- Linux-kselftest-mirror - lists.linaro.org

[PATCH 0/6] selftests: powerpc build fixes

by Joel Stanley

This series fixes issues I encountered building and running the selftests on a Ubuntu Cosmic ppc64le system. Joel Stanley (6): selftests: powerpc/ptrace: Make tests build selftests: powerpc/ptrace: Remove clean rule selftests: powerpc/ptrace: Fix linking against pthread selftests: powerpc/signal: Make tests build selftests: powerpc/signal: Fix signal_tm CFLAGS selftests: powerpc/pmu: Link ebb tests with -no-pie tools/testing/selftests/powerpc/pmu/ebb/Makefile | 3 +++ tools/testing/selftests/powerpc/ptrace/Makefile | 11 ++++------- tools/testing/selftests/powerpc/signal/Makefile | 9 +++------ 3 files changed, 10 insertions(+), 13 deletions(-) -- 2.19.1

7 years, 2 months

1
6
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[PATCH v3 1/2] mm: Add an F_SEAL_FUTURE_WRITE seal to memfd

by Joel Fernandes (Google)

Android uses ashmem for sharing memory regions. We are looking forward to migrating all usecases of ashmem to memfd so that we can possibly remove the ashmem driver in the future from staging while also benefiting from using memfd and contributing to it. Note staging drivers are also not ABI and generally can be removed at anytime. One of the main usecases Android has is the ability to create a region and mmap it as writeable, then add protection against making any "future" writes while keeping the existing already mmap'ed writeable-region active. This allows us to implement a usecase where receivers of the shared memory buffer can get a read-only view, while the sender continues to write to the buffer. See CursorWindow documentation in Android for more details: https://developer.android.com/reference/android/database/CursorWindow This usecase cannot be implemented with the existing F_SEAL_WRITE seal. To support the usecase, this patch adds a new F_SEAL_FUTURE_WRITE seal which prevents any future mmap and write syscalls from succeeding while keeping the existing mmap active. The following program shows the seal working in action: #include <stdio.h> #include <errno.h> #include <sys/mman.h> #include <linux/memfd.h> #include <linux/fcntl.h> #include <asm/unistd.h> #include <unistd.h> #define F_SEAL_FUTURE_WRITE 0x0010 #define REGION_SIZE (5 * 1024 * 1024) int memfd_create_region(const char *name, size_t size) { int ret; int fd = syscall(__NR_memfd_create, name, MFD_ALLOW_SEALING); if (fd < 0) return fd; ret = ftruncate(fd, size); if (ret < 0) { close(fd); return ret; } return fd; } int main() { int ret, fd; void *addr, *addr2, *addr3, *addr1; ret = memfd_create_region("test_region", REGION_SIZE); printf("ret=%d\n", ret); fd = ret; // Create map addr = mmap(0, REGION_SIZE, PROT_READ|PROT_WRITE, MAP_SHARED, fd, 0); if (addr == MAP_FAILED) printf("map 0 failed\n"); else printf("map 0 passed\n"); if ((ret = write(fd, "test", 4)) != 4) printf("write failed even though no future-write seal " "(ret=%d errno =%d)\n", ret, errno); else printf("write passed\n"); addr1 = mmap(0, REGION_SIZE, PROT_READ|PROT_WRITE, MAP_SHARED, fd, 0); if (addr1 == MAP_FAILED) perror("map 1 prot-write failed even though no seal\n"); else printf("map 1 prot-write passed as expected\n"); ret = fcntl(fd, F_ADD_SEALS, F_SEAL_FUTURE_WRITE | F_SEAL_GROW | F_SEAL_SHRINK); if (ret == -1) printf("fcntl failed, errno: %d\n", errno); else printf("future-write seal now active\n"); if ((ret = write(fd, "test", 4)) != 4) printf("write failed as expected due to future-write seal\n"); else printf("write passed (unexpected)\n"); addr2 = mmap(0, REGION_SIZE, PROT_READ|PROT_WRITE, MAP_SHARED, fd, 0); if (addr2 == MAP_FAILED) perror("map 2 prot-write failed as expected due to seal\n"); else printf("map 2 passed\n"); addr3 = mmap(0, REGION_SIZE, PROT_READ, MAP_SHARED, fd, 0); if (addr3 == MAP_FAILED) perror("map 3 failed\n"); else printf("map 3 prot-read passed as expected\n"); } The output of running this program is as follows: ret=3 map 0 passed write passed map 1 prot-write passed as expected future-write seal now active write failed as expected due to future-write seal map 2 prot-write failed as expected due to seal : Permission denied map 3 prot-read passed as expected Cc: jreck(a)google.com Cc: john.stultz(a)linaro.org Cc: tkjos(a)google.com Cc: gregkh(a)linuxfoundation.org Cc: hch(a)infradead.org Reviewed-by: John Stultz <john.stultz(a)linaro.org> Signed-off-by: Joel Fernandes (Google) <joel(a)joelfernandes.org> --- v1->v2: No change, just added selftests to the series. manpages are ready and I'll submit them once the patches are accepted. v2->v3: Updated commit message to have more support code (John Stultz) Renamed seal from F_SEAL_FS_WRITE to F_SEAL_FUTURE_WRITE (Christoph Hellwig) Allow for this seal only if grow/shrink seals are also either previous set, or are requested along with this seal. (Christoph Hellwig) Added locking to synchronize access to file->f_mode. (Christoph Hellwig) include/uapi/linux/fcntl.h | 1 + mm/memfd.c | 22 +++++++++++++++++++++- 2 files changed, 22 insertions(+), 1 deletion(-) diff --git a/include/uapi/linux/fcntl.h b/include/uapi/linux/fcntl.h index 6448cdd9a350..a2f8658f1c55 100644 --- a/include/uapi/linux/fcntl.h +++ b/include/uapi/linux/fcntl.h @@ -41,6 +41,7 @@ #define F_SEAL_SHRINK 0x0002 /* prevent file from shrinking */ #define F_SEAL_GROW 0x0004 /* prevent file from growing */ #define F_SEAL_WRITE 0x0008 /* prevent writes */ +#define F_SEAL_FUTURE_WRITE 0x0010 /* prevent future writes while mapped */ /* (1U << 31) is reserved for signed error codes */ /* diff --git a/mm/memfd.c b/mm/memfd.c index 2bb5e257080e..5ba9804e9515 100644 --- a/mm/memfd.c +++ b/mm/memfd.c @@ -150,7 +150,8 @@ static unsigned int *memfd_file_seals_ptr(struct file *file) #define F_ALL_SEALS (F_SEAL_SEAL | \ F_SEAL_SHRINK | \ F_SEAL_GROW | \ - F_SEAL_WRITE) + F_SEAL_WRITE | \ + F_SEAL_FUTURE_WRITE) static int memfd_add_seals(struct file *file, unsigned int seals) { @@ -219,6 +220,25 @@ static int memfd_add_seals(struct file *file, unsigned int seals) } } + if ((seals & F_SEAL_FUTURE_WRITE) && + !(*file_seals & F_SEAL_FUTURE_WRITE)) { + /* + * The FUTURE_WRITE seal also prevents growing and shrinking + * so we need them to be already set, or requested now. + */ + int test_seals = (seals | *file_seals) & + (F_SEAL_GROW | F_SEAL_SHRINK); + + if (test_seals != (F_SEAL_GROW | F_SEAL_SHRINK)) { + error = -EINVAL; + goto unlock; + } + + spin_lock(&file->f_lock); + file->f_mode &= ~(FMODE_WRITE | FMODE_PWRITE); + spin_unlock(&file->f_lock); + } + *file_seals |= seals; error = 0; -- 2.19.1.331.ge82ca0e54c-goog

