From 2912f9f2a2e5997df069d38e20d85ff4cc51acef Mon Sep 17 00:00:00 2001 From: Koen Vandeputte Date: Thu, 22 Dec 2016 17:17:04 +0100 Subject: musl: backport various post-1.1.15 fixes Backport most important fixes up to latest HEAD - Taken post-commit reverts/fixes into account Compile tested Run-tested on cns3xxx & imx6 targets Signed-off-by: Koen Vandeputte --- ...float-printf-needed-precision-computation.patch | 35 ++++++++++++++++++++++ 1 file changed, 35 insertions(+) create mode 100644 toolchain/musl/patches/039-fix-integer-overflow-in-float-printf-needed-precision-computation.patch (limited to 'toolchain/musl/patches/039-fix-integer-overflow-in-float-printf-needed-precision-computation.patch') diff --git a/toolchain/musl/patches/039-fix-integer-overflow-in-float-printf-needed-precision-computation.patch b/toolchain/musl/patches/039-fix-integer-overflow-in-float-printf-needed-precision-computation.patch new file mode 100644 index 0000000000..cfbd94f9a4 --- /dev/null +++ b/toolchain/musl/patches/039-fix-integer-overflow-in-float-printf-needed-precision-computation.patch @@ -0,0 +1,35 @@ +From 70d2687d85c314963cf280759b23fd4573ff0d82 Mon Sep 17 00:00:00 2001 +From: Rich Felker +Date: Wed, 19 Oct 2016 20:17:16 -0400 +Subject: fix integer overflow in float printf needed-precision computation + +if the requested precision is close to INT_MAX, adding +LDBL_MANT_DIG/3+8 overflows. in practice the resulting undefined +behavior manifests as a large negative result, which is then used to +compute the new end pointer (z) with a wildly out-of-bounds value +(more overflow, more undefined behavior). the end result is at least +incorrect output and character count (return value); worse things do +not seem to happen, but detailed analysis has not been done. + +this patch fixes the overflow by performing the intermediate +computation as unsigned; after division by 9, the final result +necessarily fits in int. +--- + src/stdio/vfprintf.c | 2 +- + 1 file changed, 1 insertion(+), 1 deletion(-) + +diff --git a/src/stdio/vfprintf.c b/src/stdio/vfprintf.c +index e439a07..cd17ad7 100644 +--- a/src/stdio/vfprintf.c ++++ b/src/stdio/vfprintf.c +@@ -312,7 +312,7 @@ static int fmt_fp(FILE *f, long double y, int w, int p, int fl, int t) + } + while (e2<0) { + uint32_t carry=0, *b; +- int sh=MIN(9,-e2), need=1+(p+LDBL_MANT_DIG/3+8)/9; ++ int sh=MIN(9,-e2), need=1+(p+LDBL_MANT_DIG/3U+8)/9; + for (d=a; d>sh) + carry; +-- +cgit v0.11.2 -- cgit v1.2.3