From: Changbin Du <[email protected]>
Hi all,
I know some kernel developers was searching for a method to dissable GCC
optimizations, probably they want to apply GCC '-O0' option. But since Linux
kernel replys on GCC optimization to remove some dead code, so '-O0' just
breaks the build. They do need this because they want to debug kernel with
qemu, simics, kgtp or kgdb.
Thanks for the GCC '-Og' optimization level introduced in GCC 4.8, which
offers a reasonable level of optimization while maintaining fast compilation
and a good debugging experience. It is similar to '-O1' while perferring to
keep debug ability over runtime speed. With '-Og', we can build a kernel with
better debug ability and little performance drop after some simple change.
In this series, firstly introduce a new config CONFIG_NO_AUTO_INLINE after two
fixes for this new option. With this option, only functions explicitly marked
with "inline" will be inlined. This will allow the function tracer to trace
more functions because it only traces functions that the compiler has not
inlined.
Then introduce new config CC_OPTIMIZE_FOR_DEBUGGING which apply '-Og'
optimization level for whole kernel, with a simple fix in fix_to_virt().
Currently I have only tested this option on x86 and ARM platform. Other
platforms should also work but probably need some compiling fixes as what
having done in this series. I leave that to who want to try this debug
option.
Comparison of vmlinux size: a bit smaller.
w/o CONFIG_DEBUG_EXPERIENCE
$ size vmlinux
text data bss dec hex filename
22665554 9709674 2920908 35296136 21a9388 vmlinux
w/ CONFIG_DEBUG_EXPERIENCE
$ size vmlinux
text data bss dec hex filename
21499032 10102758 2920908 34522698 20ec64a vmlinux
Comparison of system performance: a bit drop (~6%).
This benchmark of kernel compilation is suggested by Ingo Molnar.
https://lkml.org/lkml/2018/5/2/74
Preparation: Set cpufreq to 'performance'.
for ((cpu=0; cpu<120; cpu++)); do
G=/sys/devices/system/cpu/cpu$cpu/cpufreq/scaling_governor
[ -f $G ] && echo performance > $G
done
w/o CONFIG_DEBUG_EXPERIENCE
$ perf stat --repeat 5 --null --pre '\
cp -a kernel ../kernel.copy.$(date +%s); \
rm -rf *; \
git checkout .; \
echo 1 > /proc/sys/vm/drop_caches; \
find ../kernel* -type f | xargs cat >/dev/null; \
make -j kernel >/dev/null; \
make clean >/dev/null 2>&1; \
sync '\
\
make -j8 >/dev/null
Performance counter stats for 'make -j8' (5 runs):
219.764246652 seconds time elapsed ( +- 0.78% )
w/ CONFIG_DEBUG_EXPERIENCE
$ perf stat --repeat 5 --null --pre '\
cp -a kernel ../kernel.copy.$(date +%s); \
rm -rf *; \
git checkout .; \
echo 1 > /proc/sys/vm/drop_caches; \
find ../kernel* -type f | xargs cat >/dev/null; \
make -j kernel >/dev/null; \
make clean >/dev/null 2>&1; \
sync '\
\
make -j8 >/dev/null
Performance counter stats for 'make -j8' (5 runs):
233.574187771 seconds time elapsed ( +- 0.19% )
Changbin Du (5):
x86/mm: surround level4_kernel_pgt with #ifdef
CONFIG_X86_5LEVEL...#endif
regulator: add dummy function of_find_regulator_by_node
kernel hacking: new config NO_AUTO_INLINE to disable compiler
auto-inline optimizations
kernel hacking: new config CC_OPTIMIZE_FOR_DEBUGGING to apply GCC -Og
optimization
asm-generic: fix build error in fix_to_virt with
CONFIG_CC_OPTIMIZE_FOR_DEBUGGING
Makefile | 10 ++++++++++
arch/arm/mm/mmu.c | 2 +-
arch/x86/include/asm/pgtable_64.h | 2 ++
arch/x86/kernel/head64.c | 13 ++++++-------
drivers/regulator/internal.h | 9 +++++++--
include/linux/compiler-gcc.h | 2 +-
include/linux/compiler.h | 2 +-
init/Kconfig | 19 +++++++++++++++++++
lib/Kconfig.debug | 17 +++++++++++++++++
9 files changed, 64 insertions(+), 12 deletions(-)
--
2.7.4
From: Changbin Du <[email protected]>
If device tree is not enabled, of_find_regulator_by_node() should have
a dummy function since the function call is still there.
This is to fix build error after CONFIG_NO_AUTO_INLINE is introduced.
If this option is enabled, GCC will not auto-inline functions that are
not explicitly marked as inline.
In this case (no CONFIG_OF), the copmiler will report error in function
regulator_dev_lookup().
W/O NO_AUTO_INLINE, function of_get_regulator() is auto-inlined and then
the call to of_find_regulator_by_node() is optimized out since
of_get_regulator() always return NULL.
W/ NO_AUTO_INLINE, the return value of of_get_regulator() is a variable
so the call to of_find_regulator_by_node() cannot be optimized out. So
we need a stub of_find_regulator_by_node().
static struct regulator_dev *regulator_dev_lookup(struct device *dev,
const char *supply)
{
struct regulator_dev *r = NULL;
struct device_node *node;
struct regulator_map *map;
const char *devname = NULL;
regulator_supply_alias(&dev, &supply);
/* first do a dt based lookup */
if (dev && dev->of_node) {
node = of_get_regulator(dev, supply);
if (node) {
r = of_find_regulator_by_node(node);
if (r)
return r;
...
Signed-off-by: Changbin Du <[email protected]>
---
drivers/regulator/internal.h | 9 +++++++--
1 file changed, 7 insertions(+), 2 deletions(-)
diff --git a/drivers/regulator/internal.h b/drivers/regulator/internal.h
index abfd56e..24fde1e 100644
--- a/drivers/regulator/internal.h
+++ b/drivers/regulator/internal.h
@@ -56,14 +56,19 @@ static inline struct regulator_dev *dev_to_rdev(struct device *dev)
return container_of(dev, struct regulator_dev, dev);
}
-struct regulator_dev *of_find_regulator_by_node(struct device_node *np);
-
#ifdef CONFIG_OF
+struct regulator_dev *of_find_regulator_by_node(struct device_node *np);
struct regulator_init_data *regulator_of_get_init_data(struct device *dev,
const struct regulator_desc *desc,
struct regulator_config *config,
struct device_node **node);
#else
+static inline struct regulator_dev *
+of_find_regulator_by_node(struct device_node *np)
+{
+ return NULL;
+}
+
static inline struct regulator_init_data *
regulator_of_get_init_data(struct device *dev,
const struct regulator_desc *desc,
--
2.7.4
From: Changbin Du <[email protected]>
This patch add a new kernel hacking option NO_AUTO_INLINE. Selecting
this option will prevent the compiler from optimizing the kernel by
auto-inlining functions not marked with the inline keyword.
