| Message ID | 20180615062547.4798-1-richard.henderson@linaro.org |
|---|---|
| State | Superseded |
| Headers | show |
| Series | tcg: Reduce max TB opcode count | expand |
On Thu, Jun 14, 2018 at 08:25:47PM -1000, Richard Henderson wrote: > Also, assert that we don't overflow any of two different offsets into > the TB. Both unwind and goto_tb both record a uint16_t for later use. > > Signed-off-by: Richard Henderson <richard.henderson@linaro.org> > --- > > This fixes an arm-softmmu test case forwarded to me by Michael Tsirkin. > > There is a TB generated from that test case that runs to 7800 opcodes, > and compiles to 96k on an x64 host. This overflows the 16-bit offset > in which we record the goto_tb reset offset. Because of that overflow, > we install a jump destination that goes to neverland. Boom. > > With this reduced op count, the same TB compiles to about 48k for > both x64 and ppc64le hosts, and neither assertion fires. > > > r~ I just forwarded it: Reported-by: "Jason A. Donenfeld" <Jason@zx2c4.com> > > --- > tcg/tcg.h | 2 +- > tcg/aarch64/tcg-target.inc.c | 2 +- > tcg/arm/tcg-target.inc.c | 2 +- > tcg/i386/tcg-target.inc.c | 2 +- > tcg/mips/tcg-target.inc.c | 2 +- > tcg/ppc/tcg-target.inc.c | 4 ++-- > tcg/s390/tcg-target.inc.c | 2 +- > tcg/sparc/tcg-target.inc.c | 4 ++-- > tcg/tcg.c | 13 ++++++++++++- > tcg/tci/tcg-target.inc.c | 2 +- > 10 files changed, 23 insertions(+), 12 deletions(-) > > diff --git a/tcg/tcg.h b/tcg/tcg.h > index 532d2a0710..2902a51505 100644 > --- a/tcg/tcg.h > +++ b/tcg/tcg.h > @@ -852,7 +852,7 @@ static inline bool tcg_op_buf_full(void) > * such that a RISC host can reasonably use a 16-bit signed > * branch within the TB. > */ > - return tcg_ctx->nb_ops >= 8000; > + return tcg_ctx->nb_ops >= 4000; > } > > /* pool based memory allocation */ > diff --git a/tcg/aarch64/tcg-target.inc.c b/tcg/aarch64/tcg-target.inc.c > index be3192078d..4562d36d1b 100644 > --- a/tcg/aarch64/tcg-target.inc.c > +++ b/tcg/aarch64/tcg-target.inc.c > @@ -1733,7 +1733,7 @@ static void tcg_out_op(TCGContext *s, TCGOpcode opc, > tcg_out_insn(s, 3305, LDR, offset, TCG_REG_TMP); > } > tcg_out_insn(s, 3207, BR, TCG_REG_TMP); > - s->tb_jmp_reset_offset[a0] = tcg_current_code_size(s); > + set_jmp_reset_offset(s, a0); > break; > > case INDEX_op_goto_ptr: > diff --git a/tcg/arm/tcg-target.inc.c b/tcg/arm/tcg-target.inc.c > index 56a32a470f..e1fbf465cb 100644 > --- a/tcg/arm/tcg-target.inc.c > +++ b/tcg/arm/tcg-target.inc.c > @@ -1822,7 +1822,7 @@ static inline void tcg_out_op(TCGContext *s, TCGOpcode opc, > tcg_out_movi32(s, COND_AL, base, ptr - dil); > } > tcg_out_ld32_12(s, COND_AL, TCG_REG_PC, base, dil); > - s->tb_jmp_reset_offset[args[0]] = tcg_current_code_size(s); > + set_jmp_reset_offset(s, args[0]); > } > break; > case INDEX_op_goto_ptr: > diff --git a/tcg/i386/tcg-target.inc.c b/tcg/i386/tcg-target.inc.c > index 0d0ff524b7..e87b0d445e 100644 > --- a/tcg/i386/tcg-target.inc.c > +++ b/tcg/i386/tcg-target.inc.c > @@ -2245,7 +2245,7 @@ static inline void tcg_out_op(TCGContext *s, TCGOpcode