linuxkm: add macros mapping malloc(), free(), and realloc() to the kernel equivalents, don't set WOLFSSL_NO_MALLOC, and reduce -Wframe-larger-than= from 256k to 64k; tweak fix for HAVE_INTEL_RDSEED conflict with WOLFSSL_LINUXKM; add clean rule to linuxkm/Makefile.

2025-08-01 03:34:39 +02:00 · 2020-08-18 23:51:32 -05:00
parent 911b23d2b4
commit 2591479866
6 changed files with 23 additions and 44 deletions
--- a/linuxkm/Makefile
+++ b/linuxkm/Makefile
@@ -22,9 +22,10 @@ ifeq "$(src_libwolfssl_la_OBJECTS)" ""
 $(error $$src_libwolfssl_la_OBJECTS is unset.)
 endif

-WOLFSSL_CFLAGS=-DHAVE_CONFIG_H -I$(SRC_TOP) -DBUILDING_WOLFSSL $(AM_CFLAGS) $(CFLAGS) -Wframe-larger-than=262144
+WOLFSSL_CFLAGS=-DHAVE_CONFIG_H -I$(SRC_TOP) -DBUILDING_WOLFSSL $(AM_CFLAGS) $(CFLAGS) -Wframe-larger-than=65536 -mpreferred-stack-boundary=4
 WOLFSSL_ASFLAGS=-DHAVE_CONFIG_H -I$(SRC_TOP) -DBUILDING_WOLFSSL $(AM_CCASFLAGS) $(CCASFLAGS)
-WOLFSSL_OBJ_FILES=linuxkm/module_hooks.o $(patsubst %.lo, %.o, $(patsubst src/libwolfssl_la-%, src/%, $(patsubst wolfcrypt/src/src_libwolfssl_la-%, wolfcrypt/src/%, $(src_libwolfssl_la_OBJECTS))))
+
+WOLFSSL_OBJ_FILES=linuxkm/module_hooks.o $(patsubst %.lo, %.o, $(patsubst src/src_libwolfssl_la-%, src/%, $(patsubst src/libwolfssl_la-%, src/%, $(patsubst wolfcrypt/src/src_libwolfssl_la-%, wolfcrypt/src/%, $(src_libwolfssl_la_OBJECTS)))))

 export WOLFSSL_CFLAGS WOLFSSL_ASFLAGS WOLFSSL_OBJ_FILES

@@ -32,3 +33,8 @@ libwolfssl.ko:
 	@mkdir -p linuxkm src wolfcrypt/src
 	@if [[ ! -h $(SRC_TOP)/Kbuild ]]; then ln -s $(MODULE_TOP)/Kbuild $(SRC_TOP)/Kbuild; fi
 	make -C $(KROOT) M=$(MODULE_TOP) src=$(SRC_TOP)
+
+.PHONY: clean
+
+clean:
+	@cd $(MODULE_TOP) && rm -f libwolfssl.ko Module.symvers built-in.a modules.order libwolfssl.mod libwolfssl.mod.c src/*.o wolfcrypt/src/*.o
--- a/m4/ax_linuxkm.m4
+++ b/m4/ax_linuxkm.m4
@@ -27,16 +27,3 @@ else
  AC_MSG_RESULT([no default configured kernel arch found])
 fi
 ])
-
-dnl AC_DEFUN([AC_DEFINE_KERNEL_KFLAGS],
-dnl [
-dnl     AC_MSG_CHECKING([flags for compiling objects for kernel module])
-dnl     if test -z "${KROOT}" || test -z "${KARCH}"; then
-dnl         AC_MSG_ERROR([Linux kernel configuration incomplete (KROOT=${KROOT}, KARCH=${KARCH}).])
-dnl     else
-dnl         GCC_SHORT_VERSION="$($CC -dumpversion)"
-dnl         KFLAGS="-I${KROOT}/include -I${KROOT}/include/uapi -I${KROOT}/arch/${KARCH}/include -I${KROOT}/arch/${KARCH}/include/generated -I${KROOT}/arch/${KARCH}/include/generated/uapi -I${KROOT}/arch/${KARCH}/include/uapi -I${KROOT}/tools/include -I${KROOT}/tools/arch/${KARCH}/include -I${KROOT}/tools/include/uapi -I/usr/lib/gcc/${host_cpu}-${host_vendor}-${host_os}/${GCC_SHORT_VERSION}/include"
-dnl         AC_MSG_RESULT([$KFLAGS])
-dnl     fi
-dnl ])
-dnl
--- a/wolfcrypt/src/random.c
+++ b/wolfcrypt/src/random.c
@@ -176,7 +176,7 @@ int wc_RNG_GenerateByte(WC_RNG* rng, byte* b)
    {
        intel_flags = cpuid_get_flags();
    }
-    #ifdef HAVE_INTEL_RDSEED
+    #if defined(HAVE_INTEL_RDSEED) && !defined(WOLFSSL_LINUXKM)
    static int wc_GenerateSeed_IntelRD(OS_Seed* os, byte* output, word32 sz);
    #endif
    #ifdef HAVE_INTEL_RDRAND
@@ -1438,6 +1438,7 @@ static WC_INLINE int IntelRDseed64_r(word64* rnd)
    return -1;
 }