With this option, only functions explicitly marked with "inline" will
be inlined. This will allow the function tracer to trace more functions
because it only traces functions that the compiler has not inlined.
Signed-off-by: Changbin Du <[email protected]>
Cc: Steven Rostedt <[email protected]>
---
v2: Some grammar updates from Steven.
---
Makefile | 6 ++++++
lib/Kconfig.debug | 17 +++++++++++++++++
2 files changed, 23 insertions(+)
diff --git a/Makefile b/Makefile
index 619a85a..eb694f6 100644
--- a/Makefile
+++ b/Makefile
@@ -775,6 +775,12 @@ KBUILD_CFLAGS += $(call cc-option, -femit-struct-debug-baseonly) \
$(call cc-option,-fno-var-tracking)
endif
+ifdef CONFIG_NO_AUTO_INLINE
+KBUILD_CFLAGS += $(call cc-option, -fno-inline-functions) \
+ $(call cc-option, -fno-inline-small-functions) \
+ $(call cc-option, -fno-inline-functions-called-once)
+endif
+
ifdef CONFIG_FUNCTION_TRACER
ifndef CC_FLAGS_FTRACE
CC_FLAGS_FTRACE := -pg
diff --git a/lib/Kconfig.debug b/lib/Kconfig.debug
index c40c7b7..da52243 100644
--- a/lib/Kconfig.debug
+++ b/lib/Kconfig.debug
@@ -198,6 +198,23 @@ config GDB_SCRIPTS
instance. See Documentation/dev-tools/gdb-kernel-debugging.rst
for further details.
+config NO_AUTO_INLINE
+ bool "Disable compiler auto-inline optimizations"
+ help
+ This will prevent the compiler from optimizing the kernel by
+ auto-inlining functions not marked with the inline keyword.
+ With this option, only functions explicitly marked with
+ "inline" will be inlined. This will allow the function tracer
+ to trace more functions because it only traces functions that
+ the compiler has not inlined.
+
+ Enabling this function can help debugging a kernel if using
+ the function tracer. But it can also change how the kernel
+ works, because inlining functions may change the timing,
+ which could make it difficult while debugging race conditions.
+
+ If unsure, select N.
+
config ENABLE_WARN_DEPRECATED
bool "Enable __deprecated logic"
default y
--
2.7.4
From: Changbin Du <[email protected]>
With '-Og' optimization level, GCC would not optimize a count for a loop
as a constant value. But BUILD_BUG_ON() only accept compile-time constant
values. Let's use __fix_to_virt() to avoid the error.
arch/arm/mm/mmu.o: In function `fix_to_virt':
/home/changbin/work/linux/./include/asm-generic/fixmap.h:31: undefined reference to `__compiletime_assert_31'
Makefile:1051: recipe for target 'vmlinux' failed
make: *** [vmlinux] Error 1
Signed-off-by: Changbin Du <[email protected]>
---
v2: use __fix_to_virt() to fix the issue.
---
arch/arm/mm/mmu.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/arch/arm/mm/mmu.c b/arch/arm/mm/mmu.c
index e46a6a4..c08d74e 100644
--- a/arch/arm/mm/mmu.c
+++ b/arch/arm/mm/mmu.c
@@ -1599,7 +1599,7 @@ static void __init early_fixmap_shutdown(void)
pte_t *pte;
struct map_desc map;
- map.virtual = fix_to_virt(i);
+ map.virtual = __fix_to_virt(i);
pte = pte_offset_early_fixmap(pmd_off_k(map.virtual), map.virtual);
/* Only i/o device mappings are supported ATM */
--
2.7.4
From: Changbin Du <[email protected]>
This will apply GCC '-Og' optimization level which is supported
since GCC 4.8. This optimization level offers a reasonable level
of optimization while maintaining fast compilation and a good
debugging experience. It is similar to '-O1' while perferring
to keep debug ability over runtime speed.
If enabling this option breaks your kernel, you should either
disable this or find a fix (mostly in the arch code). Currently
this option has only been tested on x86_64 and arm platform.
This option can satisfy people who was searching for a method
to disable compiler optimizations so to achieve better kernel
debugging experience with kgdb or qemu.
The main problem of '-Og' is we must not use __attribute__((error(msg))).
The compiler will report error though the call to error function
still can be optimize out. So we must fallback to array tricky.
Comparison of vmlinux size: a bit smaller.
w/o CONFIG_CC_OPTIMIZE_FOR_DEBUGGING
$ size vmlinux
text data bss dec hex filename
22665554 9709674 2920908 35296136 21a9388 vmlinux
w/ CONFIG_CC_OPTIMIZE_FOR_DEBUGGING
$ size vmlinux
text data bss dec hex filename
21499032 10102758 2920908 34522698 20ec64a vmlinux
Comparison of system performance: a bit drop (~6%).
This benchmark of kernel compilation is suggested by Ingo Molnar.
https://lkml.org/lkml/2018/5/2/74
Preparation: Set cpufreq to 'performance'.
for ((cpu=0; cpu<120; cpu++)); do
G=/sys/devices/system/cpu/cpu$cpu/cpufreq/scaling_governor
[ -f $G ] && echo performance > $G
done
w/o CONFIG_CC_OPTIMIZE_FOR_DEBUGGING
$ perf stat --repeat 5 --null --pre '\
cp -a kernel ../kernel.copy.$(date +%s); \
rm -rf *; \
git checkout .; \
echo 1 > /proc/sys/vm/drop_caches; \
find ../kernel* -type f | xargs cat >/dev/null; \
make -j kernel >/dev/null; \
make clean >/dev/null 2>&1; \
sync '\
\
make -j8 >/dev/null
Performance counter stats for 'make -j8' (5 runs):
219.764246652 seconds time elapsed ( +- 0.78% )
w/ CONFIG_CC_OPTIMIZE_FOR_DEBUGGING
$ perf stat --repeat 5 --null --pre '\
cp -a kernel ../kernel.copy.$(date +%s); \
rm -rf *; \
git checkout .; \
echo 1 > /proc/sys/vm/drop_caches; \
find ../kernel* -type f | xargs cat >/dev/null; \
make -j kernel >/dev/null; \
make clean >/dev/null 2>&1; \
sync '\
\
make -j8 >/dev/null
Performance counter stats for 'make -j8' (5 runs):
233.574187771 seconds time elapsed ( +- 0.19% )
Signed-off-by: Changbin Du <[email protected]>
---
v3:
o Rename DEBUG_EXPERIENCE to CC_OPTIMIZE_FOR_DEBUGGING
o Move new configuration item to "General setup->Compiler optimization level"
v2:
o Improve performance benchmark as suggested by Ingo.
