diff options
| -rw-r--r-- | include/qemu/memfd.h | 1 | ||||
| -rw-r--r-- | util/memfd.c | 61 |
2 files changed, 37 insertions, 25 deletions
diff --git a/include/qemu/memfd.h b/include/qemu/memfd.h index 745a8c501e..41c24d807c 100644 --- a/include/qemu/memfd.h +++ b/include/qemu/memfd.h @@ -16,6 +16,7 @@ #define F_SEAL_WRITE 0x0008 /* prevent writes */ #endif +int qemu_memfd_create(const char *name, size_t size, unsigned int seals); void *qemu_memfd_alloc(const char *name, size_t size, unsigned int seals, int *fd); void qemu_memfd_free(void *ptr, size_t size, int fd); diff --git a/util/memfd.c b/util/memfd.c index 412e94a405..3a82505f8d 100644 --- a/util/memfd.c +++ b/util/memfd.c @@ -53,6 +53,38 @@ static int memfd_create(const char *name, unsigned int flags) #define MFD_ALLOW_SEALING 0x0002U #endif +int qemu_memfd_create(const char *name, size_t size, unsigned int seals) +{ + int mfd = -1; + +#ifdef CONFIG_LINUX + unsigned int flags = MFD_CLOEXEC; + + if (seals) { + flags |= MFD_ALLOW_SEALING; + } + + mfd = memfd_create(name, flags); + if (mfd < 0) { + return -1; + } + + if (ftruncate(mfd, size) == -1) { + perror("ftruncate"); + close(mfd); + return -1; + } + + if (seals && fcntl(mfd, F_ADD_SEALS, seals) == -1) { + perror("fcntl"); + close(mfd); + return -1; + } +#endif + + return mfd; +} + /* * This is a best-effort helper for shared memory allocation, with * optional sealing. The helper will do his best to allocate using @@ -63,35 +95,14 @@ void *qemu_memfd_alloc(const char *name, size_t size, unsigned int seals, int *fd) { void *ptr; - int mfd = -1; - - *fd = -1; - -#ifdef CONFIG_LINUX - if (seals) { - mfd = memfd_create(name, MFD_ALLOW_SEALING | MFD_CLOEXEC); - } + int mfd = qemu_memfd_create(name, size, seals); + /* some systems have memfd without sealing */ if (mfd == -1) { - /* some systems have memfd without sealing */ - mfd = memfd_create(name, MFD_CLOEXEC); - seals = 0; + mfd = qemu_memfd_create(name, size, 0); } -#endif - - if (mfd != -1) { - if (ftruncate(mfd, size) == -1) { - perror("ftruncate"); - close(mfd); - return NULL; - } - if (seals && fcntl(mfd, F_ADD_SEALS, seals) == -1) { - perror("fcntl"); - close(mfd); - return NULL; - } - } else { + if (mfd == -1) { const char *tmpdir = g_get_tmp_dir(); gchar *fname; |