From 921a7acd85ebbab1b3cd99828e6842fd3e78df24 Mon Sep 17 00:00:00 2001 From: Changbin Du Date: Tue, 16 Jan 2018 17:02:28 +0800 Subject: tracing: Detect the string nul character when parsing user input string User space can pass in a C nul character '\0' along with its input. The function trace_get_user() will try to process it as a normal character, and that will fail to parse. open("/sys/kernel/debug/tracing//set_ftrace_pid", O_WRONLY|O_TRUNC) = 3 write(3, " \0", 2) = -1 EINVAL (Invalid argument) while parse can handle spaces, so below works. $ echo "" > set_ftrace_pid $ echo " " > set_ftrace_pid $ echo -n " " > set_ftrace_pid Have the parser stop on '\0' and cease any further parsing. Only process the characters up to the nul '\0' character and do not process it. Link: http://lkml.kernel.org/r/1516093350-12045-2-git-send-email-changbin.du@intel.com Acked-by: Namhyung Kim Signed-off-by: Changbin Du Signed-off-by: Steven Rostedt (VMware) --- kernel/trace/trace.c | 6 +++--- 1 file changed, 3 insertions(+), 3 deletions(-) (limited to 'kernel') diff --git a/kernel/trace/trace.c b/kernel/trace/trace.c index 8e3f20a18a06..c00a31d18f8a 100644 --- a/kernel/trace/trace.c +++ b/kernel/trace/trace.c @@ -1237,7 +1237,7 @@ int trace_get_user(struct trace_parser *parser, const char __user *ubuf, } /* only spaces were written */ - if (isspace(ch)) { + if (isspace(ch) || !ch) { *ppos += read; ret = read; goto out; @@ -1247,7 +1247,7 @@ int trace_get_user(struct trace_parser *parser, const char __user *ubuf, } /* read the non-space input */ - while (cnt && !isspace(ch)) { + while (cnt && !isspace(ch) && ch) { if (parser->idx < parser->size - 1) parser->buffer[parser->idx++] = ch; else { @@ -1262,7 +1262,7 @@ int trace_get_user(struct trace_parser *parser, const char __user *ubuf, } /* We either got finished input or we have to wait for another call. */ - if (isspace(ch)) { + if (isspace(ch) || !ch) { parser->buffer[parser->idx] = 0; parser->cont = false; } else if (parser->idx < parser->size - 1) { -- cgit v1.2.3-70-g09d2 From 76638d96502744b0d593f2386b75ae5a017c13bb Mon Sep 17 00:00:00 2001 From: Changbin Du Date: Tue, 16 Jan 2018 17:02:29 +0800 Subject: tracing: Clear parser->idx if only spaces are read If only spaces were read while parsing the next string, then parser->idx should be cleared in order to make trace_parser_loaded() return false. Link: http://lkml.kernel.org/r/1516093350-12045-3-git-send-email-changbin.du@intel.com Acked-by: Namhyung Kim Signed-off-by: Changbin Du Signed-off-by: Steven Rostedt (VMware) --- kernel/trace/trace.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) (limited to 'kernel') diff --git a/kernel/trace/trace.c b/kernel/trace/trace.c index c00a31d18f8a..cb90435e63da 100644 --- a/kernel/trace/trace.c +++ b/kernel/trace/trace.c @@ -1236,14 +1236,14 @@ int trace_get_user(struct trace_parser *parser, const char __user *ubuf, cnt--; } + parser->idx = 0; + /* only spaces were written */ if (isspace(ch) || !ch) { *ppos += read; ret = read; goto out; } - - parser->idx = 0; } /* read the non-space input */ -- cgit v1.2.3-70-g09d2 From f4d0706cde27f29ff89e6bf94ded4113f8fe6e80 Mon Sep 17 00:00:00 2001 From: Changbin Du Date: Tue, 16 Jan 2018 17:02:30 +0800 Subject: tracing: Make sure the parsed string always terminates with '\0' Always mark the parsed string with a terminated nul '\0' character. This removes the need for the users to have to append the '\0' before using the parsed string. Link: http://lkml.kernel.org/r/1516093350-12045-4-git-send-email-changbin.du@intel.com Acked-by: Namhyung Kim Signed-off-by: Changbin Du Signed-off-by: Steven Rostedt (VMware) --- kernel/trace/ftrace.c | 2 -- kernel/trace/trace.c | 4 ++-- kernel/trace/trace_events.c | 2 -- 3 files changed, 2 insertions(+), 6 deletions(-) (limited to 'kernel') diff --git a/kernel/trace/ftrace.c b/kernel/trace/ftrace.c index 554b517c61a0..dabd9d167d42 100644 --- a/kernel/trace/ftrace.c +++ b/kernel/trace/ftrace.c @@ -5015,7 +5015,6 @@ int ftrace_regex_release(struct inode *inode, struct file *file) parser = &iter->parser; if (trace_parser_loaded(parser)) { - parser->buffer[parser->idx] = 0; ftrace_match_records(iter->hash, parser->buffer, parser->idx); } @@ -5329,7 +5328,6 @@ ftrace_graph_release(struct inode *inode, struct file *file) parser = &fgd->parser; if (trace_parser_loaded((parser))) { - parser->buffer[parser->idx] = 0; ret = ftrace_graph_set_hash(fgd->new_hash, parser->buffer); } diff --git a/kernel/trace/trace.c b/kernel/trace/trace.c index cb90435e63da..58de825df19c 100644 --- a/kernel/trace/trace.c +++ b/kernel/trace/trace.c @@ -530,8 +530,6 @@ int trace_pid_write(struct trace_pid_list *filtered_pids, ubuf += ret; cnt -= ret; - parser.buffer[parser.idx] = 0; - ret = -EINVAL; if (kstrtoul(parser.buffer, 0, &val)) break; @@ -1268,6 +1266,8 @@ int trace_get_user(struct trace_parser *parser, const char __user *ubuf, } else if (parser->idx < parser->size - 1) { parser->cont = true; parser->buffer[parser->idx++] = ch; + /* Make sure the parsed string always terminates with '\0'. */ + parser->buffer[parser->idx] = 0; } else { ret = -EINVAL; goto out; diff --git a/kernel/trace/trace_events.c b/kernel/trace/trace_events.c index 1b87157edbff..05c7172c6667 100644 --- a/kernel/trace/trace_events.c +++ b/kernel/trace/trace_events.c @@ -885,8 +885,6 @@ ftrace_event_write(struct file *file, const char __user *ubuf, if (*parser.buffer == '!') set = 0; - parser.buffer[parser.idx] = 0; - ret = ftrace_set_clr_event(tr, parser.buffer + !set, set); if (ret) goto out_put; -- cgit v1.2.3-70-g09d2 From 0e4d819d0893dc043ea7b7cb6baf4be1e310bd96 Mon Sep 17 00:00:00 2001 From: Ravi Bangoria Date: Sat, 6 Jan 2018 11:12:46 +0530 Subject: trace_uprobe: Display correct offset in uprobe_events Recently, how the pointers being printed with %p has been changed by commit ad67b74d2469 ("printk: hash addresses printed with %p"). This is causing a regression while showing offset in the uprobe_events file. Instead of %p, use %px to display offset. Before patch: # perf probe -vv -x /tmp/a.out main Opening /sys/kernel/debug/tracing//uprobe_events write=1 Writing event: p:probe_a/main /tmp/a.out:0x58c # cat /sys/kernel/debug/tracing/uprobe_events p:probe_a/main /tmp/a.out:0x0000000049a0f352 After patch: # cat /sys/kernel/debug/tracing/uprobe_events p:probe_a/main /tmp/a.out:0x000000000000058c Link: http://lkml.kernel.org/r/20180106054246.15375-1-ravi.bangoria@linux.vnet.ibm.com Cc: stable@vger.kernel.org Fixes: ad67b74d2469 ("printk: hash addresses printed with %p") Acked-by: Srikar Dronamraju Signed-off-by: Ravi Bangoria Signed-off-by: Steven Rostedt (VMware) --- kernel/trace/trace_uprobe.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'kernel') diff --git a/kernel/trace/trace_uprobe.c b/kernel/trace/trace_uprobe.c index 40592e7b3568..268029ae1be6 100644 --- a/kernel/trace/trace_uprobe.c +++ b/kernel/trace/trace_uprobe.c @@ -608,7 +608,7 @@ static int probes_seq_show(struct seq_file *m, void *v) /* Don't print "0x (null)" when offset is 0 */ if (tu->offset) { - seq_printf(m, "0x%p", (void *)tu->offset); + seq_printf(m, "0x%px", (void *)tu->offset); } else { switch (sizeof(void *)) { case 4: -- cgit v1.2.3-70-g09d2 From dd3dad0d716dbb9fccadcc8709900d9cac6ca252 Mon Sep 17 00:00:00 2001 From: Andi Kleen Date: Thu, 21 Dec 2017 15:37:32 -0800 Subject: ftrace: Mark function tracer test functions noinline/noclone The ftrace function tracer self tests calls some functions to verify the get traced. This relies on them not being inlined. Previously this was ensured by putting them into another file, but with LTO the compiler can inline across files, which makes the tests fail. Mark these functions as noinline and noclone. Link: http://lkml.kernel.org/r/20171221233732.31896-1-andi@firstfloor.org Signed-off-by: Andi Kleen Signed-off-by: Steven Rostedt (VMware) --- kernel/trace/trace_selftest_dynamic.c | 5 +++-- 1 file changed, 3 insertions(+), 2 deletions(-) (limited to 'kernel') diff --git a/kernel/trace/trace_selftest_dynamic.c b/kernel/trace/trace_selftest_dynamic.c index 8cda06a10d66..c364cf777e1a 100644 --- a/kernel/trace/trace_selftest_dynamic.c +++ b/kernel/trace/trace_selftest_dynamic.c @@ -1,13 +1,14 @@ // SPDX-License-Identifier: GPL-2.0 +#include #include "trace.h" -int DYN_FTRACE_TEST_NAME(void) +noinline __noclone int DYN_FTRACE_TEST_NAME(void) { /* used to call mcount */ return 0; } -int DYN_FTRACE_TEST_NAME2(void) +noinline __noclone int DYN_FTRACE_TEST_NAME2(void) { /* used to call mcount */ return 0; -- cgit v1.2.3-70-g09d2