From 93faccbbfa958a9668d3ab4e30f38dd205cee8d8 Mon Sep 17 00:00:00 2001 From: "Eric W. Biederman" Date: Wed, 1 Feb 2017 06:06:16 +1300 Subject: fs: Better permission checking for submounts To support unprivileged users mounting filesystems two permission checks have to be performed: a test to see if the user allowed to create a mount in the mount namespace, and a test to see if the user is allowed to access the specified filesystem. The automount case is special in that mounting the original filesystem grants permission to mount the sub-filesystems, to any user who happens to stumble across the their mountpoint and satisfies the ordinary filesystem permission checks. Attempting to handle the automount case by using override_creds almost works. It preserves the idea that permission to mount the original filesystem is permission to mount the sub-filesystem. Unfortunately using override_creds messes up the filesystems ordinary permission checks. Solve this by being explicit that a mount is a submount by introducing vfs_submount, and using it where appropriate. vfs_submount uses a new mount internal mount flags MS_SUBMOUNT, to let sget and friends know that a mount is a submount so they can take appropriate action. sget and sget_userns are modified to not perform any permission checks on submounts. follow_automount is modified to stop using override_creds as that has proven problemantic. do_mount is modified to always remove the new MS_SUBMOUNT flag so that we know userspace will never by able to specify it. autofs4 is modified to stop using current_real_cred that was put in there to handle the previous version of submount permission checking. cifs is modified to pass the mountpoint all of the way down to vfs_submount. debugfs is modified to pass the mountpoint all of the way down to trace_automount by adding a new parameter. To make this change easier a new typedef debugfs_automount_t is introduced to capture the type of the debugfs automount function. Cc: stable@vger.kernel.org Fixes: 069d5ac9ae0d ("autofs: Fix automounts by using current_real_cred()->uid") Fixes: aeaa4a79ff6a ("fs: Call d_automount with the filesystems creds") Reviewed-by: Trond Myklebust Reviewed-by: Seth Forshee Signed-off-by: "Eric W. Biederman" --- kernel/trace/trace.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) (limited to 'kernel/trace/trace.c') diff --git a/kernel/trace/trace.c b/kernel/trace/trace.c index d7449783987a..310f0ea0d1a2 100644 --- a/kernel/trace/trace.c +++ b/kernel/trace/trace.c @@ -7503,7 +7503,7 @@ init_tracer_tracefs(struct trace_array *tr, struct dentry *d_tracer) ftrace_init_tracefs(tr, d_tracer); } -static struct vfsmount *trace_automount(void *ingore) +static struct vfsmount *trace_automount(struct dentry *mntpt, void *ingore) { struct vfsmount *mnt; struct file_system_type *type; @@ -7516,7 +7516,7 @@ static struct vfsmount *trace_automount(void *ingore) type = get_fs_type("tracefs"); if (!type) return NULL; - mnt = vfs_kern_mount(type, 0, "tracefs", NULL); + mnt = vfs_submount(mntpt, type, "tracefs", NULL); put_filesystem(type); if (IS_ERR(mnt)) return NULL; -- cgit From 0e684b6578ee463ecb5c9a1cd0c20069f063d9f0 Mon Sep 17 00:00:00 2001 From: "Steven Rostedt (VMware)" Date: Thu, 2 Feb 2017 17:58:18 -0500 Subject: tracing: Reset parser->buffer to allow multiple "puts" trace_parser_put() simply frees the allocated parser buffer. But it does not reset the pointer that was freed. This means that if trace_parser_put() is called on the same parser