Re: [PATCH v9 01/15] modpost: fix removing numeric suffixes

On Thu, Dec 23, 2021 at 01:21:55AM +0100, Alexander Lobakin wrote:

For now, that condition from remove_dot():

if (m && (s[n + m] == '.' || s[n + m] == 0))

which was designed to test if it's a dot or a \0 after the suffix
is never satisfied.
This is due to that s[n + m] always points to the last digit of a
numeric suffix, not on the symbol next to it:

param_set_uint.0, s[n + m] is '0', s[n + m + 1] is '\0'

So it's off by one and was like that since 2014.

What's the relevance of this? Looking at

  7d02b490e93c ("Kbuild, lto: Drop .number postfixes in modpost")

what you're fixing here is something LTO-related. How do you trigger
this?

For a Cc:stable patch, I'm missing a lot of context.

`-z uniq-symbol` linker flag which we are planning to use to

				     ^^

Who's "we"?

simplify livepatching brings numeric suffixes back, fix this.
Otherwise:

ERROR: modpost: "param_set_uint.0" [vmlinux] is a static EXPORT_SYMBOL

Fixes: fcd38ed0ff26 ("scripts: modpost: fix compilation warning")
Cc: stable@vger.kernel.org # 3.17+
Signed-off-by: Alexander Lobakin <redacted>

...

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Regards/Gruss,
    Boris.

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