o Grammar updates in description. (Randy Dunlap)
---
Makefile | 4 ++++
include/linux/compiler-gcc.h | 2 +-
include/linux/compiler.h | 2 +-
init/Kconfig | 19 +++++++++++++++++++
4 files changed, 25 insertions(+), 2 deletions(-)
diff --git a/Makefile b/Makefile
index eb694f6..ae1dea7 100644
--- a/Makefile
+++ b/Makefile
@@ -639,6 +639,9 @@ KBUILD_CFLAGS += $(call cc-disable-warning, format-truncation)
KBUILD_CFLAGS += $(call cc-disable-warning, format-overflow)
KBUILD_CFLAGS += $(call cc-disable-warning, int-in-bool-context)
+ifdef CONFIG_CC_OPTIMIZE_FOR_DEBUGGING
+KBUILD_CFLAGS += $(call cc-option, -Og)
+else
ifdef CONFIG_CC_OPTIMIZE_FOR_SIZE
KBUILD_CFLAGS += $(call cc-option,-Oz,-Os)
KBUILD_CFLAGS += $(call cc-disable-warning,maybe-uninitialized,)
@@ -649,6 +652,7 @@ else
KBUILD_CFLAGS += -O2
endif
endif
+endif
KBUILD_CFLAGS += $(call cc-ifversion, -lt, 0409, \
$(call cc-disable-warning,maybe-uninitialized,))
diff --git a/include/linux/compiler-gcc.h b/include/linux/compiler-gcc.h
index b4bf73f..586ed11 100644
--- a/include/linux/compiler-gcc.h
+++ b/include/linux/compiler-gcc.h
@@ -192,7 +192,7 @@
#define __UNIQUE_ID(prefix) __PASTE(__PASTE(__UNIQUE_ID_, prefix), __COUNTER__)
-#ifndef __CHECKER__
+#if !defined(__CHECKER__) && !defined(CONFIG_CC_OPTIMIZE_FOR_DEBUGGING)
# define __compiletime_warning(message) __attribute__((warning(message)))
# define __compiletime_error(message) __attribute__((error(message)))
#endif /* __CHECKER__ */
diff --git a/include/linux/compiler.h b/include/linux/compiler.h
index ab4711c..e97caf4 100644
--- a/include/linux/compiler.h
+++ b/include/linux/compiler.h
@@ -301,7 +301,7 @@ unsigned long read_word_at_a_time(const void *addr)
* sparse see a constant array size without breaking compiletime_assert on old
* versions of GCC (e.g. 4.2.4), so hide the array from sparse altogether.
*/
-# ifndef __CHECKER__
+# if !defined(__CHECKER__) && !defined(CONFIG_CC_OPTIMIZE_FOR_DEBUGGING)
# define __compiletime_error_fallback(condition) \
do { ((void)sizeof(char[1 - 2 * condition])); } while (0)
# endif
diff --git a/init/Kconfig b/init/Kconfig
index f013afc..aa52535 100644
--- a/init/Kconfig
+++ b/init/Kconfig
@@ -1036,6 +1036,25 @@ config CC_OPTIMIZE_FOR_SIZE
If unsure, say N.
+config CC_OPTIMIZE_FOR_DEBUGGING
+ bool "Optimize for better debugging experience (-Og)"
+ select NO_AUTO_INLINE
+ help
+ This will apply GCC '-Og' optimization level which is supported
+ since GCC 4.8. This optimization level offers a reasonable level
+ of optimization while maintaining fast compilation and a good
+ debugging experience. It is similar to '-O1' while preferring to
+ keep debug ability over runtime speed. The overall performance
+ will drop a bit (~6%).
+
+ Use only if you want to debug the kernel, especially if you want
+ to have better kernel debugging experience with gdb facilities
+ like kgdb or qemu. If enabling this option breaks your kernel,
+ you should either disable this or find a fix (mostly in the arch
+ code).
+
+ If unsure, select N.
+
endchoice
config SYSCTL
--
2.7.4
From: Changbin Du <[email protected]>
The level4_kernel_pgt is only defined when X86_5LEVEL is enabled. So
surround level4_kernel_pgt with #ifdef CONFIG_X86_5LEVEL...#endif to
make code correct.
Signed-off-by: Changbin Du <[email protected]>
---
arch/x86/include/asm/pgtable_64.h | 2 ++
arch/x86/kernel/head64.c | 13 ++++++-------
2 files changed, 8 insertions(+), 7 deletions(-)
diff --git a/arch/x86/include/asm/pgtable_64.h b/arch/x86/include/asm/pgtable_64.h
index 877bc27..9e7f667 100644
--- a/arch/x86/include/asm/pgtable_64.h
+++ b/arch/x86/include/asm/pgtable_64.h
@@ -15,7 +15,9 @@
#include <linux/bitops.h>
#include <linux/threads.h>
+#ifdef CONFIG_X86_5LEVEL
extern p4d_t level4_kernel_pgt[512];
+#endif
extern p4d_t level4_ident_pgt[512];
extern pud_t level3_kernel_pgt[512];
extern pud_t level3_ident_pgt[512];
diff --git a/arch/x86/kernel/head64.c b/arch/x86/kernel/head64.c
index 0c408f8..775d7a6 100644
--- a/arch/x86/kernel/head64.c
+++ b/arch/x86/kernel/head64.c
@@ -143,16 +143,15 @@ unsigned long __head __startup_64(unsigned long physaddr,
pgd = fixup_pointer(&early_top_pgt, physaddr);
p = pgd + pgd_index(__START_KERNEL_map);
- if (la57)
- *p = (unsigned long)level4_kernel_pgt;
- else
- *p = (unsigned long)level3_kernel_pgt;
- *p += _PAGE_TABLE_NOENC - __START_KERNEL_map + load_delta;
-
+#ifdef CONFIG_X86_5LEVEL
if (la57) {
+ *p = (unsigned long)level4_kernel_pgt;
p4d = fixup_pointer(&level4_kernel_pgt, physaddr);
p4d[511] += load_delta;
- }
+ } else
+#endif
+ *p = (unsigned long)level3_kernel_pgt;
+ *p += _PAGE_TABLE_NOENC - __START_KERNEL_map + load_delta;
pud = fixup_pointer(&level3_kernel_pgt, physaddr);
pud[510] += load_delta;
--
2.7.4
Hi Changbin,
Thank you for the patch! Perhaps something to improve:
[auto build test WARNING on linus/master]
[also build test WARNING on v4.17-rc3 next-20180504]
[if your patch is applied to the wrong git tree, please drop us a note to help improve the system]
url: https://github.com/0day-ci/linux/commits/changbin-du-intel-com/kernel-hacking-GCC-optimization-for-better-debug-experience-Og/20180506-110946
config: arm64-allmodconfig (attached as .config)
compiler: aarch64-linux-gnu-gcc (Debian 7.2.0-11) 7.2.0
reproduce:
wget https://raw.githubusercontent.com/intel/lkp-tests/master/sbin/make.cross -O ~/bin/make.cross
chmod +x ~/bin/make.cross
# save the attached .config to linux build tree
make.cross ARCH=arm64
Note: it may well be a FALSE warning. FWIW you are at least aware of it now.
