* [PATCH-for-4.2 v3 0/3] hw: Remove dynamic field width from trace events
@ 2019-11-18 21:04 Philippe Mathieu-Daudé
2019-11-18 21:04 ` [PATCH-for-4.2 v3 1/3] hw/block/pflash: " Philippe Mathieu-Daudé
` (3 more replies)
0 siblings, 4 replies; 10+ messages in thread
From: Philippe Mathieu-Daudé @ 2019-11-18 21:04 UTC (permalink / raw)
To: Eric Blake, qemu-devel
Cc: Kevin Wolf, Stefan Hajnoczi, qemu-block, qemu-trivial, Max Reitz,
Aleksandar Markovic, Aleksandar Rikalo,
Philippe Mathieu-Daudé,
Aurelien Jarno
Eric noted in [1] the dtrace via stap backend can not support
the dynamic '*' width format.
I'd really like to use dynamic width in trace event because the
read/write accesses are easier to read but it is not a priority.
Since next release is close, time to fix LP#1844817 [2].
Since v2:
- addressed Eric review comments from v2
- improved the documentation
Since v1:
- Do not update the qemu_log_mask() calls in hw/mips/gt64xxx_pci.c
[1] https://lists.gnu.org/archive/html/qemu-devel/2019-09/msg04720.html
[2] https://bugs.launchpad.net/qemu/+bug/1844817
Philippe Mathieu-Daudé (3):
hw/block/pflash: Remove dynamic field width from trace events
hw/mips/gt64xxx: Remove dynamic field width from trace events
trace: Forbid dynamic field width in event format
docs/devel/tracing.txt | 3 ++-
hw/block/pflash_cfi01.c | 8 ++++----
hw/block/pflash_cfi02.c | 8 ++++----
hw/mips/gt64xxx_pci.c | 16 ++++++++--------
hw/block/trace-events | 8 ++++----
hw/mips/trace-events | 4 ++--
scripts/tracetool/__init__.py | 3 +++
7 files changed, 27 insertions(+), 23 deletions(-)
--
2.21.0
^ permalink raw reply [flat|nested] 10+ messages in thread
* [PATCH-for-4.2 v3 1/3] hw/block/pflash: Remove dynamic field width from trace events
2019-11-18 21:04 [PATCH-for-4.2 v3 0/3] hw: Remove dynamic field width from trace events Philippe Mathieu-Daudé
@ 2019-11-18 21:04 ` Philippe Mathieu-Daudé
2019-11-18 21:15 ` Eric Blake
2019-11-18 21:04 ` [PATCH-for-4.2 v3 2/3] hw/mips/gt64xxx: " Philippe Mathieu-Daudé
` (2 subsequent siblings)
3 siblings, 1 reply; 10+ messages in thread
From: Philippe Mathieu-Daudé @ 2019-11-18 21:04 UTC (permalink / raw)
To: Eric Blake, qemu-devel
Cc: Kevin Wolf, Stefan Hajnoczi, qemu-block, qemu-trivial, Max Reitz,
Aleksandar Markovic, Aleksandar Rikalo,
Philippe Mathieu-Daudé,
Aurelien Jarno
Since not all trace backends support dynamic field width in
format (dtrace via stap does not), replace by a static field
width instead.
We previously passed to the trace API 'width << 1' as the number
of hex characters to display (the dynamic field width). We don't
need this anymore. Instead, display the size of bytes accessed.
