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89604523a7
When using plugins, GCC requires that the -fplugin= options precedes
any of its plugin arguments appearing on the command line as well.
This is usually not a concern, but as it turns out, this requirement
is causing some issues with ARM's per-task stack protector plugin
and Kbuild's implementation of $(cc-option).
When the per-task stack protector plugin is enabled, and we tweak
the implementation of cc-option not to pipe the stderr output of
GCC to /dev/null, the following output is generated when GCC is
executed in the context of cc-option:
cc1: error: plugin arm_ssp_per_task_plugin should be specified before \
-fplugin-arg-arm_ssp_per_task_plugin-tso=1 in the command line
cc1: error: plugin arm_ssp_per_task_plugin should be specified before \
-fplugin-arg-arm_ssp_per_task_plugin-offset=24 in the command line
These errors will cause any option passed to cc-option to be treated
as unsupported, which is obviously incorrect.
The cause of this issue is the fact that the -fplugin= argument is
added to GCC_PLUGINS_CFLAGS, whereas the arguments above are added
to KBUILD_CFLAGS, and the contents of the former get filtered out of
the latter before being passed to the GCC running the cc-option test,
and so the -fplugin= option does not appear at all on the GCC command
line.
Adding the arguments to GCC_PLUGINS_CFLAGS instead of KBUILD_CFLAGS
would be the correct approach here, if it weren't for the fact that we
are using $(eval) to defer the moment that they are added until after
asm-offsets.h is generated, which is after the point where the contents
of GCC_PLUGINS_CFLAGS are added to KBUILD_CFLAGS. So instead, we have
to add our plugin arguments to both.
For similar reasons, we cannot append DISABLE_ARM_SSP_PER_TASK_PLUGIN
to KBUILD_CFLAGS, as it will be passed to GCC when executing in the
context of cc-option, whereas the other plugin arguments will have
been filtered out, resulting in a similar error and false negative
result as above. So add it to ccflags-y instead.
Fixes:
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|---|---|---|
| .. | ||
| .gitignore | ||
| atags_to_fdt.c | ||
| big-endian.S | ||
| debug.S | ||
| decompress.c | ||
| efi-header.S | ||
| head-sa1100.S | ||
| head-sharpsl.S | ||
| head-xscale.S | ||
| head.S | ||
| libfdt_env.h | ||
| ll_char_wr.S | ||
| Makefile | ||
| misc.c | ||
| misc.h | ||
| piggy.S | ||
| string.c | ||
| vmlinux.lds.S | ||