arch/csky/mm/fault.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-)
In the csky_cmpxchg_fixup function, using the global variable
csky_cmpxchg_stw to determine the address where the exception
occurred is incorrect. The global variable csky_cmpxchg_stw
stores the opcode at the time of the exception, while
&csky_cmpxchg_stw is the address where the exception occurred.
Signed-off-by: Yang Li <yang.li85200@gmail.com>
---
arch/csky/mm/fault.c | 4 ++--
1 file changed, 2 insertions(+), 2 deletions(-)
diff --git a/arch/csky/mm/fault.c b/arch/csky/mm/fault.c
index a885518ce1dd..87ff26212261 100644
--- a/arch/csky/mm/fault.c
+++ b/arch/csky/mm/fault.c
@@ -45,8 +45,8 @@ static inline void csky_cmpxchg_fixup(struct pt_regs *regs)
if (trap_no(regs) != VEC_TLBMODIFIED)
return;
- if (instruction_pointer(regs) == csky_cmpxchg_stw)
- instruction_pointer_set(regs, csky_cmpxchg_ldw);
+ if (instruction_pointer(regs) == &csky_cmpxchg_stw)
+ instruction_pointer_set(regs, &csky_cmpxchg_ldw);
return;
}
#endif
--
2.34.1Hi Yang,
kernel test robot noticed the following build errors:
[auto build test ERROR on linus/master]
[also build test ERROR on v6.12-rc3 next-20241015]
[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/Yang-Li/csky-fix-csky_cmpxchg_fixup-not-working/20241008-134806
base: linus/master
patch link: https://lore.kernel.org/r/20241008054615.43062-1-yang.li85200%40gmail.com
patch subject: [PATCH] csky: fix csky_cmpxchg_fixup not working
config: csky-allnoconfig (https://download.01.org/0day-ci/archive/20241016/202410160952.7oClZ4pG-lkp@intel.com/config)
compiler: csky-linux-gcc (GCC) 14.1.0
reproduce (this is a W=1 build): (https://download.01.org/0day-ci/archive/20241016/202410160952.7oClZ4pG-lkp@intel.com/reproduce)
If you fix the issue in a separate patch/commit (i.e. not just a new version of
the same patch/commit), kindly add following tags
| Reported-by: kernel test robot <lkp@intel.com>
| Closes: https://lore.kernel.org/oe-kbuild-all/202410160952.7oClZ4pG-lkp@intel.com/
All error/warnings (new ones prefixed by >>):
arch/csky/mm/fault.c: In function 'csky_cmpxchg_fixup':
>> arch/csky/mm/fault.c:48:39: warning: comparison between pointer and integer
48 | if (instruction_pointer(regs) == &csky_cmpxchg_stw)
| ^~
>> arch/csky/mm/fault.c:49:47: error: passing argument 2 of 'instruction_pointer_set' makes integer from pointer without a cast [-Wint-conversion]
49 | instruction_pointer_set(regs, &csky_cmpxchg_ldw);
| ^~~~~~~~~~~~~~~~~
| |
| long unsigned int *
In file included from arch/csky/include/asm/processor.h:8,
from arch/csky/include/asm/thread_info.h:10,
from include/linux/thread_info.h:60,
from include/asm-generic/current.h:6,
from ./arch/csky/include/generated/asm/current.h:1,
from include/linux/mutex.h:14,
from include/linux/notifier.h:14,
from include/linux/kprobes.h:21,
from arch/csky/mm/fault.c:5:
arch/csky/include/asm/ptrace.h:29:58: note: expected 'long unsigned int' but argument is of type 'long unsigned int *'
29 | unsigned long val)
| ~~~~~~~~~~~~~~^~~
vim +/instruction_pointer_set +49 arch/csky/mm/fault.c
34
35 #ifdef CONFIG_CPU_HAS_LDSTEX
36 static inline void csky_cmpxchg_fixup(struct pt_regs *regs)
37 {
38 return;
39 }
40 #else
41 extern unsigned long csky_cmpxchg_ldw;
42 extern unsigned long csky_cmpxchg_stw;
43 static inline void csky_cmpxchg_fixup(struct pt_regs *regs)
44 {
45 if (trap_no(regs) != VEC_TLBMODIFIED)
46 return;
47
> 48 if (instruction_pointer(regs) == &csky_cmpxchg_stw)
> 49 instruction_pointer_set(regs, &csky_cmpxchg_ldw);
50 return;
51 }
52 #endif
53
--
0-DAY CI Kernel Test Service
https://github.com/intel/lkp-tests/wiki
In the csky_cmpxchg_fixup function, it is incorrect to use the global
variable csky_cmpxchg_stw to determine the address where the exception
occurred.The global variable csky_cmpxchg_stw stores the opcode at the
time of the exception, while &csky_cmpxchg_stw shows the address where
the exception occurred.
