| Message ID | 20240322064308.284457-3-yebin10@huawei.com (mailing list archive) |
|---|---|
| State | Accepted |
| Commit | 1ed6a9fd250c401f9403818fe08dfd6877a84c9b |
| Headers | show |
| Series | support '%pd' and '%pD' for print file name | expand |
On Fri, 22 Mar 2024 14:43:05 +0800 Ye Bin <yebin10@huawei.com> wrote: > As like previous patch, this patch support print type '%pD' for print file's nit: Note that "previous patch" is obscure after it is merged with other patches in other trees/branches. So it should be "As like %pd". Anyway, let me change it. Thank you, > 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. > > Signed-off-by: Ye Bin <yebin10@huawei.com> > --- > kernel/trace/trace.c | 2 +- > kernel/trace/trace_probe.c | 57 +++++++++++++++++++++++--------------- > 2 files changed, 36 insertions(+), 23 deletions(-) > > diff --git a/kernel/trace/trace.c b/kernel/trace/trace.c > index ac26b8446337..831dfd0773a4 100644 > --- a/kernel/trace/trace.c > +++ b/kernel/trace/trace.c > @@ -5510,7 +5510,7 @@ 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, char, string, symbol,\n" > "\t b<bit-width>@<bit-offset>/<container-size>, ustring,\n" > - "\t symstr, %pd, <type>\\[<array-size>\\]\n" > + "\t symstr, %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 a27567e16c36..7bfc6c0d5436 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 <linux/bpf.h> > +#include <linux/fs.h> > #include "trace_btf.h" > > #include "trace_probe.h" > @@ -1581,35 +1582,47 @@ 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; > -- > 2.31.1 >
diff --git a/kernel/trace/trace.c b/kernel/trace/trace.c index ac26b8446337..831dfd0773a4 100644 --- a/kernel/trace/trace.c +++ b/kernel/trace/trace.c @@ -5510,7 +5510,7 @@ 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, char, string, symbol,\n" "\t b<bit-width>@<bit-offset>/<container-size>, ustring,\n" - "\t symstr, %pd, <type>\\[<array-size>\\]\n" + "\t symstr, %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 a27567e16c36..7bfc6c0d5436 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 <linux/bpf.h> +#include <linux/fs.h> #include "trace_btf.h" #include "trace_probe.h" @@ -1581,35 +1582,47 @@ 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;
As like previous patch, this patch support 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. Signed-off-by: Ye Bin <yebin10@huawei.com> --- kernel/trace/trace.c | 2 +- kernel/trace/trace_probe.c | 57 +++++++++++++++++++++++--------------- 2 files changed, 36 insertions(+), 23 deletions(-)