From 7d8296b250f2eed73f1758607926d4d258dea5d4 Mon Sep 17 00:00:00 2001 From: Alexander Lobakin Date: Wed, 27 Mar 2024 16:23:42 +0100 Subject: bitops: make BYTES_TO_BITS() treewide-available Avoid open-coding that simple expression each time by moving BYTES_TO_BITS() from the probes code to to export it to the rest of the kernel. Simplify the macro while at it. `BITS_PER_LONG / sizeof(long)` always equals to %BITS_PER_BYTE, regardless of the target architecture. Do the same for the tools ecosystem as well (incl. its version of bitops.h). The previous implementation had its implicit type of long, while the new one is int, so adjust the format literal accordingly in the perf code. Suggested-by: Andy Shevchenko Reviewed-by: Przemek Kitszel Acked-by: Yury Norov Signed-off-by: Alexander Lobakin Signed-off-by: David S. Miller --- kernel/trace/trace_probe.c | 2 -- 1 file changed, 2 deletions(-) (limited to 'kernel/trace/trace_probe.c') diff --git a/kernel/trace/trace_probe.c b/kernel/trace/trace_probe.c index dfe3ee6035ec..87337a0c8e03 100644 --- a/kernel/trace/trace_probe.c +++ b/kernel/trace/trace_probe.c @@ -1180,8 +1180,6 @@ parse_probe_arg(char *arg, const struct fetch_type *type, return ret; } -#define BYTES_TO_BITS(nb) ((BITS_PER_LONG * (nb)) / sizeof(long)) - /* Bitfield type needs to be parsed into a fetch function */ static int __parse_bitfield_probe_arg(const char *bf, const struct fetch_type *t, -- cgit v1.2.3 From dce3696271af7765f04428ec31b1b87dc7d016c6 Mon Sep 17 00:00:00 2001 From: LuMingYin Date: Sat, 27 Apr 2024 08:23:47 +0100 Subject: tracing/probes: Fix memory leak in traceprobe_parse_probe_arg_body() If traceprobe_parse_probe_arg_body() failed to allocate 'parg->fmt', it jumps to the label 'out' instead of 'fail' by mistake.In the result, the buffer 'tmp' is not freed in this case and leaks its memory. Thus jump to the label 'fail' in that error case. Link: https://lore.kernel.org/all/20240427072347.1421053-1-lumingyindetect@126.com/ Fixes: 032330abd08b ("tracing/probes: Cleanup probe argument parser") Signed-off-by: LuMingYin Acked-by: Masami Hiramatsu (Google) Signed-off-by: Masami Hiramatsu (Google) --- kernel/trace/trace_probe.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'kernel/trace/trace_probe.c') diff --git a/kernel/trace/trace_probe.c b/kernel/trace/trace_probe.c index dfe3ee6035ec..42bc0f362226 100644 --- a/kernel/trace/trace_probe.c +++ b/kernel/trace/trace_probe.c @@ -1466,7 +1466,7 @@ static int traceprobe_parse_probe_arg_body(const char *argv, ssize_t *size, parg->fmt = kmalloc(len, GFP_KERNEL); if (!parg->fmt) { ret = -ENOMEM; - goto out; + goto fail; } snprintf(parg->fmt, len, "%s[%d]", parg->type->fmttype, parg->count); -- cgit v1.2.3 From d9b15224dd8ff83b2aef87e4cd5ad10c875ef7d6 Mon Sep 17 00:00:00 2001 From: Ye Bin Date: Fri, 22 Mar 2024 14:43:04 +0800 Subject: tracing/probes: support '%pd' type for print struct dentry's name During fault locating, the file name needs to be printed based on the dentry address. The offset needs to be calculated each time, which is troublesome. Similar to printk, kprobe support print type '%pd' for print dentry's name. For example "name=$arg1:%pd" casts the `$arg1` as (struct dentry *), dereferences the "d_name.name" field and stores it to "name" argument as a kernel string. Here is an example: [tracing]# echo 'p:testprobe dput name=$arg1:%pd' > kprobe_events [tracing]# echo 1 > events/kprobes/testprobe/enable [tracing]# grep -q "1" events/kprobes/testprobe/enable [tracing]# echo 0 > events/kprobes/testprobe/enable [tracing]# cat trace | grep "enable" bash-14844 [002] ..... 16912.889543: testprobe: (dput+0x4/0x30) name="enable" grep-15389 [003] ..... 16922.834182: testprobe: (dput+0x4/0x30) name="enable" grep-15389 [003] ..... 16922.836103: testprobe: (dput+0x4/0x30) name="enable" bash-14844 [001] ..... 