Signed-off-by: Yang Li <yang.li85200@gmail.com>
---
V1 -> V2:Eliminate compilation warnings
arch/csky/mm/fault.c | 4 ++--
1 file changed, 2 insertions(+), 2 deletions(-)
diff --git a/arch/csky/mm/fault.c b/arch/csky/mm/fault.c
index a885518ce1dd..5226bc08c336 100644
--- a/arch/csky/mm/fault.c
+++ b/arch/csky/mm/fault.c
@@ -45,8 +45,8 @@ static inline void csky_cmpxchg_fixup(struct pt_regs *regs)
if (trap_no(regs) != VEC_TLBMODIFIED)
return;
- if (instruction_pointer(regs) == csky_cmpxchg_stw)
- instruction_pointer_set(regs, csky_cmpxchg_ldw);
+ if (instruction_pointer(regs) == (unsigned long)&csky_cmpxchg_stw)
+ instruction_pointer_set(regs, (unsigned long)&csky_cmpxchg_ldw);
return;
}
#endif
--
2.34.1On Wed, Oct 16, 2024 at 5:56 PM Yang Li <yang.li85200@gmail.com> wrote:
>
> In the csky_cmpxchg_fixup function, it is incorrect to use the global
> variable csky_cmpxchg_stw to determine the address where the exception
> occurred.The global variable csky_cmpxchg_stw stores the opcode at the
> time of the exception, while &csky_cmpxchg_stw shows the address where
> the exception occurred.
>
> Signed-off-by: Yang Li <yang.li85200@gmail.com>
> ---
> V1 -> V2:Eliminate compilation warnings
>
> arch/csky/mm/fault.c | 4 ++--
> 1 file changed, 2 insertions(+), 2 deletions(-)
>
> diff --git a/arch/csky/mm/fault.c b/arch/csky/mm/fault.c
> index a885518ce1dd..5226bc08c336 100644
> --- a/arch/csky/mm/fault.c
> +++ b/arch/csky/mm/fault.c
> @@ -45,8 +45,8 @@ static inline void csky_cmpxchg_fixup(struct pt_regs *regs)
> if (trap_no(regs) != VEC_TLBMODIFIED)
> return;
>
> - if (instruction_pointer(regs) == csky_cmpxchg_stw)
> - instruction_pointer_set(regs, csky_cmpxchg_ldw);
> + if (instruction_pointer(regs) == (unsigned long)&csky_cmpxchg_stw)
> + instruction_pointer_set(regs, (unsigned long)&csky_cmpxchg_ldw);
csky_cmpxchg_ldw(stw) is a label symbol, not a variable.
arch/csky/kernel/atomic.S:
GLOBAL(csky_cmpxchg_ldw)
GLOBAL(csky_cmpxchg_stw)
Your modification does not affect the ASM output.
