| lists.openwall.net | lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC | |
|
Open Source and information security mailing list archives
| ||
|
Message-Id: <20181029192634.30078-3-palmer@sifive.com>
Date: Mon, 29 Oct 2018 12:26:34 -0700
From: Palmer Dabbelt <palmer@...ive.com>
To: linux-riscv@...ts.infradead.org, zongbox@...il.com
Cc: Palmer Dabbelt <palmer@...ive.com>, aou@...s.berkeley.edu,
khandual@...ux.vnet.ibm.com, colyli@...e.de,
andriy.shevchenko@...ux.intel.com, akpm@...ux-foundation.org,
willy@...radead.org, yuanzhichang@...ilicon.com,
matt.redfearn@...s.com, robh@...nel.org,
boris.brezillon@...tlin.com, Greg KH <gregkh@...uxfoundation.org>,
alexander.shishkin@...ux.intel.com, ynorov@...iumnetworks.com,
keescook@...omium.org, bigeasy@...utronix.de,
linux-riscv@...ts.infradead.org, linux-kernel@...r.kernel.org
Subject: [PATCH 2/2] Revert "lib: Add umoddi3 and udivmoddi4 of GCC library routines"
We don't want 64-bit divide in the kernel.
This reverts commit 6315730e9eab7de5fa9864bb13a352713f48aef1.
Signed-off-by: Palmer Dabbelt <palmer@...ive.com>
---
lib/Kconfig | 3 -
lib/Makefile | 1 -
lib/udivmoddi4.c | 310 -----------------------------------------------
lib/umoddi3.c | 32 -----
4 files changed, 346 deletions(-)
delete mode 100644 lib/udivmoddi4.c
delete mode 100644 lib/umoddi3.c
diff --git a/lib/Kconfig b/lib/Kconfig
index d1573a16aa92..a9965f4af4dd 100644
--- a/lib/Kconfig
+++ b/lib/Kconfig
@@ -624,6 +624,3 @@ config GENERIC_LIB_CMPDI2
config GENERIC_LIB_UCMPDI2
bool
-
-config GENERIC_LIB_UMODDI3
- bool
diff --git a/lib/Makefile b/lib/Makefile
index 988949c4fd3a..db06d1237898 100644
--- a/lib/Makefile
+++ b/lib/Makefile
@@ -274,4 +274,3 @@ obj-$(CONFIG_GENERIC_LIB_LSHRDI3) += lshrdi3.o
obj-$(CONFIG_GENERIC_LIB_MULDI3) += muldi3.o
obj-$(CONFIG_GENERIC_LIB_CMPDI2) += cmpdi2.o
obj-$(CONFIG_GENERIC_LIB_UCMPDI2) += ucmpdi2.o
-obj-$(CONFIG_GENERIC_LIB_UMODDI3) += umoddi3.o udivmoddi4.o
diff --git a/lib/udivmoddi4.c b/lib/udivmoddi4.c
deleted file mode 100644
index c08bc8a5f1cf..000000000000
--- a/lib/udivmoddi4.c
+++ /dev/null
@@ -1,310 +0,0 @@
-// SPDX-License-Identifier: GPL-2.0
-
-/*
- * This program is free software; you can redistribute it and/or modify
- * it under the terms of the GNU General Public License as published by
- * the Free Software Foundation; either version 2 of the License, or
- * (at your option) any later version.
- *
- * This program is distributed in the hope that it will be useful,
- * but WITHOUT ANY WARRANTY; without even the implied warranty of
- * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
- * GNU General Public License for more details.
- *
- * You should have received a copy of the GNU General Public License
- * along with this program; if not, see the file COPYING, or write
- * to the Free Software Foundation, Inc.
