| Message ID | 20230111145842.847715402@goodmis.org (mailing list archive) |
|---|---|
| State | Superseded |
| Headers | show |
| Series | tracing: Addition of tracing instances via kernel command line | expand |
Hi Steven,
Thank you for the patch! Yet something to improve:
[auto build test ERROR on akpm-mm/mm-everything]
[also build test ERROR on linus/master v6.2-rc3 next-20230111]
[If your patch is applied to the wrong git tree, kindly drop us a note.
And when submitting patch, we suggest to use '--base' as documented in
https://git-scm.com/docs/git-format-patch#_base_tree_information]
url: https://github.com/intel-lab-lkp/linux/commits/Steven-Rostedt/tracing-Add-creation-of-instances-at-boot-command-line/20230111-230425
base: https://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm.git mm-everything
patch link: https://lore.kernel.org/r/20230111145842.847715402%40goodmis.org
patch subject: [PATCH 4/4] tracing: Allow boot instances to have snapshot buffers
config: arc-defconfig
compiler: arc-elf-gcc (GCC) 12.1.0
reproduce (this is a W=1 build):
wget https://raw.githubusercontent.com/intel/lkp-tests/master/sbin/make.cross -O ~/bin/make.cross
chmod +x ~/bin/make.cross
# https://github.com/intel-lab-lkp/linux/commit/b4515aa1407184147348b74b42bf10af90b905e7
git remote add linux-review https://github.com/intel-lab-lkp/linux
git fetch --no-tags linux-review Steven-Rostedt/tracing-Add-creation-of-instances-at-boot-command-line/20230111-230425
git checkout b4515aa1407184147348b74b42bf10af90b905e7
# save the config file
mkdir build_dir && cp config build_dir/.config
COMPILER_INSTALL_PATH=$HOME/0day COMPILER=gcc-12.1.0 make.cross W=1 O=build_dir ARCH=arc olddefconfig
COMPILER_INSTALL_PATH=$HOME/0day COMPILER=gcc-12.1.0 make.cross W=1 O=build_dir ARCH=arc SHELL=/bin/bash
If you fix the issue, kindly add following tag where applicable
| Reported-by: kernel test robot <lkp@intel.com>
All errors (new ones prefixed by >>):
kernel/trace/trace.c: In function 'enable_instances':
>> kernel/trace/trace.c:10244:25: error: implicit declaration of function 'do_allocate_snapshot'; did you mean 'boot_alloc_snapshot'? [-Werror=implicit-function-declaration]
10244 | do_allocate_snapshot(tok);
| ^~~~~~~~~~~~~~~~~~~~
| boot_alloc_snapshot
cc1: some warnings being treated as errors
vim +10244 kernel/trace/trace.c
10227
10228 __init static void enable_instances(void)
10229 {
10230 struct trace_array *tr;
10231 char *curr_str;
10232 char *str;
10233 char *tok;
10234
10235 /* A tab is always appended */
10236 boot_instance_info[boot_instance_index - 1] = '\0';
10237 str = boot_instance_info;
10238
10239 while ((curr_str = strsep(&str, "\t"))) {
10240
10241 tok = strsep(&curr_str, ",");
10242
10243 if (IS_ENABLED(CONFIG_TRACER_MAX_TRACE))
10244 do_allocate_snapshot(tok);
10245
10246 tr = trace_array_get_by_name(tok);
10247 if (!tr) {
10248 pr_warn("Failed to create instance buffer %s\n", curr_str);
10249 continue;
10250 }
10251 /* Allow user space to delete it */
10252 trace_array_put(tr);
10253
10254 while ((tok = strsep(&curr_str, ","))) {
10255 early_enable_events(tr, tok, true);
10256 }
10257 }
10258 }
10259
Hi Steven,
Thank you for the patch! Yet something to improve:
[auto build test ERROR on akpm-mm/mm-everything]
[also build test ERROR on linus/master v6.2-rc3 next-20230111]
[If your patch is applied to the wrong git tree, kindly drop us a note.