opc, > tcg_out_modrm_offset(s, OPC_GRP5, EXT5_JMPN_Ev, -1, > (intptr_t)(s->tb_jmp_target_addr + a0)); > } > - s->tb_jmp_reset_offset[a0] = tcg_current_code_size(s); > + set_jmp_reset_offset(s, a0); > break; > case INDEX_op_goto_ptr: > /* jmp to the given host address (could be epilogue) */ > diff --git a/tcg/mips/tcg-target.inc.c b/tcg/mips/tcg-target.inc.c > index ca5f1d4894..cff525373b 100644 > --- a/tcg/mips/tcg-target.inc.c > +++ b/tcg/mips/tcg-target.inc.c > @@ -1744,7 +1744,7 @@ static inline void tcg_out_op(TCGContext *s, TCGOpcode opc, > tcg_out_opc_reg(s, OPC_JR, 0, TCG_TMP0, 0); > } > tcg_out_nop(s); > - s->tb_jmp_reset_offset[a0] = tcg_current_code_size(s); > + set_jmp_reset_offset(s, a0); > break; > case INDEX_op_goto_ptr: > /* jmp to the given host address (could be epilogue) */ > diff --git a/tcg/ppc/tcg-target.inc.c b/tcg/ppc/tcg-target.inc.c > index 86f7de5f7e..c2f729ee8f 100644 > --- a/tcg/ppc/tcg-target.inc.c > +++ b/tcg/ppc/tcg-target.inc.c > @@ -2025,10 +2025,10 @@ static void tcg_out_op(TCGContext *s, TCGOpcode opc, const TCGArg *args, > } > tcg_out32(s, MTSPR | RS(TCG_REG_TB) | CTR); > tcg_out32(s, BCCTR | BO_ALWAYS); > - s->tb_jmp_reset_offset[args[0]] = c = tcg_current_code_size(s); > + set_jmp_reset_offset(s, args[0]); > if (USE_REG_TB) { > /* For the unlinked case, need to reset TCG_REG_TB. */ > - c = -c; > + c = -tcg_current_code_size(s); > assert(c == (int16_t)c); > tcg_out32(s, ADDI | TAI(TCG_REG_TB, TCG_REG_TB, c)); > } > diff --git a/tcg/s390/tcg-target.inc.c b/tcg/s390/tcg-target.inc.c > index 9af6dcef05..17c435ade5 100644 > --- a/tcg/s390/tcg-target.inc.c > +++ b/tcg/s390/tcg-target.inc.c > @@ -1783,7 +1783,7 @@ static inline void tcg_out_op(TCGContext *s, TCGOpcode opc, > /* and go there */ > tcg_out_insn(s, RR, BCR, S390_CC_ALWAYS, TCG_REG_TB); > } > - s->tb_jmp_reset_offset[a0] = tcg_current_code_size(s); > + set_jmp_reset_offset(s, a0); > > /* For the unlinked path of goto_tb, we need to reset > TCG_REG_TB to the beginning of this TB. */ > diff --git a/tcg/sparc/tcg-target.inc.c b/tcg/sparc/tcg-target.inc.c > index bc673bd8c6..04bdc3df5e 100644 > --- a/tcg/sparc/tcg-target.inc.c > +++ b/tcg/sparc/tcg-target.inc.c > @@ -1388,12 +1388,12 @@ static void tcg_out_op(TCGContext *s, TCGOpcode opc, > tcg_out_arithi(s, TCG_REG_G0, TCG_REG_TB, 0, JMPL); > tcg_out_nop(s); > } > - s->tb_jmp_reset_offset[a0] = c = tcg_current_code_size(s); > + set_jmp_reset_offset(s, a0); > > /* For the unlinked path of goto_tb, we need to reset > TCG_REG_TB to the beginning of this TB. */ > if (USE_REG_TB) { > - c = -c; > + c = -tcg_current_code_size(s); > if (check_fit_i32(c, 13)) { > tcg_out_arithi(s, TCG_REG_TB, TCG_REG_TB, c, ARITH_ADD); > } else { > diff --git a/tcg/tcg.c b/tcg/tcg.c > index 1d1dfd7f7c..f27b22bd3c 100644 > --- a/tcg/tcg.c > +++ b/tcg/tcg.c > @@ -306,6 +306,14 @@ TCGLabel *gen_new_label(void) > return l; > } > > +static void set_jmp_reset_offset(TCGContext *s, int which) > +{ > + size_t off = tcg_current_code_size(s); > + s->tb_jmp_reset_offset[which] = off; > + /* Make sure that we didn't overflow the stored