http://gcc.gnu.org/wiki/Better_Uninitialized_Warnings
All warnings (new ones prefixed by >>):
drivers/pci/host/pci-xgene.c: In function 'xgene_pcie_setup_ib_reg':
>> drivers/pci/host/pci-xgene.c:532:2: warning: 'pim_reg' may be used uninitialized in this function [-Wmaybe-uninitialized]
xgene_pcie_setup_pims(port, pim_reg, pci_addr, ~(size - 1));
^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
--
drivers/scsi/ufs/ufs-qcom.c: In function 'ufs_qcom_testbus_config':
>> drivers/scsi/ufs/ufs-qcom.c:1527:6: warning: 'offset' may be used uninitialized in this function [-Wmaybe-uninitialized]
int offset;
^~~~~~
>> drivers/scsi/ufs/ufs-qcom.c:1526:6: warning: 'reg' may be used uninitialized in this function [-Wmaybe-uninitialized]
int reg;
^~~
vim +/pim_reg +532 drivers/pci/host/pci-xgene.c
5f6b6ccd Tanmay Inamdar 2014-10-01 484
5f6b6ccd Tanmay Inamdar 2014-10-01 485 static void xgene_pcie_setup_ib_reg(struct xgene_pcie_port *port,
5f6b6ccd Tanmay Inamdar 2014-10-01 486 struct of_pci_range *range, u8 *ib_reg_mask)
5f6b6ccd Tanmay Inamdar 2014-10-01 487 {
5f6b6ccd Tanmay Inamdar 2014-10-01 488 void __iomem *cfg_base = port->cfg_base;
d963ab22 Bjorn Helgaas 2016-10-06 489 struct device *dev = port->dev;
5f6b6ccd Tanmay Inamdar 2014-10-01 490 void *bar_addr;
4ecf6b0f Bjorn Helgaas 2016-10-06 491 u32 pim_reg;
5f6b6ccd Tanmay Inamdar 2014-10-01 492 u64 cpu_addr = range->cpu_addr;
5f6b6ccd Tanmay Inamdar 2014-10-01 493 u64 pci_addr = range->pci_addr;
5f6b6ccd Tanmay Inamdar 2014-10-01 494 u64 size = range->size;
5f6b6ccd Tanmay Inamdar 2014-10-01 495 u64 mask = ~(size - 1) | EN_REG;
5f6b6ccd Tanmay Inamdar 2014-10-01 496 u32 flags = PCI_BASE_ADDRESS_MEM_TYPE_64;
5f6b6ccd Tanmay Inamdar 2014-10-01 497 u32 bar_low;
5f6b6ccd Tanmay Inamdar 2014-10-01 498 int region;
5f6b6ccd Tanmay Inamdar 2014-10-01 499
5f6b6ccd Tanmay Inamdar 2014-10-01 500 region = xgene_pcie_select_ib_reg(ib_reg_mask, range->size);
5f6b6ccd Tanmay Inamdar 2014-10-01 501 if (region < 0) {
d963ab22 Bjorn Helgaas 2016-10-06 502 dev_warn(dev, "invalid pcie dma-range config\n");
5f6b6ccd Tanmay Inamdar 2014-10-01 503 return;
5f6b6ccd Tanmay Inamdar 2014-10-01 504 }
5f6b6ccd Tanmay Inamdar 2014-10-01 505
5f6b6ccd Tanmay Inamdar 2014-10-01 506 if (range->flags & IORESOURCE_PREFETCH)
5f6b6ccd Tanmay Inamdar 2014-10-01 507 flags |= PCI_BASE_ADDRESS_MEM_PREFETCH;
5f6b6ccd Tanmay Inamdar 2014-10-01 508
5f6b6ccd Tanmay Inamdar 2014-10-01 509 bar_low = pcie_bar_low_val((u32)cpu_addr, flags);
5f6b6ccd Tanmay Inamdar 2014-10-01 510 switch (region) {
5f6b6ccd Tanmay Inamdar 2014-10-01 511 case 0:
4ecf6b0f Bjorn Helgaas 2016-10-06 512 xgene_pcie_set_ib_mask(port, BRIDGE_CFG_4, flags, size);
5f6b6ccd Tanmay Inamdar 2014-10-01 513 bar_addr = cfg_base + PCI_BASE_ADDRESS_0;
5f6b6ccd Tanmay Inamdar 2014-10-01 514 writel(bar_low, bar_addr);
5f6b6ccd Tanmay Inamdar 2014-10-01 515 writel(upper_32_bits(cpu_addr), bar_addr + 0x4);
4ecf6b0f Bjorn Helgaas 2016-10-06 516 pim_reg = PIM1_1L;
5f6b6ccd Tanmay Inamdar 2014-10-01 517 break;
5f6b6ccd Tanmay Inamdar 2014-10-01 518 case 1:
8e93c513 Bjorn Helgaas 2016-10-06 519 xgene_pcie_writel(port, IBAR2, bar_low);
8e93c513 Bjorn Helgaas 2016-10-06 520 xgene_pcie_writel(port, IR2MSK, lower_32_bits(mask));
4ecf6b0f Bjorn Helgaas 2016-10-06 521 pim_reg = PIM2_1L;
5f6b6ccd Tanmay Inamdar 2014-10-01 522 break;
5f6b6ccd Tanmay Inamdar 2014-10-01 523 case 2:
8e93c513 Bjorn Helgaas 2016-10-06 524 xgene_pcie_writel(port, IBAR3L, bar_low);
8e93c513 Bjorn Helgaas 2016-10-06 525 xgene_pcie_writel(port, IBAR3L + 0x4, upper_32_bits(cpu_addr));
8e93c513 Bjorn Helgaas 2016-10-06 526 xgene_pcie_writel(port, IR3MSKL, lower_32_bits(mask));
8e93c513 Bjorn Helgaas 2016-10-06 527 xgene_pcie_writel(port, IR3MSKL + 0x4, upper_32_bits(mask));
4ecf6b0f Bjorn Helgaas 2016-10-06 528 pim_reg = PIM3_1L;
5f6b6ccd Tanmay Inamdar 2014-10-01 529 break;
5f6b6ccd Tanmay Inamdar 2014-10-01 530 }
5f6b6ccd Tanmay Inamdar 2014-10-01 531
4ecf6b0f Bjorn Helgaas 2016-10-06 @532 xgene_pcie_setup_pims(port, pim_reg, pci_addr, ~(size - 1));
5f6b6ccd Tanmay Inamdar 2014-10-01 533 }
5f6b6ccd Tanmay Inamdar 2014-10-01 534
:::::: The code at line 532 was first introduced by commit
:::::: 4ecf6b0f83523fb186dd1de9e2f1d324a2a413d9 PCI: xgene: Pass struct xgene_pcie_port to setup functions
:::::: TO: Bjorn Helgaas <[email protected]>
:::::: CC: Bjorn Helgaas <[email protected]>
---
0-DAY kernel test infrastructure Open Source Technology Center
https://lists.01.org/pipermail/kbuild-all Intel Corporation
Hi Changbin,
Thank you for the patch! Perhaps something to improve:
[auto build test WARNING on linus/master]
[also build test WARNING on v4.17-rc3 next-20180504]
[if your patch is applied to the wrong git tree, please drop us a note to help improve the system]
url: https://github.com/0day-ci/linux/commits/changbin-du-intel-com/kernel-hacking-GCC-optimization-for-better-debug-experience-Og/20180506-110946
config: x86_64-allmodconfig (attached as .config)
compiler: gcc-7 (Debian 7.3.0-16) 7.3.0
reproduce:
# save the attached .config to linux build tree
make ARCH=x86_64
Note: it may well be a FALSE warning. FWIW you are at least aware of it now.