7 years, 2 months

3
7
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[PATCH] selftests/bpf: add missing executables to .gitignore

by Anders Roxell

Fixes: 371e4fcc9d96 ("selftests/bpf: cgroup local storage-based network counters") Fixes: 370920c47b26 ("selftests/bpf: Test libbpf_{prog,attach}_type_by_name") Signed-off-by: Anders Roxell <anders.roxell(a)linaro.org> --- tools/testing/selftests/bpf/.gitignore | 2 ++ 1 file changed, 2 insertions(+) diff --git a/tools/testing/selftests/bpf/.gitignore b/tools/testing/selftests/bpf/.gitignore index 8a60c9b9892d..1b799e30c06d 100644 --- a/tools/testing/selftests/bpf/.gitignore +++ b/tools/testing/selftests/bpf/.gitignore @@ -25,3 +25,5 @@ test_cgroup_storage test_select_reuseport test_flow_dissector flow_dissector_load +test_netcnt +test_section_names -- 2.19.1

7 years, 2 months

3
2
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[PATCH] selftests/kvm: add missing executables to .gitignore

by Anders Roxell

Fixes: 18178ff86217 ("KVM: selftests: add Enlightened VMCS test") Signed-off-by: Anders Roxell <anders.roxell(a)linaro.org> --- tools/testing/selftests/kvm/.gitignore | 1 + 1 file changed, 1 insertion(+) diff --git a/tools/testing/selftests/kvm/.gitignore b/tools/testing/selftests/kvm/.gitignore index 552b0d9a49f4..6210ba41c29e 100644 --- a/tools/testing/selftests/kvm/.gitignore +++ b/tools/testing/selftests/kvm/.gitignore @@ -1,4 +1,5 @@ /x86_64/cr4_cpuid_sync_test +/x86_64/evmcs_test /x86_64/platform_info_test /x86_64/set_sregs_test /x86_64/sync_regs_test -- 2.19.1

7 years, 2 months

2
1
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[PATCH v7 0/8] arm64: untag user pointers passed to the kernel