And when submitting patch, we suggest to use '--base' as documented in
https://git-scm.com/docs/git-format-patch#_base_tree_information]
url: https://github.com/intel-lab-lkp/linux/commits/Steven-Rostedt/tracing-Add-creation-of-instances-at-boot-command-line/20230111-230425
base: https://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm.git mm-everything
patch link: https://lore.kernel.org/r/20230111145842.847715402%40goodmis.org
patch subject: [PATCH 4/4] tracing: Allow boot instances to have snapshot buffers
config: hexagon-randconfig-r012-20230110
compiler: clang version 16.0.0 (https://github.com/llvm/llvm-project 8d9828ef5aa9688500657d36cd2aefbe12bbd162)
reproduce (this is a W=1 build):
wget https://raw.githubusercontent.com/intel/lkp-tests/master/sbin/make.cross -O ~/bin/make.cross
chmod +x ~/bin/make.cross
# https://github.com/intel-lab-lkp/linux/commit/b4515aa1407184147348b74b42bf10af90b905e7
git remote add linux-review https://github.com/intel-lab-lkp/linux
git fetch --no-tags linux-review Steven-Rostedt/tracing-Add-creation-of-instances-at-boot-command-line/20230111-230425
git checkout b4515aa1407184147348b74b42bf10af90b905e7
# save the config file
mkdir build_dir && cp config build_dir/.config
COMPILER_INSTALL_PATH=$HOME/0day COMPILER=clang make.cross W=1 O=build_dir ARCH=hexagon olddefconfig
COMPILER_INSTALL_PATH=$HOME/0day COMPILER=clang make.cross W=1 O=build_dir ARCH=hexagon SHELL=/bin/bash kernel/trace/
If you fix the issue, kindly add following tag where applicable
| Reported-by: kernel test robot <lkp@intel.com>
All errors (new ones prefixed by >>):
In file included from kernel/trace/trace.c:18:
In file included from include/linux/writeback.h:13:
In file included from include/linux/blk_types.h:10:
In file included from include/linux/bvec.h:10:
In file included from include/linux/highmem.h:12:
In file included from include/linux/hardirq.h:11:
In file included from ./arch/hexagon/include/generated/asm/hardirq.h:1:
In file included from include/asm-generic/hardirq.h:17:
In file included from include/linux/irq.h:20:
In file included from include/linux/io.h:13:
In file included from arch/hexagon/include/asm/io.h:334:
include/asm-generic/io.h:547:31: warning: performing pointer arithmetic on a null pointer has undefined behavior [-Wnull-pointer-arithmetic]
val = __raw_readb(PCI_IOBASE + addr);
~~~~~~~~~~ ^
include/asm-generic/io.h:560:61: warning: performing pointer arithmetic on a null pointer has undefined behavior [-Wnull-pointer-arithmetic]
val = __le16_to_cpu((__le16 __force)__raw_readw(PCI_IOBASE + addr));
~~~~~~~~~~ ^
include/uapi/linux/byteorder/little_endian.h:37:51: note: expanded from macro '__le16_to_cpu'
#define __le16_to_cpu(x) ((__force __u16)(__le16)(x))
^
In file included from kernel/trace/trace.c:18:
In file included from include/linux/writeback.h:13:
In file included from include/linux/blk_types.h:10:
In file included from include/linux/bvec.h:10:
In file included from include/linux/highmem.h:12:
In file included from include/linux/hardirq.h:11:
In file included from ./arch/hexagon/include/generated/asm/hardirq.h:1:
In file included from include/asm-generic/hardirq.h:17:
In file included from include/linux/irq.h:20:
