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drivers/xen/xenbus: Fix namespace collision and split() section placement with AutoFDO 

When compiling the kernel with -ffunction-sections enabled, the split()
function gets compiled into the .text.split section.  In some cases it
can even be cloned into .text.split.constprop.0 or .text.split.isra.0.

However, .text.split.* is already reserved for use by the Clang
-fsplit-machine-functions flag, which is used by AutoFDO.  That may
place part of a function's code in a .text.split.<func> section.

This naming conflict causes the vmlinux linker script to wrongly place
split() with other .text.split.* code, rather than where it belongs with
regular text.

Fix it by renaming split() to split_strings().

Fixes: 6568f14cb5 ("vmlinux.lds: Exclude .text.startup and .text.exit from TEXT_MAIN")
Signed-off-by: Josh Poimboeuf <jpoimboe@kernel.org>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: live-patching@vger.kernel.org
Cc: Juergen Gross <jgross@suse.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Link: https://patch.msgid.link/92a194234a0f757765e275b288bb1a7236c2c35c.1762991150.git.jpoimboe@kernel.org
This commit is contained in:
Josh Poimboeuf 2025-11-12 15:47:50 -08:00 committed by Ingo Molnar
parent 56255fa968
commit 0330b7fbbf
1 changed files with 2 additions and 2 deletions
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4
drivers/xen/xenbus/xenbus_xs.c
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@ -410,7 +410,7 @@ static char *join(const char *dir, const char *name)
return (!buffer) ? ERR_PTR(-ENOMEM) : buffer; return (!buffer) ? ERR_PTR(-ENOMEM) : buffer;
} }
static char **split(char *strings, unsigned int len, unsigned int *num) static char **split_strings(char *strings, unsigned int len, unsigned int *num)
{ {
char *p, **ret; char *p, **ret;
@ -448,7 +448,7 @@ char **xenbus_directory(struct xenbus_transaction t,
if (IS_ERR(strings)) if (IS_ERR(strings))
return ERR_CAST(strings); return ERR_CAST(strings);
return split(strings, len, num); return split_strings(strings, len, num);
} }
EXPORT_SYMBOL_GPL(xenbus_directory); EXPORT_SYMBOL_GPL(xenbus_directory);