+#ifndef WOLFSSL_LINUXKM
 /* return 0 on success */
 static int wc_GenerateSeed_IntelRD(OS_Seed* os, byte* output, word32 sz)
 {
@@ -1468,6 +1469,7 @@ static int wc_GenerateSeed_IntelRD(OS_Seed* os, byte* output, word32 sz)

    return 0;
 }
+#endif

 #endif /* HAVE_INTEL_RDSEED */

--- a/wolfssl/wolfcrypt/settings.h
+++ b/wolfssl/wolfcrypt/settings.h
@@ -2099,10 +2099,8 @@ extern void uITRON4_free(void *p) ;
    #undef WOLFSSL_HAVE_MIN
    #undef WOLFSSL_HAVE_MAX
    #define WOLFSSL_DH_CONST 1 /* Linux kernel doesn't have floating point math facilities. */
-    #define WOLFSSL_NO_MALLOC 1
    #define WOLFSSL_NO_SOCK 1
    #define WOLFSSL_USER_IO 1
-    #undef HAVE_INTEL_RDSEED /* prevents -Wunused-function on wc_GenerateSeed_IntelRD() */
    #define USE_WOLF_STRTOK
    #define NO_CRYPT_BENCHMARK 1
    #define NO_CRYPT_TEST 1
--- a/wolfssl/wolfcrypt/types.h
+++ b/wolfssl/wolfcrypt/types.h
@@ -357,7 +357,7 @@ decouple library dependencies with standard string, memory and so on.
        #endif

    #elif defined(WOLFSSL_LINUXKM)
-        #include <linux/slab.h>
+	/* the requisite linux/slab.h is included in wc_port.h, with incompatible warnings masked out. */
        #define XMALLOC(s, h, t)     ((void)h, (void)t, kmalloc((s), GFP_KERNEL))
        #define XFREE(p, h, t)       {void* xp = (p); if((xp)) kfree((xp));}
        #define XREALLOC(p, n, h, t) krealloc((p), (n), GFP_KERNEL)
--- a/wolfssl/wolfcrypt/wc_port.h
+++ b/wolfssl/wolfcrypt/wc_port.h
@@ -55,23 +55,6 @@
 #endif

