| Message ID | 20210510073524.85951-4-thuth@redhat.com |
|---|---|
| State | New |
| Headers | show |
| Series | [PULL,1/9] pc-bios/s390-ccw: don't try to read the next block if end of chunk is reached | expand |
diff --git a/pc-bios/s390-ccw/jump2ipl.c b/pc-bios/s390-ccw/jump2ipl.c index b9c70d64a5..73e4367e09 100644 --- a/pc-bios/s390-ccw/jump2ipl.c +++ b/pc-bios/s390-ccw/jump2ipl.c @@ -82,8 +82,8 @@ void jump_to_low_kernel(void) jump_to_IPL_code(KERN_IMAGE_START); } - /* Trying to get PSW at zero address */ - if (*((uint64_t *)0) & RESET_PSW_MASK) { + /* Trying to get PSW at zero address (pointed to by reset_psw) */ + if (*reset_psw & RESET_PSW_MASK) { /* * Surely nobody will try running directly from lowcore, so * let's use 0 as an indication that we want to load the reset
When compiling the s390-ccw bios with clang, it emits a warning like this: pc-bios/s390-ccw/jump2ipl.c:86:9: warning: indirection of non-volatile null pointer will be deleted, not trap [-Wnull-dereference] if (*((uint64_t *)0) & RESET_PSW_MASK) { ^~~~~~~~~~~~~~~~ pc-bios/s390-ccw/jump2ipl.c:86:9: note: consider using __builtin_trap() or qualifying pointer with 'volatile' We could add a "volatile" here to shut it up, but on the other hand, we also have a pointer variable called "reset_psw" in this file already that points to the PSW at address 0, so we can simply use that pointer variable instead. Reviewed-by: Philippe Mathieu-Daudé <philmd@redhat.com> Message-Id: <20210423142440.582188-1-thuth@redhat.com> Reviewed-by: Janosch Frank <frankja@linux.ibm.com> Signed-off-by: Thomas Huth <thuth@redhat.com> --- pc-bios/s390-ccw/jump2ipl.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-)