In file included from include/linux/io.h:13:
In file included from arch/hexagon/include/asm/io.h:334:
include/asm-generic/io.h:573:61: warning: performing pointer arithmetic on a null pointer has undefined behavior [-Wnull-pointer-arithmetic]
val = __le32_to_cpu((__le32 __force)__raw_readl(PCI_IOBASE + addr));
~~~~~~~~~~ ^
include/uapi/linux/byteorder/little_endian.h:35:51: note: expanded from macro '__le32_to_cpu'
#define __le32_to_cpu(x) ((__force __u32)(__le32)(x))
^
In file included from kernel/trace/trace.c:18:
In file included from include/linux/writeback.h:13:
In file included from include/linux/blk_types.h:10:
In file included from include/linux/bvec.h:10:
In file included from include/linux/highmem.h:12:
In file included from include/linux/hardirq.h:11:
In file included from ./arch/hexagon/include/generated/asm/hardirq.h:1:
In file included from include/asm-generic/hardirq.h:17:
In file included from include/linux/irq.h:20:
In file included from include/linux/io.h:13:
In file included from arch/hexagon/include/asm/io.h:334:
include/asm-generic/io.h:584:33: warning: performing pointer arithmetic on a null pointer has undefined behavior [-Wnull-pointer-arithmetic]
__raw_writeb(value, PCI_IOBASE + addr);
~~~~~~~~~~ ^
include/asm-generic/io.h:594:59: warning: performing pointer arithmetic on a null pointer has undefined behavior [-Wnull-pointer-arithmetic]
__raw_writew((u16 __force)cpu_to_le16(value), PCI_IOBASE + addr);
~~~~~~~~~~ ^
include/asm-generic/io.h:604:59: warning: performing pointer arithmetic on a null pointer has undefined behavior [-Wnull-pointer-arithmetic]
__raw_writel((u32 __force)cpu_to_le32(value), PCI_IOBASE + addr);
~~~~~~~~~~ ^
>> kernel/trace/trace.c:10244:4: error: call to undeclared function 'do_allocate_snapshot'; ISO C99 and later do not support implicit function declarations [-Wimplicit-function-declaration]
do_allocate_snapshot(tok);
^
kernel/trace/trace.c:10244:4: note: did you mean 'boot_alloc_snapshot'?
kernel/trace/trace.c:232:19: note: 'boot_alloc_snapshot' declared here
static int __init boot_alloc_snapshot(char *str)
^
6 warnings and 1 error generated.
vim +/do_allocate_snapshot +10244 kernel/trace/trace.c
10227
10228 __init static void enable_instances(void)
10229 {
10230 struct trace_array *tr;
10231 char *curr_str;
10232 char *str;
10233 char *tok;
10234
10235 /* A tab is always appended */
10236 boot_instance_info[boot_instance_index - 1] = '\0';
10237 str = boot_instance_info;
10238
10239 while ((curr_str = strsep(&str, "\t"))) {
10240
10241 tok = strsep(&curr_str, ",");
10242
10243 if (IS_ENABLED(CONFIG_TRACER_MAX_TRACE))
10244 do_allocate_snapshot(tok);
10245
10246 tr = trace_array_get_by_name(tok);
10247 if (!tr) {
10248 pr_warn("Failed to create instance buffer %s\n", curr_str);
10249 continue;
10250 }
10251 /* Allow user space to delete it */
10252 trace_array_put(tr);
10253
10254 while ((tok = strsep(&curr_str, ","))) {
10255 early_enable_events(tr, tok, true);
10256 }
10257 }
10258 }
10259
Hi Steven,
Thank you for the patch! Perhaps something to improve:
[auto build test WARNING on akpm-mm/mm-everything]
[also build test WARNING on linus/master v6.2-rc3 next-20230111]
[If your patch is applied to the wrong git tree, kindly drop us a note.