by Andrey Konovalov

arm64 has a feature called Top Byte Ignore, which allows to embed pointer tags into the top byte of each pointer. Userspace programs (such as HWASan, a memory debugging tool [1]) might use this feature and pass tagged user pointers to the kernel through syscalls or other interfaces. Right now the kernel is already able to handle user faults with tagged pointers, due to these patches: 1. 81cddd65 ("arm64: traps: fix userspace cache maintenance emulation on a tagged pointer") 2. 7dcd9dd8 ("arm64: hw_breakpoint: fix watchpoint matching for tagged pointers") 3. 276e9327 ("arm64: entry: improve data abort handling of tagged pointers") When passing tagged pointers to syscalls, there's a special case of such a pointer being passed to one of the memory syscalls (mmap, mprotect, etc.). These syscalls don't do memory accesses but rather deal with memory ranges, hence an untagged pointer is better suited. This patchset extends tagged pointer support to non-memory syscalls. This is done by reusing the untagged_addr macro to untag user pointers when the kernel performs pointer checking to find out whether the pointer comes from userspace (most notably in access_ok). The following testing approaches has been taken to find potential issues with user pointer untagging: 1. Static testing (with sparse [2] and separately with a custom static analyzer based on Clang) to track casts of __user pointers to integer types to find places where untagging needs to be done. 2. Dynamic testing: adding BUG_ON(has_tag(addr)) to find_vma() and running a modified syzkaller version that passes tagged pointers to the kernel. Based on the results of the testing the requried patches have been added to the patchset. This patchset is a prerequisite for ARM's memory tagging hardware feature support [3]. Thanks! [1] http://clang.llvm.org/docs/HardwareAssistedAddressSanitizerDesign.html [2] https://github.com/lucvoo/sparse-dev/commit/5f960cb10f56ec2017c128ef9d16060… [3] https://community.arm.com/processors/b/blog/posts/arm-a-profile-architectur… Changes in v7: - Rebased onto 17b57b18 (4.19-rc6). - Dropped the "arm64: untag user address in __do_user_fault" patch, since the existing patches already handle user faults properly. - Dropped the "usb, arm64: untag user addresses in devio" patch, since the passed pointer must come from a vma and therefore be untagged. - Dropped the "arm64: annotate user pointers casts detected by sparse" patch (see the discussion to the replies of the v6 of this patchset). - Added more context to the cover letter. - Updated Documentation/arm64/tagged-pointers.txt. Changes in v6: - Added annotations for user pointer casts found by sparse. - Rebased onto 050cdc6c (4.19-rc1+). Changes in v5: - Added 3 new patches that add untagging to places found with static analysis. - Rebased onto 44c929e1 (4.18-rc8). Changes in v4: - Added a selftest for checking that passing tagged pointers to the kernel succeeds. - Rebased onto 81e97f013 (4.18-rc1+). Changes in v3: - Rebased onto e5c51f30 (4.17-rc6+). - Added linux-arch@ to the list of recipients. Changes in v2: - Rebased onto 2d618bdf (4.17-rc3+). - Removed excessive untagging in gup.c. - Removed untagging pointers returned from __uaccess_mask_ptr. Changes in v1: - Rebased onto 4.17-rc1. Changes in RFC v2: - Added "#ifndef untagged_addr..." fallback in linux/uaccess.h instead of defining it for each arch individually. - Updated Documentation/arm64/tagged-pointers.txt. - Dropped "mm, arm64: untag user addresses in memory syscalls". - Rebased onto 3eb2ce82 (4.16-rc7). Andrey Konovalov (8): arm64: add type casts to untagged_addr macro uaccess: add untagged_addr definition for other arches arm64: untag user addresses in access_ok and __uaccess_mask_ptr mm, arm64: untag user addresses in mm/gup.c lib, arm64: untag addrs passed to strncpy_from_user and strnlen_user fs, arm64: untag user address in copy_mount_options arm64: update Documentation/arm64/tagged-pointers.txt selftests, arm64: add a selftest for passing tagged pointers to kernel Documentation/arm64/tagged-pointers.txt | 24 +++++++++++-------- arch/arm64/include/asm/uaccess.h | 14 +++++++---- fs/namespace.c | 2 +- include/linux/uaccess.h | 4 ++++ lib/strncpy_from_user.c | 2 ++ lib/strnlen_user.c | 2 ++ mm/gup.c | 4 ++++ tools/testing/selftests/arm64/.gitignore | 1 + tools/testing/selftests/arm64/Makefile | 11 +++++++++ .../testing/selftests/arm64/run_tags_test.sh | 12 ++++++++++ tools/testing/selftests/arm64/tags_test.c | 19 +++++++++++++++ 11 files changed, 79 insertions(+), 16 deletions(-) create mode 100644 tools/testing/selftests/arm64/.gitignore create mode 100644 tools/testing/selftests/arm64/Makefile create mode 100755 tools/testing/selftests/arm64/run_tags_test.sh create mode 100644 tools/testing/selftests/arm64/tags_test.c -- 2.19.0.605.g01d371f741-goog