(gdb) p main
$1 = {void (void)} 0x5fa <main>
(gdb) p &main
$2 = (void (*)(void)) 0x5fa <main>
> return;
> }
> #endif
> --
> 2.34.1
>
--
Best Regards
Guo Ren
Hi Guo Ren:
In C language, your conclusion is correct, but in assembly language,
global_symbol != &global_symbol
I did the following experiment:
liyang@liyang-virtual-machine:~/Desktop/test$ ls
main.c test.s
liyang@liyang-virtual-machine:~/Desktop/test$ cat test.s
.globl test_symbol
test_symbol:
nop
liyang@liyang-virtual-machine:~/Desktop/test$ cat main.c
#include <stdio.h>
extern unsigned long test_symbol;
int main(void)
{
printf("test_symbol = 0x%lx\n",(unsigned long)test_symbol);
printf("&test_symbol = 0x%lx\n",(unsigned long)&test_symbol);
printf("main = 0x%lx\n",(unsigned long)main);
printf("&main = 0x%lx\n",(unsigned long)&main);
}
liyang@liyang-virtual-machine:~/Desktop/test$ gcc main.c test.s --static -o test
liyang@liyang-virtual-machine:~/Desktop/test$ ls
main.c test test.s
liyang@liyang-virtual-machine:~/Desktop/test$ readelf test -s | grep test_symbol
884: 000000000040170c 0 NOTYPE GLOBAL DEFAULT 7 test_symbol
liyang@liyang-virtual-machine:~/Desktop/test$ readelf test -s | grep main -w
1605: 0000000000401685 135 FUNC GLOBAL DEFAULT 7 main
liyang@liyang-virtual-machine:~/Desktop/test$ ./test
test_symbol = 0x4b853001f0f90
&test_symbol = 0x40170c
main = 0x401685
&main = 0x401685
The above test can lead to the conclusion that:
Both c_symbol and &c_symbol represent the address of a symbol, but
&ASM_symbol represents the address of a symbol while ASM_symbol
represents the opcode stored at that address.
On Thu, Oct 17, 2024 at 2:05 PM Guo Ren <guoren@kernel.org> wrote:
>
> On Wed, Oct 16, 2024 at 5:56 PM Yang Li <yang.li85200@gmail.com> wrote:
> >
> > In the csky_cmpxchg_fixup function, it is incorrect to use the global
> > variable csky_cmpxchg_stw to determine the address where the exception
> > occurred.The global variable csky_cmpxchg_stw stores the opcode at the
> > time of the exception, while &csky_cmpxchg_stw shows the address where
> > the exception occurred.
> >
> > Signed-off-by: Yang Li <yang.li85200@gmail.com>
> > ---
> > V1 -> V2:Eliminate compilation warnings
> >
> > arch/csky/mm/fault.c | 4 ++--
> > 1 file changed, 2 insertions(+), 2 deletions(-)
> >
> > diff --git a/arch/csky/mm/fault.c b/arch/csky/mm/fault.c
> > index a885518ce1dd..5226bc08c336 100644
> > --- a/arch/csky/mm/fault.c
> > +++ b/arch/csky/mm/fault.c
> > @@ -45,8 +45,8 @@ static inline void csky_cmpxchg_fixup(struct pt_regs *regs)
> > if (trap_no(regs) != VEC_TLBMODIFIED)
> > return;
> >
> > - if (instruction_pointer(regs) == csky_cmpxchg_stw)
> > - instruction_pointer_set(regs, csky_cmpxchg_ldw);
> > + if (instruction_pointer(regs) == (unsigned long)&csky_cmpxchg_stw)
> > + instruction_pointer_set(regs, (unsigned long)&csky_cmpxchg_ldw);
> csky_cmpxchg_ldw(stw) is a label symbol, not a variable.
>
> arch/csky/kernel/atomic.S:
> GLOBAL(csky_cmpxchg_ldw)
> GLOBAL(csky_cmpxchg_stw)
>
> Your modification does not affect the ASM output.
