FAILED: patch "[PATCH] tracing/kprobes: Return EADDRNOTAVAIL when func matches" failed to apply to 5.4-stable tree
Subsystems (2)
[email protected]
maintainerThe patch below does not apply to the 5.4-stable tree.
If someone wants it applied there, or to any other stable or longterm tree, then please email the backport, including the original git commit id to <[email protected]>.
To reproduce the conflict and resubmit, you may use the following commands:
git fetch https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/ linux-5.4.y
git checkout FETCH_HEAD
git cherry-pick -x b022f0c7e404887a7c5229788fc99eff9f9a80d5
# <resolve conflicts, build, test, etc.>
git commit -s
git send-email --to '<[email protected]>' --in-reply-to '2023102137-mobster-sheath-bfb3@gregkh' --subject-prefix 'PATCH 5.4.y' HEAD^..
Possible dependencies:
thanks,
greg k-h
------------------ original commit in Linus's tree ------------------
From b022f0c7e404887a7c5229788fc99eff9f9a80d5 Mon Sep 17 00:00:00 2001
From: Francis Laniel <[email protected]>
Date: Fri, 20 Oct 2023 13:42:49 +0300
Subject: [PATCH] tracing/kprobes: Return EADDRNOTAVAIL when func matches
several symbols
When a kprobe is attached to a function that's name is not unique (is static and shares the name with other functions in the kernel), the kprobe is attached to the first function it finds. This is a bug as the function that it is attaching to is not necessarily the one that the user wants to attach to.
Instead of blindly picking a function to attach to what is ambiguous, error with EADDRNOTAVAIL to let the user know that this function is not unique, and that the user must use another unique function with an address offset to get to the function they want to attach to.
kernel/trace/trace_kprobe.c +63 -0
@@ -705,6 +705,25 @@ static struct notifier_block trace_kprobe_module_nb = { .priority = 1 /* Invoked after kprobe module callback */ }; +static int count_symbols (void *data,unsigned long unused) +{ +unsigned int *count = data; + + (*count)++; + +return 0 ; +} + +static unsigned int number_of_same_symbols (char *func_name) +{ +unsigned int count; + + count =0 ; +kallsyms_on_each_match_symbol (count_symbols, func_name, &count); + +return count; +} +static int __trace_kprobe_create (int argc,const char *argv[]) {/*
@@ -836,6 +855,31 @@ static int __trace_kprobe_create(int argc, const char *argv[]) } } +if (symbol && !strchr (symbol,':' )) { +unsigned int count; + + count =number_of_same_symbols (symbol); +if (count >1 ) { +/* +* Users should use ADDR to remove the ambiguity of +* using KSYM only. +*/ +trace_probe_log_err (0 ,NON_UNIQ_SYMBOL ); + ret = -EADDRNOTAVAIL ; + + goto error; + }else if (count ==0 ) { +/* +* We can return ENOENT earlier than when register the +* kprobe. +*/ +trace_probe_log_err (0 ,BAD_PROBE_ADDR ); + ret = -ENOENT ; + + goto error; + } + } +trace_probe_log_set_index (0 );if (event) { ret = traceprobe_parse_event_name(&event, &group, gbuf,
@@ -1695,6 +1739,7 @@ static int unregister_kprobe_event(struct trace_kprobe *tk) }#ifdef CONFIG_PERF_EVENTS +/* create a trace_kprobe, but don't add it to global lists */ struct trace_event_call * create_local_trace_kprobe(char *func, void *addr, unsigned long offs,
@@ -1705,6 +1750,24 @@ create_local_trace_kprobe(char *func, void *addr, unsigned long offs,int ret;char *event; +if (func) { +unsigned int count; + + count =number_of_same_symbols (func); +if (count >1 ) +/* +* Users should use addr to remove the ambiguity of +* using func only. +*/ +return ERR_PTR (-EADDRNOTAVAIL ); +else if (count ==0 ) +/* +* We can return ENOENT earlier than when register the +* kprobe. +*/ +return ERR_PTR (-ENOENT ); + } +/* * local trace_kprobes are not added to dyn_event, so they are never * searched in find_trace_kprobe(). Therefore, there is no concern of
kernel/trace/trace_probe.h +1 -0
@@ -450,6 +450,7 @@ extern int traceprobe_define_arg_fields(struct trace_event_call *event_call,C (BAD_MAXACT ,"Invalid maxactive number" ), \C (MAXACT_TOO_BIG ,"Maxactive is too big" ), \C (BAD_PROBE_ADDR ,"Invalid probed address or symbol" ), \ +C (NON_UNIQ_SYMBOL ,"The symbol is not unique" ), \C (BAD_RETPROBE ,"Retprobe address must be an function entry" ), \C (NO_TRACEPOINT ,"Tracepoint is not found" ), \ C(BAD_ADDR_SUFFIX, "Invalid probed address suffix"), \
cover Return EADDRNOTAVAIL when func matches several symbols during kprobe creation
Hi.