7 years, 2 months

5
17
0 0

[RFC v1 00/31] kunit: Introducing KUnit, the Linux kernel unit testing framework

by Brendan Higgins

This patch set proposes KUnit, a lightweight unit testing and mocking framework for the Linux kernel. Unlike Autotest and kselftest, KUnit is a true unit testing framework; it does not require installing the kernel on a test machine or in a VM and does not require tests to be written in userspace running on a host kernel. Additionally, KUnit is fast: From invocation to completion KUnit can run several dozen tests in under a second. Currently, the entire KUnit test suite for KUnit runs in under a second from the initial invocation (build time excluded). KUnit is heavily inspired by JUnit, Python's unittest.mock, and Googletest/Googlemock for C++. KUnit provides facilities for defining unit test cases, grouping related test cases into test suites, providing common infrastructure for running tests, mocking, spying, and much more. ## What's so special about unit testing? A unit test is supposed to test a single unit of code in isolation, hence the name. There should be no dependencies outside the control of the test; this means no external dependencies, which makes tests orders of magnitudes faster. Likewise, since there are no external dependencies, there are no hoops to jump through to run the tests. Additionally, this makes unit tests deterministic: a failing unit test always indicates a problem. Finally, because unit tests necessarily have finer granularity, they are able to test all code paths easily solving the classic problem of difficulty in exercising error handling code. ## Is KUnit trying to replace other testing frameworks for the kernel? No. Most existing tests for the Linux kernel are end-to-end tests, which have their place. A well tested system has lots of unit tests, a reasonable number of integration tests, and some end-to-end tests. KUnit is just trying to address the unit test space which is currently not being addressed. ## More information on KUnit There is a bunch of documentation near the end of this patch set that describes how to use KUnit and best practices for writing unit tests. For convenience I am hosting the compiled docs here: https://google.github.io/kunit-docs/third_party/kernel/docs/ -- 2.19.1.331.ge82ca0e54c-goog

7 years, 2 months

9
51
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[PATCH bpf-next] selftests/bpf: fix file resource leak

by Peng Hao

FILE pointer variable f is opened but never closed. Signed-off-by:Peng Hao <peng.hao2(a)zte.com.cn> --- tools/testing/selftests/bpf/trace_helpers.c | 1 + 1 file changed, 1 insertion(+) diff --git a/tools/testing/selftests/bpf/trace_helpers.c b/tools/testing/selftests/bpf/trace_helpers.c index cabe2a3..a3d1dac 100644 --- a/tools/testing/selftests/bpf/trace_helpers.c +++ b/tools/testing/selftests/bpf/trace_helpers.c @@ -41,6 +41,7 @@ int load_kallsyms(void) syms[i].name = strdup(func); i++; } + fclose(f); sym_cnt = i; qsort(syms, sym_cnt, sizeof(struct ksym), ksym_cmp); return 0; -- 1.8.3.1

7 years, 2 months

2
1
0 0

[PATCH] selftest/bpf : file resource leak

by Peng Hao

From: Peng Hao <peng.hao2(a)zte.com.cn> FILE pointer variable f is opened but never closed. Signed-off-by: Peng Hao <peng.hao2(a)zte.com.cn> --- tools/testing/selftests/bpf/trace_helpers.c | 1 + 1 file changed, 1 insertion(+) diff --git a/tools/testing/selftests/bpf/trace_helpers.c b/tools/testing/selftests/bpf/trace_helpers.c index cabe2a3..a3d1dac 100644 --- a/tools/testing/selftests/bpf/trace_helpers.c +++ b/tools/testing/selftests/bpf/trace_helpers.c @@ -41,6 +41,7 @@ int load_kallsyms(void) syms[i].name = strdup(func); i++; } + fclose(f); sym_cnt = i; qsort(syms, sym_cnt, sizeof(struct ksym), ksym_cmp); return 0; -- 1.8.3.1

7 years, 2 months

2
1
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[PATCH] selftests/ftrace: Use colored output when available