And when submitting patch, we suggest to use '--base' as documented in
https://git-scm.com/docs/git-format-patch#_base_tree_information]
url: https://github.com/intel-lab-lkp/linux/commits/Steven-Rostedt/tracing-Add-creation-of-instances-at-boot-command-line/20230111-230425
base: https://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm.git mm-everything
patch link: https://lore.kernel.org/r/20230111145842.847715402%40goodmis.org
patch subject: [PATCH 4/4] tracing: Allow boot instances to have snapshot buffers
config: i386-randconfig-s001
compiler: gcc-11 (Debian 11.3.0-8) 11.3.0
reproduce:
# apt-get install sparse
# sparse version: v0.6.4-39-gce1a6720-dirty
# https://github.com/intel-lab-lkp/linux/commit/b4515aa1407184147348b74b42bf10af90b905e7
git remote add linux-review https://github.com/intel-lab-lkp/linux
git fetch --no-tags linux-review Steven-Rostedt/tracing-Add-creation-of-instances-at-boot-command-line/20230111-230425
git checkout b4515aa1407184147348b74b42bf10af90b905e7
# save the config file
mkdir build_dir && cp config build_dir/.config
make W=1 C=1 CF='-fdiagnostic-prefix -D__CHECK_ENDIAN__' O=build_dir ARCH=i386 olddefconfig
make W=1 C=1 CF='-fdiagnostic-prefix -D__CHECK_ENDIAN__' O=build_dir ARCH=i386 SHELL=/bin/bash kernel/trace/
If you fix the issue, kindly add following tag where applicable
| Reported-by: kernel test robot <lkp@intel.com>
sparse warnings: (new ones prefixed by >>)
kernel/trace/trace.c:5809:1: sparse: sparse: trying to concatenate 11905-character string (8191 bytes max)
kernel/trace/trace.c:444:28: sparse: sparse: incorrect type in argument 1 (different address spaces) @@ expected struct trace_export **list @@ got struct trace_export [noderef] __rcu ** @@
kernel/trace/trace.c:444:28: sparse: expected struct trace_export **list
kernel/trace/trace.c:444:28: sparse: got struct trace_export [noderef] __rcu **
kernel/trace/trace.c:458:33: sparse: sparse: incorrect type in argument 1 (different address spaces) @@ expected struct trace_export **list @@ got struct trace_export [noderef] __rcu ** @@
kernel/trace/trace.c:458:33: sparse: expected struct trace_export **list
kernel/trace/trace.c:458:33: sparse: got struct trace_export [noderef] __rcu **
kernel/trace/trace.c:2934:38: sparse: sparse: incorrect type in argument 1 (different address spaces) @@ expected struct event_filter *filter @@ got struct event_filter [noderef] __rcu *filter @@
kernel/trace/trace.c:2934:38: sparse: expected struct event_filter *filter
kernel/trace/trace.c:2934:38: sparse: got struct event_filter [noderef] __rcu *filter
>> kernel/trace/trace.c:10208:51: sparse: sparse: Using plain integer as NULL pointer
kernel/trace/trace.c:398:9: sparse: sparse: incompatible types in comparison expression (different address spaces):
kernel/trace/trace.c:398:9: sparse: struct trace_export [noderef] __rcu *
kernel/trace/trace.c:398:9: sparse: struct trace_export *
kernel/trace/trace.c:413:9: sparse: sparse: incompatible types in comparison expression (different address spaces):
kernel/trace/trace.c:413:9: sparse: struct trace_export [noderef] __rcu *
kernel/trace/trace.c:413:9: sparse: struct trace_export *
vim +10208 kernel/trace/trace.c
10188
10189 #ifdef CONFIG_TRACER_MAX_TRACE
10190 __init static bool tr_needs_alloc_snapshot(const char *name)
10191 {
10192 char *test;
10193 int len = strlen(name);
10194 bool ret;
10195
10196 if (!boot_snapshot_index)
10197 return false;
10198
10199 if (strncmp(name, boot_snapshot_info, len) == 0 &&
10200 boot_snapshot_info[len] == '\t')
10201 return true;
10202
10203 test = kmalloc(strlen(name) + 3, GFP_KERNEL);
10204 if (!test)
10205 return false;
10206
10207 sprintf(test, "\t%s\t", name);
10208 ret = strstr(boot_snapshot_info, test) == 0;
10209 kfree(test);
10210 return ret;
10211 }
10212
Hi Steven,
Thank you for the patch! Yet something to improve:
[auto build test ERROR on akpm-mm/mm-everything]
[also build test ERROR on linus/master v6.2-rc3 next-20230111]
[If your patch is applied to the wrong git tree, kindly drop us a note.