offset. */ > + assert(s->tb_jmp_reset_offset[which] == off); > +} > + > #include "tcg-target.inc.c" > > /* compare a pointer @ptr and a tb_tc @s */ > @@ -3532,7 +3540,10 @@ int tcg_gen_code(TCGContext *s, TranslationBlock *tb) > break; > case INDEX_op_insn_start: > if (num_insns >= 0) { > - s->gen_insn_end_off[num_insns] = tcg_current_code_size(s); > + size_t off = tcg_current_code_size(s); > + s->gen_insn_end_off[num_insns] = off; > + /* Assert that we do not overflow our stored offset. */ > + assert(s->gen_insn_end_off[num_insns] == off); > } > num_insns++; > for (i = 0; i < TARGET_INSN_START_WORDS; ++i) { > diff --git a/tcg/tci/tcg-target.inc.c b/tcg/tci/tcg-target.inc.c > index cc949bea85..62ed097254 100644 > --- a/tcg/tci/tcg-target.inc.c > +++ b/tcg/tci/tcg-target.inc.c > @@ -574,7 +574,7 @@ static void tcg_out_op(TCGContext *s, TCGOpcode opc, const TCGArg *args, > /* Indirect jump method. */ > TODO(); > } > - s->tb_jmp_reset_offset[args[0]] = tcg_current_code_size(s); > + set_jmp_reset_offset(s, args[0]); > break; > case INDEX_op_br: > tci_out_label(s, arg_label(args[0])); > -- > 2.17.1
On 06/15/2018 03:25 AM, Richard Henderson wrote: > Also, assert that we don't overflow any of two different offsets into > the TB. Both unwind and goto_tb both record a uint16_t for later use. > > Signed-off-by: Richard Henderson <richard.henderson@linaro.org> > --- > > This fixes an arm-softmmu test case forwarded to me by Michael Tsirkin. > > There is a TB generated from that test case that runs to 7800 opcodes, > and compiles to 96k on an x64 host. This overflows the 16-bit offset > in which we record the goto_tb reset offset. Because of that overflow, > we install a jump destination that goes to neverland. Boom. > > With this reduced op count, the same TB compiles to about 48k for > both x64 and ppc64le hosts, and neither assertion fires. Why not keep that comment in the git history, to follow the 8k -> 4k change? Reviewed-by: Philippe Mathieu-Daudé <f4bug@amsat.org> > > > r~ > > --- > tcg/tcg.h | 2 +- > tcg/aarch64/tcg-target.inc.c | 2 +- > tcg/arm/tcg-target.inc.c | 2 +- > tcg/i386/tcg-target.inc.c | 2 +- > tcg/mips/tcg-target.inc.c | 2 +- > tcg/ppc/tcg-target.inc.c | 4 ++-- > tcg/s390/tcg-target.inc.c | 2 +- > tcg/sparc/tcg-target.inc.c | 4 ++-- > tcg/tcg.c | 13 ++++++++++++- > tcg/tci/tcg-target.inc.c | 2 +- > 10 files changed, 23 insertions(+), 12 deletions(-) > > diff --git a/tcg/tcg.h b/tcg/tcg.h > index 532d2a0710..2902a51505 100644 > --- a/tcg/tcg.h > +++ b/tcg/tcg.h > @@ -852,7 +852,7 @@ static inline bool tcg_op_buf_full(void) > * such that a RISC host can reasonably use a 16-bit signed > * branch within the TB. > */ > - return tcg_ctx->nb_ops >= 8000; > + return tcg_ctx->nb_ops >= 4000; > } > > /* pool based memory allocation */ > diff --git a/tcg/aarch64/tcg-target.inc.c b/tcg/aarch64/tcg-target.inc.c > index be3192078d..4562d36d1b 100644 > --- a/tcg/aarch64/tcg-target.inc.c > +++ b/tcg/aarch64/tcg-target.inc.c > @@ -1733,7 +1733,7 @@ static void tcg_out_op(TCGContext *s, TCGOpcode opc, > tcg_out_insn(s, 