mirror of
https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git
synced 2024-09-12 05:48:40 +00:00
![]() Directives such as .long and .word do not magically cause the assembler location counter to become aligned in gas. As a result, using these directives in code sections can result in misaligned data words when building a Thumb-2 kernel (CONFIG_THUMB2_KERNEL). This is a Bad Thing, since the ABI permits the compiler to assume that fundamental types of word size or above are word- aligned when accessing them from C. If the data is not really word-aligned, this can cause impaired performance and stray alignment faults in some circumstances. In general, the following rules should be applied when using data word declaration directives inside code sections: * .quad and .double: .align 3 * .long, .word, .single, .float: .align (or .align 2) * .short: No explicit alignment required, since Thumb-2 instructions are always 2 or 4 bytes in size. immediately after an instruction. Reviewed-by: Will Deacon <will.deacon@arm.com> Signed-off-by: Dave Martin <dave.martin@linaro.org> Acked-by: Catalin Marinas <catalin.marinas@arm.com> Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk> |
||
---|---|---|
.. | ||
alpha | ||
arm | ||
avr32 | ||
blackfin | ||
cris | ||
frv | ||
h8300 | ||
ia64 | ||
m32r | ||
m68k | ||
m68knommu | ||
microblaze | ||
mips | ||
mn10300 | ||
parisc | ||
powerpc | ||
s390 | ||
score | ||
sh | ||
sparc | ||
tile | ||
um | ||
x86 | ||
xtensa | ||
.gitignore | ||
Kconfig |