Reported-by: Eric Blake <eblake@redhat.com>
Buglink: https://bugs.launchpad.net/qemu/+bug/1844817
Signed-off-by: Philippe Mathieu-Daudé <philmd@redhat.com>
---
v3: display size (in byte)
hw/block/pflash_cfi01.c | 8 ++++----
hw/block/pflash_cfi02.c | 8 ++++----
hw/block/trace-events | 8 ++++----
3 files changed, 12 insertions(+), 12 deletions(-)
diff --git a/hw/block/pflash_cfi01.c b/hw/block/pflash_cfi01.c
index 566c0acb77..54e6ebd385 100644
--- a/hw/block/pflash_cfi01.c
+++ b/hw/block/pflash_cfi01.c
@@ -276,7 +276,7 @@ static uint32_t pflash_data_read(PFlashCFI01 *pfl, hwaddr offset,
DPRINTF("BUG in %s\n", __func__);
abort();
}
- trace_pflash_data_read(offset, width << 1, ret);
+ trace_pflash_data_read(offset, width, ret);
return ret;
}
@@ -389,7 +389,7 @@ static uint32_t pflash_read(PFlashCFI01 *pfl, hwaddr offset,
break;
}
- trace_pflash_io_read(offset, width, width << 1, ret, pfl->cmd, pfl->wcycle);
+ trace_pflash_io_read(offset, width, ret, pfl->cmd, pfl->wcycle);
return ret;
}
@@ -414,7 +414,7 @@ static inline void pflash_data_write(PFlashCFI01 *pfl, hwaddr offset,
{
uint8_t *p = pfl->storage;
- trace_pflash_data_write(offset, width << 1, value, pfl->counter);
+ trace_pflash_data_write(offset, width, value, pfl->counter);
switch (width) {
case 1:
p[offset] = value;
@@ -453,7 +453,7 @@ static void pflash_write(PFlashCFI01 *pfl, hwaddr offset,
cmd = value;
- trace_pflash_io_write(offset, width, width << 1, value, pfl->wcycle);
+ trace_pflash_io_write(offset, width, value, pfl->wcycle);
if (!pfl->wcycle) {
/* Set the device in I/O access mode */
memory_region_rom_device_set_romd(&pfl->mem, false);
diff --git a/hw/block/pflash_cfi02.c b/hw/block/pflash_cfi02.c
index 4baca701b7..c7d92c3e79 100644
--- a/hw/block/pflash_cfi02.c
+++ b/hw/block/pflash_cfi02.c
@@ -260,7 +260,7 @@ static uint64_t pflash_data_read(PFlashCFI02 *pfl, hwaddr offset,
{
uint8_t *p = (uint8_t *)pfl->storage + offset;
uint64_t ret = pfl->be ? ldn_be_p(p, width) : ldn_le_p(p, width);
- trace_pflash_data_read(offset, width << 1, ret);
+ trace_pflash_data_read(offset, width, ret);
return ret;
}
@@ -385,7 +385,7 @@ static uint64_t pflash_read(void *opaque, hwaddr offset, unsigned int width)
}
break;
}
- trace_pflash_io_read(offset, width, width << 1, ret, pfl->cmd, pfl->wcycle);
+ trace_pflash_io_read(offset, width, ret, pfl->cmd, pfl->wcycle);
return ret;
}
@@ -432,7 +432,7 @@ static void pflash_write(void *opaque, hwaddr offset, uint64_t value,
uint8_t *p;
uint8_t cmd;
- trace_pflash_io_write(offset, width, width << 1, value, pfl->wcycle);
+ trace_pflash_io_write(offset, width, value, pfl->wcycle);
cmd = value;
if (pfl->cmd != 0xA0) {
/* Reset does nothing during chip erase and sector erase. */
@@ -542,7 +542,7 @@ static void pflash_write(void *opaque, hwaddr offset, uint64_t value,
}
goto reset_flash;
}
- trace_pflash_data_write(offset, width << 1, value, 0);
+ trace_pflash_data_write(offset, width, value, 0);
if (!pfl->ro) {
p = (uint8_t *)pfl->storage + offset;
if (pfl->be) {
diff --git a/hw/block/trace-events b/hw/block/trace-events
index 13d1b21dd4..c03e80c2c9 100644
--- a/hw/block/trace-events
+++ b/hw/block/trace-events
@@ -8,10 +8,10 @@ fdc_ioport_write(uint8_t reg, uint8_t value) "write reg 0x%02x val 0x%02x"
# pflash_cfi01.c
pflash_reset(void) "reset"
pflash_timer_expired(uint8_t cmd) "command 0x%02x done"
-pflash_io_read(uint64_t offset, int width, int fmt_width, uint32_t value, uint8_t cmd, uint8_t wcycle) "offset:0x%04"PRIx64" width:%d value:0x%0*x cmd:0x%02x wcycle:%u"
-pflash_io_write(uint64_t offset, int width, int fmt_width, uint32_t value, uint8_t wcycle) "offset:0x%04"PRIx64" width:%d value:0x%0*x wcycle:%u"
-pflash_data_read(uint64_t offset, int width, uint32_t value) "data offset:0x%04"PRIx64" value:0x%0*x"