- */
-
-#include <linux/libgcc.h>
-
-#define count_leading_zeros(COUNT, X) ((COUNT) = __builtin_clz(X))
-
-#define W_TYPE_SIZE 32
-
-#define __ll_B ((unsigned long) 1 << (W_TYPE_SIZE / 2))
-#define __ll_lowpart(t) ((unsigned long) (t) & (__ll_B - 1))
-#define __ll_highpart(t) ((unsigned long) (t) >> (W_TYPE_SIZE / 2))
-
-/* If we still don't have umul_ppmm, define it using plain C. */
-#if !defined(umul_ppmm)
-#define umul_ppmm(w1, w0, u, v) \
- do { \
- unsigned long __x0, __x1, __x2, __x3; \
- unsigned short __ul, __vl, __uh, __vh; \
- \
- __ul = __ll_lowpart(u); \
- __uh = __ll_highpart(u); \
- __vl = __ll_lowpart(v); \
- __vh = __ll_highpart(v); \
- \
- __x0 = (unsigned long) __ul * __vl; \
- __x1 = (unsigned long) __ul * __vh; \
- __x2 = (unsigned long) __uh * __vl; \
- __x3 = (unsigned long) __uh * __vh; \
- \
- __x1 += __ll_highpart(__x0); \
- __x1 += __x2; \
- if (__x1 < __x2) \
- __x3 += __ll_B; \
- \
- (w1) = __x3 + __ll_highpart(__x1); \
- (w0) = __ll_lowpart(__x1) * __ll_B + __ll_lowpart(__x0);\
- } while (0)
-#endif
-
-#if !defined(sub_ddmmss)
-#define sub_ddmmss(sh, sl, ah, al, bh, bl) \
- do { \
- unsigned long __x; \
- __x = (al) - (bl); \
- (sh) = (ah) - (bh) - (__x > (al)); \
- (sl) = __x; \
- } while (0)
-#endif
-
-/* Define this unconditionally, so it can be used for debugging. */
-#define __udiv_qrnnd_c(q, r, n1, n0, d) \
- do { \
- unsigned long __d1, __d0, __q1, __q0; \
- unsigned long __r1, __r0, __m; \
- __d1 = __ll_highpart(d); \
- __d0 = __ll_lowpart(d); \
- \
- __r1 = (n1) % __d1; \
- __q1 = (n1) / __d1; \
- __m = (unsigned long) __q1 * __d0; \
- __r1 = __r1 * __ll_B | __ll_highpart(n0); \
- if (__r1 < __m) { \
- __q1--, __r1 += (d); \
- if (__r1 >= (d)) \
- if (__r1 < __m) \
- __q1--, __r1 += (d); \
- } \
- __r1 -= __m; \
- \
- __r0 = __r1 % __d1; \
- __q0 = __r1 / __d1; \
- __m = (unsigned long) __q0 * __d0; \
- __r0 = __r0 * __ll_B | __ll_lowpart(n0); \
- if (__r0 < __m) { \
- __q0--, __r0 += (d); \
- if (__r0 >= (d)) \
- if (__r0 < __m) \
- __q0--, __r0 += (d); \
- } \
- __r0 -= __m; \
- \
- (q) = (unsigned long) __q1 * __ll_B | __q0; \
- (r) = __r0; \
- } while (0)
-
-/* If udiv_qrnnd was not defined for this processor, use __udiv_qrnnd_c. */
-#if !defined(udiv_qrnnd)
-#define UDIV_NEEDS_NORMALIZATION 1
-#define udiv_qrnnd __udiv_qrnnd_c
-#endif
-
-unsigned long long __udivmoddi4(unsigned long long u, unsigned long long v,
- unsigned long long *rp)
-{
- const DWunion nn = {.ll = u };
- const DWunion dd = {.ll = v };
- DWunion rr, ww;
- unsigned long d0, d1, n0, n1, n2;
- unsigned long q0 = 0, q1 = 0;
- unsigned long b, bm;
-
- d0 = dd.s.low;
- d1 = dd.s.high;
- n0 = nn.s.low;
- n1 = nn.s.high;
-
-#if !UDIV_NEEDS_NORMALIZATION
-
- if (d1 == 0) {
- if (d0 > n1) {
- /* 0q = nn / 0D */
-
- udiv_qrnnd(q0, n0, n1, n0, d0);
- q1 = 0;
-
- /* Remainder in n0. */
- } else {
- /* qq = NN / 0d */
-
- if (d0 == 0)
- /* Divide intentionally by zero. */
- d0 = 1 / d0;
-
- udiv_qrnnd(q1, n1, 0, n1, d0);
- udiv_qrnnd(q0, n0, n1, n0, d0);
-
- /* Remainder in n0. */
- }
-
- if (rp != 0) {
- rr.s.low = n0;
- rr.s.high = 0;
- *rp = rr.ll;
- }
-
-#else /* UDIV_NEEDS_NORMALIZATION */
-
- if (d1 == 0) {
- if (d0 > n1) {
- /* 0q = nn / 0D */
-
- count_leading_zeros(bm, d0);
-
- if (bm != 0) {
- /*
- * Normalize, i.e. make the most significant bit
- * of the denominator set.
- */
-
- d0 = d0 << bm;
- n1 = (n1 << bm) | (n0 >> (W_TYPE_SIZE - bm));
- n0 = n0 << bm;
- }
-
- udiv_qrnnd(q0, n0, n1, n0, d0);
- q1 = 0;
-
- /* Remainder in n0 >> bm. */
- } else {
- /* qq = NN / 0d */
-
- if (d0 == 0)
- /* Divide intentionally by zero. */
- d0 = 1 / d0;
-
- count_leading_zeros(bm, d0);
-
- if (bm == 0) {
- /*
- * From (n1 >= d0) /\ (the most significant bit
- * of d0 is set), conclude (the most significant
- * bit of n1 is set) /\ (theleading quotient
- * digit q1 = 1).
