| Message ID | 20240614192938.1690188-1-rkir@google.com |
|---|---|
| State | New |
| Headers | show |
| Series | Make TARGET_PAGE_MASK typed as target_ulong | expand |
On 6/14/24 12:29, Roman Kiryanov wrote: > this fixes the build warnings like > > accel/tcg/cputlb.c:416:13: warning: shifting a negative signed value is undefined [-Wshift-negative-value] > mask &= TARGET_PAGE_MASK | TLB_INVALID_MASK; > ^~~~~~~~~~~~~~~~ > include/exec/cpu-all.h:169:45: note: expanded from macro 'TARGET_PAGE_MASK' > ~~~~~~~~~~~~~~~ ^ > > also this fixes the inconsitency in the return > type of qemu_target_page_mask (int could be > shorter than target_long). > > Signed-off-by: Roman Kiryanov <rkir@google.com> No, this will cause failures, because we need this value to sign-extend to when the context includes {u}int64_t, and target_ulong is uint32_t. What options are you using, because this warning should not be generated with -fwrapv. r~
Hi Richard, thank you for looking into this. > No, this will cause failures, because we need this value to sign-extend to when the > context includes {u}int64_t, and target_ulong is uint32_t. I did not expect this, good catch. I see QEMU uses size_t as the return type in qemu_target_page_size which returns TARGET_PAGE_SIZE. Maybe use size_t for TARGET_PAGE_MASK everywhere (including qemu_target_page_mask) as well? > What options are you using, because this warning should not be generated with -fwrapv. Good point, I think we missed this option. Regards, Roman.
On 6/16/24 10:40, Roman Kiryanov wrote: > Hi Richard, > > thank you for looking into this. > >> No, this will cause failures, because we need this value to sign-extend to when the >> context includes {u}int64_t, and target_ulong is uint32_t. > > I did not expect this, good catch. I see QEMU uses size_t as the > return type in qemu_target_page_size which returns TARGET_PAGE_SIZE. > Maybe use size_t for TARGET_PAGE_MASK everywhere (including > qemu_target_page_mask) as well? No, because size_t != uint64_t. We still support 32-bit hosts. r~
diff --git a/include/exec/cpu-all.h b/include/exec/cpu-all.h index 6f09b86e7f..238a847eca 100644 --- a/include/exec/cpu-all.h +++ b/include/exec/cpu-all.h @@ -152,8 +152,8 @@ extern const TargetPageBits target_page; # define TARGET_PAGE_SIZE (-(int)TARGET_PAGE_MASK) #else # define TARGET_PAGE_BITS_MIN TARGET_PAGE_BITS -# define TARGET_PAGE_SIZE (1 << TARGET_PAGE_BITS) -# define TARGET_PAGE_MASK ((target_long)-1 << TARGET_PAGE_BITS) +# define TARGET_PAGE_SIZE ((target_ulong)1 << TARGET_PAGE_BITS) +# define TARGET_PAGE_MASK ((target_ulong)-1 << TARGET_PAGE_BITS) #endif #define TARGET_PAGE_ALIGN(addr) ROUND_UP((addr), TARGET_PAGE_SIZE) diff --git a/include/exec/target_page.h b/include/exec/target_page.h index 98ffbb5c23..57d60f2b06 100644 --- a/include/exec/target_page.h +++ b/include/exec/target_page.h @@ -15,7 +15,7 @@ #define EXEC_TARGET_PAGE_H size_t qemu_target_page_size(void); -int qemu_target_page_mask(void); +target_ulong qemu_target_page_mask(void); int qemu_target_page_bits(void); int qemu_target_page_bits_min(void); diff --git a/page-target.c b/page-target.c index 82211c8593..7176c29555 100644 --- a/page-target.c +++ b/page-target.c @@ -17,7 +17,7 @@ size_t qemu_target_page_size(void) return TARGET_PAGE_SIZE; } -int qemu_target_page_mask(void) +target_ulong qemu_target_page_mask(void) { return TARGET_PAGE_MASK; }
this fixes the build warnings like accel/tcg/cputlb.c:416:13: warning: shifting a negative signed value is undefined [-Wshift-negative-value] mask &= TARGET_PAGE_MASK | TLB_INVALID_MASK; ^~~~~~~~~~~~~~~~ include/exec/cpu-all.h:169:45: note: expanded from macro 'TARGET_PAGE_MASK' ~~~~~~~~~~~~~~~ ^ also this fixes the inconsitency in the return type of qemu_target_page_mask (int could be shorter than target_long). Signed-off-by: Roman Kiryanov <rkir@google.com> --- include/exec/cpu-all.h | 4 ++-- include/exec/target_page.h | 2 +- page-target.c | 2 +- 3 files changed, 4 insertions(+), 4 deletions(-)