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61d7ebe037
When JUMP_LABEL=n, the tracepoint refcount test in the pre-call stores
the refcount value to the stack, so the same value can be used for the
post-call (presumably to avoid racing with the value concurrently
changing).
On little-endian (ELFv2) that might have just worked by luck, because
32(r1) is STK_PARAM(R3) there and so the value save gets clobbered by
the tracing code when it's non-zero, but fortunately r3 is the hcall
number and 0 is an invalid hcall number so it should get clobbered by
another non-zero value. In any case, commit cc1adb5f32
("powerpc/pseries: Use jump labels for hcall tracepoints") removed the
code that actually used the value stored, so now it's just dead code.
It's fragile to be storing to the stack like this, and confusing. Better
remove it.
Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://msgid.link/20230509091600.70994-2-npiggin@gmail.com
Linux kernel
============
There are several guides for kernel developers and users. These guides can
be rendered in a number of formats, like HTML and PDF. Please read
Documentation/admin-guide/README.rst first.
In order to build the documentation, use ``make htmldocs`` or
``make pdfdocs``. The formatted documentation can also be read online at:
https://www.kernel.org/doc/html/latest/
There are various text files in the Documentation/ subdirectory,
several of them using the Restructured Text markup notation.
Please read the Documentation/process/changes.rst file, as it contains the
requirements for building and running the kernel, and information about
the problems which may result by upgrading your kernel.