 #ifdef WOLFSSL_LINUXKM
-
-/*
-note, leaving out --enable-pkcs11 in this (depends on -ldl):
-
-KROOT=/usr/src/linux KARCH=x86 CFLAGS="-I${KROOT}/include -I${KROOT}/arch/${KARCH}/include -I${KROOT}/arch/${KARCH}/include/generated -I${KROOT}/arch/${KARCH}/include/generated/uapi -I${KROOT}/arch/${KARCH}/include/uapi -I${KROOT}/include/uapi -I${KROOT}/tools/include/uapi -I${KROOT}/tools/arch/${KARCH}/include -I${KROOT}/tools/include -I/usr/lib/gcc/${KARCH}_64-pc-linux-gnu/9.3.0/include" ./configure --disable-jobserver --enable-keygen --enable-tls13 --enable-dtls --enable-dtls-mtu --enable-openssh --enable-wpas --enable-wpas-dpp --enable-opensslall --enable-opensslextra --enable-aesccm --enable-aesctr --enable-aesofb --enable-intelasm --enable-sp --enable-sp-asm --enable-curve25519 --enable-ed25519 --enable-curve448 --enable-blake2 --enable-blake2s --enable-camellia --enable-ed448 --enable-hc128 --enable-idea --enable-md2 --enable-rabbit --enable-srp --enable-fpecc --enable-certreq --enable-certgen --enable-certext --enable-certgencache --enable-eccencrypt --enable-mcast --enable-ssh --enable-pkcs7 --enable-pkcallbacks --enable-cryptocb --enable-libwebsockets --enable-linuxkm --disable-examples
-
-(for coverage, build with and without --enable-fpecc, and with and without --enable-intelasm --enable-sp --enable-sp-asm)
-
-probably better if lib objs are compiled -ffreestanding -nostdinc.
-
-building so far:
-
-make -j src/libwolfssl.la
-
-still to do: actual kernel module construction per https://www.kernel.org/doc/Documentation/kbuild/modules.txt
-*/
-
    #ifdef HAVE_CONFIG_H
        #ifndef PACKAGE_NAME
            #error wc_port.h included before config.h
@@ -80,10 +63,6 @@ still to do: actual kernel module construction per https://www.kernel.org/doc/Do
        #undef HAVE_CONFIG_H
    #endif

-    #ifndef __KERNEL__
-    #define __KERNEL__
-    #endif
-
    _Pragma("GCC diagnostic push");
    /* Linux kernel header files generate profuse warnings unless these are masked out: */
    _Pragma("GCC diagnostic ignored \"-Wunused-parameter\"");
@@ -94,6 +73,10 @@ still to do: actual kernel module construction per https://www.kernel.org/doc/Do
    _Pragma("GCC diagnostic ignored \"-Wsign-compare\"");
    _Pragma("GCC diagnostic ignored \"-Wpointer-sign\"");
    _Pragma("GCC diagnostic ignored \"-Wbad-function-cast\"");
+    /* these includes bring in all the needed kernel headers.
+     * they need to be included here while the incompatible warnings are disabled,
+     * and before undefining conflicting kernel macros afterward.
+     */
    #include <linux/kconfig.h>
    #include <linux/kernel.h>
    #include <linux/version.h>
@@ -103,19 +86,22 @@ still to do: actual kernel module construction per https://www.kernel.org/doc/Do
    #ifndef SINGLE_THREADED
        #include <linux/kthread.h>
    #endif
-    #include <linux/net.h> /* include this here, while the incompatible warnings are disabled, and before undefining conflicting kernel macros below. */
+    #include <linux/net.h>
    #include <linux/slab.h>
    _Pragma("GCC diagnostic pop");

-    /* a multifariously conflicting macro is picked up from
-     * Linux arch/<arch>/include/asm/current.h, which must be
-     * removed here.
+    /* remove this multifariously conflicting macro, picked up from
+     * Linux arch/<arch>/include/asm/current.h.
     */
    #undef current

    /* prevent gcc's mm_malloc.h from being included, since it unconditionally includes stdlib.h, which is kernel-incompatible: */
    #define _MM_MALLOC_H_INCLUDED

+    #define malloc(x) kmalloc(x, GFP_KERNEL)
+    #define free(x) kfree(x)
+    #define realloc(x,y) krealloc(x, y, GFP_KERNEL)
+
    /* min() and max() in linux/kernel.h over-aggressively type-check, producing myriad spurious -Werrors throughout the codebase. */
    #undef min
    #undef max