more than once, it will corrupt the allocation system. Setting parser->buffer to NULL after free allows it to be called more than once without any ill effect. Acked-by: Namhyung Kim Signed-off-by: Steven Rostedt (VMware) --- kernel/trace/trace.c | 1 + 1 file changed, 1 insertion(+) (limited to 'kernel/trace/trace.c') diff --git a/kernel/trace/trace.c b/kernel/trace/trace.c index d7449783987a..4589b67168fc 100644 --- a/kernel/trace/trace.c +++ b/kernel/trace/trace.c @@ -1193,6 +1193,7 @@ int trace_parser_get_init(struct trace_parser *parser, int size) void trace_parser_put(struct trace_parser *parser) { kfree(parser->buffer); + parser->buffer = NULL; } /* -- cgit From 67d04bb2bcbd3e99f4c4daa58599c90a83ad314a Mon Sep 17 00:00:00 2001 From: Joel Fernandes Date: Thu, 16 Feb 2017 20:10:58 -0800 Subject: tracing: Remove outdated ring buffer comment The comment about ring buffer's organization is outdated and the code sits elsewhere, remove the comment. Link: http://lkml.kernel.org/r/20170217041058.23904-1-joelaf@google.com Cc: Ingo Molnar Signed-off-by: Joel Fernandes Signed-off-by: Steven Rostedt (VMware) --- kernel/trace/trace.c | 12 ++---------- 1 file changed, 2 insertions(+), 10 deletions(-) (limited to 'kernel/trace/trace.c') diff --git a/kernel/trace/trace.c b/kernel/trace/trace.c index 4589b67168fc..54e3b8711aca 100644 --- a/kernel/trace/trace.c +++ b/kernel/trace/trace.c @@ -260,16 +260,8 @@ unsigned long long ns2usecs(u64 nsec) TRACE_ITER_EVENT_FORK /* - * The global_trace is the descriptor that holds the tracing - * buffers for the live tracing. For each CPU, it contains - * a link list of pages that will store trace entries. The - * page descriptor of the pages in the memory is used to hold - * the link list by linking the lru item in the page descriptor - * to each of the pages in the buffer per CPU. - * - * For each active CPU there is a data field that holds the - * pages for the buffer for that CPU. Each CPU has the same number - * of pages allocated for its buffer. + * The global_trace is the descriptor that holds the top-level tracing + * buffers for the live tracing. */ static struct trace_array global_trace = { .trace_flags = TRACE_DEFAULT_FLAGS, -- cgit From 6b0b7551428e4caae1e2c023a529465a9a9ae2d4 Mon Sep 17 00:00:00 2001 From: Anton Blanchard Date: Thu, 16 Feb 2017 17:00:50 +1100 Subject: perf/core: Rename CONFIG_[UK]PROBE_EVENT to CONFIG_[UK]PROBE_EVENTS We have uses of CONFIG_UPROBE_EVENT and CONFIG_KPROBE_EVENT as well as CONFIG_UPROBE_EVENTS and CONFIG_KPROBE_EVENTS. Consistently use the plurals. Signed-off-by: Anton Blanchard Cc: Andy Lutomirski Cc: Borislav Petkov Cc: Brian Gerst Cc: Denys Vlasenko Cc: H. Peter Anvin Cc: Josh Poimboeuf Cc: Linus Torvalds Cc: Peter Zijlstra Cc: Thomas Gleixner Cc: acme@kernel.org Cc: alexander.shishkin@linux.intel.com Cc: davem@davemloft.net Cc: sparclinux@vger.kernel.org Link: http://lkml.kernel.org/r/20170216060050.20866-1-anton@ozlabs.org Signed-off-by: Ingo Molnar --- Documentation/trace/kprobetrace.txt | 2 +- Documentation/trace/uprobetracer.txt | 2 +- arch/powerpc/configs/85xx/kmp204x_defconfig | 2 +- arch/s390/configs/default_defconfig | 2 +- arch/s390/configs/gcov_defconfig | 2 +- arch/s390/configs/performance_defconfig | 2 +- arch/s390/defconfig | 2 +- kernel/trace/Kconfig | 6 +++--- kernel/trace/Makefile | 4 ++-- kernel/trace/trace.c | 10 +++++----- kernel/trace/trace_probe.h | 4 ++-- 11 files changed, 19 insertions(+), 19 deletions(-) (limited to 'kernel/trace/trace.c') diff --git a/Documentation/trace/kprobetrace.txt b/Documentation/trace/kprobetrace.txt index e4991fb1eedc..41ef9d8efe95 100644 --- a/Documentation/trace/kprobetrace.txt +++ b/Documentation/trace/kprobetrace.txt @@ -12,7 +12,7 @@ kprobes can probe (this means, all functions body except for __kprobes functions). Unlike the Tracepoint based event, this can be added and removed dynamically, on the fly. -To enable this feature, build your kernel with CONFIG_KPROBE_EVENT=y. +To enable this feature, build your kernel with CONFIG_KPROBE_EVENTS=y. Similar to the events tracer, this doesn't need to be activated via current_tracer. Instead of that, add probe points via diff --git a/Documentation/trace/uprobetracer.txt b/Documentation/trace/uprobetracer.txt index fa7b680ee8a0..bf526a7c5559 100644 --- a/Documentation/trace/uprobetracer.txt +++ b/Documentation/trace/uprobetracer.txt @@ -7,7 +7,7 @@ Overview -------- Uprobe based trace events are similar to kprobe based trace events. -To enable this feature, build your kernel with CONFIG_UPROBE_EVENT=y. +To enable this feature, build your kernel with CONFIG_UPROBE_EVENTS=y. Similar to the kprobe-event tracer, this doesn't need to be activated via current_tracer. Instead of that, add probe points via diff --git a/arch/powerpc/configs/85xx/kmp204x_defconfig b/arch/powerpc/configs/85xx/kmp204x_defconfig index aaaaa609cd24..34a4da23f000 100644 --- a/arch/powerpc/configs/85xx/kmp204x_defconfig +++ b/arch/powerpc/configs/85xx/kmp204x_defconfig @@ -210,7 +210,7 @@ CONFIG_DEBUG_SHIRQ=y CONFIG_DETECT_HUNG_TASK=y CONFIG_SCHEDSTATS=y CONFIG_RCU_TRACE=y -CONFIG_UPROBE_EVENT=y +CONFIG_UPROBE_EVENTS=y CONFIG_CRYPTO_NULL=y CONFIG_CRYPTO_PCBC=m CONFIG_CRYPTO_MD4=y diff --git a/arch/s390/configs/default_defconfig b/arch/s390/configs/default_defconfig index 143b1e00b818..4b176fe83da4 100644 --- a/arch/s390/configs/default_defconfig +++ b/arch/s390/configs/default_defconfig @@ -609,7 +609,7 @@ CONFIG_SCHED_TRACER=y CONFIG_FTRACE_SYSCALLS=y CONFIG_STACK_TRACER=y CONFIG_BLK_DEV_IO_TRACE=y -CONFIG_UPROBE_EVENT=y +CONFIG_UPROBE_EVENTS=y CONFIG_FUNCTION_PROFILER=y CONFIG_HIST_TRIGGERS=y CONFIG_TRACE_ENUM_MAP_FILE=y diff --git a/arch/s390/configs/gcov_defconfig b/arch/s390/configs/gcov_defconfig index f05d2d6e1087..0de46cc397f6 100644 --- a/arch/s390/configs/gcov_defconfig +++ b/arch/s390/configs/gcov_defconfig @@ -560,7 +560,7 @@ CONFIG_SCHED_TRACER=y CONFIG_FTRACE_SYSCALLS=y CONFIG_STACK_TRACER=y CONFIG_BLK_DEV_IO_TRACE=y -CONFIG_UPROBE_EVENT=y +CONFIG_UPROBE_EVENTS=y CONFIG_FUNCTION_PROFILER=y CONFIG_HIST_TRIGGERS=y CONFIG_TRACE_ENUM_MAP_FILE=y diff --git a/arch/s390/configs/performance_defconfig b/arch/s390/configs/performance_defconfig index 2358bf33c5ef..e167557b434c 100644 --- a/arch/s390/configs/performance_defconfig +++ b/arch/s390/configs/performance_defconfig @@ -558,7 +558,7 @@ CONFIG_SCHED_TRACER=y CONFIG_FTRACE_SYSCALLS=y CONFIG_STACK_TRACER=y CONFIG_BLK_DEV_IO_TRACE=y -CONFIG_UPROBE_EVENT=y +CONFIG_UPROBE_EVENTS=y CONFIG_FUNCTION_PROFILER=y CONFIG_HIST_TRIGGERS=y CONFIG_TRACE_ENUM_MAP_FILE=y diff --git a/arch/s390/defconfig b/arch/s390/defconfig index 68bfd09f1b02..97189dbaf34b 100644 --- a/arch/s390/defconfig +++ b/arch/s390/defconfig @@ -179,7 +179,7 @@ CONFIG_FTRACE_SYSCALLS=y CONFIG_TRACER_SNAPSHOT_PER_CPU_SWAP=y CONFIG_STACK_TRACER=y CONFIG_BLK_DEV_IO_TRACE=y -CONFIG_UPROBE_EVENT=y +CONFIG_UPROBE_EVENTS=y CONFIG_FUNCTION_PROFILER=y CONFIG_TRACE_ENUM_MAP_FILE=y CONFIG_KPROBES_SANITY_TEST=y diff --git a/kernel/trace/Kconfig