http://gcc.gnu.org/wiki/Better_Uninitialized_Warnings
All warnings (new ones prefixed by >>):
arch/x86/entry/vsyscall/vsyscall_64.c: In function 'emulate_vsyscall':
>> arch/x86/entry/vsyscall/vsyscall_64.c:127:19: warning: 'syscall_nr' may be used uninitialized in this function [-Wmaybe-uninitialized]
int vsyscall_nr, syscall_nr, tmp;
^~~~~~~~~~
vim +/syscall_nr +127 arch/x86/entry/vsyscall/vsyscall_64.c
4fc34901 arch/x86/kernel/vsyscall_64.c Andy Lutomirski 2011-11-07 122
3ae36655 arch/x86/kernel/vsyscall_64.c Andy Lutomirski 2011-08-10 123 bool emulate_vsyscall(struct pt_regs *regs, unsigned long address)
5cec93c2 arch/x86/kernel/vsyscall_64.c Andy Lutomirski 2011-06-05 124 {
5cec93c2 arch/x86/kernel/vsyscall_64.c Andy Lutomirski 2011-06-05 125 struct task_struct *tsk;
5cec93c2 arch/x86/kernel/vsyscall_64.c Andy Lutomirski 2011-06-05 126 unsigned long caller;
87b526d3 arch/x86/kernel/vsyscall_64.c Andy Lutomirski 2012-10-01 @127 int vsyscall_nr, syscall_nr, tmp;
2a53ccbc arch/x86/entry/vsyscall/vsyscall_64.c Ingo Molnar 2016-07-15 128 int prev_sig_on_uaccess_err;
5cec93c2 arch/x86/kernel/vsyscall_64.c Andy Lutomirski 2011-06-05 129 long ret;
fa697140 arch/x86/entry/vsyscall/vsyscall_64.c Dominik Brodowski 2018-04-05 130 unsigned long orig_dx;
7460ed28 arch/x86_64/kernel/vsyscall.c John Stultz 2007-02-16 131
c9712944 arch/x86/kernel/vsyscall_64.c Andy Lutomirski 2011-07-13 132 /*
3ae36655 arch/x86/kernel/vsyscall_64.c Andy Lutomirski 2011-08-10 133 * No point in checking CS -- the only way to get here is a user mode
3ae36655 arch/x86/kernel/vsyscall_64.c Andy Lutomirski 2011-08-10 134 * trap to a high address, which means that we're in 64-bit user code.
c9712944 arch/x86/kernel/vsyscall_64.c Andy Lutomirski 2011-07-13 135 */
7460ed28 arch/x86_64/kernel/vsyscall.c John Stultz 2007-02-16 136
3ae36655 arch/x86/kernel/vsyscall_64.c Andy Lutomirski 2011-08-10 137 WARN_ON_ONCE(address != regs->ip);
3ae36655 arch/x86/kernel/vsyscall_64.c Andy Lutomirski 2011-08-10 138
3ae36655 arch/x86/kernel/vsyscall_64.c Andy Lutomirski 2011-08-10 139 if (vsyscall_mode == NONE) {
3ae36655 arch/x86/kernel/vsyscall_64.c Andy Lutomirski 2011-08-10 140 warn_bad_vsyscall(KERN_INFO, regs,
3ae36655 arch/x86/kernel/vsyscall_64.c Andy Lutomirski 2011-08-10 141 "vsyscall attempted with vsyscall=none");
3ae36655 arch/x86/kernel/vsyscall_64.c Andy Lutomirski 2011-08-10 142 return false;
c9712944 arch/x86/kernel/vsyscall_64.c Andy Lutomirski 2011-07-13 143 }
7460ed28 arch/x86_64/kernel/vsyscall.c John Stultz 2007-02-16 144
3ae36655 arch/x86/kernel/vsyscall_64.c Andy Lutomirski 2011-08-10 145 vsyscall_nr = addr_to_vsyscall_nr(address);
c149a665 arch/x86/kernel/vsyscall_64.c Andy Lutomirski 2011-08-03 146
c149a665 arch/x86/kernel/vsyscall_64.c Andy Lutomirski 2011-08-03 147 trace_emulate_vsyscall(vsyscall_nr);
c149a665 arch/x86/kernel/vsyscall_64.c Andy Lutomirski 2011-08-03 148
c9712944 arch/x86/kernel/vsyscall_64.c Andy Lutomirski 2011-07-13 149 if (vsyscall_nr < 0) {
c9712944 arch/x86/kernel/vsyscall_64.c Andy Lutomirski 2011-07-13 150 warn_bad_vsyscall(KERN_WARNING, regs,
3ae36655 arch/x86/kernel/vsyscall_64.c Andy Lutomirski 2011-08-10 151 "misaligned vsyscall (exploit attempt or buggy program) -- look up the vsyscall kernel parameter if you need a workaround");
5cec93c2 arch/x86/kernel/vsyscall_64.c Andy Lutomirski 2011-06-05 152 goto sigsegv;
7460ed28 arch/x86_64/kernel/vsyscall.c John Stultz 2007-02-16 153 }
7460ed28 arch/x86_64/kernel/vsyscall.c John Stultz 2007-02-16 154
5cec93c2 arch/x86/kernel/vsyscall_64.c Andy Lutomirski 2011-06-05 155 if (get_user(caller, (unsigned long __user *)regs->sp) != 0) {
3ae36655 arch/x86/kernel/vsyscall_64.c Andy Lutomirski 2011-08-10 156 warn_bad_vsyscall(KERN_WARNING, regs,
3ae36655 arch/x86/kernel/vsyscall_64.c Andy Lutomirski 2011-08-10 157 "vsyscall with bad stack (exploit attempt?)");
5cec93c2 arch/x86/kernel/vsyscall_64.c Andy Lutomirski 2011-06-05 158 goto sigsegv;
^1da177e arch/x86_64/kernel/vsyscall.c Linus Torvalds 2005-04-16 159 }
^1da177e arch/x86_64/kernel/vsyscall.c Linus Torvalds 2005-04-16 160
5cec93c2 arch/x86/kernel/vsyscall_64.c Andy Lutomirski 2011-06-05 161 tsk = current;
4fc34901 arch/x86/kernel/vsyscall_64.c Andy Lutomirski 2011-11-07 162
4fc34901 arch/x86/kernel/vsyscall_64.c Andy Lutomirski 2011-11-07 163 /*
87b526d3 arch/x86/kernel/vsyscall_64.c Andy Lutomirski 2012-10-01 164 * Check for access_ok violations and find the syscall nr.