There was problem to apply upstream patch on kernel 5.4.
I adapted the patch and came up with the attached one, it was tested and validated:
root@vm-amd64:~# uname -a Linux vm-amd64 5.4.258+ #121 SMP Mon Oct 23 14:22:43 EEST 2023 x86_64 GNU/Linux root@vm-amd64:~# echo 'p:probe/name_show name_show' > /sys/kernel/tracing/kprobe_events bash: echo: write error: Cannot assign requested address
As I had to modify the patch, I would like to get reviews before getting it merged in stable.
Francis Laniel (1):
tracing/kprobes: Return EADDRNOTAVAIL when func matches several
symbols
kernel/trace/trace_kprobe.c | 74 +++++++++++++++++++++++++++++++++++++ kernel/trace/trace_probe.h | 1 + 2 files changed, 75 insertions(+)
Best regards and thank you in advance.
--
2.34.1
PATCH 1/1 tracing/kprobes: Return EADDRNOTAVAIL when func matches several symbols
When a kprobe is attached to a function that's name is not unique (is static and shares the name with other functions in the kernel), the kprobe is attached to the first function it finds. This is a bug as the function that it is attaching to is not necessarily the one that the user wants to attach to.
Instead of blindly picking a function to attach to what is ambiguous, error with EADDRNOTAVAIL to let the user know that this function is not unique, and that the user must use another unique function with an address offset to get to the function they want to attach to.
--- kernel/trace/trace_kprobe.c | 74 +++++++++++++++++++++++++++++++++++++ kernel/trace/trace_probe.h | 1 + 2 files changed, 75 insertions(+)
kernel/trace/trace_kprobe.c +74 -0
@@ -714,6 +714,36 @@ static inline void sanitize_event_name(char *name) *name ='_' ; } +struct count_symbols_struct { +const char *func_name; +unsigned int count; +}; + +static int count_symbols (void *data,const char *name,struct module *unused0, +unsigned long unused1) +{ +struct count_symbols_struct *args = data; + +if (strcmp (args->func_name, name)) +return 0 ; + + args->count++; + +return 0 ; +} + +static unsigned int number_of_same_symbols (char *func_name) +{ +struct count_symbols_struct args = { + .func_name = func_name, + .count =0 , + }; + +kallsyms_on_each_symbol (count_symbols, &args); + +return args.count; +} +static int trace_kprobe_create (int argc,const char *argv[]) {/*
@@ -825,6 +855,31 @@ static int trace_kprobe_create(int argc, const char *argv[]) } } +if (symbol && !strchr (symbol,':' )) { +unsigned int count; + + count =number_of_same_symbols (symbol); +if (count >1 ) { +/* +* Users should use ADDR to remove the ambiguity of +* using KSYM only. +*/ +trace_probe_log_err (0 ,NON_UNIQ_SYMBOL ); + ret = -EADDRNOTAVAIL ; + + goto error; + }else if (count ==0 ) { +/* +* We can return ENOENT earlier than when register the +* kprobe. +*/ +trace_probe_log_err (0 ,BAD_PROBE_ADDR ); + ret = -ENOENT ; + + goto error; + } + } +trace_probe_log_set_index (0 );if (event) { ret = traceprobe_parse_event_name(&event, &group, buf,
@@ -1596,6 +1651,7 @@ static int unregister_kprobe_event(struct trace_kprobe *tk) }#ifdef CONFIG_PERF_EVENTS +/* create a trace_kprobe, but don't add it to global lists */ struct trace_event_call * create_local_trace_kprobe(char *func, void *addr, unsigned long offs,
