| Message ID | 20210304152607.1817648-2-f4bug@amsat.org |
|---|---|
| State | New |
| Headers | show |
| Series | user-mode: Rename CPUState::opaque as CPUState::task_state | expand |
On Thu, 4 Mar 2021 at 15:31, Philippe Mathieu-Daudé <f4bug@amsat.org> wrote: > > The rest of the codebase uses the QEMU_ALIGNED() introduced in > commit 911a4d2215b ("compiler.h: add QEMU_ALIGNED() to enforce > struct alignment"). Use it for the TaskState structure too. > > Signed-off-by: Philippe Mathieu-Daudé <f4bug@amsat.org> > --- > bsd-user/qemu.h | 2 +- > linux-user/qemu.h | 2 +- > 2 files changed, 2 insertions(+), 2 deletions(-) > > diff --git a/bsd-user/qemu.h b/bsd-user/qemu.h > index d2bcaab7413..1ec14010216 100644 > --- a/bsd-user/qemu.h > +++ b/bsd-user/qemu.h > @@ -96,7 +96,7 @@ typedef struct TaskState { > int signal_pending; /* non zero if a signal may be pending */ > > uint8_t stack[]; > -} __attribute__((aligned(16))) TaskState; > +} QEMU_ALIGNED(16) TaskState; > > void init_task_state(TaskState *ts); > extern const char *qemu_uname_release; > diff --git a/linux-user/qemu.h b/linux-user/qemu.h > index 52c981710b4..d7815bfb845 100644 > --- a/linux-user/qemu.h > +++ b/linux-user/qemu.h > @@ -157,7 +157,7 @@ typedef struct TaskState { > > /* This thread's sigaltstack, if it has one */ > struct target_sigaltstack sigaltstack_used; > -} __attribute__((aligned(16))) TaskState; > +} QEMU_ALIGNED(16) TaskState; Does this struct need to be 16-aligned these days? When it was first added in commit 851e67a1b46f in 2003, there was a justification in a comment (still present in the source today): /* NOTE: we force a big alignment so that the stack stored after is aligned too */ because the final field in the struct was "uint8_t stack[0];" But that field was removed in commit 48e15fc2d in 2010 which switched us to allocating the stack and the TaskState separately. So I think that at least for linux-user the alignment attribute is no longer needed. bsd-user's struct still has the 'stack' field but as far as I can tell it is never used, so it and the alignment could be deleted there too. (bsd-user is missing the changes that 48e15fc2d makes for linux-user, but less harmfully since it appears not to implement either threads or fork (?!). In any case the plan at the moment is to blow away bsd-user/ entirely so spending much thought on it is wasted effort.) thanks -- PMM
diff --git a/bsd-user/qemu.h b/bsd-user/qemu.h index d2bcaab7413..1ec14010216 100644 --- a/bsd-user/qemu.h +++ b/bsd-user/qemu.h @@ -96,7 +96,7 @@ typedef struct TaskState { int signal_pending; /* non zero if a signal may be pending */ uint8_t stack[]; -} __attribute__((aligned(16))) TaskState; +} QEMU_ALIGNED(16) TaskState; void init_task_state(TaskState *ts); extern const char *qemu_uname_release; diff --git a/linux-user/qemu.h b/linux-user/qemu.h index 52c981710b4..d7815bfb845 100644 --- a/linux-user/qemu.h +++ b/linux-user/qemu.h @@ -157,7 +157,7 @@ typedef struct TaskState { /* This thread's sigaltstack, if it has one */ struct target_sigaltstack sigaltstack_used; -} __attribute__((aligned(16))) TaskState; +} QEMU_ALIGNED(16) TaskState; extern char *exec_path; void init_task_state(TaskState *ts);
The rest of the codebase uses the QEMU_ALIGNED() introduced in commit 911a4d2215b ("compiler.h: add QEMU_ALIGNED() to enforce struct alignment"). Use it for the TaskState structure too. Signed-off-by: Philippe Mathieu-Daudé <f4bug@amsat.org> --- bsd-user/qemu.h | 2 +- linux-user/qemu.h | 2 +- 2 files changed, 2 insertions(+), 2 deletions(-)