- *
- * This special case is necessary, not an
- * optimization. (Shifts counts of W_TYPE_SIZE
- * are undefined.)
- */
-
- n1 -= d0;
- q1 = 1;
- } else {
- /* Normalize. */
-
- b = W_TYPE_SIZE - bm;
-
- d0 = d0 << bm;
- n2 = n1 >> b;
- n1 = (n1 << bm) | (n0 >> b);
- n0 = n0 << bm;
-
- udiv_qrnnd(q1, n1, n2, n1, d0);
- }
-
- /* n1 != d0... */
-
- udiv_qrnnd(q0, n0, n1, n0, d0);
-
- /* Remainder in n0 >> bm. */
- }
-
- if (rp != 0) {
- rr.s.low = n0 >> bm;
- rr.s.high = 0;
- *rp = rr.ll;
- }
-
-#endif /* UDIV_NEEDS_NORMALIZATION */
-
- } else {
- if (d1 > n1) {
- /* 00 = nn / DD */
-
- q0 = 0;
- q1 = 0;
-
- /* Remainder in n1n0. */
- if (rp != 0) {
- rr.s.low = n0;
- rr.s.high = n1;
- *rp = rr.ll;
- }
- } else {
- /* 0q = NN / dd */
-
- count_leading_zeros(bm, d1);
- if (bm == 0) {
- /*
- * From (n1 >= d1) /\ (the most significant bit
- * of d1 is set), conclude (the most significant
- * bit of n1 is set) /\ (the quotient digit q0 =
- * 0 or 1).
- *
- * This special case is necessary, not an
- * optimization.
- */
-
- /*
- * The condition on the next line takes
- * advantage of that n1 >= d1 (true due to
- * program flow).
- */
- if (n1 > d1 || n0 >= d0) {
- q0 = 1;
- sub_ddmmss(n1, n0, n1, n0, d1, d0);
- } else {
- q0 = 0;
- }
-
- q1 = 0;
-
- if (rp != 0) {
- rr.s.low = n0;
- rr.s.high = n1;
- *rp = rr.ll;
- }
- } else {
- unsigned long m1, m0;
- /* Normalize. */
-
- b = W_TYPE_SIZE - bm;
-
- d1 = (d1 << bm) | (d0 >> b);
- d0 = d0 << bm;
- n2 = n1 >> b;
- n1 = (n1 << bm) | (n0 >> b);
- n0 = n0 << bm;
-
- udiv_qrnnd(q0, n1, n2, n1, d1);
- umul_ppmm(m1, m0, q0, d0);
-
- if (m1 > n1 || (m1 == n1 && m0 > n0)) {
- q0--;
- sub_ddmmss(m1, m0, m1, m0, d1, d0);
- }
-
- q1 = 0;
-
- /* Remainder in (n1n0 - m1m0) >> bm. */
- if (rp != 0) {
- sub_ddmmss(n1, n0, n1, n0, m1, m0);
- rr.s.low = (n1 << b) | (n0 >> bm);
- rr.s.high = n1 >> bm;
- *rp = rr.ll;
- }
- }
- }
- }
-
- ww.s.low = q0;
- ww.s.high = q1;
-
- return ww.ll;
-}
diff --git a/lib/umoddi3.c b/lib/umoddi3.c
deleted file mode 100644
index d7bbf0f85197..000000000000
--- a/lib/umoddi3.c
+++ /dev/null
@@ -1,32 +0,0 @@
-// SPDX-License-Identifier: GPL-2.0
-
-/*
- * This program is free software; you can redistribute it and/or modify
- * it under the terms of the GNU General Public License as published by
- * the Free Software Foundation; either version 2 of the License, or
- * (at your option) any later version.
- *
- * This program is distributed in the hope that it will be useful,
- * but WITHOUT ANY WARRANTY; without even the implied warranty of
- * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
- * GNU General Public License for more details.
- *
- * You should have received a copy of the GNU General Public License
- * along with this program; if not, see the file COPYING, or write
- * to the Free Software Foundation, Inc.
- */
-
-#include <linux/module.h>
-#include <linux/libgcc.h>
-
-extern unsigned long long __udivmoddi4(unsigned long long u,
- unsigned long long v,
- unsigned long long *rp);
-
-unsigned long long __umoddi3(unsigned long long u, unsigned long long v)
-{
- unsigned long long w;
- (void)__udivmoddi4(u, v, &w);
- return w;
-}
-EXPORT_SYMBOL(__umoddi3);
--
2.18.1
Powered by blists - more mailing lists