> When building OpenSSL 1.1.0 pre 5 or pre 6 on Sparc I get: > > /usr/ccs/bin/as: "crypto/ec/ecp_nistz256-sparcv9.s", line 4811: warning: > stack alignment problem; second operand is not a multiple of 8 > /usr/ccs/bin/as: "crypto/ec/ecp_nistz256-sparcv9.s", line 5063: warning: > stack alignment problem; second operand is not a multiple of 8 > /usr/ccs/bin/as: "crypto/ec/ecp_nistz256-sparcv9.s", line 5539: warning: > stack alignment problem; second operand is not a multiple of 8 > > The lines in question in crypto/ec/ecp_nistz256-sparcv9.s are: > > save %sp,-(2047+192)-32*10,%sp > save %sp,-(2047+192)-32*18-32,%sp > save %sp,-(2047+192)-32*15-32,%sp > > They probably go back to the following lines in > crypto/ec/ecp_nistz256-sparcv9.s.S: > > ... > #ifdef __arch64__ > .register %g2,#scratch > .register %g3,#scratch > # define STACK64_FRAME STACK_FRAME > # define LOCALS64 LOCALS > #else > # define STACK64_FRAME (2047+192) > # define LOCALS64 STACK64_FRAME > #endif > ... > save %sp,-STACK64_FRAME-32*10,%sp > ... > save %sp,-STACK64_FRAME-32*18-32,%sp > ... > save %sp,-STACK64_FRAME-32*15-32,%sp > > I can't judge on the validity of the "stack alignment problem", but at > least 2047 is indeed not divisible by 8 (but all other offsets added or > subtracted from 2047 are).
Thing there is following. If if have close look you'll notice that those functions are VIS3 ones. They use 64-bit multiplication and addition instructions. Normally you can't use them in 32-bit application context, because higher halves of most registers are not preserved upon context switch or trap delivery. But there is one special thing about stack in 64-bit[!] application context, namely that it's biased by 2047 bytes. Yes, %sp in 64-bit application is actually misaligned. Linux kernel was modified to recognize misaligned stack *even* in 32-bit application context and preserve full registers' contents, which makes it possible to use faster code path even in 32-bit application (it's discussed in commentary section in bn/asm/sparct4-mont.pl. Solaris doesn't recognize misaligned 32-bit stack, corresponding capability bit in never set, and code is never called. In other words warning is benign. Since you haven't seen similar warning from sparct4-mont module I suppose assembler looks one at save instruction. This in turn should mean that it's possible to work around it... -- openssl-dev mailing list To unsubscribe: https://mta.openssl.org/mailman/listinfo/openssl-dev
