| Message ID | 20190819180947.180725-1-scw@google.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | [v3] linux-user: add memfd_create | expand |
Le 19/08/2019 à 20:09, Shu-Chun Weng via Qemu-devel a écrit : > Add support for the memfd_create syscall. If the host does not have the > libc wrapper, translate to a direct syscall with NC-macro. > > Buglink: https://bugs.launchpad.net/qemu/+bug/1734792 > Signed-off-by: Shu-Chun Weng <scw@google.com> > --- Please, next time, to help review, add an history here, something like: v3: add fd_trans_unregister() v2: no change And don't send new versions as a reply to the previous ones. > include/qemu/memfd.h | 4 ++++ > linux-user/syscall.c | 12 ++++++++++++ > util/memfd.c | 2 +- > 3 files changed, 17 insertions(+), 1 deletion(-) > > diff --git a/include/qemu/memfd.h b/include/qemu/memfd.h > index d551c28b68..975b6bdb77 100644 > --- a/include/qemu/memfd.h > +++ b/include/qemu/memfd.h > @@ -32,6 +32,10 @@ > #define MFD_HUGE_SHIFT 26 > #endif > > +#if defined CONFIG_LINUX && !defined CONFIG_MEMFD > +int memfd_create(const char *name, unsigned int flags); > +#endif > + > int qemu_memfd_create(const char *name, size_t size, bool hugetlb, > uint64_t hugetlbsize, unsigned int seals, Error **errp); > bool qemu_memfd_alloc_check(void); > diff --git a/linux-user/syscall.c b/linux-user/syscall.c > index 8367cb138d..f3f9311e9c 100644 > --- a/linux-user/syscall.c > +++ b/linux-user/syscall.c > @@ -20,6 +20,7 @@ > #include "qemu/osdep.h" > #include "qemu/cutils.h" > #include "qemu/path.h" > +#include "qemu/memfd.h" > #include <elf.h> > #include <endian.h> > #include <grp.h> > @@ -11938,6 +11939,17 @@ static abi_long do_syscall1(void *cpu_env, int num, abi_long arg1, > /* PowerPC specific. */ > return do_swapcontext(cpu_env, arg1, arg2, arg3); > #endif > +#ifdef TARGET_NR_memfd_create > + case TARGET_NR_memfd_create: > + p = lock_user_string(arg1); > + if (!p) { > + return -TARGET_EFAULT; > + } > + ret = get_errno(memfd_create(p, arg2)); > + fd_trans_unregister(ret); > + unlock_user(p, arg1, 0); > + return ret; > +#endif > > default: > qemu_log_mask(LOG_UNIMP, "Unsupported syscall: %d\n", num); > diff --git a/util/memfd.c b/util/memfd.c > index 00334e5b21..4a3c07e0be 100644 > --- a/util/memfd.c > +++ b/util/memfd.c > @@ -35,7 +35,7 @@ > #include <sys/syscall.h> > #include <asm/unistd.h> > > -static int memfd_create(const char *name, unsigned int flags) > +int memfd_create(const char *name, unsigned int flags) > { > #ifdef __NR_memfd_create > return syscall(__NR_memfd_create, name, flags); > Reviewed-by: Laurent Vivier <laurent@vivier.eu>
On 19/08/2019 20:09, Shu-Chun Weng wrote: > Add support for the memfd_create syscall. If the host does not have the > libc wrapper, translate to a direct syscall with NC-macro. > > Buglink: https://bugs.launchpad.net/qemu/+bug/1734792 > Signed-off-by: Shu-Chun Weng <scw@google.com> > --- > include/qemu/memfd.h | 4 ++++ > linux-user/syscall.c | 12 ++++++++++++ > util/memfd.c | 2 +- > 3 files changed, 17 insertions(+), 1 deletion(-) A nice follow up to this patch would be to implement the file-sealing APIs provided by fnctl (see memfd_create(2) and fcntl(2), File sealing). Thanks, Laurent
diff --git a/include/qemu/memfd.h b/include/qemu/memfd.h index d551c28b68..975b6bdb77 100644 --- a/include/qemu/memfd.h +++ b/include/qemu/memfd.h @@ -32,6 +32,10 @@ #define MFD_HUGE_SHIFT 26 #endif +#if defined CONFIG_LINUX && !defined CONFIG_MEMFD +int memfd_create(const char *name, unsigned int flags); +#endif + int qemu_memfd_create(const char *name, size_t size, bool hugetlb, uint64_t hugetlbsize, unsigned int seals, Error **errp); bool qemu_memfd_alloc_check(void); diff --git a/linux-user/syscall.c b/linux-user/syscall.c index 8367cb138d..f3f9311e9c 100644 --- a/linux-user/syscall.c +++ b/linux-user/syscall.c @@ -20,6 +20,7 @@ #include "qemu/osdep.h" #include "qemu/cutils.h" #include "qemu/path.h" +#include "qemu/memfd.h" #include <elf.h> #include <endian.h> #include <grp.h> @@ -11938,6 +11939,17 @@ static abi_long do_syscall1(void *cpu_env, int num, abi_long arg1, /* PowerPC specific. */ return do_swapcontext(cpu_env, arg1, arg2, arg3); #endif +#ifdef TARGET_NR_memfd_create + case TARGET_NR_memfd_create: + p = lock_user_string(arg1); + if (!p) { + return -TARGET_EFAULT; + } + ret = get_errno(memfd_create(p, arg2)); + fd_trans_unregister(ret); + unlock_user(p, arg1, 0); + return ret; +#endif default: qemu_log_mask(LOG_UNIMP, "Unsupported syscall: %d\n", num); diff --git a/util/memfd.c b/util/memfd.c index 00334e5b21..4a3c07e0be 100644 --- a/util/memfd.c +++ b/util/memfd.c @@ -35,7 +35,7 @@ #include <sys/syscall.h> #include <asm/unistd.h> -static int memfd_create(const char *name, unsigned int flags) +int memfd_create(const char *name, unsigned int flags) { #ifdef __NR_memfd_create return syscall(__NR_memfd_create, name, flags);
Add support for the memfd_create syscall. If the host does not have the libc wrapper, translate to a direct syscall with NC-macro. Buglink: https://bugs.launchpad.net/qemu/+bug/1734792 Signed-off-by: Shu-Chun Weng <scw@google.com> --- include/qemu/memfd.h | 4 ++++ linux-user/syscall.c | 12 ++++++++++++ util/memfd.c | 2 +- 3 files changed, 17 insertions(+), 1 deletion(-)