by Daniel Díaz

If test is being directly executed (with stdout opened on the terminal) and the terminal capabilities indicate enough colors, then use the existing scheme of green, red, and blue to show when tests pass, fail or end in a different way. When running the tests redirecting the stdout, for instance, to a file, then colors are not shown, thus producing a more readable output. Signed-off-by: Daniel Díaz <daniel.diaz(a)linaro.org> --- tools/testing/selftests/ftrace/ftracetest | 29 +++++++++++++++++------ 1 file changed, 22 insertions(+), 7 deletions(-) diff --git a/tools/testing/selftests/ftrace/ftracetest b/tools/testing/selftests/ftrace/ftracetest index 4946b2edfcff..d987bbec675f 100755 --- a/tools/testing/selftests/ftrace/ftracetest +++ b/tools/testing/selftests/ftrace/ftracetest @@ -152,6 +152,21 @@ else date > $LOG_FILE fi +# Define text colors +# Check available colors on the terminal, if any +ncolors=`tput colors 2>/dev/null` +color_reset= +color_red= +color_green= +color_blue= +# If stdout exists and number of colors is eight or more, use them +if [ -t 1 -a "$ncolors" -a "$ncolors" -ge 8 ]; then + color_reset="\e[0m" + color_red="\e[31m" + color_green="\e[32m" + color_blue="\e[34m" +fi + prlog() { # messages [ -z "$LOG_FILE" ] && echo -e "$@" || echo -e "$@" | tee -a $LOG_FILE } @@ -195,37 +210,37 @@ test_on_instance() { # testfile eval_result() { # sigval case $1 in $PASS) - prlog " [\e[32mPASS\e[30m]" + prlog " [${color_green}PASS${color_reset}]" PASSED_CASES="$PASSED_CASES $CASENO" return 0 ;; $FAIL) - prlog " [\e[31mFAIL\e[30m]" + prlog " [${color_red}FAIL${color_reset}]" FAILED_CASES="$FAILED_CASES $CASENO" return 1 # this is a bug. ;; $UNRESOLVED) - prlog " [\e[34mUNRESOLVED\e[30m]" + prlog " [${color_blue}UNRESOLVED${color_reset}]" UNRESOLVED_CASES="$UNRESOLVED_CASES $CASENO" return 1 # this is a kind of bug.. something happened. ;; $UNTESTED) - prlog " [\e[34mUNTESTED\e[30m]" + prlog " [${color_blue}UNTESTED${color_reset}]" UNTESTED_CASES="$UNTESTED_CASES $CASENO" return 0 ;; $UNSUPPORTED) - prlog " [\e[34mUNSUPPORTED\e[30m]" + prlog " [${color_blue}UNSUPPORTED${color_reset}]" UNSUPPORTED_CASES="$UNSUPPORTED_CASES $CASENO" return $UNSUPPORTED_RESULT # depends on use case ;; $XFAIL) - prlog " [\e[31mXFAIL\e[30m]" + prlog " [${color_red}XFAIL${color_reset}]" XFAILED_CASES="$XFAILED_CASES $CASENO" return 0 ;; *) - prlog " [\e[34mUNDEFINED\e[30m]" + prlog " [${color_blue}UNDEFINED${color_reset}]" UNDEFINED_CASES="$UNDEFINED_CASES $CASENO" return 1 # this must be a test bug ;; -- 2.17.1

7 years, 2 months

5
11
0 0

[PATCH v2 1/2] mm: Add an F_SEAL_FS_WRITE seal to memfd

by Joel Fernandes (Google)