87b526d3 arch/x86/kernel/vsyscall_64.c Andy Lutomirski 2012-10-01 165 *
46ed99d1 arch/x86/kernel/vsyscall_64.c Emil Goode 2012-04-01 166 * NULL is a valid user pointer (in the access_ok sense) on 32-bit and
4fc34901 arch/x86/kernel/vsyscall_64.c Andy Lutomirski 2011-11-07 167 * 64-bit, so we don't need to special-case it here. For all the
46ed99d1 arch/x86/kernel/vsyscall_64.c Emil Goode 2012-04-01 168 * vsyscalls, NULL means "don't write anything" not "write it at
4fc34901 arch/x86/kernel/vsyscall_64.c Andy Lutomirski 2011-11-07 169 * address 0".
4fc34901 arch/x86/kernel/vsyscall_64.c Andy Lutomirski 2011-11-07 170 */
5cec93c2 arch/x86/kernel/vsyscall_64.c Andy Lutomirski 2011-06-05 171 switch (vsyscall_nr) {
5cec93c2 arch/x86/kernel/vsyscall_64.c Andy Lutomirski 2011-06-05 172 case 0:
4fc34901 arch/x86/kernel/vsyscall_64.c Andy Lutomirski 2011-11-07 173 if (!write_ok_or_segv(regs->di, sizeof(struct timeval)) ||
87b526d3 arch/x86/kernel/vsyscall_64.c Andy Lutomirski 2012-10-01 174 !write_ok_or_segv(regs->si, sizeof(struct timezone))) {
87b526d3 arch/x86/kernel/vsyscall_64.c Andy Lutomirski 2012-10-01 175 ret = -EFAULT;
87b526d3 arch/x86/kernel/vsyscall_64.c Andy Lutomirski 2012-10-01 176 goto check_fault;
87b526d3 arch/x86/kernel/vsyscall_64.c Andy Lutomirski 2012-10-01 177 }
4fc34901 arch/x86/kernel/vsyscall_64.c Andy Lutomirski 2011-11-07 178
87b526d3 arch/x86/kernel/vsyscall_64.c Andy Lutomirski 2012-10-01 179 syscall_nr = __NR_gettimeofday;
5cec93c2 arch/x86/kernel/vsyscall_64.c Andy Lutomirski 2011-06-05 180 break;
5cec93c2 arch/x86/kernel/vsyscall_64.c Andy Lutomirski 2011-06-05 181
5cec93c2 arch/x86/kernel/vsyscall_64.c Andy Lutomirski 2011-06-05 182 case 1:
87b526d3 arch/x86/kernel/vsyscall_64.c Andy Lutomirski 2012-10-01 183 if (!write_ok_or_segv(regs->di, sizeof(time_t))) {
87b526d3 arch/x86/kernel/vsyscall_64.c Andy Lutomirski 2012-10-01 184 ret = -EFAULT;
87b526d3 arch/x86/kernel/vsyscall_64.c Andy Lutomirski 2012-10-01 185 goto check_fault;
87b526d3 arch/x86/kernel/vsyscall_64.c Andy Lutomirski 2012-10-01 186 }
5651721e arch/x86/kernel/vsyscall_64.c Will Drewry 2012-07-13 187
87b526d3 arch/x86/kernel/vsyscall_64.c Andy Lutomirski 2012-10-01 188 syscall_nr = __NR_time;
4fc34901 arch/x86/kernel/vsyscall_64.c Andy Lutomirski 2011-11-07 189 break;
4fc34901 arch/x86/kernel/vsyscall_64.c Andy Lutomirski 2011-11-07 190
87b526d3 arch/x86/kernel/vsyscall_64.c Andy Lutomirski 2012-10-01 191 case 2:
87b526d3 arch/x86/kernel/vsyscall_64.c Andy Lutomirski 2012-10-01 192 if (!write_ok_or_segv(regs->di, sizeof(unsigned)) ||
87b526d3 arch/x86/kernel/vsyscall_64.c Andy Lutomirski 2012-10-01 193 !write_ok_or_segv(regs->si, sizeof(unsigned))) {
87b526d3 arch/x86/kernel/vsyscall_64.c Andy Lutomirski 2012-10-01 194 ret = -EFAULT;
87b526d3 arch/x86/kernel/vsyscall_64.c Andy Lutomirski 2012-10-01 195 goto check_fault;
87b526d3 arch/x86/kernel/vsyscall_64.c Andy Lutomirski 2012-10-01 196 }
87b526d3 arch/x86/kernel/vsyscall_64.c Andy Lutomirski 2012-10-01 197
87b526d3 arch/x86/kernel/vsyscall_64.c Andy Lutomirski 2012-10-01 198 syscall_nr = __NR_getcpu;
5cec93c2 arch/x86/kernel/vsyscall_64.c Andy Lutomirski 2011-06-05 199 break;
87b526d3 arch/x86/kernel/vsyscall_64.c Andy Lutomirski 2012-10-01 200 }
5cec93c2 arch/x86/kernel/vsyscall_64.c Andy Lutomirski 2011-06-05 201
87b526d3 arch/x86/kernel/vsyscall_64.c Andy Lutomirski 2012-10-01 202 /*
87b526d3 arch/x86/kernel/vsyscall_64.c Andy Lutomirski 2012-10-01 203 * Handle seccomp. regs->ip must be the original value.
