Commit Graph

2 Commits

Author SHA1 Message Date
Richard Henderson
44b99a6d5f exec: Build page-vary-common.c with -fno-lto
In bbc17caf81, we used an alias attribute to allow target_page
to be declared const, and yet be initialized late.

This fails when using LTO with several versions of gcc.
The compiler looks through the alias and decides that the const
variable is statically initialized to zero, then propagates that
zero to many uses of the variable.

This can be avoided by compiling one object file with -fno-lto.
In this way, any initializer cannot be seen, and the constant
propagation does not occur.

Since we are certain to have this separate compilation unit, we
can drop the alias attribute as well.  We simply have differing
declarations for target_page in different compilation units.
Drop the use of init_target_page, and drop the configure detection
for CONFIG_ATTRIBUTE_ALIAS.

In order to change the compilation flags for a file with meson,
we must use a static_library.  This runs into specific_ss, where
we would need to create many static_library instances.

Fix this by splitting page-vary.c: the page-vary-common.c part is
compiled once as a static_library, while the page-vary.c part is
left in specific_ss in order to handle the target-specific value
of TARGET_PAGE_BITS_MIN.

Reported-by: Gavin Shan <gshan@redhat.com>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Message-Id: <20210321211534.2101231-1-richard.henderson@linaro.org>
[PMD: Fix typo in subject, split original patch in 3]
Signed-off-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
Tested-by: Gavin Shan <gshan@redhat.com>
Message-Id: <20210322112427.4045204-4-f4bug@amsat.org>
[rth: Update MAINTAINERS]
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
2021-03-23 19:36:47 -06:00
Richard Henderson
27eb9d65ff exec: Extract 'page-vary.h' header
In the next commit we will extract the generic code out of
page-vary.c, only keeping the target specific code. Both
files will use the same TargetPageBits structure, so make
its declaration in a shared header.

As the common header can not use target specific types,
use a uint64_t to hold the page mask value, and add a
cast back to target_long in the TARGET_PAGE_MASK definitions.

Signed-off-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
Message-Id: <20210322112427.4045204-3-f4bug@amsat.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
2021-03-23 19:36:36 -06:00