On Tuesday 09 December 2008, you wrote: > > You had called my attention to problems with libnuma's read_mask() on > a big-endian 64-bit machine. > I rolled my proposed patches into numactl-2.0.3-rc1.tar.gz on > ftp://oss.sgi.com/www/projects/libnuma/download/ > > I tested on one 64-bit big-endian system (mips). > Could you see if that version works on your systems? Sorry for the long delay. I have now been able to work on this a bit and come up with a not so broken version of the read_mask function. The patch you have in 2.0.3-rc1 did not fix the original problem, but also introduced other bugs, so please revert it. This is the best I could come up with, haven't tested on little-endian though because I lack appropriate hardware. --- >From 6009179978adcf787226cfb09e9b8471ded4c8b4 Mon Sep 17 00:00:00 2001 From: Arnd Bergmann <arnd@xxxxxxxx> Date: Tue, 20 Jan 2009 20:50:39 +0100 Subject: [PATCH] Next attempt to fix libnuma for bit-endian 64-bit systems This fixes the read_mask function for me on ppc64. The changes are: * Correct bit-order on 64 bit systems. * Fix off-by-one error in counting single-value fields * No longer skip zero values in the middle of a sparse bitmask. Signed-off-by: Arnd Bergmann <arnd@xxxxxxxx> --- libnuma.c | 42 +++++++++++++++++++++++------------------- 1 files changed, 23 insertions(+), 19 deletions(-) diff --git a/libnuma.c b/libnuma.c index 87176ac..f645528 100755 --- a/libnuma.c +++ b/libnuma.c @@ -368,11 +368,10 @@ static int read_mask(char *s, struct bitmask *bmp) { char *end = s; - unsigned int *start = (unsigned int *)bmp->maskp; - unsigned int *p = start; - unsigned int *q; - unsigned int i; - unsigned int n = 0; + int tmplen = (bmp->size + bitsperint - 1) / bitsperint; + unsigned int tmp[tmplen]; + unsigned int *start = tmp; + unsigned int i, n = 0, m = 0; i = strtoul(s, &end, 16); @@ -380,7 +379,6 @@ read_mask(char *s, struct bitmask *bmp) while (!i && *end++ == ',') { i = strtoul(end, &end, 16); } - end++; /* past the , */ if (!i) /* End of string. No mask */ @@ -388,33 +386,39 @@ read_mask(char *s, struct bitmask *bmp) start[n++] = i; /* Read sequence of ints */ - do { + while (*end++ == ',') { i = strtoul(end, &end, 16); - if (i) - start[n++] = i; - } while (*end++ == ','); - n--; + start[n++] = i; + + /* buffer overflow */ + if (n > tmplen) + return -1; + } /* * Invert sequence of ints if necessary since the first int * is the highest and we put it first because we read it first. */ - for (q = start + n, p = start; p < q; q--, p++) { - unsigned int x = *q; - - *q = *p; - *p = x; + while (n) { + int w; + unsigned long x = 0; + /* read into long values in an endian-safe way */ + for (w = 0; n && w < bitsperlong; w += bitsperint) + x |= ((unsigned long)start[n-- - 1] << w); + + bmp->maskp[m++] = x; } + m--; /* Poor mans fls() */ - for(i = 31; i >= 0; i--) - if (test_bit(i, start + n)) + for(i = bitsperlong - 1; i >= 0; i--) + if (test_bit(i, bmp->maskp + m)) break; /* * Return the last bit set */ - return ((sizeof(unsigned int)*8) * n) + i; + return bitsperlong * m + i; } /* -- 1.5.4.5 -- To unsubscribe from this list: send the line "unsubscribe linux-numa" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