And when submitting patch, we suggest to use '--base' as documented in
https://git-scm.com/docs/git-format-patch#_base_tree_information]
url: https://github.com/intel-lab-lkp/linux/commits/Steven-Rostedt/tracing-Add-creation-of-instances-at-boot-command-line/20230111-230425
base: https://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm.git mm-everything
patch link: https://lore.kernel.org/r/20230111145842.847715402%40goodmis.org
patch subject: [PATCH 4/4] tracing: Allow boot instances to have snapshot buffers
config: i386-randconfig-a002
compiler: clang version 14.0.6 (https://github.com/llvm/llvm-project f28c006a5895fc0e329fe15fead81e37457cb1d1)
reproduce (this is a W=1 build):
wget https://raw.githubusercontent.com/intel/lkp-tests/master/sbin/make.cross -O ~/bin/make.cross
chmod +x ~/bin/make.cross
# https://github.com/intel-lab-lkp/linux/commit/b4515aa1407184147348b74b42bf10af90b905e7
git remote add linux-review https://github.com/intel-lab-lkp/linux
git fetch --no-tags linux-review Steven-Rostedt/tracing-Add-creation-of-instances-at-boot-command-line/20230111-230425
git checkout b4515aa1407184147348b74b42bf10af90b905e7
# save the config file
mkdir build_dir && cp config build_dir/.config
COMPILER_INSTALL_PATH=$HOME/0day COMPILER=clang make.cross W=1 O=build_dir ARCH=i386 olddefconfig
COMPILER_INSTALL_PATH=$HOME/0day COMPILER=clang make.cross W=1 O=build_dir ARCH=i386 SHELL=/bin/bash
If you fix the issue, kindly add following tag where applicable
| Reported-by: kernel test robot <lkp@intel.com>
All errors (new ones prefixed by >>):
>> kernel/trace/trace.c:10244:4: error: implicit declaration of function 'do_allocate_snapshot' is invalid in C99 [-Werror,-Wimplicit-function-declaration]
do_allocate_snapshot(tok);
^
kernel/trace/trace.c:10244:4: note: did you mean 'boot_alloc_snapshot'?
kernel/trace/trace.c:232:19: note: 'boot_alloc_snapshot' declared here
static int __init boot_alloc_snapshot(char *str)
^
1 error generated.
vim +/do_allocate_snapshot +10244 kernel/trace/trace.c
10227
10228 __init static void enable_instances(void)
10229 {
10230 struct trace_array *tr;
10231 char *curr_str;
10232 char *str;
10233 char *tok;
10234
10235 /* A tab is always appended */
10236 boot_instance_info[boot_instance_index - 1] = '\0';
10237 str = boot_instance_info;
10238
10239 while ((curr_str = strsep(&str, "\t"))) {
10240
10241 tok = strsep(&curr_str, ",");
10242
10243 if (IS_ENABLED(CONFIG_TRACER_MAX_TRACE))
10244 do_allocate_snapshot(tok);
10245
10246 tr = trace_array_get_by_name(tok);
10247 if (!tr) {
10248 pr_warn("Failed to create instance buffer %s\n", curr_str);
10249 continue;
10250 }
10251 /* Allow user space to delete it */
10252 trace_array_put(tr);
10253
10254 while ((tok = strsep(&curr_str, ","))) {
10255 early_enable_events(tr, tok, true);
10256 }
10257 }
10258 }
10259
On Wed, Jan 11, 2023 at 09:56:40AM -0500, Steven Rostedt wrote: > From: "Steven Rostedt (Google)" <rostedt@goodmis.org> > > Add to ftrace_boot_snapshot, "=<instance>" name, where the instance will > get a snapshot buffer, and will take a snapshot at the end of boot (which > will save the boot traces). > > Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org> > --- > .../admin-guide/kernel-parameters.txt | 9 +++ > kernel/trace/trace.c | 77 +++++++++++++++++-- > 2 files changed, 79 insertions(+), 7 deletions(-) > > diff --git a/Documentation/admin-guide/kernel-parameters.txt b/Documentation/admin-guide/kernel-parameters.txt > index 7a7f41652719..f4e87b17427f 100644 > --- a/Documentation/admin-guide/kernel-parameters.txt > +++ b/Documentation/admin-guide/kernel-parameters.txt > @@ -1532,6 +1532,15 @@ > boot up that is likely to be overridden by user space > start up functionality. > > + Optionally, the