mainline inclusion from mainline-v6.10-rc1 commit 20fe4d07bde67ec26716835b61be2c4eeca1c6bc category: feature bugzilla: https://gitee.com/openeuler/kernel/issues/IAMXDU
Reference: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?i...
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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 yebin10@huawei.com Acked-by: Masami Hiramatsu (Google) mhiramat@kernel.org Signed-off-by: Masami Hiramatsu (Google) mhiramat@kernel.org Conflicts: kernel/trace/trace.c kernel/trace/trace_probe.c [Fix context diff] Signed-off-by: Ye Bin yebin10@huawei.com --- kernel/trace/trace.c | 2 +- kernel/trace/trace_probe.c | 58 +++++++++++++++++++++++--------------- 2 files changed, 37 insertions(+), 23 deletions(-)
diff --git a/kernel/trace/trace.c b/kernel/trace/trace.c index 7d7418781fba..3c776919305a 100644 --- a/kernel/trace/trace.c +++ b/kernel/trace/trace.c @@ -5284,7 +5284,7 @@ static const char readme_msg[] = "\t +|-[u]<offset>(<fetcharg>), \imm-value, \"imm-string"\n" "\t type: s8/16/32/64, u8/16/32/64, x8/16/32/64, string, symbol,\n" "\t b<bit-width>@<bit-offset>/<container-size>, ustring,\n" - "\t %pd, <type>\[<array-size>\]\n" + "\t %pd/%pD, <type>\[<array-size>\]\n" #ifdef CONFIG_HIST_TRIGGERS "\t field: <stype> <name>;\n" "\t stype: u8/u16/u32/u64, s8/s16/s32/s64, pid_t,\n" diff --git a/kernel/trace/trace_probe.c b/kernel/trace/trace_probe.c index aafa3aa41d6e..2b309dfc5b7f 100644 --- a/kernel/trace/trace_probe.c +++ b/kernel/trace/trace_probe.c @@ -11,6 +11,8 @@ */ #define pr_fmt(fmt) "trace_probe: " fmt
+#include <linux/fs.h> + #include "trace_probe.h"
#undef C @@ -815,35 +817,47 @@ 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; + + if (!glob_match("*:%p[dD]", argv[i])) + continue; + + if (!tmpbuf) { + tmpbuf = kmalloc(bufsize, GFP_KERNEL); + if (!tmpbuf) + return -ENOMEM; + }
- tmp = kstrdup(argv[i], GFP_KERNEL); - if (!tmp) - goto nomem; + tmp = kstrdup(argv[i], GFP_KERNEL); + if (!tmp) + goto nomem;
- equal = strchr(tmp, '='); - if (equal) - *equal = '\0'; - tmp[strlen(argv[i]) - 4] = '\0'; + 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;