On Fri, 20 May 2022 16:05:46 +0200 Janis Schoetterl-Glausch <scgl@xxxxxxxxxxxxx> wrote: > gcc 12 warns about pointer constant <4k dereference. > Silence the warning by using the extern lowcore symbol to derive the > pointers. This way gcc cannot conclude that the pointer is <4k. > > Signed-off-by: Janis Schoetterl-Glausch <scgl@xxxxxxxxxxxxx> > --- > lib/s390x/asm/mem.h | 4 ++++ > s390x/emulator.c | 5 +++-- > s390x/skey.c | 2 +- > 3 files changed, 8 insertions(+), 3 deletions(-) > > diff --git a/lib/s390x/asm/mem.h b/lib/s390x/asm/mem.h > index 845c00cc..e7901fe0 100644 > --- a/lib/s390x/asm/mem.h > +++ b/lib/s390x/asm/mem.h > @@ -7,6 +7,10 @@ > */ > #ifndef _ASMS390X_MEM_H_ > #define _ASMS390X_MEM_H_ > +#include <asm/arch_def.h> > + > +/* pointer to 0 used to avoid compiler warnings */ > +uint8_t *mem_all = (uint8_t *)&lowcore; this is defined in a .h, so maybe it's better to declare it static? although maybe you can simply declare a macro like this: #define MEM(x) ((void *)((uint8_t *)&lowcore + (x))) and then just use MEM(x)... (please find a less generic name for MEM, though) > > #define SKEY_ACC 0xf0 > #define SKEY_FP 0x08 > diff --git a/s390x/emulator.c b/s390x/emulator.c > index c9182ea4..afc3c213 100644 > --- a/s390x/emulator.c > +++ b/s390x/emulator.c > @@ -12,6 +12,7 @@ > #include <asm/cpacf.h> > #include <asm/interrupt.h> > #include <asm/float.h> > +#include <asm/mem.h> > #include <linux/compiler.h> > > static inline void __test_spm_ipm(uint8_t cc, uint8_t key) > @@ -138,7 +139,7 @@ static __always_inline void __test_cpacf_invalid_parm(unsigned int opcode) > { > report_prefix_push("invalid parm address"); > expect_pgm_int(); > - __cpacf_query(opcode, (void *) -1); > + __cpacf_query(opcode, (cpacf_mask_t *)&mem_all[-1]); ...for example here MEM(-1) > check_pgm_int_code(PGM_INT_CODE_ADDRESSING); > report_prefix_pop(); > } > @@ -148,7 +149,7 @@ static __always_inline void __test_cpacf_protected_parm(unsigned int opcode) > report_prefix_push("protected parm address"); > expect_pgm_int(); > low_prot_enable(); > - __cpacf_query(opcode, (void *) 8); > + __cpacf_query(opcode, (cpacf_mask_t *)&mem_all[8]); ... MEM(8) > low_prot_disable(); > check_pgm_int_code(PGM_INT_CODE_PROTECTION); > report_prefix_pop(); > diff --git a/s390x/skey.c b/s390x/skey.c > index 32bf1070..42bf598c 100644 > --- a/s390x/skey.c > +++ b/s390x/skey.c > @@ -349,7 +349,7 @@ static void test_set_prefix(void) > set_storage_key(pagebuf, 0x28, 0); > expect_pgm_int(); > install_page(root, virt_to_pte_phys(root, pagebuf), 0); > - set_prefix_key_1((uint32_t *)2048); > + set_prefix_key_1((uint32_t *)&mem_all[2048]); ... MEM(2048) > install_page(root, 0, 0); > check_pgm_int_code(PGM_INT_CODE_PROTECTION); > report(get_prefix() == old_prefix, "did not set prefix");