-pflash_data_write(uint64_t offset, int width, uint32_t value, uint64_t counter) "data offset:0x%04"PRIx64" value:0x%0*x counter:0x%016"PRIx64
+pflash_io_read(uint64_t offset, unsigned size, uint32_t value, uint8_t cmd, uint8_t wcycle) "offset:0x%04"PRIx64" size:%u value:0x%04x cmd:0x%02x wcycle:%u"
+pflash_io_write(uint64_t offset, unsigned size, uint32_t value, uint8_t wcycle) "offset:0x%04"PRIx64" size:%u value:0x%04x wcycle:%u"
+pflash_data_read(uint64_t offset, unsigned size, uint32_t value) "data offset:0x%04"PRIx64" size:%u value:0x%04x"
+pflash_data_write(uint64_t offset, unsigned size, uint32_t value, uint64_t counter) "data offset:0x%04"PRIx64" size:%u value:0x%04x counter:0x%016"PRIx64
pflash_manufacturer_id(uint16_t id) "Read Manufacturer ID: 0x%04x"
pflash_device_id(uint16_t id) "Read Device ID: 0x%04x"
pflash_device_info(uint64_t offset) "Read Device Information offset:0x%04"PRIx64
--
2.21.0
^ permalink raw reply related [flat|nested] 10+ messages in thread
* [PATCH-for-4.2 v3 2/3] hw/mips/gt64xxx: Remove dynamic field width from trace events
2019-11-18 21:04 [PATCH-for-4.2 v3 0/3] hw: Remove dynamic field width from trace events Philippe Mathieu-Daudé
2019-11-18 21:04 ` [PATCH-for-4.2 v3 1/3] hw/block/pflash: " Philippe Mathieu-Daudé
@ 2019-11-18 21:04 ` Philippe Mathieu-Daudé
2019-11-18 21:17 ` Eric Blake
2019-11-18 21:04 ` [PATCH-for-4.2 v3 3/3] trace: Forbid dynamic field width in event format Philippe Mathieu-Daudé
2019-11-19 7:32 ` [PATCH-for-4.2 v3 0/3] hw: Remove dynamic field width from trace events Richard Henderson
3 siblings, 1 reply; 10+ messages in thread
From: Philippe Mathieu-Daudé @ 2019-11-18 21:04 UTC (permalink / raw)
To: Eric Blake, qemu-devel
Cc: Kevin Wolf, Stefan Hajnoczi, qemu-block, qemu-trivial, Max Reitz,
Aleksandar Markovic, Aleksandar Rikalo,
Philippe Mathieu-Daudé,
Aurelien Jarno
Since not all trace backends support dynamic field width in
format (dtrace via stap does not), replace by a static field
width instead.
We previously passed to the trace API 'width << 1' as the number
of hex characters to display (the dynamic field width). We don't
need this anymore. Instead, display the size of bytes accessed.
Reported-by: Eric Blake <eblake@redhat.com>
Buglink: https://bugs.launchpad.net/qemu/+bug/1844817
Signed-off-by: Philippe Mathieu-Daudé <philmd@redhat.com>
---
v2: Do not update qemu_log_mask()
v3: display size (in byte)
---
hw/mips/gt64xxx_pci.c | 16 ++++++++--------
hw/mips/trace-events | 4 ++--
2 files changed, 10 insertions(+), 10 deletions(-)
diff --git a/hw/mips/gt64xxx_pci.c b/hw/mips/gt64xxx_pci.c
index 5cab9c1ee1..f1af840d8e 100644
--- a/hw/mips/gt64xxx_pci.c
+++ b/hw/mips/gt64xxx_pci.c
@@ -642,19 +642,19 @@ static void gt64120_writel(void *opaque, hwaddr addr,
/* not really implemented */
s->regs[saddr] = ~(~(s->regs[saddr]) | ~(val & 0xfffffffe));
s->regs[saddr] |= !!(s->regs[saddr] & 0xfffffffe);
- trace_gt64120_write("INTRCAUSE", size << 1, val);
+ trace_gt64120_write("INTRCAUSE", size, val);
break;
case GT_INTRMASK:
s->regs[saddr] = val & 0x3c3ffffe;
- trace_gt64120_write("INTRMASK", size << 1, val);
+ trace_gt64120_write("INTRMASK", size, val);
break;
case GT_PCI0_ICMASK:
s->regs[saddr] = val & 0x03fffffe;
- trace_gt64120_write("ICMASK", size << 1, val);
+ trace_gt64120_write("ICMASK", size, val);
break;
case GT_PCI0_SERR0MASK:
s->regs[saddr] = val & 0x0000003f;
- trace_gt64120_write("SERR0MASK", size << 1, val);
+ trace_gt64120_write("SERR0MASK", size, val);
break;
/* Reserved when only PCI_0 is configured. */
@@ -930,19 +930,19 @@ static uint64_t gt64120_readl(void *opaque,
/* Interrupts */
case GT_INTRCAUSE:
val = s->regs[saddr];
- trace_gt64120_read("INTRCAUSE", size << 1, val);
+ trace_gt64120_read("INTRCAUSE", size, val);
break;
case GT_INTRMASK:
