22eeafc735
Backports PR https://github.com/ARMmbed/mbedtls/pull/4948 to fix a regression
with our macOS builds using Clang 12.
Fixes #53297.
(cherry picked from commit 4cf3056ca6)
37 lines
1.5 KiB
Diff
37 lines
1.5 KiB
Diff
From 7c847235e8f0e0b877c505f19733b417bb65ff2e Mon Sep 17 00:00:00 2001
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From: Gilles Peskine <Gilles.Peskine@arm.com>
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Date: Tue, 14 Sep 2021 00:13:05 +0200
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Subject: [PATCH] x86_64 MULADDC assembly: add missing constraints about memory
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MULADDC_CORE reads from (%%rsi) and writes to (%%rdi). This fragment is
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repeated up to 16 times, and %%rsi and %%rdi are s and d on entry
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respectively. Hence the complete asm statement reads 16 64-bit words
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from memory starting at s, and writes 16 64-bit words starting at d.
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Without any declaration of modified memory, Clang 12 and Clang 13 generated
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non-working code for mbedtls_mpi_mod_exp. The constraints make the unit
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tests pass with Clang 12.
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Signed-off-by: Gilles Peskine <Gilles.Peskine@arm.com>
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---
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include/mbedtls/bn_mul.h | 6 +++---
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1 file changed, 3 insertions(+), 3 deletions(-)
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diff --git a/include/mbedtls/bn_mul.h b/include/mbedtls/bn_mul.h
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index 6f1201bf50a..f84f9650ddc 100644
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--- a/include/mbedtls/bn_mul.h
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+++ b/include/mbedtls/bn_mul.h
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@@ -256,9 +256,9 @@
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"addq $8, %%rdi\n"
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#define MULADDC_STOP \
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- : "+c" (c), "+D" (d), "+S" (s) \
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- : "b" (b) \
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- : "rax", "rdx", "r8" \
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+ : "+c" (c), "+D" (d), "+S" (s), "+m" (*(uint64_t (*)[16]) d) \
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+ : "b" (b), "m" (*(const uint64_t (*)[16]) s) \
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+ : "rax", "rdx", "r8" \
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);
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#endif /* AMD64 */
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