From 6f81bd1a3ec3b8c06ec614f09eac688c6053f412 Mon Sep 17 00:00:00 2001 From: "Dr. David Alan Gilbert" Date: Thu, 19 Sep 2024 14:46:24 +0100 Subject: [PATCH] util/userfaultfd: Return -errno on error Convert (the currently unused) uffd_wakeup, uffd_copy_page and uffd_zero_page to return -errno on error rather than -1. That will make it easier to reuse in postcopy. Signed-off-by: Dr. David Alan Gilbert Reviewed-by: Peter Xu Link: https://lore.kernel.org/r/20240919134626.166183-6-dave@treblig.org Signed-off-by: Peter Xu --- util/userfaultfd.c | 21 ++++++++++++--------- 1 file changed, 12 insertions(+), 9 deletions(-) diff --git a/util/userfaultfd.c b/util/userfaultfd.c index 1b2fa949d4..518d5c3586 100644 --- a/util/userfaultfd.c +++ b/util/userfaultfd.c @@ -240,7 +240,7 @@ int uffd_change_protection(int uffd_fd, void *addr, uint64_t length, * Copy range of source pages to the destination to resolve * missing page fault somewhere in the destination range. * - * Returns 0 on success, negative value in case of an error + * Returns 0 on success, -errno in case of an error * * @uffd_fd: UFFD file descriptor * @dst_addr: destination base address @@ -259,10 +259,11 @@ int uffd_copy_page(int uffd_fd, void *dst_addr, void *src_addr, uffd_copy.mode = dont_wake ? UFFDIO_COPY_MODE_DONTWAKE : 0; if (ioctl(uffd_fd, UFFDIO_COPY, &uffd_copy)) { + int e = errno; error_report("uffd_copy_page() failed: dst_addr=%p src_addr=%p length=%" PRIu64 " mode=%" PRIx64 " errno=%i", dst_addr, src_addr, - length, (uint64_t) uffd_copy.mode, errno); - return -1; + length, (uint64_t) uffd_copy.mode, e); + return -e; } return 0; @@ -273,7 +274,7 @@ int uffd_copy_page(int uffd_fd, void *dst_addr, void *src_addr, * * Fill range pages with zeroes to resolve missing page fault within the range. * - * Returns 0 on success, negative value in case of an error + * Returns 0 on success, -errno in case of an error * * @uffd_fd: UFFD file descriptor * @addr: base address @@ -289,10 +290,11 @@ int uffd_zero_page(int uffd_fd, void *addr, uint64_t length, bool dont_wake) uffd_zeropage.mode = dont_wake ? UFFDIO_ZEROPAGE_MODE_DONTWAKE : 0; if (ioctl(uffd_fd, UFFDIO_ZEROPAGE, &uffd_zeropage)) { + int e = errno; error_report("uffd_zero_page() failed: addr=%p length=%" PRIu64 " mode=%" PRIx64 " errno=%i", addr, length, - (uint64_t) uffd_zeropage.mode, errno); - return -1; + (uint64_t) uffd_zeropage.mode, e); + return -e; } return 0; @@ -306,7 +308,7 @@ int uffd_zero_page(int uffd_fd, void *addr, uint64_t length, bool dont_wake) * via UFFD-IO IOCTLs with MODE_DONTWAKE flag set, then after that all waits * for the whole memory range are satisfied in a single call to uffd_wakeup(). * - * Returns 0 on success, negative value in case of an error + * Returns 0 on success, -errno in case of an error * * @uffd_fd: UFFD file descriptor * @addr: base address @@ -320,9 +322,10 @@ int uffd_wakeup(int uffd_fd, void *addr, uint64_t length) uffd_range.len = length; if (ioctl(uffd_fd, UFFDIO_WAKE, &uffd_range)) { + int e = errno; error_report("uffd_wakeup() failed: addr=%p length=%" PRIu64 " errno=%i", - addr, length, errno); - return -1; + addr, length, e); + return -e; } return 0;