val = s->regs[saddr];
- trace_gt64120_read("INTRMASK", size << 1, val);
+ trace_gt64120_read("INTRMASK", size, val);
break;
case GT_PCI0_ICMASK:
val = s->regs[saddr];
- trace_gt64120_read("ICMASK", size << 1, val);
+ trace_gt64120_read("ICMASK", size, val);
break;
case GT_PCI0_SERR0MASK:
val = s->regs[saddr];
- trace_gt64120_read("SERR0MASK", size << 1, val);
+ trace_gt64120_read("SERR0MASK", size, val);
break;
/* Reserved when only PCI_0 is configured. */
diff --git a/hw/mips/trace-events b/hw/mips/trace-events
index 75d4c73f2e..321933283f 100644
--- a/hw/mips/trace-events
+++ b/hw/mips/trace-events
@@ -1,4 +1,4 @@
# gt64xxx.c
-gt64120_read(const char *regname, int width, uint64_t value) "gt64120 read %s value:0x%0*" PRIx64
-gt64120_write(const char *regname, int width, uint64_t value) "gt64120 write %s value:0x%0*" PRIx64
+gt64120_read(const char *regname, unsigned size, uint64_t value) "gt64120 read %s size:%u value:0x%08" PRIx64
+gt64120_write(const char *regname, unsigned size, uint64_t value) "gt64120 write %s size:%u value:0x%08" PRIx64
gt64120_isd_remap(uint64_t from_length, uint64_t from_addr, uint64_t to_length, uint64_t to_addr) "ISD: 0x%08" PRIx64 "@0x%08" PRIx64 " -> 0x%08" PRIx64 "@0x%08" PRIx64
--
2.21.0
^ permalink raw reply related [flat|nested] 10+ messages in thread
* [PATCH-for-4.2 v3 3/3] trace: Forbid dynamic field width in event format
2019-11-18 21:04 [PATCH-for-4.2 v3 0/3] hw: Remove dynamic field width from trace events Philippe Mathieu-Daudé
2019-11-18 21:04 ` [PATCH-for-4.2 v3 1/3] hw/block/pflash: " Philippe Mathieu-Daudé
2019-11-18 21:04 ` [PATCH-for-4.2 v3 2/3] hw/mips/gt64xxx: " Philippe Mathieu-Daudé
@ 2019-11-18 21:04 ` Philippe Mathieu-Daudé
2019-11-18 21:26 ` Eric Blake
2019-11-19 7:32 ` [PATCH-for-4.2 v3 0/3] hw: Remove dynamic field width from trace events Richard Henderson
3 siblings, 1 reply; 10+ messages in thread
From: Philippe Mathieu-Daudé @ 2019-11-18 21:04 UTC (permalink / raw)
To: Eric Blake, qemu-devel
Cc: Kevin Wolf, Stefan Hajnoczi, qemu-block, qemu-trivial, Max Reitz,
Aleksandar Markovic, Aleksandar Rikalo,
Philippe Mathieu-Daudé,
Aurelien Jarno
Since not all trace backends support dynamic field width in
format (dtrace via stap does not), forbid them.
Add a check to refuse field width in new formats:
$ make
[...]
GEN hw/block/trace.h
Traceback (most recent call last):
File "scripts/tracetool.py", line 152, in <module>
main(sys.argv)
File "scripts/tracetool.py", line 143, in main
events.extend(tracetool.read_events(fh, arg))
File "scripts/tracetool/__init__.py", line 371, in read_events
event = Event.build(line)
File "scripts/tracetool/__init__.py", line 285, in build
raise ValueError("Event format must not contain field width '%*'")
ValueError: Error at hw/block/trace-events:11: Event format must not contain field width '%*'
Reported-by: Eric Blake <eblake@redhat.com>
Buglink: https://bugs.launchpad.net/qemu/+bug/1844817
Signed-off-by: Philippe Mathieu-Daudé <philmd@redhat.com>
---
v3:
- use better regex provided by Eric,
- instead of re.match(), use re.search() which takes unanchored regex,
- added a comment in tracing.txt
---
docs/devel/tracing.txt | 3 ++-
scripts/tracetool/__init__.py | 3 +++
2 files changed, 5 insertions(+), 1 deletion(-)
diff --git a/docs/devel/tracing.txt b/docs/devel/tracing.txt
index 8c0376fefa..6c01ce801e 100644
--- a/docs/devel/tracing.txt
+++ b/docs/devel/tracing.txt
@@ -113,7 +113,8 @@ Format strings should reflect the types defined in the trace event. Take
special care to use PRId64 and PRIu64 for int64_t and uint64_t types,
respectively. This ensures portability between 32- and 64-bit platforms.
Format strings must not end with a newline character. It is the responsibility
-of backends to adapt line ending for proper logging.
