On Wed, May 20, 2020 at 12:01:32AM +0930, Andrew Jeffery wrote:
> This allows extraction of kernel function arguments via kprobes on ARM.
> Based on the arm64 implementation and adapted for the 32-bit AAPCS.
>
> Signed-off-by: Andrew Jeffery <[email protected]>
> ---
> The description for HAVE_FUNCTION_ARG_ACCESS_API was pretty vague on what was
> required. I've implemented enough to enable argument extraction for kprobes;
> is
> there anything else needed to satisfy HAVE_FUNCTION_ARG_ACCESS_API?
What about 64-bit arguments? How do they get handled?
regs_get_kernel_argument() talks about 'n' being the argument number,
and maps this directly to a register. If a function argument
prototype is:
(something *foo, long long bar, int baz)
The foo is in r0, bar is in r2/r3 on EABI, and baz is on the stack.
n=0 will return foo. n=1 will be undefined. n=2 will return part of
bar, and n=3 will return the other half. Is this what is expected?
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