Committed, thanks :)
On Mon, Nov 29, 2021 at 8:48 PM Nelson Chu <nelson....@sifive.com> wrote: > > This is the original binutils bugzilla report, > https://sourceware.org/bugzilla/show_bug.cgi?id=28509 > > And this is the first version of the proposed binutils patch, > https://sourceware.org/pipermail/binutils/2021-November/118398.html > > After applying the binutils patch, I get the the unexpected error when > building libgcc, > > /scratch/nelsonc/riscv-gnu-toolchain/riscv-gcc/libgcc/config/riscv/div.S:42: > /scratch/nelsonc/build-upstream/rv64gc-linux/build-install/riscv64-unknown-linux-gnu/bin/ld: > relocation R_RISCV_JAL against `__udivdi3' which may bind externally can not > be used when making a shared object; recompile with -fPIC > > Therefore, this patch add an extra hidden alias symbol for __udivdi3, and > then use HIDDEN_JUMPTARGET to target a non-preemptible symbol instead. > The solution is similar to glibc as follows, > https://sourceware.org/git/?p=glibc.git;a=commit;h=68389203832ab39dd0dbaabbc4059e7fff51c29b > > libgcc/ChangeLog: > > * config/riscv/div.S: Add the hidden alias symbol for __udivdi3, and > then use HIDDEN_JUMPTARGET to target it since it is non-preemptible. > * config/riscv/riscv-asm.h: Added new macros HIDDEN_JUMPTARGET and > HIDDEN_DEF. > --- > libgcc/config/riscv/div.S | 15 ++++++++------- > libgcc/config/riscv/riscv-asm.h | 6 ++++++ > 2 files changed, 14 insertions(+), 7 deletions(-) > > diff --git a/libgcc/config/riscv/div.S b/libgcc/config/riscv/div.S > index c9bd787..723c3b8 100644 > --- a/libgcc/config/riscv/div.S > +++ b/libgcc/config/riscv/div.S > @@ -40,7 +40,7 @@ FUNC_BEGIN (__udivsi3) > sll a0, a0, 32 > sll a1, a1, 32 > move t0, ra > - jal __udivdi3 > + jal HIDDEN_JUMPTARGET(__udivdi3) > sext.w a0, a0 > jr t0 > FUNC_END (__udivsi3) > @@ -52,7 +52,7 @@ FUNC_BEGIN (__umodsi3) > srl a0, a0, 32 > srl a1, a1, 32 > move t0, ra > - jal __udivdi3 > + jal HIDDEN_JUMPTARGET(__udivdi3) > sext.w a0, a1 > jr t0 > FUNC_END (__umodsi3) > @@ -95,11 +95,12 @@ FUNC_BEGIN (__udivdi3) > .L5: > ret > FUNC_END (__udivdi3) > +HIDDEN_DEF (__udivdi3) > > FUNC_BEGIN (__umoddi3) > /* Call __udivdi3(a0, a1), then return the remainder, which is in a1. */ > move t0, ra > - jal __udivdi3 > + jal HIDDEN_JUMPTARGET(__udivdi3) > move a0, a1 > jr t0 > FUNC_END (__umoddi3) > @@ -111,12 +112,12 @@ FUNC_END (__umoddi3) > bgtz a1, .L12 /* Compute __udivdi3(-a0, a1), then negate the result. > */ > > neg a1, a1 > - j __udivdi3 /* Compute __udivdi3(-a0, -a1). */ > + j HIDDEN_JUMPTARGET(__udivdi3) /* Compute __udivdi3(-a0, -a1). */ > .L11: /* Compute __udivdi3(a0, -a1), then negate the result. > */ > neg a1, a1 > .L12: > move t0, ra > - jal __udivdi3 > + jal HIDDEN_JUMPTARGET(__udivdi3) > neg a0, a0 > jr t0 > FUNC_END (__divdi3) > @@ -126,7 +127,7 @@ FUNC_BEGIN (__moddi3) > bltz a1, .L31 > bltz a0, .L32 > .L30: > - jal __udivdi3 /* The dividend is not negative. */ > + jal HIDDEN_JUMPTARGET(__udivdi3) /* The dividend is not negative. */ > move a0, a1 > jr t0 > .L31: > @@ -134,7 +135,7 @@ FUNC_BEGIN (__moddi3) > bgez a0, .L30 > .L32: > neg a0, a0 > - jal __udivdi3 /* The dividend is hella negative. */ > + jal HIDDEN_JUMPTARGET(__udivdi3) /* The dividend is hella negative. > */ > neg a0, a1 > jr t0 > FUNC_END (__moddi3) > diff --git a/libgcc/config/riscv/riscv-asm.h b/libgcc/config/riscv/riscv-asm.h > index 8550707..96dd85b 100644 > --- a/libgcc/config/riscv/riscv-asm.h > +++ b/libgcc/config/riscv/riscv-asm.h > @@ -33,3 +33,9 @@ X: > #define FUNC_ALIAS(X,Y) \ > .globl X; \ > X = Y > + > +#define CONCAT1(a, b) CONCAT2(a, b) > +#define CONCAT2(a, b) a ## b > +#define HIDDEN_JUMPTARGET(X) CONCAT1(__hidden_, X) > +#define HIDDEN_DEF(X) FUNC_ALIAS(HIDDEN_JUMPTARGET(X), X); \ > + .hidden HIDDEN_JUMPTARGET(X) > -- > 2.7.4 >
