commit d877322bc1adcab9850732275670409e8bcca4c4 upstream.
A build failure was raised by kbuild with the following error.
drivers/android/binder.c: Assembler messages:
drivers/android/binder.c:3861: Error: unrecognized keyword/register name `l.lwz ?ap,4(r24)'
drivers/android/binder.c:3866: Error: unrecognized keyword/register name `l.addi ?ap,r0,0'
The issue is with 64-bit get_user() calls on openrisc. I traced this to
a problem where in the internally in the get_user macros there is a cast
to long __gu_val this causes GCC to think the get_user call is 32-bit.
This binder code is really long and GCC allocates register r30, which
triggers the issue. The 64-bit get_user asm tries to get the 64-bit pair
register, which for r30 overflows the general register names and returns
the dummy register ?ap.
The fix here is to move the temporary variables into the asm macros. We
use a 32-bit __gu_tmp for 32-bit and smaller macro and a 64-bit tmp in
the 64-bit macro. The cast in the 64-bit macro has a trick of casting
through __typeof__((x)-(x)) which avoids the below warning. This was
barrowed from riscv.
arch/openrisc/include/asm/uaccess.h:240:8: warning: cast to pointer from integer of different size
I tested this in a small unit test to check reading between 64-bit and
32-bit pointers to 64-bit and 32-bit values in all combinations. Also I
ran make C=1 to confirm no new sparse warnings came up. It all looks
clean to me.
Link: https://lore.kernel.org/lkml/202008200453.ohnhqkjQ%25lkp@intel.com/
Signed-off-by: Stafford Horne <shorne@gmail.com>
Reviewed-by: Luc Van Oostenryck <luc.vanoostenryck@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
[ Upstream commit 3ae90d764093dfcd6ab8ab6875377302892c87d4 ]
I found this when compiling a kbuild random config with GCC 11. The
config enables CONFIG_DEBUG_SECTION_MISMATCH, which sets CFLAGS
-fno-inline-functions-called-once. This causes the call to cache_loop in
cache.c to not be inlined causing the below compile error.
In file included from arch/openrisc/mm/cache.c:13:
arch/openrisc/mm/cache.c: In function 'cache_loop':
./arch/openrisc/include/asm/spr.h:16:27: warning: 'asm' operand 0 probably does not match constraints
16 | #define mtspr(_spr, _val) __asm__ __volatile__ ( \
| ^~~~~~~
arch/openrisc/mm/cache.c:25:3: note: in expansion of macro 'mtspr'
25 | mtspr(reg, line);
| ^~~~~
./arch/openrisc/include/asm/spr.h:16:27: error: impossible constraint in 'asm'
16 | #define mtspr(_spr, _val) __asm__ __volatile__ ( \
| ^~~~~~~
arch/openrisc/mm/cache.c:25:3: note: in expansion of macro 'mtspr'
25 | mtspr(reg, line);
| ^~~~~
make[1]: *** [scripts/Makefile.build:283: arch/openrisc/mm/cache.o] Error 1
The asm constraint "K" requires a immediate constant argument to mtspr,
however because of no inlining a register argument is passed causing a
failure. Fix this by using __always_inline.
Link: https://lore.kernel.org/lkml/202008200453.ohnhqkjQ%25lkp@intel.com/
Signed-off-by: Stafford Horne <shorne@gmail.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit 57b8e277c33620e115633cdf700a260b55095460 ]
When dumping a stack with 'cat /proc/#/stack' the kernel would oops.
For example:
# cat /proc/690/stack
Unable to handle kernel access
at virtual address 0x7fc60f58
Oops#: 0000
CPU #: 0
PC: c00097fc SR: 0000807f SP: d6f09b9c
GPR00: 00000000 GPR01: d6f09b9c GPR02: d6f09bb8 GPR03: d6f09bc4
GPR04: 7fc60f5c GPR05: c00099b4 GPR06: 00000000 GPR07: d6f09ba3
GPR08: ffffff00 GPR09: c0009804 GPR10: d6f08000 GPR11: 00000000
GPR12: ffffe000 GPR13: dbb86000 GPR14: 00000001 GPR15: dbb86250
GPR16: 7fc60f63 GPR17: 00000f5c GPR18: d6f09bc4 GPR19: 00000000
GPR20: c00099b4 GPR21: ffffffc0 GPR22: 00000000 GPR23: 00000000
GPR24: 00000001 GPR25: 000002c6 GPR26: d78b6850 GPR27: 00000001
GPR28: 00000000 GPR29: dbb86000 GPR30: ffffffff GPR31: dbb862fc
RES: 00000000 oGPR11: ffffffff
Process cat (pid: 702, stackpage=d79d6000)
Stack:
Call trace:
[<598977f2>] save_stack_trace_tsk+0x40/0x74
[<95063f0e>] stack_trace_save_tsk+0x44/0x58
[<b557bfdd>] proc_pid_stack+0xd0/0x13c
[<a2df8eda>] proc_single_show+0x6c/0xf0
[<e5a737b7>] seq_read+0x1b4/0x688
[<2d6c7480>] do_iter_read+0x208/0x248
[<2182a2fb>] vfs_readv+0x64/0x90
This was caused by the stack trace code in save_stack_trace_tsk using
the wrong stack pointer. It was using the user stack pointer instead of
the kernel stack pointer. Fix this by using the right stack.
Also for good measure we add try_get_task_stack/put_task_stack to ensure
the task is not lost while we are walking it's stack.
Fixes: eecac38b0423a ("openrisc: support framepointers and STACKTRACE_SUPPORT")
Signed-off-by: Stafford Horne <shorne@gmail.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit 6bd140e14d9aaa734ec37985b8b20a96c0ece948 ]
Working on the OpenRISC glibc port I found that sometimes clone was
working strange. That the tls data argument sent in r7 was always
wrong. Further investigation revealed that the arguments were getting
clobbered in the entry code. This patch removes the code that writes to
the argument registers. This was likely due to some old code hanging
around.
This patch fixes this up for clone and fork. This fork clobber is
harmless but also useless so remove.
Signed-off-by: Stafford Horne <shorne@gmail.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
Stafford Horne