tools/nolibc: i386: fix initial stack alignment
authorWilly Tarreau <w@1wt.eu>
Sun, 24 Oct 2021 17:28:15 +0000 (19:28 +0200)
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>
Thu, 27 Jan 2022 09:53:42 +0000 (10:53 +0100)
commit5e258640ba549a3a2d053a917b353889beab09f4
treef68f1adab4df921d52282f985d7509593439517d
parent06f7528d641bf685dd9bc55e85afbf7c3843b8de
tools/nolibc: i386: fix initial stack alignment

commit ebbe0d8a449d183fa43b42d84fcb248e25303985 upstream.

After re-checking in the spec and comparing stack offsets with glibc,
The last pushed argument must be 16-byte aligned (i.e. aligned before the
call) so that in the callee esp+4 is multiple of 16, so the principle is
the 32-bit equivalent to what Ammar fixed for x86_64. It's possible that
32-bit code using SSE2 or MMX could have been affected. In addition the
frame pointer ought to be zero at the deepest level.

Link: https://gitlab.com/x86-psABIs/i386-ABI/-/wikis/Intel386-psABI
Cc: Ammar Faizi <ammar.faizi@students.amikom.ac.id>
Cc: stable@vger.kernel.org
Signed-off-by: Willy Tarreau <w@1wt.eu>
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
tools/include/nolibc/nolibc.h