b/kernel/trace/Kconfig index d5038005eb5d..d4a06e714645 100644 --- a/kernel/trace/Kconfig +++ b/kernel/trace/Kconfig @@ -429,7 +429,7 @@ config BLK_DEV_IO_TRACE If unsure, say N. -config KPROBE_EVENT +config KPROBE_EVENTS depends on KPROBES depends on HAVE_REGS_AND_STACK_ACCESS_API bool "Enable kprobes-based dynamic events" @@ -447,7 +447,7 @@ config KPROBE_EVENT This option is also required by perf-probe subcommand of perf tools. If you want to use perf tools, this option is strongly recommended. -config UPROBE_EVENT +config UPROBE_EVENTS bool "Enable uprobes-based dynamic events" depends on ARCH_SUPPORTS_UPROBES depends on MMU @@ -466,7 +466,7 @@ config UPROBE_EVENT config BPF_EVENTS depends on BPF_SYSCALL - depends on (KPROBE_EVENT || UPROBE_EVENT) && PERF_EVENTS + depends on (KPROBE_EVENTS || UPROBE_EVENTS) && PERF_EVENTS bool default y help diff --git a/kernel/trace/Makefile b/kernel/trace/Makefile index e57980845549..90f2701d92a7 100644 --- a/kernel/trace/Makefile +++ b/kernel/trace/Makefile @@ -57,7 +57,7 @@ obj-$(CONFIG_EVENT_TRACING) += trace_events_filter.o obj-$(CONFIG_EVENT_TRACING) += trace_events_trigger.o obj-$(CONFIG_HIST_TRIGGERS) += trace_events_hist.o obj-$(CONFIG_BPF_EVENTS) += bpf_trace.o -obj-$(CONFIG_KPROBE_EVENT) += trace_kprobe.o +obj-$(CONFIG_KPROBE_EVENTS) += trace_kprobe.o obj-$(CONFIG_TRACEPOINTS) += power-traces.o ifeq ($(CONFIG_PM),y) obj-$(CONFIG_TRACEPOINTS) += rpm-traces.o @@ -66,7 +66,7 @@ ifeq ($(CONFIG_TRACING),y) obj-$(CONFIG_KGDB_KDB) += trace_kdb.o endif obj-$(CONFIG_PROBE_EVENTS) += trace_probe.o -obj-$(CONFIG_UPROBE_EVENT) += trace_uprobe.o +obj-$(CONFIG_UPROBE_EVENTS) += trace_uprobe.o obj-$(CONFIG_TRACEPOINT_BENCHMARK) += trace_benchmark.o diff --git a/kernel/trace/trace.c b/kernel/trace/trace.c index 707445ceb7ef..f35109514a01 100644 --- a/kernel/trace/trace.c +++ b/kernel/trace/trace.c @@ -4341,22 +4341,22 @@ static const char readme_msg[] = "\t\t\t traces\n" #endif #endif /* CONFIG_STACK_TRACER */ -#ifdef CONFIG_KPROBE_EVENT +#ifdef CONFIG_KPROBE_EVENTS " kprobe_events\t\t- Add/remove/show the kernel dynamic events\n" "\t\t\t Write into this file to define/undefine new trace events.\n" #endif -#ifdef CONFIG_UPROBE_EVENT +#ifdef CONFIG_UPROBE_EVENTS " uprobe_events\t\t- Add/remove/show the userspace dynamic events\n" "\t\t\t Write into this file to define/undefine new trace events.\n" #endif -#if defined(CONFIG_KPROBE_EVENT) || defined(CONFIG_UPROBE_EVENT) +#if defined(CONFIG_KPROBE_EVENTS) || defined(CONFIG_UPROBE_EVENTS) "\t accepts: event-definitions (one definition per line)\n" "\t Format: p|r[:[/]] []\n" "\t -:[/]\n" -#ifdef CONFIG_KPROBE_EVENT +#ifdef CONFIG_KPROBE_EVENTS "\t place: [:][+]|\n" #endif -#ifdef CONFIG_UPROBE_EVENT +#ifdef CONFIG_UPROBE_EVENTS "\t place: :\n" #endif "\t args: =fetcharg[:type]\n" diff --git a/kernel/trace/trace_probe.h b/kernel/trace/trace_probe.h index 0c0ae54d44c6..903273c93e61 100644 --- a/kernel/trace/trace_probe.h +++ b/kernel/trace/trace_probe.h @@ -248,7 +248,7 @@ ASSIGN_FETCH_FUNC(file_offset, ftype), \ #define FETCH_TYPE_STRING 0 #define FETCH_TYPE_STRSIZE 1 -#ifdef CONFIG_KPROBE_EVENT +#ifdef CONFIG_KPROBE_EVENTS struct symbol_cache; unsigned long update_symbol_cache(struct symbol_cache *sc); void free_symbol_cache(struct symbol_cache *sc); @@ -278,7 +278,7 @@ alloc_symbol_cache(const char *sym, long offset) { return NULL; } -#endif /* CONFIG_KPROBE_EVENT */ +#endif /* CONFIG_KPROBE_EVENTS */ struct probe_arg { struct fetch_param fetch; -- cgit