diff mbox series

[v2,22/28] arm64: export CC_USING_PATCHABLE_FUNCTION_ENTRY

Message ID 20200903203053.3411268-23-samitolvanen@google.com
State New, archived
Headers show
Series Add support for Clang LTO | expand

Commit Message

Sami Tolvanen Sept. 3, 2020, 8:30 p.m. UTC
Since arm64 does not use -pg in CC_FLAGS_FTRACE with
DYNAMIC_FTRACE_WITH_REGS, skip running recordmcount by
exporting CC_USING_PATCHABLE_FUNCTION_ENTRY.

Signed-off-by: Sami Tolvanen <samitolvanen@google.com>
---
 arch/arm64/Makefile | 1 +
 1 file changed, 1 insertion(+)

Comments

Kees Cook Sept. 3, 2020, 10:44 p.m. UTC | #1
On Thu, Sep 03, 2020 at 01:30:47PM -0700, Sami Tolvanen wrote:
> Since arm64 does not use -pg in CC_FLAGS_FTRACE with
> DYNAMIC_FTRACE_WITH_REGS, skip running recordmcount by
> exporting CC_USING_PATCHABLE_FUNCTION_ENTRY.
> 
> Signed-off-by: Sami Tolvanen <samitolvanen@google.com>

How stand-alone is this? Does it depend on the earlier mcount fixes?

Reviewed-by: Kees Cook <keescook@chromium.org>
Sami Tolvanen Sept. 8, 2020, 9:23 p.m. UTC | #2
On Thu, Sep 03, 2020 at 03:44:18PM -0700, Kees Cook wrote:
> On Thu, Sep 03, 2020 at 01:30:47PM -0700, Sami Tolvanen wrote:
> > Since arm64 does not use -pg in CC_FLAGS_FTRACE with
> > DYNAMIC_FTRACE_WITH_REGS, skip running recordmcount by
> > exporting CC_USING_PATCHABLE_FUNCTION_ENTRY.
> > 
> > Signed-off-by: Sami Tolvanen <samitolvanen@google.com>
> 
> How stand-alone is this? Does it depend on the earlier mcount fixes?

It does, because exporting CC_USING_PATCHABLE_FUNCTION_ENTRY doesn't
change anything without the earlier mcount changes.

Sami
diff mbox series

Patch

diff --git a/arch/arm64/Makefile b/arch/arm64/Makefile
index 130569f90c54..eeaf3c2e0971 100644
--- a/arch/arm64/Makefile
+++ b/arch/arm64/Makefile
@@ -127,6 +127,7 @@  endif
 ifeq ($(CONFIG_DYNAMIC_FTRACE_WITH_REGS),y)
   KBUILD_CPPFLAGS += -DCC_USING_PATCHABLE_FUNCTION_ENTRY
   CC_FLAGS_FTRACE := -fpatchable-function-entry=2
+  export CC_USING_PATCHABLE_FUNCTION_ENTRY := 1
 endif
 
 # Default value