68 lines
2.3 KiB
Diff
68 lines
2.3 KiB
Diff
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From f0d3a6149158f682230ae9a1e69289431974f635 Mon Sep 17 00:00:00 2001
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From: Sebastian Wick <sebastian@sebastianwick.net>
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Date: Wed, 5 Feb 2020 10:27:23 +0100
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Subject: [PATCH] shared: guard all the seal logic behind HAVE_MEMFD_CREATE
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The initial version of os_ro_anonymous_file missed two guards around the
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seal logic which leads to a compilation error on older systems.
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Also make the check for a read-only file symmetric in
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os_ro_anonymous_file_get_fd and os_ro_anonymous_file_put_fd.
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Signed-off-by: Sebastian Wick <sebastian@sebastianwick.net>
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[james.hilliard1@gmail.com: backport from upstream commit
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f0d3a6149158f682230ae9a1e69289431974f635]
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Signed-off-by: James Hilliard <james.hilliard1@gmail.com>
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---
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shared/os-compatibility.c | 15 +++++++++------
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1 file changed, 9 insertions(+), 6 deletions(-)
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diff --git a/shared/os-compatibility.c b/shared/os-compatibility.c
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index 041c929f..2e12b7cc 100644
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--- a/shared/os-compatibility.c
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+++ b/shared/os-compatibility.c
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@@ -340,6 +340,7 @@ os_ro_anonymous_file_get_fd(struct ro_anonymous_file *file,
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void *src, *dst;
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int seals, fd;
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+#ifdef HAVE_MEMFD_CREATE
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seals = fcntl(file->fd, F_GET_SEALS);
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/* file was sealed for read-only and we don't have to support MAP_SHARED
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@@ -348,6 +349,7 @@ os_ro_anonymous_file_get_fd(struct ro_anonymous_file *file,
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if (seals != -1 && mapmode == RO_ANONYMOUS_FILE_MAPMODE_PRIVATE &&
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(seals & READONLY_SEALS) == READONLY_SEALS)
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return file->fd;
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+#endif
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/* for all other cases we create a new anonymous file that can be mapped
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* with MAP_SHARED and copy the contents to it and return that instead
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@@ -388,17 +390,18 @@ os_ro_anonymous_file_get_fd(struct ro_anonymous_file *file,
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int
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os_ro_anonymous_file_put_fd(int fd)
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{
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+#ifdef HAVE_MEMFD_CREATE
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int seals = fcntl(fd, F_GET_SEALS);
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if (seals == -1 && errno != EINVAL)
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return -1;
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- /* If the fd cannot be sealed seals is -1 at this point
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- * or the file can be sealed but has not been sealed for writing.
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- * In both cases we created a new anonymous file that we have to
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- * close.
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+ /* The only case in which we do NOT have to close the file is when the file
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+ * was sealed for read-only
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*/
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- if (seals == -1 || !(seals & F_SEAL_WRITE))
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- close(fd);
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+ if (seals != -1 && (seals & READONLY_SEALS) == READONLY_SEALS)
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+ return 0;
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+#endif
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+ close(fd);
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return 0;
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}
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--
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2.20.1
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