snapshot can also be defined for a tracing > + instance that was created by the trace_instance= command > + line parameter. > + > + trace_instance=foo,sched_switch ftrace_boot_snapshot=foo > + > + The above will cause the "foo" tracing instance to trigger > + a snapshot at the end of boot up. > + > ftrace_dump_on_oops[=orig_cpu] > [FTRACE] will dump the trace buffers on oops. > If no parameter is passed, ftrace will dump > diff --git a/kernel/trace/trace.c b/kernel/trace/trace.c > index 3cb9bbc0f076..d445789dc247 100644 > --- a/kernel/trace/trace.c > +++ b/kernel/trace/trace.c > @@ -192,6 +192,9 @@ static bool snapshot_at_boot; > static char boot_instance_info[COMMAND_LINE_SIZE] __initdata; > static int boot_instance_index; > > +static char boot_snapshot_info[COMMAND_LINE_SIZE] __initdata; For x86 machines at least COMMAND_LINE_SIZE is pretty big (2048), so between boot_instance_info and boot_snapshot_info we are using an entire 4k of memory. It seems unlikely that any user would need a string this long for these options. Should we trim this down to something smaller? > +static int boot_snapshot_index; > + > static int __init set_cmdline_ftrace(char *str) > { > strlcpy(bootup_tracer_buf, str, MAX_TRACER_SIZE); > @@ -228,9 +231,22 @@ __setup("traceoff_on_warning", stop_trace_on_warning); > > static int __init boot_alloc_snapshot(char *str) > { > - allocate_snapshot = true; > - /* We also need the main ring buffer expanded */ > - ring_buffer_expanded = true; > + char *slot = boot_snapshot_info + boot_snapshot_index; > + int left = COMMAND_LINE_SIZE - boot_snapshot_index; sizeof(boot_snapshot_info) is a bit safer than COMMAND_LINE_SIZE so they don't get out of sync, plus we may also want to shrink it a bit as mentioned above. Just two nits, other than that you can add: Reviewed-by: Ross Zwisler <zwisler@google.com>
On Fri, 13 Jan 2023 17:08:09 -0700 Ross Zwisler <zwisler@google.com> wrote: > > +++ b/kernel/trace/trace.c > > @@ -192,6 +192,9 @@ static bool snapshot_at_boot; > > static char boot_instance_info[COMMAND_LINE_SIZE] __initdata; > > static int boot_instance_index; > > > > +static char boot_snapshot_info[COMMAND_LINE_SIZE] __initdata; > > For x86 machines at least COMMAND_LINE_SIZE is pretty big (2048), so between > boot_instance_info and boot_snapshot_info we are using an entire 4k of memory. > It seems unlikely that any user would need a string this long for these > options. Should we trim this down to something smaller? They are both empty (BSS) and initdata. So they get allocated at boot up and freed at the end of boot. > > > +static int boot_snapshot_index; > > + > > static int __init set_cmdline_ftrace(char *str) > > { > > strlcpy(bootup_tracer_buf, str, MAX_TRACER_SIZE); > > @@ -228,9 +231,22 @@ __setup("traceoff_on_warning", stop_trace_on_warning); > > > > static int __init boot_alloc_snapshot(char *str) > > { > > - allocate_snapshot = true; > > - /* We also need the main ring buffer expanded */ > > - ring_buffer_expanded = true; > > + char *slot = boot_snapshot_info + boot_snapshot_index; > > + int left = COMMAND_LINE_SIZE - boot_snapshot_index; > > sizeof(boot_snapshot_info) is a bit safer than COMMAND_LINE_SIZE so they don't > get out of sync, plus we may also want to shrink it a bit as mentioned above. Yeah, I'm willing to do this (as mentioned before). > > Just two nits, other than that you can add: > > Reviewed-by: Ross Zwisler <zwisler@google.com> Thanks! -- Steve