87b526d3 arch/x86/kernel/vsyscall_64.c Andy Lutomirski 2012-10-01 204 * See seccomp_send_sigsys and Documentation/prctl/seccomp_filter.txt.
87b526d3 arch/x86/kernel/vsyscall_64.c Andy Lutomirski 2012-10-01 205 *
87b526d3 arch/x86/kernel/vsyscall_64.c Andy Lutomirski 2012-10-01 206 * We could optimize the seccomp disabled case, but performance
87b526d3 arch/x86/kernel/vsyscall_64.c Andy Lutomirski 2012-10-01 207 * here doesn't matter.
87b526d3 arch/x86/kernel/vsyscall_64.c Andy Lutomirski 2012-10-01 208 */
87b526d3 arch/x86/kernel/vsyscall_64.c Andy Lutomirski 2012-10-01 209 regs->orig_ax = syscall_nr;
87b526d3 arch/x86/kernel/vsyscall_64.c Andy Lutomirski 2012-10-01 210 regs->ax = -ENOSYS;
2f275de5 arch/x86/entry/vsyscall/vsyscall_64.c Andy Lutomirski 2016-05-27 211 tmp = secure_computing(NULL);
87b526d3 arch/x86/kernel/vsyscall_64.c Andy Lutomirski 2012-10-01 212 if ((!tmp && regs->orig_ax != syscall_nr) || regs->ip != address) {
87b526d3 arch/x86/kernel/vsyscall_64.c Andy Lutomirski 2012-10-01 213 warn_bad_vsyscall(KERN_DEBUG, regs,
87b526d3 arch/x86/kernel/vsyscall_64.c Andy Lutomirski 2012-10-01 214 "seccomp tried to change syscall nr or ip");
87b526d3 arch/x86/kernel/vsyscall_64.c Andy Lutomirski 2012-10-01 215 do_exit(SIGSYS);
87b526d3 arch/x86/kernel/vsyscall_64.c Andy Lutomirski 2012-10-01 216 }
26893107 arch/x86/kernel/vsyscall_64.c Andy Lutomirski 2014-11-04 217 regs->orig_ax = -1;
87b526d3 arch/x86/kernel/vsyscall_64.c Andy Lutomirski 2012-10-01 218 if (tmp)
87b526d3 arch/x86/kernel/vsyscall_64.c Andy Lutomirski 2012-10-01 219 goto do_ret; /* skip requested */
87b526d3 arch/x86/kernel/vsyscall_64.c Andy Lutomirski 2012-10-01 220
87b526d3 arch/x86/kernel/vsyscall_64.c Andy Lutomirski 2012-10-01 221 /*
87b526d3 arch/x86/kernel/vsyscall_64.c Andy Lutomirski 2012-10-01 222 * With a real vsyscall, page faults cause SIGSEGV. We want to
87b526d3 arch/x86/kernel/vsyscall_64.c Andy Lutomirski 2012-10-01 223 * preserve that behavior to make writing exploits harder.
87b526d3 arch/x86/kernel/vsyscall_64.c Andy Lutomirski 2012-10-01 224 */
2a53ccbc arch/x86/entry/vsyscall/vsyscall_64.c Ingo Molnar 2016-07-15 225 prev_sig_on_uaccess_err = current->thread.sig_on_uaccess_err;
2a53ccbc arch/x86/entry/vsyscall/vsyscall_64.c Ingo Molnar 2016-07-15 226 current->thread.sig_on_uaccess_err = 1;
87b526d3 arch/x86/kernel/vsyscall_64.c Andy Lutomirski 2012-10-01 227
87b526d3 arch/x86/kernel/vsyscall_64.c Andy Lutomirski 2012-10-01 228 ret = -EFAULT;
87b526d3 arch/x86/kernel/vsyscall_64.c Andy Lutomirski 2012-10-01 229 switch (vsyscall_nr) {
87b526d3 arch/x86/kernel/vsyscall_64.c Andy Lutomirski 2012-10-01 230 case 0:
fa697140 arch/x86/entry/vsyscall/vsyscall_64.c Dominik Brodowski 2018-04-05 231 /* this decodes regs->di and regs->si on its own */
d5a00528 arch/x86/entry/vsyscall/vsyscall_64.c Dominik Brodowski 2018-04-09 232 ret = __x64_sys_gettimeofday(regs);
5651721e arch/x86/kernel/vsyscall_64.c Will Drewry 2012-07-13 233 break;
5651721e arch/x86/kernel/vsyscall_64.c Will Drewry 2012-07-13 234
87b526d3 arch/x86/kernel/vsyscall_64.c Andy Lutomirski 2012-10-01 235 case 1:
fa697140 arch/x86/entry/vsyscall/vsyscall_64.c Dominik Brodowski 2018-04-05 236 /* this decodes regs->di on its own */
d5a00528 arch/x86/entry/vsyscall/vsyscall_64.c Dominik Brodowski 2018-04-09 237 ret = __x64_sys_time(regs);
4fc34901 arch/x86/kernel/vsyscall_64.c Andy Lutomirski 2011-11-07 238 break;
4fc34901 arch/x86/kernel/vsyscall_64.c Andy Lutomirski 2011-11-07 239
87b526d3 arch/x86/kernel/vsyscall_64.c Andy Lutomirski 2012-10-01 240 case 2:
fa697140 arch/x86/entry/vsyscall/vsyscall_64.c Dominik Brodowski 2018-04-05 241 /* while we could clobber regs->dx, we didn't in the past... */
fa697140 arch/x86/entry/vsyscall/vsyscall_64.c Dominik Brodowski 2018-04-05 242 orig_dx = regs->dx;
fa697140 arch/x86/entry/vsyscall/vsyscall_64.c Dominik Brodowski 2018-04-05 243 regs->dx = 0;
fa697140 arch/x86/entry/vsyscall/vsyscall_64.c Dominik Brodowski 2018-04-05 244 /* this decodes regs->di, regs->si and regs->dx on its own */
d5a00528 arch/x86/entry/vsyscall/vsyscall_64.c Dominik Brodowski 2018-04-09 245 ret = __x64_sys_getcpu(regs);
fa697140 arch/x86/entry/vsyscall/vsyscall_64.c Dominik Brodowski 2018-04-05 246 regs->dx = orig_dx;
5cec93c2 arch/x86/kernel/vsyscall_64.c Andy Lutomirski 2011-06-05 247 break;
5cec93c2 arch/x86/kernel/vsyscall_64.c Andy Lutomirski 2011-06-05 248 }
8c73626a arch/x86/kernel/vsyscall_64.c John Stultz 2010-07-13 249
2a53ccbc arch/x86/entry/vsyscall/vsyscall_64.c Ingo Molnar 2016-07-15 250 current->thread.sig_on_uaccess_err = prev_sig_on_uaccess_err;
4fc34901 arch/x86/kernel/vsyscall_64.c Andy Lutomirski 2011-11-07 251
87b526d3 arch/x86/kernel/vsyscall_64.c Andy Lutomirski 2012-10-01 252 check_fault:
5cec93c2 arch/x86/kernel/vsyscall_64.c Andy Lutomirski 2011-06-05 253 if (ret == -EFAULT) {
4fc34901 arch/x86/kernel/vsyscall_64.c Andy Lutomirski 2011-11-07 254 /* Bad news -- userspace fed a bad pointer to a vsyscall. */
5cec93c2 arch/x86/kernel/vsyscall_64.c Andy Lutomirski 2011-06-05 255 warn_bad_vsyscall(KERN_INFO, regs,
5cec93c2 arch/x86/kernel/vsyscall_64.c Andy Lutomirski 2011-06-05 256 "vsyscall fault (exploit attempt?)");
4fc34901 arch/x86/kernel/vsyscall_64.c Andy Lutomirski 2011-11-07 257
4fc34901 arch/x86/kernel/vsyscall_64.c Andy Lutomirski 2011-11-07 258 /*
4fc34901 arch/x86/kernel/vsyscall_64.c Andy Lutomirski 2011-11-07 259 * If we failed to generate a signal for any reason,
4fc34901 arch/x86/kernel/vsyscall_64.c Andy Lutomirski 2011-11-07 260 * generate one here. (This should be impossible.)
