FAILED: patch "[PATCH] kcmp: Support selection of SYS_kcmp without" failed to apply to 4.14-stable tree
From: <gregkh@linuxfoundation.org>
Date: 2021-03-01 13:24:08
Subsystem:
drm drivers, drm drivers and misc gpu patches, filesystems (vfs and infrastructure), kernel selftest framework, secure computing, the rest · Maintainers:
David Airlie, Simona Vetter, Maarten Lankhorst, Maxime Ripard, Thomas Zimmermann, Alexander Viro, Christian Brauner, Shuah Khan, Shuah Khan, Kees Cook, Linus Torvalds
The patch below does not apply to the 4.14-stable tree. If someone wants it applied there, or to any other stable or longterm tree, then please email the backport, including the original git commit id to [off-list ref]. thanks, greg k-h ------------------ original commit in Linus's tree ------------------ From bfe3911a91047557eb0e620f95a370aee6a248c7 Mon Sep 17 00:00:00 2001 From: Chris Wilson <redacted> Date: Fri, 5 Feb 2021 22:00:12 +0000 Subject: [PATCH] kcmp: Support selection of SYS_kcmp without CHECKPOINT_RESTORE Userspace has discovered the functionality offered by SYS_kcmp and has started to depend upon it. In particular, Mesa uses SYS_kcmp for os_same_file_description() in order to identify when two fd (e.g. device or dmabuf) point to the same struct file. Since they depend on it for core functionality, lift SYS_kcmp out of the non-default CONFIG_CHECKPOINT_RESTORE into the selectable syscall category. Rasmus Villemoes also pointed out that systemd uses SYS_kcmp to deduplicate the per-service file descriptor store. Note that some distributions such as Ubuntu are already enabling CHECKPOINT_RESTORE in their configs and so, by extension, SYS_kcmp. References: https://gitlab.freedesktop.org/drm/intel/-/issues/3046 Signed-off-by: Chris Wilson <redacted> Cc: Kees Cook <redacted> Cc: Andy Lutomirski <luto@amacapital.net> Cc: Will Drewry <wad@chromium.org> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Dave Airlie <airlied@gmail.com> Cc: Daniel Vetter <redacted> Cc: Lucas Stach <l.stach@pengutronix.de> Cc: Rasmus Villemoes <linux@rasmusvillemoes.dk> Cc: Cyrill Gorcunov <redacted> Cc: stable@vger.kernel.org Acked-by: Daniel Vetter <redacted> # DRM depends on kcmp Acked-by: Rasmus Villemoes <linux@rasmusvillemoes.dk> # systemd uses kcmp Reviewed-by: Cyrill Gorcunov <redacted> Reviewed-by: Kees Cook <redacted> Acked-by: Thomas Zimmermann <tzimmermann@suse.de> Signed-off-by: Daniel Vetter <redacted> Link: https://patchwork.freedesktop.org/patch/msgid/20210205220012.1983-1-chris@chris-wilson.co.uk
diff --git a/drivers/gpu/drm/Kconfig b/drivers/gpu/drm/Kconfig
index 0973f408d75f..af6c6d214d91 100644
--- a/drivers/gpu/drm/Kconfig
+++ b/drivers/gpu/drm/Kconfig@@ -15,6 +15,9 @@ menuconfig DRM select I2C_ALGOBIT select DMA_SHARED_BUFFER select SYNC_FILE +# gallium uses SYS_kcmp for os_same_file_description() to de-duplicate +# device and dmabuf fd. Let's make sure that is available for our userspace. + select KCMP help Kernel-level support for the Direct Rendering Infrastructure (DRI) introduced in XFree86 4.0. If you say Y here, you need to select
diff --git a/fs/eventpoll.c b/fs/eventpoll.c
index a829af074eb5..3196474cbe24 100644
--- a/fs/eventpoll.c
+++ b/fs/eventpoll.c@@ -979,7 +979,7 @@ static struct epitem *ep_find(struct eventpoll *ep, struct file *file, int fd) return epir; } -#ifdef CONFIG_CHECKPOINT_RESTORE +#ifdef CONFIG_KCMP static struct epitem *ep_find_tfd(struct eventpoll *ep, int tfd, unsigned long toff) { struct rb_node *rbp;
@@ -1021,7 +1021,7 @@ struct file *get_epoll_tfile_raw_ptr(struct file *file, int tfd, return file_raw; } -#endif /* CONFIG_CHECKPOINT_RESTORE */ +#endif /* CONFIG_KCMP */ /** * Adds a new entry to the tail of the list in a lockless way, i.e.
diff --git a/include/linux/eventpoll.h b/include/linux/eventpoll.h
index 0350393465d4..593322c946e6 100644
--- a/include/linux/eventpoll.h
+++ b/include/linux/eventpoll.h@@ -18,7 +18,7 @@ struct file; #ifdef CONFIG_EPOLL -#ifdef CONFIG_CHECKPOINT_RESTORE +#ifdef CONFIG_KCMP struct file *get_epoll_tfile_raw_ptr(struct file *file, int tfd, unsigned long toff); #endif
diff --git a/init/Kconfig b/init/Kconfig
index 29ad68325028..b7d3c6a12196 100644
--- a/init/Kconfig
+++ b/init/Kconfig@@ -1193,6 +1193,7 @@ endif # NAMESPACES config CHECKPOINT_RESTORE bool "Checkpoint/restore support" select PROC_CHILDREN + select KCMP default n help Enables additional kernel features in a sake of checkpoint/restore.
@@ -1736,6 +1737,16 @@ config ARCH_HAS_MEMBARRIER_CALLBACKS config ARCH_HAS_MEMBARRIER_SYNC_CORE bool +config KCMP + bool "Enable kcmp() system call" if EXPERT + help + Enable the kernel resource comparison system call. It provides + user-space with the ability to compare two processes to see if they + share a common resource, such as a file descriptor or even virtual + memory space. + + If unsure, say N. + config RSEQ bool "Enable rseq() system call" if EXPERT default y
diff --git a/kernel/Makefile b/kernel/Makefile
index aa7368c7eabf..320f1f3941b7 100644
--- a/kernel/Makefile
+++ b/kernel/Makefile@@ -51,7 +51,7 @@ obj-y += livepatch/ obj-y += dma/ obj-y += entry/ -obj-$(CONFIG_CHECKPOINT_RESTORE) += kcmp.o +obj-$(CONFIG_KCMP) += kcmp.o obj-$(CONFIG_FREEZER) += freezer.o obj-$(CONFIG_PROFILING) += profile.o obj-$(CONFIG_STACKTRACE) += stacktrace.o
diff --git a/tools/testing/selftests/seccomp/seccomp_bpf.c b/tools/testing/selftests/seccomp/seccomp_bpf.c
index 26c72f2b61b1..1b6c7d33c4ff 100644
--- a/tools/testing/selftests/seccomp/seccomp_bpf.c
+++ b/tools/testing/selftests/seccomp/seccomp_bpf.c@@ -315,7 +315,7 @@ TEST(kcmp) ret = __filecmp(getpid(), getpid(), 1, 1); EXPECT_EQ(ret, 0); if (ret != 0 && errno == ENOSYS) - SKIP(return, "Kernel does not support kcmp() (missing CONFIG_CHECKPOINT_RESTORE?)"); + SKIP(return, "Kernel does not support kcmp() (missing CONFIG_KCMP?)"); } TEST(mode_strict_support)