+of backends to adapt line ending for proper logging. Format strings must not
+use numeric field width dynamic precision (SystemTap does not support them).
Each event declaration will start with the event name, then its arguments,
finally a format string for pretty-printing. For example:
diff --git a/scripts/tracetool/__init__.py b/scripts/tracetool/__init__.py
index 44c118bc2a..ec7fe9fa4a 100644
--- a/scripts/tracetool/__init__.py
+++ b/scripts/tracetool/__init__.py
@@ -206,6 +206,7 @@ class Event(object):
"\s*"
"(?:(?:(?P<fmt_trans>\".+),)?\s*(?P<fmt>\".+))?"
"\s*")
+ _DFWRE = re.compile(r"%[\d\.\- +#']*\*") # dynamic width precision
_VALID_PROPS = set(["disable", "tcg", "tcg-trans", "tcg-exec", "vcpu"])
@@ -280,6 +281,8 @@ class Event(object):
if fmt.endswith(r'\n"'):
raise ValueError("Event format must not end with a newline "
"character")
+ if Event._DFWRE.search(fmt):
+ raise ValueError("Event format must not contain field width '%*'")
if len(fmt_trans) > 0:
fmt = [fmt_trans, fmt]
--
2.21.0
^ permalink raw reply related [flat|nested] 10+ messages in thread
* Re: [PATCH-for-4.2 v3 1/3] hw/block/pflash: Remove dynamic field width from trace events
2019-11-18 21:04 ` [PATCH-for-4.2 v3 1/3] hw/block/pflash: " Philippe Mathieu-Daudé
@ 2019-11-18 21:15 ` Eric Blake
2019-11-18 21:20 ` Philippe Mathieu-Daudé
0 siblings, 1 reply; 10+ messages in thread
From: Eric Blake @ 2019-11-18 21:15 UTC (permalink / raw)
To: Philippe Mathieu-Daudé, qemu-devel
Cc: Kevin Wolf, Stefan Hajnoczi, qemu-block, qemu-trivial, Max Reitz,
Aleksandar Markovic, Aleksandar Rikalo, Aurelien Jarno
On 11/18/19 3:04 PM, Philippe Mathieu-Daudé wrote:
> Since not all trace backends support dynamic field width in
> format (dtrace via stap does not), replace by a static field
> width instead.
>
> We previously passed to the trace API 'width << 1' as the number
> of hex characters to display (the dynamic field width). We don't
> need this anymore. Instead, display the size of bytes accessed.
>
> Reported-by: Eric Blake <eblake@redhat.com>
> Buglink: https://bugs.launchpad.net/qemu/+bug/1844817
> Signed-off-by: Philippe Mathieu-Daudé <philmd@redhat.com>
Is it worth a Fixes: XXX calling out the commit that introduced the '*'?
/me goes and searches
Fixes: e8aa2d95ea
Fixes: c1474acd5d
Reviewed-by: Eric Blake <eblake@redhat.com>
--
Eric Blake, Principal Software Engineer
Red Hat, Inc. +1-919-301-3226
Virtualization: qemu.org | libvirt.org
^ permalink raw reply [flat|nested] 10+ messages in thread
* Re: [PATCH-for-4.2 v3 2/3] hw/mips/gt64xxx: Remove dynamic field width from trace events
2019-11-18 21:04 ` [PATCH-for-4.2 v3 2/3] hw/mips/gt64xxx: " Philippe Mathieu-Daudé
@ 2019-11-18 21:17 ` Eric Blake
0 siblings, 0 replies; 10+ messages in thread
From: Eric Blake @ 2019-11-18 21:17 UTC (permalink / raw)
To: Philippe Mathieu-Daudé, qemu-devel
Cc: Kevin Wolf, Stefan Hajnoczi, qemu-block, qemu-trivial, Max Reitz,
Aleksandar Markovic, Aleksandar Rikalo, Aurelien Jarno
On 11/18/19 3:04 PM, Philippe Mathieu-Daudé wrote:
> Since not all trace backends support dynamic field width in
> format (dtrace via stap does not), replace by a static field
> width instead.
>
> We previously passed to the trace API 'width << 1' as the number
> of hex characters to display (the dynamic field width). We don't
> need this anymore. Instead, display the size of bytes accessed.