4fc34901 arch/x86/kernel/vsyscall_64.c Andy Lutomirski 2011-11-07 261 */
4fc34901 arch/x86/kernel/vsyscall_64.c Andy Lutomirski 2011-11-07 262 if (WARN_ON_ONCE(!sigismember(&tsk->pending.signal, SIGBUS) &&
4fc34901 arch/x86/kernel/vsyscall_64.c Andy Lutomirski 2011-11-07 263 !sigismember(&tsk->pending.signal, SIGSEGV)))
5cec93c2 arch/x86/kernel/vsyscall_64.c Andy Lutomirski 2011-06-05 264 goto sigsegv;
4fc34901 arch/x86/kernel/vsyscall_64.c Andy Lutomirski 2011-11-07 265
4fc34901 arch/x86/kernel/vsyscall_64.c Andy Lutomirski 2011-11-07 266 return true; /* Don't emulate the ret. */
5cec93c2 arch/x86/kernel/vsyscall_64.c Andy Lutomirski 2011-06-05 267 }
8c73626a arch/x86/kernel/vsyscall_64.c John Stultz 2010-07-13 268
5cec93c2 arch/x86/kernel/vsyscall_64.c Andy Lutomirski 2011-06-05 269 regs->ax = ret;
8c73626a arch/x86/kernel/vsyscall_64.c John Stultz 2010-07-13 270
5651721e arch/x86/kernel/vsyscall_64.c Will Drewry 2012-07-13 271 do_ret:
5cec93c2 arch/x86/kernel/vsyscall_64.c Andy Lutomirski 2011-06-05 272 /* Emulate a ret instruction. */
5cec93c2 arch/x86/kernel/vsyscall_64.c Andy Lutomirski 2011-06-05 273 regs->ip = caller;
5cec93c2 arch/x86/kernel/vsyscall_64.c Andy Lutomirski 2011-06-05 274 regs->sp += 8;
3ae36655 arch/x86/kernel/vsyscall_64.c Andy Lutomirski 2011-08-10 275 return true;
c08c8205 arch/x86_64/kernel/vsyscall.c Vojtech Pavlik 2006-09-26 276
5cec93c2 arch/x86/kernel/vsyscall_64.c Andy Lutomirski 2011-06-05 277 sigsegv:
5cec93c2 arch/x86/kernel/vsyscall_64.c Andy Lutomirski 2011-06-05 278 force_sig(SIGSEGV, current);
3ae36655 arch/x86/kernel/vsyscall_64.c Andy Lutomirski 2011-08-10 279 return true;
^1da177e arch/x86_64/kernel/vsyscall.c Linus Torvalds 2005-04-16 280 }
^1da177e arch/x86_64/kernel/vsyscall.c Linus Torvalds 2005-04-16 281
:::::: The code at line 127 was first introduced by commit
:::::: 87b526d349b04c31d7b3a40b434eb3f825d22305 seccomp: Make syscall skipping and nr changes more consistent
:::::: TO: Andy Lutomirski <[email protected]>
:::::: CC: James Morris <[email protected]>
---
0-DAY kernel test infrastructure Open Source Technology Center
https://lists.01.org/pipermail/kbuild-all Intel Corporation
On Sun, May 06, 2018 at 08:20:13AM +0800, [email protected] wrote:
> From: Changbin Du <[email protected]>
>
> If device tree is not enabled, of_find_regulator_by_node() should have
> a dummy function since the function call is still there.
Please do not submit new versions of already applied patches, please
submit incremental updates to the existing code. Modifying existing
commits creates problems for other users building on top of those
commits so it's best practice to only change pubished git commits if
absolutely essential.
On Wed, May 09, 2018 at 05:21:14PM +0900, Mark Brown wrote:
> On Sun, May 06, 2018 at 08:20:13AM +0800, [email protected] wrote:
> > From: Changbin Du <[email protected]>
> >
> > If device tree is not enabled, of_find_regulator_by_node() should have
> > a dummy function since the function call is still there.
>
> Please do not submit new versions of already applied patches, please
> submit incremental updates to the existing code. Modifying existing
> commits creates problems for other users building on top of those
> commits so it's best practice to only change pubished git commits if
> absolutely essential.
Hmm, I saw your merging notification too late. Let me refresh the series. Sorry
for confusing.
--
Thanks,
Changbin Du
On Wed, May 09, 2018 at 04:13:42PM +0800, Du, Changbin wrote:
> On Wed, May 09, 2018 at 05:21:14PM +0900, Mark Brown wrote:
> > Please do not submit new versions of already applied patches, please
> > submit incremental updates to the existing code. Modifying existing
> > commits creates problems for other users building on top of those
> > commits so it's best practice to only change pubished git commits if
> > absolutely essential.
> Hmm, I saw your merging notification too late. Let me refresh the series. Sorry
> for confusing.
No problem, just wanted to make sure I wasn't missing any updates from
this new version.