16931.820909: testprobe: (dput+0x4/0x30) name="enable" Note that this expects the given argument (e.g. $arg1) is an address of struct dentry. User must ensure it. Link: https://lore.kernel.org/all/20240322064308.284457-2-yebin10@huawei.com/ Signed-off-by: Ye Bin Acked-by: Masami Hiramatsu (Google) Signed-off-by: Masami Hiramatsu (Google) --- kernel/trace/trace_probe.c | 50 ++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 50 insertions(+) (limited to 'kernel/trace/trace_probe.c') diff --git a/kernel/trace/trace_probe.c b/kernel/trace/trace_probe.c index dfe3ee6035ec..f7ee97e45d1f 100644 --- a/kernel/trace/trace_probe.c +++ b/kernel/trace/trace_probe.c @@ -1739,6 +1739,56 @@ error: return ERR_PTR(ret); } +/* @buf: *buf must be equal to NULL. Caller must to free *buf */ +int traceprobe_expand_dentry_args(int argc, const char *argv[], char **buf) +{ + int i, used, ret; + const int bufsize = MAX_DENTRY_ARGS_LEN; + char *tmpbuf = NULL; + + if (*buf) + return -EINVAL; + + used = 0; + for (i = 0; i < argc; i++) { + if (glob_match("*:%pd", argv[i])) { + char *tmp; + char *equal; + + if (!tmpbuf) { + tmpbuf = kmalloc(bufsize, GFP_KERNEL); + if (!tmpbuf) + return -ENOMEM; + } + + tmp = kstrdup(argv[i], GFP_KERNEL); + if (!tmp) + goto nomem; + + equal = strchr(tmp, '='); + if (equal) + *equal = '\0'; + tmp[strlen(argv[i]) - 4] = '\0'; + ret = snprintf(tmpbuf + used, bufsize - used, + "%s%s+0x0(+0x%zx(%s)):string", + equal ? tmp : "", equal ? "=" : "", + offsetof(struct dentry, d_name.name), + equal ? equal + 1 : tmp); + kfree(tmp); + if (ret >= bufsize - used) + goto nomem; + argv[i] = tmpbuf + used; + used += ret + 1; + } + } + + *buf = tmpbuf; + return 0; +nomem: + kfree(tmpbuf); + return -ENOMEM; +} + void traceprobe_finish_parse(struct traceprobe_parse_context *ctx) { clear_btf_context(ctx); -- cgit v1.2.3 From 20fe4d07bde67ec26716835b61be2c4eeca1c6bc Mon Sep 17 00:00:00 2001 From: Ye Bin Date: Fri, 22 Mar 2024 14:43:05 +0800 Subject: tracing/probes: support '%pD' type for print struct file's name As like '%pd' type, this patch supports print type '%pD' for print file's name. For example "name=$arg1:%pD" casts the `$arg1` as (struct file*), dereferences the "file.f_path.dentry.d_name.name" field and stores it to "name" argument as a kernel string. Here is an example: [tracing]# echo 'p:testprobe vfs_read name=$arg1:%pD' > kprobe_event [tracing]# echo 1 > events/kprobes/testprobe/enable [tracing]# grep -q "1" events/kprobes/testprobe/enable [tracing]# echo 0 > events/kprobes/testprobe/enable [tracing]# grep "vfs_read" trace | grep "enable" grep-15108 [003] ..... 5228.328609: testprobe: (vfs_read+0x4/0xbb0) name="enable" Note that this expects the given argument (e.g. $arg1) is an address of struct file. User must ensure it. Link: https://lore.kernel.org/all/20240322064308.284457-3-yebin10@huawei.com/ [Masami: replaced "previous patch" with '%pd' type] Signed-off-by: Ye Bin Acked-by: Masami Hiramatsu (Google) Signed-off-by: Masami Hiramatsu (Google) --- kernel/trace/trace_probe.c | 57 ++++++++++++++++++++++++++++------------------ 1 file changed, 35 insertions(+), 22 deletions(-) (limited to 'kernel/trace/trace_probe.c') diff --git a/kernel/trace/trace_probe.c b/kernel/trace/trace_probe.c index f7ee97e45d1f..d4a887dac821 100644 --- a/kernel/trace/trace_probe.c +++ b/kernel/trace/trace_probe.c @@ -12,6 +12,7 @@ #define pr_fmt(fmt) "trace_probe: " fmt #include +#include #include "trace_btf.h" #include "trace_probe.h" @@ -1751,35 +1752,47 @@ int traceprobe_expand_dentry_args(int argc, const char *argv[], char **buf) used = 0; for (i = 0; i < argc; i++) { - if (glob_match("*:%pd", argv[i])) { - char *tmp; - char *equal; - - if (!tmpbuf) { - tmpbuf = kmalloc(bufsize, GFP_KERNEL); - if (!tmpbuf) - return -ENOMEM; - } + char *tmp; + char *equal; + size_t arg_len; - tmp = kstrdup(argv[i], GFP_KERNEL); - if (!tmp) - goto nomem; + if (!glob_match("*:%p[dD]", argv[i])) + continue; - equal = strchr(tmp, '='); - if (equal) - *equal = '\0'; - tmp[strlen(argv[i]) - 4] = '\0'; + if (!tmpbuf) { + tmpbuf = kmalloc(bufsize, GFP_KERNEL); + if (!tmpbuf) + return -ENOMEM; + } + + tmp = kstrdup(argv[i], GFP_KERNEL); + if (!tmp) + goto nomem; + + equal = strchr(tmp, '='); + if (equal) + *equal = '\0'; + arg_len = strlen(argv[i]); + tmp[arg_len - 4] = '\0'; + if (argv[i][arg_len - 1] == 'd') ret = snprintf(tmpbuf + used, bufsize - used, "%s%s+0x0(+0x%zx(%s)):string", equal ? tmp : "", equal ? "=" : "", offsetof(struct dentry, d_name.name), equal ? equal + 1 : tmp); - kfree(tmp); - if (ret >= bufsize - used) - goto nomem; - argv[i] = tmpbuf + used; - used += ret + 1; - } + else + ret = snprintf(tmpbuf + used, bufsize - used, + "%s%s+0x0(+0x%zx(+0x%zx(%s))):string", + equal ? tmp : "", equal ? "=" : "", + offsetof(struct dentry, d_name.name), + offsetof(struct file, f_path.dentry), + equal ? equal + 1 : tmp); + + kfree(tmp); + if (ret >= bufsize - used) + goto nomem; + argv[i] = tmpbuf + used; + used += ret + 1; } *buf = tmpbuf; -- cgit v1.2.3