>
> Reported-by: Eric Blake <eblake@redhat.com>
> Buglink: https://bugs.launchpad.net/qemu/+bug/1844817
> Signed-off-by: Philippe Mathieu-Daudé <philmd@redhat.com>
Fixes: ab6bff424f
Reviewed-by: Eric Blake <eblake@redhat.com>
--
Eric Blake, Principal Software Engineer
Red Hat, Inc. +1-919-301-3226
Virtualization: qemu.org | libvirt.org
^ permalink raw reply [flat|nested] 10+ messages in thread
* Re: [PATCH-for-4.2 v3 1/3] hw/block/pflash: Remove dynamic field width from trace events
2019-11-18 21:15 ` Eric Blake
@ 2019-11-18 21:20 ` Philippe Mathieu-Daudé
0 siblings, 0 replies; 10+ messages in thread
From: Philippe Mathieu-Daudé @ 2019-11-18 21:20 UTC (permalink / raw)
To: Eric Blake, qemu-devel
Cc: Kevin Wolf, Stefan Hajnoczi, qemu-block, qemu-trivial, Max Reitz,
Aleksandar Markovic, Aleksandar Rikalo, Aurelien Jarno
On 11/18/19 10:15 PM, Eric Blake wrote:
> On 11/18/19 3:04 PM, Philippe Mathieu-Daudé wrote:
>> Since not all trace backends support dynamic field width in
>> format (dtrace via stap does not), replace by a static field
>> width instead.
>>
>> We previously passed to the trace API 'width << 1' as the number
>> of hex characters to display (the dynamic field width). We don't
>> need this anymore. Instead, display the size of bytes accessed.
>>
>> Reported-by: Eric Blake <eblake@redhat.com>
>> Buglink: https://bugs.launchpad.net/qemu/+bug/1844817
>> Signed-off-by: Philippe Mathieu-Daudé <philmd@redhat.com>
>
> Is it worth a Fixes: XXX calling out the commit that introduced the '*'?
Yes, good idea.
>
> /me goes and searches
>
> Fixes: e8aa2d95ea
> Fixes: c1474acd5d
Similarly the next patch (hw/mips/gt64xxx_pci.c) fixes ab6bff424f4.
> Reviewed-by: Eric Blake <eblake@redhat.com>
Thanks!
^ permalink raw reply [flat|nested] 10+ messages in thread
* Re: [PATCH-for-4.2 v3 3/3] trace: Forbid dynamic field width in event format
2019-11-18 21:04 ` [PATCH-for-4.2 v3 3/3] trace: Forbid dynamic field width in event format Philippe Mathieu-Daudé
@ 2019-11-18 21:26 ` Eric Blake
2019-11-18 21:31 ` Philippe Mathieu-Daudé
0 siblings, 1 reply; 10+ messages in thread
From: Eric Blake @ 2019-11-18 21:26 UTC (permalink / raw)
To: Philippe Mathieu-Daudé, qemu-devel
Cc: Kevin Wolf, Stefan Hajnoczi, qemu-block, qemu-trivial, Max Reitz,
Aleksandar Markovic, Aleksandar Rikalo, Aurelien Jarno
On 11/18/19 3:04 PM, Philippe Mathieu-Daudé wrote:
> Since not all trace backends support dynamic field width in
> format (dtrace via stap does not), forbid them.
>
> Add a check to refuse field width in new formats:
>
> $ make
> [...]
> GEN hw/block/trace.h
> Traceback (most recent call last):
> File "scripts/tracetool.py", line 152, in <module>
> main(sys.argv)
> File "scripts/tracetool.py", line 143, in main
> events.extend(tracetool.read_events(fh, arg))
> File "scripts/tracetool/__init__.py", line 371, in read_events
> event = Event.build(line)
> File "scripts/tracetool/__init__.py", line 285, in build
> raise ValueError("Event format must not contain field width '%*'")
> ValueError: Error at hw/block/trace-events:11: Event format must not contain field width '%*'
>
> Reported-by: Eric Blake <eblake@redhat.com>
> Buglink: https://bugs.launchpad.net/qemu/+bug/1844817
> Signed-off-by: Philippe Mathieu-Daudé <philmd@redhat.com>
> ---
> +++ b/docs/devel/tracing.txt
> @@ -113,7 +113,8 @@ Format strings should reflect the types defined in the trace event. Take
> special care to use PRId64 and PRIu64 for int64_t and uint64_t types,
> respectively. This ensures portability between 32- and 64-bit platforms.
> Format strings must not end with a newline character. It is the responsibility
> -of backends to adapt line ending for proper logging.
> +of backends to adapt line ending for proper logging. Format strings must not
> +use numeric field width dynamic precision (SystemTap does not support them).
Reads awkwardly - a dynamic precision is not numeric in the format
string (but '*' instead). Better might be:
Format strings must not use dynamic field width or precision ('*'), as
at least SystemTap does not support them.
Or even:
Format strings may use numeric field width or precision, but must not
use dynamic forms ('*') as at least SystemTap does not support that.