Android uses ashmem for sharing memory regions. We are looking forward to migrating all usecases of ashmem to memfd so that we can possibly remove the ashmem driver in the future from staging while also benefiting from using memfd and contributing to it. Note staging drivers are also not ABI and generally can be removed at anytime. One of the main usecases Android has is the ability to create a region and mmap it as writeable, then drop its protection for "future" writes while keeping the existing already mmap'ed writeable-region active. This allows us to implement a usecase where receivers of the shared memory buffer can get a read-only view, while the sender continues to write to the buffer. See CursorWindow in Android for more details: https://developer.android.com/reference/android/database/CursorWindow This usecase cannot be implemented with the existing F_SEAL_WRITE seal. To support the usecase, this patch adds a new F_SEAL_FS_WRITE seal which prevents any future mmap and write syscalls from succeeding while keeping the existing mmap active. The following program shows the seal working in action: int main() { int ret, fd; void *addr, *addr2, *addr3, *addr1; ret = memfd_create_region("test_region", REGION_SIZE); printf("ret=%d\n", ret); fd = ret; // Create map addr = mmap(0, REGION_SIZE, PROT_READ|PROT_WRITE, MAP_SHARED, fd, 0); if (addr == MAP_FAILED) printf("map 0 failed\n"); else printf("map 0 passed\n"); if ((ret = write(fd, "test", 4)) != 4) printf("write failed even though no fs-write seal " "(ret=%d errno =%d)\n", ret, errno); else printf("write passed\n"); addr1 = mmap(0, REGION_SIZE, PROT_READ|PROT_WRITE, MAP_SHARED, fd, 0); if (addr1 == MAP_FAILED) perror("map 1 prot-write failed even though no seal\n"); else printf("map 1 prot-write passed as expected\n"); ret = fcntl(fd, F_ADD_SEALS, F_SEAL_FS_WRITE); if (ret == -1) printf("fcntl failed, errno: %d\n", errno); else printf("fs-write seal now active\n"); if ((ret = write(fd, "test", 4)) != 4) printf("write failed as expected due to fs-write seal\n"); else printf("write passed (unexpected)\n"); addr2 = mmap(0, REGION_SIZE, PROT_READ|PROT_WRITE, MAP_SHARED, fd, 0); if (addr2 == MAP_FAILED) perror("map 2 prot-write failed as expected due to seal\n"); else printf("map 2 passed\n"); addr3 = mmap(0, REGION_SIZE, PROT_READ, MAP_SHARED, fd, 0); if (addr3 == MAP_FAILED) perror("map 3 failed\n"); else printf("map 3 prot-read passed as expected\n"); } The output of running this program is as follows: ret=3 map 0 passed write passed map 1 prot-write passed as expected fs-write seal now active write failed as expected due to fs-write seal map 2 prot-write failed as expected due to seal : Permission denied map 3 prot-read passed as expected Note: This seal will also prevent growing and shrinking of the memfd. This is not something we do in Android so it does not affect us, however I have mentioned this behavior of the seal in the manpage. Cc: jreck(a)google.com Cc: john.stultz(a)linaro.org Cc: tkjos(a)google.com Cc: gregkh(a)linuxfoundation.org Signed-off-by: Joel Fernandes (Google) <joel(a)joelfernandes.org> --- v1->v2: No change, just added selftests to the series. manpages are ready and I'll submit them once the patches are accepted. include/uapi/linux/fcntl.h | 1 + mm/memfd.c | 6 +++++- 2 files changed, 6 insertions(+), 1 deletion(-) diff --git a/include/uapi/linux/fcntl.h b/include/uapi/linux/fcntl.h index c98312fa78a5..fe44a2035edf 100644 --- a/include/uapi/linux/fcntl.h +++ b/include/uapi/linux/fcntl.h @@ -41,6 +41,7 @@ #define F_SEAL_SHRINK 0x0002 /* prevent file from shrinking */ #define F_SEAL_GROW 0x0004 /* prevent file from growing */ #define F_SEAL_WRITE 0x0008 /* prevent writes */ +#define F_SEAL_FS_WRITE 0x0010 /* prevent all write-related syscalls */ /* (1U << 31) is reserved for signed error codes */ /* diff --git a/mm/memfd.c b/mm/memfd.c index 27069518e3c5..9b8855b80de9 100644 --- a/mm/memfd.c +++ b/mm/memfd.c @@ -150,7 +150,8 @@ static unsigned int *memfd_file_seals_ptr(struct file *file) #define F_ALL_SEALS (F_SEAL_SEAL | \ F_SEAL_SHRINK | \ F_SEAL_GROW | \ - F_SEAL_WRITE) + F_SEAL_WRITE | \ + F_SEAL_FS_WRITE) static int memfd_add_seals(struct file *file, unsigned int seals) { @@ -219,6 +220,9 @@ static int memfd_add_seals(struct file *file, unsigned int seals) } } + if ((seals & F_SEAL_FS_WRITE) && !(*file_seals & F_SEAL_FS_WRITE)) + file->f_mode &= ~(FMODE_WRITE | FMODE_PWRITE); + *file_seals |= seals; error = 0; -- 2.19.0.605.g01d371f741-goog

7 years, 2 months

5
9
0 0

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