > + unlock_user(holdp, oldp, holdlen); And writeback vs error. r~
On Sat, Feb 11, 2023 at 5:13 PM Richard Henderson <richard.henderson@linaro.org> wrote: > > On 2/10/23 13:18, Warner Losh wrote: > > From: Kyle Evans <kevans@FreeBSD.org> > > > > do_freebsd_sysctlbyname needs to translate the 'name' back down to a OID > > so we can intercept the special ones. Do that and call the common wrapper > > do_freebsd_sysctl_oid. > > > > Signed-off-by: Kyle Evans <kevans@FreeBSD.org> > > Signed-off-by: Warner Losh <imp@bsdimp.com> > > --- > > bsd-user/freebsd/os-sys.c | 58 +++++++++++++++++++++++++++++++++++ > > bsd-user/freebsd/os-syscall.c | 4 +++ > > 2 files changed, 62 insertions(+) > > > > diff --git a/bsd-user/freebsd/os-sys.c b/bsd-user/freebsd/os-sys.c > > index 13736936e5f..62c729dfe47 100644 > > --- a/bsd-user/freebsd/os-sys.c > > +++ b/bsd-user/freebsd/os-sys.c > > @@ -345,6 +345,64 @@ out: > > return ret; > > } > > > > +/* > > + * This syscall was created to make sysctlbyname(3) more efficient. > > + * Unfortunately, because we have to fake some sysctls, we can't do that. > > Can't do what? Directly use sysctlbyname? > How about: /* * This syscall was created to make sysctlbyname(3) more efficient, but * we can't really provide it in bsd-user. Notably, we must always translate * the names independently since some sysctl values have to be faked * for the target environment, so it still has to break down to two syscalls * for the underlying implementation. */ > > + if (oldlenp) { > > + if (get_user_ual(oldlen, oldlenp)) { > > + return -TARGET_EFAULT; > > + } > > Same comment about verifying write early. > > > + unlock_user(holdp, oldp, holdlen); > > And writeback vs error. > > > r~
On 2/11/23 18:23, Kyle Evans wrote: >>> +/* >>> + * This syscall was created to make sysctlbyname(3) more efficient. >>> + * Unfortunately, because we have to fake some sysctls, we can't do that. >> >> Can't do what? Directly use sysctlbyname? >> > > How about: > > /* > * This syscall was created to make sysctlbyname(3) more efficient, but > * we can't really provide it in bsd-user. Notably, we must always translate > * the names independently since some sysctl values have to be faked > * for the target environment, so it still has to break down to two syscalls > * for the underlying implementation. > */ Better, thanks. r~
diff --git a/bsd-user/freebsd/os-sys.c b/bsd-user/freebsd/os-sys.c index 13736936e5f..62c729dfe47 100644 --- a/bsd-user/freebsd/os-sys.c +++ b/bsd-user/freebsd/os-sys.c @@ -345,6 +345,64 @@ out: return ret; } +/* + * This syscall was created to make sysctlbyname(3) more efficient. + * Unfortunately, because we have to fake some sysctls, we can't do that. + */ +abi_long do_freebsd_sysctlbyname(CPUArchState *env, abi_ulong namep, + int32_t namelen, abi_ulong oldp, abi_ulong oldlenp, abi_ulong newp, + abi_ulong newlen) +{ + abi_long ret; + void *holdp = NULL, *hnewp = NULL; + char *snamep; + int oid[CTL_MAXNAME + 2]; + size_t holdlen, oidplen; + abi_ulong oldlen = 0; + + if (oldlenp) { + if (get_user_ual(oldlen, oldlenp)) { + return -TARGET_EFAULT; + } + } + snamep = lock_user_string(namep); + if (snamep == NULL) { + return -TARGET_EFAULT; + } + if (newp) { + hnewp = lock_user(VERIFY_READ, newp, newlen, 1); + if (hnewp == NULL) { + return -TARGET_EFAULT; + } + } + if (oldp) { + holdp = lock_user(VERIFY_WRITE, oldp, oldlen, 0); + if (holdp == NULL) { + return -TARGET_EFAULT; + } + } + holdlen = oldlen; + + oidplen = sizeof(oid) / sizeof(int); + if (sysctlnametomib(snamep, oid, &oidplen) != 0) { + return -TARGET_EINVAL; + } + + ret = do_freebsd_sysctl_oid(env, oid, oidplen, holdp, &holdlen, hnewp, + newlen); + + if (oldlenp) { + put_user_ual(holdlen, oldlenp); + } + unlock_user(snamep, namep, 0); + unlock_user(holdp, oldp, holdlen); + if (hnewp) { + unlock_user(hnewp, newp, 0); + } + + return ret; +} + abi_long do_freebsd_sysctl(CPUArchState *env, abi_ulong namep, int32_t namelen, abi_ulong oldp, abi_ulong oldlenp, abi_ulong newp, abi_ulong newlen) { diff --git a/bsd-user/freebsd/os-syscall.c b/bsd-user/freebsd/os-syscall.c index 20ab3d4d9a1..179a20c304b 100644 --- a/bsd-user/freebsd/os-syscall.c +++ b/bsd-user/freebsd/os-syscall.c @@ -498,6 +498,10 @@ static abi_long freebsd_syscall(void *cpu_env, int num, abi_long arg1, ret = do_freebsd_sysctl(cpu_env, arg1, arg2, arg3, arg4, arg5, arg6); break; + case TARGET_FREEBSD_NR___sysctlbyname: /* sysctlbyname(2) */ + ret = do_freebsd_sysctlbyname(cpu_env, arg1, arg2, arg3, arg4, arg5, arg6); + break; + case TARGET_FREEBSD_NR_sysarch: /* sysarch(2) */ ret = do_freebsd_sysarch(cpu_env, arg1, arg2); break;