diff --git a/Documentation/admin-guide/kernel-parameters.txt b/Documentation/admin-guide/kernel-parameters.txt index 7a7f41652719..f4e87b17427f 100644 --- a/Documentation/admin-guide/kernel-parameters.txt +++ b/Documentation/admin-guide/kernel-parameters.txt @@ -1532,6 +1532,15 @@ boot up that is likely to be overridden by user space start up functionality. + Optionally, the snapshot can also be defined for a tracing + instance that was created by the trace_instance= command + line parameter. + + trace_instance=foo,sched_switch ftrace_boot_snapshot=foo + + The above will cause the "foo" tracing instance to trigger + a snapshot at the end of boot up. + ftrace_dump_on_oops[=orig_cpu] [FTRACE] will dump the trace buffers on oops. If no parameter is passed, ftrace will dump diff --git a/kernel/trace/trace.c b/kernel/trace/trace.c index 3cb9bbc0f076..d445789dc247 100644 --- a/kernel/trace/trace.c +++ b/kernel/trace/trace.c @@ -192,6 +192,9 @@ static bool snapshot_at_boot; static char boot_instance_info[COMMAND_LINE_SIZE] __initdata; static int boot_instance_index; +static char boot_snapshot_info[COMMAND_LINE_SIZE] __initdata; +static int boot_snapshot_index; + static int __init set_cmdline_ftrace(char *str) { strlcpy(bootup_tracer_buf, str, MAX_TRACER_SIZE); @@ -228,9 +231,22 @@ __setup("traceoff_on_warning", stop_trace_on_warning); static int __init boot_alloc_snapshot(char *str) { - allocate_snapshot = true; - /* We also need the main ring buffer expanded */ - ring_buffer_expanded = true; + char *slot = boot_snapshot_info + boot_snapshot_index; + int left = COMMAND_LINE_SIZE - boot_snapshot_index; + int ret; + + if (str[0] == '=') { + str++; + if (strlen(str) >= left) + return -1; + + ret = snprintf(slot, left, "%s\t", str); + boot_snapshot_index += ret; + } else { + allocate_snapshot = true; + /* We also need the main ring buffer expanded */ + ring_buffer_expanded = true; + } return 1; } __setup("alloc_snapshot", boot_alloc_snapshot); @@ -9255,10 +9271,6 @@ static int allocate_trace_buffers(struct trace_array *tr, int size) } tr->allocated_snapshot = allocate_snapshot; - /* - * Only the top level trace array gets its snapshot allocated - * from the kernel command line. - */ allocate_snapshot = false; #endif @@ -10174,6 +10186,45 @@ ssize_t trace_parse_run_command(struct file *file, const char __user *buffer, return ret; } +#ifdef CONFIG_TRACER_MAX_TRACE +__init static bool tr_needs_alloc_snapshot(const char *name) +{ + char *test; + int len = strlen(name); + bool ret; + + if (!boot_snapshot_index) + return false; + + if (strncmp(name, boot_snapshot_info, len) == 0 && + boot_snapshot_info[len] == '\t') + return true; + + test = kmalloc(strlen(name) + 3, GFP_KERNEL); + if (!test) + return false; + + sprintf(test, "\t%s\t", name); + ret = strstr(boot_snapshot_info, test) == 0; + kfree(test); + return ret; +} + +__init static void do_allocate_snapshot(const char *name) +{ + if (!tr_needs_alloc_snapshot(name)) + return; + + /* + * When allocate_snapshot is set, the next call to + * allocate_trace_buffers() (called by trace_array_get_by_name()) + * will allocate the snapshot buffer. That will alse clear + * this flag. + */ + allocate_snapshot = true; +} +#endif + __init static void enable_instances(void) { struct trace_array *tr; @@ -10189,6 +10240,9 @@ __init static void enable_instances(void) tok = strsep(&curr_str, ","); + if (IS_ENABLED(CONFIG_TRACER_MAX_TRACE)) + do_allocate_snapshot(tok); + tr = trace_array_get_by_name(tok); if (!tr) { pr_warn("Failed to create instance buffer %s\n", curr_str); @@ -10336,10 +10390,19 @@ __init static int tracer_alloc_buffers(void) void __init ftrace_boot_snapshot(void) { + struct trace_array *tr; + if (snapshot_at_boot) { tracing_snapshot(); internal_trace_puts("** Boot snapshot taken **\n"); } + + list_for_each_entry(tr, &ftrace_trace_arrays, list) { + if (tr == &global_trace) + continue; + trace_array_puts(tr, "** Boot snapshot taken **\n"); + tracing_snapshot_instance(tr); + } } void __init early_trace_init(void)