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authorKoen Vandeputte <koen.vandeputte@ncentric.com>2016-12-22 17:17:04 +0100
committerFelix Fietkau <nbd@nbd.name>2016-12-26 11:17:33 +0100
commit2912f9f2a2e5997df069d38e20d85ff4cc51acef (patch)
tree783e8cd472936ac1ca9378f16fb3189a486e7a48 /toolchain/musl/patches/039-fix-integer-overflow-in-float-printf-needed-precision-computation.patch
parentb97c933ffb5aae338351a1db12a3f7cf5234f5c7 (diff)
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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 <koen.vandeputte@ncentric.com>
Diffstat (limited to 'toolchain/musl/patches/039-fix-integer-overflow-in-float-printf-needed-precision-computation.patch')
-rw-r--r--toolchain/musl/patches/039-fix-integer-overflow-in-float-printf-needed-precision-computation.patch35
1 files changed, 35 insertions, 0 deletions
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 0000000..cfbd94f
--- /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 <dalias@aerifal.cx>
+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<z; d++) {
+ uint32_t rm = *d & (1<<sh)-1;
+ *d = (*d>>sh) + carry;
+--
+cgit v0.11.2