>
> (gdb) p main
> $1 = {void (void)} 0x5fa <main>
> (gdb) p &main
> $2 = (void (*)(void)) 0x5fa <main>
>
> > return;
> > }
> > #endif
> > --
> > 2.34.1
> >
>
>
> --
> Best Regards
> Guo Ren
Hi yang,
On Mon, Oct 21, 2024 at 3:51 PM yang li <yang.li85200@gmail.com> wrote:
>
> Hi Guo Ren:
> In C language, your conclusion is correct, but in assembly language,
> global_symbol != &global_symbol
> I did the following experiment:
>
> liyang@liyang-virtual-machine:~/Desktop/test$ ls
> main.c test.s
> liyang@liyang-virtual-machine:~/Desktop/test$ cat test.s
>
> .globl test_symbol
> test_symbol:
> nop
> liyang@liyang-virtual-machine:~/Desktop/test$ cat main.c
> #include <stdio.h>
>
> extern unsigned long test_symbol;
> int main(void)
> {
> printf("test_symbol = 0x%lx\n",(unsigned long)test_symbol);
> printf("&test_symbol = 0x%lx\n",(unsigned long)&test_symbol);
>
> printf("main = 0x%lx\n",(unsigned long)main);
> printf("&main = 0x%lx\n",(unsigned long)&main);
> }
> liyang@liyang-virtual-machine:~/Desktop/test$ gcc main.c test.s --static -o test
> liyang@liyang-virtual-machine:~/Desktop/test$ ls
> main.c test test.s
> liyang@liyang-virtual-machine:~/Desktop/test$ readelf test -s | grep test_symbol
> 884: 000000000040170c 0 NOTYPE GLOBAL DEFAULT 7 test_symbol
> liyang@liyang-virtual-machine:~/Desktop/test$ readelf test -s | grep main -w
> 1605: 0000000000401685 135 FUNC GLOBAL DEFAULT 7 main
> liyang@liyang-virtual-machine:~/Desktop/test$ ./test
> test_symbol = 0x4b853001f0f90
> &test_symbol = 0x40170c
> main = 0x401685
> &main = 0x401685
>
> The above test can lead to the conclusion that:
> Both c_symbol and &c_symbol represent the address of a symbol, but
> &ASM_symbol represents the address of a symbol while ASM_symbol
> represents the opcode stored at that address.
>
> On Thu, Oct 17, 2024 at 2:05 PM Guo Ren <guoren@kernel.org> wrote:
> >
> > On Wed, Oct 16, 2024 at 5:56 PM Yang Li <yang.li85200@gmail.com> wrote:
> > >
> > > In the csky_cmpxchg_fixup function, it is incorrect to use the global
> > > variable csky_cmpxchg_stw to determine the address where the exception
> > > occurred.The global variable csky_cmpxchg_stw stores the opcode at the
> > > time of the exception, while &csky_cmpxchg_stw shows the address where
> > > the exception occurred.
> > >
> > > Signed-off-by: Yang Li <yang.li85200@gmail.com>
You convinced me. Applied to csky/linux-next, thanks!
> > > ---
> > > V1 -> V2:Eliminate compilation warnings
> > >
> > > arch/csky/mm/fault.c | 4 ++--
> > > 1 file changed, 2 insertions(+), 2 deletions(-)
> > >
> > > diff --git a/arch/csky/mm/fault.c b/arch/csky/mm/fault.c
> > > index a885518ce1dd..5226bc08c336 100644
> > > --- a/arch/csky/mm/fault.c
> > > +++ b/arch/csky/mm/fault.c
> > > @@ -45,8 +45,8 @@ static inline void csky_cmpxchg_fixup(struct pt_regs *regs)
> > > if (trap_no(regs) != VEC_TLBMODIFIED)
> > > return;
> > >
> > > - if (instruction_pointer(regs) == csky_cmpxchg_stw)
> > > - instruction_pointer_set(regs, csky_cmpxchg_ldw);
> > > + if (instruction_pointer(regs) == (unsigned long)&csky_cmpxchg_stw)
> > > + instruction_pointer_set(regs, (unsigned long)&csky_cmpxchg_ldw);
> > csky_cmpxchg_ldw(stw) is a label symbol, not a variable.
> >
> > arch/csky/kernel/atomic.S:
> > GLOBAL(csky_cmpxchg_ldw)
> > GLOBAL(csky_cmpxchg_stw)
> >
> > Your modification does not affect the ASM output.
> >
> > (gdb) p main
> > $1 = {void (void)} 0x5fa <main>
> > (gdb) p &main
> > $2 = (void (*)(void)) 0x5fa <main>
> >
> > > return;
> > > }
> > > #endif
> > > --
> > > 2.34.1
> > >
> >
> >
> > --
> > Best Regards
> > Guo Ren
--
Best Regards
Guo Ren
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