Hi Jianyu,
On Tue, 29 Jul 2014 20:50:08 +0800, Jianyu Zhan wrote:
> Sorry for the noise,
>
> plz add these Acked-by and Signed-off-by:
I think you'd better to send it as a formal patch.
Thanks,
Namhyung
>
> Acked-by: Masami Hiramatsu <masami.hiramatsu.pt@xxxxxxxxxxx>
> Signed-off-by: Jianyu Zhan <nasa4836@xxxxxxxxx>
>
> Thanks,
> Jianyu Zhan
>
>
> On Tue, Jul 29, 2014 at 8:47 PM, Jianyu Zhan <nasa4836@xxxxxxxxx> wrote:
>> Hi, Ingo,
>>
>> Here is the new patch with typo fixed.
>>
>> Thanks.
>>
>> ---8<---
>>
>> Currently, if user specifies both symbol name and address, we just
>> bail out.
>>
>> This might be too rude. This patch makes it give more tolerance.
>> If both are specified, check address first, if the symbol found
>> does not match the one user specify, print a waring. If not found,
>> return -ENOENT, because some symbols might have muplitple instances,
>> we don't bother to check symbol name.
>> ---
>> Documentation/kprobes.txt | 4 +++-
>> kernel/kprobes.c | 32 +++++++++++++++++++++++++++++---
>> 2 files changed, 32 insertions(+), 4 deletions(-)
>>
>> diff --git a/Documentation/kprobes.txt b/Documentation/kprobes.txt
>> index 4bbeca8..663b5ad 100644
>> --- a/Documentation/kprobes.txt
>> +++ b/Documentation/kprobes.txt
>> @@ -358,7 +358,9 @@ to install a probepoint is known. This field is used to calculate the
>> probepoint.
>>
>> 3. Specify either the kprobe "symbol_name" OR the "addr". If both are
>> -specified, kprobe registration will fail with -EINVAL.
>> +specified, only check "addr", because some symbols might have multiple
>> +instances. If neither is specified, kprobe registration will fail
>> +with -EINVAL.
>>
>> 4. With CISC architectures (such as i386 and x86_64), the kprobes code
>> does not validate if the kprobe.addr is at an instruction boundary.
>> diff --git a/kernel/kprobes.c b/kernel/kprobes.c
>> index 734e9a7..9768608 100644
>> --- a/kernel/kprobes.c
>> +++ b/kernel/kprobes.c
>> @@ -1358,15 +1358,41 @@ static bool within_kprobe_blacklist(unsigned long addr)
>> static kprobe_opcode_t *kprobe_addr(struct kprobe *p)
>> {
>> kprobe_opcode_t *addr = p->addr;
>> + char namebuf[KSYM_NAME_LEN];
>> + const char *sym_name = NULL;
>> + unsigned long offset;
>>
>> - if ((p->symbol_name && p->addr) ||
>> - (!p->symbol_name && !p->addr))
>> + if (!p->symbol_name && !p->addr)
>> goto invalid;
>>
>> - if (p->symbol_name) {
>> + /*
>> + * Some symbols might have multiple instances,
>> + * so if both are specified, only check address.
>> + */
>> + if (unlikely(p->addr && p->symbol_name)) {
>> + sym_name = kallsyms_lookup((unsigned long)(p->addr),
>> + NULL, &offset, NULL, namebuf);
>> + if (!sym_name)
>> + return ERR_PTR(-ENOENT);
>> +
>> + if (strncmp(sym_name, p->symbol_name, KSYM_NAME_LEN)
>> + || offset != p->offset) {
>> + pr_err("Incorrect symbol or offset, should be "
>> + "symbol=%s, offset=%ld.\n", sym_name, offset);
>> + goto invalid;
>> + }
>> + } else if (p->symbol_name) {
>> + /* Only symbol case */
>> kprobe_lookup_name(p->symbol_name, addr);
>> if (!addr)
>> return ERR_PTR(-ENOENT);
>> + } else {
>> + /*
>> + * Only address case.
>> + * Since we later will do a sanity check of the
>> + * address range in check_kprobe_address_safe(),
>> + * do nothing here.
>> + */
>> }
>>
>> addr = (kprobe_opcode_t *)(((char *)addr) + p->offset);
>> --
>> 2.0.0
>>
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