>
> Each event declaration will start with the event name, then its arguments,
> finally a format string for pretty-printing. For example:
> diff --git a/scripts/tracetool/__init__.py b/scripts/tracetool/__init__.py
> index 44c118bc2a..ec7fe9fa4a 100644
> --- a/scripts/tracetool/__init__.py
> +++ b/scripts/tracetool/__init__.py
> @@ -206,6 +206,7 @@ class Event(object):
> "\s*"
> "(?:(?:(?P<fmt_trans>\".+),)?\s*(?P<fmt>\".+))?"
> "\s*")
> + _DFWRE = re.compile(r"%[\d\.\- +#']*\*") # dynamic width precision
The comment is slightly off - this catches both dynamic field width (any
'*' before '.') and dynamic precision (any '*' after '.'), maybe the fix
is just s/width/width or/
>
> _VALID_PROPS = set(["disable", "tcg", "tcg-trans", "tcg-exec", "vcpu"])
>
> @@ -280,6 +281,8 @@ class Event(object):
> if fmt.endswith(r'\n"'):
> raise ValueError("Event format must not end with a newline "
> "character")
> + if Event._DFWRE.search(fmt):
> + raise ValueError("Event format must not contain field width '%*'")
and I don't know if you want to tweak the error message, maybe:
Event format must not use dynamic '*'
If we're trying to get stuff in 4.2-rc2, patch 1 and 2 are actual bug
fixes and deserve to go in; patch 3 is nice-to-have but doesn't affect
the build if it is omitted (as there are no other offenders left), so
slipping it into 5.0 for a v4 to clean it up slightly doesn't hurt. I
don't know who would send the pull request, though, and slipping 1 and 2
into -rc3 just because of 3 is not ideal.
--
Eric Blake, Principal Software Engineer
Red Hat, Inc. +1-919-301-3226
Virtualization: qemu.org | libvirt.org
^ permalink raw reply [flat|nested] 10+ messages in thread
* Re: [PATCH-for-4.2 v3 3/3] trace: Forbid dynamic field width in event format
2019-11-18 21:26 ` Eric Blake
@ 2019-11-18 21:31 ` Philippe Mathieu-Daudé
0 siblings, 0 replies; 10+ messages in thread
From: Philippe Mathieu-Daudé @ 2019-11-18 21:31 UTC (permalink / raw)
To: Eric Blake, qemu-devel
Cc: Kevin Wolf, Stefan Hajnoczi, qemu-block, qemu-trivial, Max Reitz,
Aleksandar Markovic, Aleksandar Rikalo, Aurelien Jarno
On 11/18/19 10:26 PM, Eric Blake wrote:
> On 11/18/19 3:04 PM, Philippe Mathieu-Daudé wrote:
>> Since not all trace backends support dynamic field width in
>> format (dtrace via stap does not), forbid them.
>>
>> Add a check to refuse field width in new formats:
>>
>> $ make
>> [...]
>> GEN hw/block/trace.h
>> Traceback (most recent call last):
>> File "scripts/tracetool.py", line 152, in <module>
>> main(sys.argv)
>> File "scripts/tracetool.py", line 143, in main
>> events.extend(tracetool.read_events(fh, arg))
>> File "scripts/tracetool/__init__.py", line 371, in read_events
>> event = Event.build(line)
>> File "scripts/tracetool/__init__.py", line 285, in build
>> raise ValueError("Event format must not contain field width '%*'")
>> ValueError: Error at hw/block/trace-events:11: Event format must
>> not contain field width '%*'
>>
>> Reported-by: Eric Blake <eblake@redhat.com>
>> Buglink: https://bugs.launchpad.net/qemu/+bug/1844817
>> Signed-off-by: Philippe Mathieu-Daudé <philmd@redhat.com>
>> ---
>
>> +++ b/docs/devel/tracing.txt
>> @@ -113,7 +113,8 @@ Format strings should reflect the types defined in
>> the trace event. Take
>> special care to use PRId64 and PRIu64 for int64_t and uint64_t types,
>> respectively. This ensures portability between 32- and 64-bit
>> platforms.
>> Format strings must not end with a newline character. It is the
>> responsibility
>> -of backends to adapt line ending for proper logging.
>> +of backends to adapt line ending for proper logging. Format strings
>> must not
>> +use numeric field width dynamic precision (SystemTap does not support
>> them).
>
> Reads awkwardly - a dynamic precision is not numeric in the format
> string (but '*' instead). Better might be:
>
> Format strings must not use dynamic field width or precision ('*'), as
> at least SystemTap does not support them.
>
> Or even:
>
> Format strings may use numeric field width or precision, but must not
> use dynamic forms ('*') as at least SystemTap does not support that.