@@ -1605,6 +1661,24 @@ create_local_trace_kprobe(char *func, void *addr, unsigned long offs,int ret;char *event; +if (func) { +unsigned int count; + + count =number_of_same_symbols (func); +if (count >1 ) +/* +* Users should use addr to remove the ambiguity of +* using func only. +*/ +return ERR_PTR (-EADDRNOTAVAIL ); +else if (count ==0 ) +/* +* We can return ENOENT earlier than when register the +* kprobe. +*/ +return ERR_PTR (-ENOENT ); + } +/* * local trace_kprobes are not added to dyn_event, so they are never * searched in find_trace_kprobe(). Therefore, there is no concern of
kernel/trace/trace_probe.h +1 -0
@@ -403,6 +403,7 @@ extern int traceprobe_define_arg_fields(struct trace_event_call *event_call,C (BAD_MAXACT ,"Invalid maxactive number" ), \C (MAXACT_TOO_BIG ,"Maxactive is too big" ), \C (BAD_PROBE_ADDR ,"Invalid probed address or symbol" ), \ +C (NON_UNIQ_SYMBOL ,"The symbol is not unique" ), \C (BAD_RETPROBE ,"Retprobe address must be an function entry" ), \C (NO_GROUP_NAME ,"Group name is not specified" ), \ C(GROUP_TOO_LONG, "Group name is too long"), \
--
2.34.1
Greg KH
maintainerRe: [PATCH 5.4.y 0/1] Return EADDRNOTAVAIL when func matches several symbols during kprobe creation
In reply to Francis LanielQuoted 15 lines · Francis Laniel
Hi.
There was problem to apply upstream patch on kernel 5.4.
I adapted the patch and came up with the attached one, it was tested and validated:
root@vm-amd64:~# uname -a Linux vm-amd64 5.4.258+ #121 SMP Mon Oct 23 14:22:43 EEST 2023 x86_64 GNU/Linux root@vm-amd64:~# echo 'p:probe/name_show name_show' > /sys/kernel/tracing/kprobe_events bash: echo: write error: Cannot assign requested addressAs I had to modify the patch, I would like to get reviews before getting it merged in stable.
Quoted 8 lines
Francis Laniel (1):
tracing/kprobes: Return EADDRNOTAVAIL when func matches several
symbolskernel/trace/trace_kprobe.c | 74 +++++++++++++++++++++++++++++++++++++ kernel/trace/trace_probe.h | 1 + 2 files changed, 75 insertions(+)
I don't see a 5.10.y version of this, did I miss it somewhere?
thanks,
greg k-h
Re: [PATCH 5.4.y 0/1] Return EADDRNOTAVAIL when func matches several symbols during kprobe creation
Hi!
Quoted 21 lines · Le mardi 31 octobre 2023, 16:16:07 EET Greg KH a écrit :
Quoted 20 lines · Francis Laniel
Hi.
There was problem to apply upstream patch on kernel 5.4.
I adapted the patch and came up with the attached one, it was tested and validated:
root@vm-amd64:~# uname -a Linux vm-amd64 5.4.258+ #121 SMP Mon Oct 23 14:22:43 EEST 2023 x86_64 GNU/Linux root@vm-amd64:~# echo 'p:probe/name_show name_show' > /sys/kernel/tracing/kprobe_events bash: echo: write error: Cannot assign requested addressAs I had to modify the patch, I would like to get reviews before getting it
merged in stable.Francis Laniel (1):
tracing/kprobes: Return EADDRNOTAVAIL when func matches several
Quoted 7 lines
Quoted 5 lines
symbols
kernel/trace/trace_kprobe.c | 74 +++++++++++++++++++++++++++++++++++++ kernel/trace/trace_probe.h | 1 + 2 files changed, 75 insertions(+)I don't see a 5.10.y version of this, did I miss it somewhere?
No, this is "normal".
As I modified the master patch, I would have liked to get other reviews before sending all the batches of patches.
Once everything is validated, I will send patches for the missing version for sure!