>
>> Each event declaration will start with the event name, then its
>> arguments,
>> finally a format string for pretty-printing. For example:
>> diff --git a/scripts/tracetool/__init__.py
>> b/scripts/tracetool/__init__.py
>> index 44c118bc2a..ec7fe9fa4a 100644
>> --- a/scripts/tracetool/__init__.py
>> +++ b/scripts/tracetool/__init__.py
>> @@ -206,6 +206,7 @@ class Event(object):
>> "\s*"
>> "(?:(?:(?P<fmt_trans>\".+),)?\s*(?P<fmt>\".+))?"
>> "\s*")
>> + _DFWRE = re.compile(r"%[\d\.\- +#']*\*") # dynamic width precision
>
> The comment is slightly off - this catches both dynamic field width (any
> '*' before '.') and dynamic precision (any '*' after '.'), maybe the fix
> is just s/width/width or/
>
>> _VALID_PROPS = set(["disable", "tcg", "tcg-trans", "tcg-exec",
>> "vcpu"])
>> @@ -280,6 +281,8 @@ class Event(object):
>> if fmt.endswith(r'\n"'):
>> raise ValueError("Event format must not end with a
>> newline "
>> "character")
>> + if Event._DFWRE.search(fmt):
>> + raise ValueError("Event format must not contain field
>> width '%*'")
>
> and I don't know if you want to tweak the error message, maybe:
> Event format must not use dynamic '*'
>
> If we're trying to get stuff in 4.2-rc2, patch 1 and 2 are actual bug
> fixes and deserve to go in; patch 3 is nice-to-have but doesn't affect
> the build if it is omitted (as there are no other offenders left), so
> slipping it into 5.0 for a v4 to clean it up slightly doesn't hurt. I
> don't know who would send the pull request, though, and slipping 1 and 2
> into -rc3 just because of 3 is not ideal.
Wise thought. I'll respin 1-2 with the Fixes: tag in case qemu-block@ or
qemu-trivial@ have pending pull-request for tomorrow, they can queue it.
Else they can go via the mips-next tree, since both patch affect the
Malta board.
Thanks!
Phil.
^ permalink raw reply [flat|nested] 10+ messages in thread
* Re: [PATCH-for-4.2 v3 0/3] hw: Remove dynamic field width from trace events
2019-11-18 21:04 [PATCH-for-4.2 v3 0/3] hw: Remove dynamic field width from trace events Philippe Mathieu-Daudé
` (2 preceding siblings ...)
2019-11-18 21:04 ` [PATCH-for-4.2 v3 3/3] trace: Forbid dynamic field width in event format Philippe Mathieu-Daudé
@ 2019-11-19 7:32 ` Richard Henderson
3 siblings, 0 replies; 10+ messages in thread
From: Richard Henderson @ 2019-11-19 7:32 UTC (permalink / raw)
To: Philippe Mathieu-Daudé, Eric Blake, qemu-devel
Cc: Kevin Wolf, Stefan Hajnoczi, qemu-block, qemu-trivial, Max Reitz,
Aleksandar Markovic, Aleksandar Rikalo, Aurelien Jarno
On 11/18/19 10:04 PM, Philippe Mathieu-Daudé wrote:
> Philippe Mathieu-Daudé (3):
> hw/block/pflash: Remove dynamic field width from trace events
> hw/mips/gt64xxx: Remove dynamic field width from trace events
> trace: Forbid dynamic field width in event format
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
r~
^ permalink raw reply [flat|nested] 10+ messages in thread
end of thread, other threads:[~2019-11-19 7:34 UTC | newest]
Thread overview: 10+ messages (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
2019-11-18 21:04 [PATCH-for-4.2 v3 0/3] hw: Remove dynamic field width from trace events Philippe Mathieu-Daudé
2019-11-18 21:04 ` [PATCH-for-4.2 v3 1/3] hw/block/pflash: " Philippe Mathieu-Daudé
2019-11-18 21:15 ` Eric Blake
2019-11-18 21:20 ` Philippe Mathieu-Daudé
2019-11-18 21:04 ` [PATCH-for-4.2 v3 2/3] hw/mips/gt64xxx: " Philippe Mathieu-Daudé
2019-11-18 21:17 ` Eric Blake
2019-11-18 21:04 ` [PATCH-for-4.2 v3 3/3] trace: Forbid dynamic field width in event format Philippe Mathieu-Daudé
2019-11-18 21:26 ` Eric Blake
2019-11-18 21:31 ` Philippe Mathieu-Daudé
2019-11-19 7:32 ` [PATCH-for-4.2 v3 0/3] hw: Remove dynamic field width from trace events Richard Henderson
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