Quoted 3 lines
thanks,
greg k-h
Best regards.
PATCH 1/1 tracing/kprobes: Return EADDRNOTAVAIL when func matches several symbols
In reply to [email protected]When a kprobe is attached to a function that's name is not unique (is static and shares the name with other functions in the kernel), the kprobe is attached to the first function it finds. This is a bug as the function that it is attaching to is not necessarily the one that the user wants to attach to.
Instead of blindly picking a function to attach to what is ambiguous, error with EADDRNOTAVAIL to let the user know that this function is not unique, and that the user must use another unique function with an address offset to get to the function they want to attach to.
--- kernel/trace/trace_kprobe.c | 74 +++++++++++++++++++++++++++++++++++++ kernel/trace/trace_probe.h | 1 + 2 files changed, 75 insertions(+)
kernel/trace/trace_kprobe.c +74 -0
@@ -714,6 +714,36 @@ static inline void sanitize_event_name(char *name) *name ='_' ; } +struct count_symbols_struct { +const char *func_name; +unsigned int count; +}; + +static int count_symbols (void *data,const char *name,struct module *unused0, +unsigned long unused1) +{ +struct count_symbols_struct *args = data; + +if (strcmp (args->func_name, name)) +return 0 ; + + args->count++; + +return 0 ; +} + +static unsigned int number_of_same_symbols (char *func_name) +{ +struct count_symbols_struct args = { + .func_name = func_name, + .count =0 , + }; + +kallsyms_on_each_symbol (count_symbols, &args); + +return args.count; +} +static int trace_kprobe_create (int argc,const char *argv[]) {/*
@@ -825,6 +855,31 @@ static int trace_kprobe_create(int argc, const char *argv[]) } } +if (symbol && !strchr (symbol,':' )) { +unsigned int count; + + count =number_of_same_symbols (symbol); +if (count >1 ) { +/* +* Users should use ADDR to remove the ambiguity of +* using KSYM only. +*/ +trace_probe_log_err (0 ,NON_UNIQ_SYMBOL ); + ret = -EADDRNOTAVAIL ; + + goto error; + }else if (count ==0 ) { +/* +* We can return ENOENT earlier than when register the +* kprobe. +*/ +trace_probe_log_err (0 ,BAD_PROBE_ADDR ); + ret = -ENOENT ; + + goto error; + } + } +trace_probe_log_set_index (0 );if (event) { ret = traceprobe_parse_event_name(&event, &group, buf,
@@ -1596,6 +1651,7 @@ static int unregister_kprobe_event(struct trace_kprobe *tk) }#ifdef CONFIG_PERF_EVENTS +/* create a trace_kprobe, but don't add it to global lists */ struct trace_event_call * create_local_trace_kprobe(char *func, void *addr, unsigned long offs,
@@ -1605,6 +1661,24 @@ create_local_trace_kprobe(char *func, void *addr, unsigned long offs,int ret;char *event; +if (func) { +unsigned int count; + + count =number_of_same_symbols (func); +if (count >1 ) +/* +* Users should use addr to remove the ambiguity of +* using func only. +*/ +return ERR_PTR (-EADDRNOTAVAIL ); +else if (count ==0 ) +/* +* We can return ENOENT earlier than when register the +* kprobe. +*/ +return ERR_PTR (-ENOENT ); + } +/* * local trace_kprobes are not added to dyn_event, so they are never * searched in find_trace_kprobe(). Therefore, there is no concern of
kernel/trace/trace_probe.h +1 -0
@@ -403,6 +403,7 @@ extern int traceprobe_define_arg_fields(struct trace_event_call *event_call,C (BAD_MAXACT ,"Invalid maxactive number" ), \C (MAXACT_TOO_BIG ,"Maxactive is too big" ), \C (BAD_PROBE_ADDR ,"Invalid probed address or symbol" ), \ +C (NON_UNIQ_SYMBOL ,"The symbol is not unique" ), \C (BAD_RETPROBE ,"Retprobe address must be an function entry" ), \C (NO_GROUP_NAME ,"Group name is not specified" ), \ C(GROUP_TOO_LONG, "Group name is too long"), \
Signature · 1 line
2.34.1