3305, LDR, offset, TCG_REG_TMP); > } > tcg_out_insn(s, 3207, BR, TCG_REG_TMP); > - s->tb_jmp_reset_offset[a0] = tcg_current_code_size(s); > + set_jmp_reset_offset(s, a0); > break; > > case INDEX_op_goto_ptr: > diff --git a/tcg/arm/tcg-target.inc.c b/tcg/arm/tcg-target.inc.c > index 56a32a470f..e1fbf465cb 100644 > --- a/tcg/arm/tcg-target.inc.c > +++ b/tcg/arm/tcg-target.inc.c > @@ -1822,7 +1822,7 @@ static inline void tcg_out_op(TCGContext *s, TCGOpcode opc, > tcg_out_movi32(s, COND_AL, base, ptr - dil); > } > tcg_out_ld32_12(s, COND_AL, TCG_REG_PC, base, dil); > - s->tb_jmp_reset_offset[args[0]] = tcg_current_code_size(s); > + set_jmp_reset_offset(s, args[0]); > } > break; > case INDEX_op_goto_ptr: > diff --git a/tcg/i386/tcg-target.inc.c b/tcg/i386/tcg-target.inc.c > index 0d0ff524b7..e87b0d445e 100644 > --- a/tcg/i386/tcg-target.inc.c > +++ b/tcg/i386/tcg-target.inc.c > @@ -2245,7 +2245,7 @@ static inline void tcg_out_op(TCGContext *s, TCGOpcode opc, > tcg_out_modrm_offset(s, OPC_GRP5, EXT5_JMPN_Ev, -1, > (intptr_t)(s->tb_jmp_target_addr + a0)); > } > - s->tb_jmp_reset_offset[a0] = tcg_current_code_size(s); > + set_jmp_reset_offset(s, a0); > break; > case INDEX_op_goto_ptr: > /* jmp to the given host address (could be epilogue) */ > diff --git a/tcg/mips/tcg-target.inc.c b/tcg/mips/tcg-target.inc.c > index ca5f1d4894..cff525373b 100644 > --- a/tcg/mips/tcg-target.inc.c > +++ b/tcg/mips/tcg-target.inc.c > @@ -1744,7 +1744,7 @@ static inline void tcg_out_op(TCGContext *s, TCGOpcode opc, > tcg_out_opc_reg(s, OPC_JR, 0, TCG_TMP0, 0); > } > tcg_out_nop(s); > - s->tb_jmp_reset_offset[a0] = tcg_current_code_size(s); > + set_jmp_reset_offset(s, a0); > break; > case INDEX_op_goto_ptr: > /* jmp to the given host address (could be epilogue) */ > diff --git a/tcg/ppc/tcg-target.inc.c b/tcg/ppc/tcg-target.inc.c > index 86f7de5f7e..c2f729ee8f 100644 > --- a/tcg/ppc/tcg-target.inc.c > +++ b/tcg/ppc/tcg-target.inc.c > @@ -2025,10 +2025,10 @@ static void tcg_out_op(TCGContext *s, TCGOpcode opc, const TCGArg *args, > } > tcg_out32(s, MTSPR | RS(TCG_REG_TB) | CTR); > tcg_out32(s, BCCTR | BO_ALWAYS); > - s->tb_jmp_reset_offset[args[0]] = c = tcg_current_code_size(s); > + set_jmp_reset_offset(s, args[0]); > if (USE_REG_TB) { > /* For the unlinked case, need to reset TCG_REG_TB. */ > - c = -c; > + c = -tcg_current_code_size(s); > assert(c == (int16_t)c); > tcg_out32(s, ADDI | TAI(TCG_REG_TB, TCG_REG_TB, c)); > } > diff --git a/tcg/s390/tcg-target.inc.c b/tcg/s390/tcg-target.inc.c > index 9af6dcef05..17c435ade5 100644 > --- a/tcg/s390/tcg-target.inc.c > +++ b/tcg/s390/tcg-target.inc.c > @@ -1783,7 +1783,7 @@ static inline void tcg_out_op(TCGContext *s, TCGOpcode opc, > /* and go there */ > tcg_out_insn(s, RR, BCR, S390_CC_ALWAYS, TCG_REG_TB); > } > - s->tb_jmp_reset_offset[a0] = tcg_current_code_size(s); > + set_jmp_reset_offset(s, a0); > > /* For the unlinked path of goto_tb, we need to reset > TCG_REG_TB to the beginning of this TB. */ > diff --git a/tcg/sparc/tcg-target.inc.c b/tcg/sparc/tcg-target.inc.c > index bc673bd8c6..04bdc3df5e 100644 > --- a/tcg/sparc/tcg-target.inc.c > +++ b/tcg/sparc/tcg-target.inc.c > @@ -1388,12 +1388,12 @@ static void tcg_out_op(TCGContext *s, TCGOpcode opc, > tcg_out_arithi(s, TCG_REG_G0, TCG_REG_TB, 0, JMPL); > tcg_out_nop(s); > } > - s->tb_jmp_reset_offset[a0] = c = tcg_current_code_size(s); > + set_jmp_reset_offset(s, a0); > > /* For the unlinked path of goto_tb, we need to reset > TCG_REG_TB to the beginning of this TB. */ > if (USE_REG_TB) { > - c = -c; > + c = -tcg_current_code_size(s); > if (check_fit_i32(c, 13)) { > tcg_out_arithi(s, TCG_REG_TB, TCG_REG_TB, c, ARITH_ADD); > } else { > diff --git a/tcg/tcg.c b/tcg/tcg.c > index 1d1dfd7f7c..f27b22bd3c 100644 > --- a/tcg/tcg.c > +++ b/tcg/tcg.c > @@ -306,6 +306,14 @@ TCGLabel *gen_new_label(void) > return l; > } > > +static void set_jmp_reset_offset(TCGContext *s, int which) > +{ > + size_t off = tcg_current_code_size(s); > + s->tb_jmp_reset_offset[which] = off; > + /* Make sure that we didn't overflow the stored offset. */ > + assert(s->tb_jmp_reset_offset[which] == off); > +} > + > #include "tcg-target.inc.c" > > /* compare a pointer @ptr and a tb_tc @s */ > @@ -3532,7 +3540,10 @@ int tcg_gen_code(TCGContext *s, TranslationBlock *tb) > break; > case INDEX_op_insn_start: > if (num_insns >= 0) { > - s->gen_insn_end_off[num_insns] = tcg_current_code_size(s); > + size_t off = tcg_current_code_size(s); > + s->gen_insn_end_off[num_insns] = off; > + /* Assert that we do not overflow our stored offset. */ > + assert(s->gen_insn_end_off[num_insns] == off); > } > num_insns++; > for (i = 0; i < TARGET_INSN_START_WORDS; ++i) { > diff --git a/tcg/tci/tcg-target.inc.c b/tcg/tci/tcg-target.inc.c > index cc949bea85..62ed097254 100644 > --- a/tcg/tci/tcg-target.inc.c > +++ b/tcg/tci/tcg-target.inc.c > @@ -574,7 +574,7 @@ static void tcg_out_op(TCGContext *s, TCGOpcode opc, const TCGArg *args, > /* Indirect jump method. */ > TODO(); > } > - s->tb_jmp_reset_offset[args[0]] = tcg_current_code_size(s); > + set_jmp_reset_offset(s, args[0]); > break; > case INDEX_op_br: > tci_out_label(s, arg_label(args[0])); >
On 06/15/2018 03:58 AM, Philippe Mathieu-Daudé wrote: > On 06/15/2018 03:25 AM, Richard Henderson wrote: >> Also, assert that we don't overflow any of two different offsets into >> the TB. Both unwind and goto_tb both record a uint16_t for later use. >> >> Signed-off-by: Richard Henderson <richard.henderson@linaro.org> >> --- >> >> This fixes an arm-softmmu test case forwarded to me by Michael Tsirkin. >> >> There is a TB generated from that test case that runs to 7800 opcodes, >> and compiles to 96k on an x64 host. This overflows the 16-bit offset >> in which we record the goto_tb reset offset. Because of that overflow, >> we install a jump destination that goes to neverland. Boom. >> >> With this reduced op count, the same TB compiles to about 48k for >> both x64 and ppc64le hosts, and neither assertion fires. > > Why not keep that comment in the git history, to follow the 8k -> 4k change? > > Reviewed-by: Philippe Mathieu-Daudé <f4bug@amsat.org> Will do, thanks. r~
diff --git a/tcg/tcg.h b/tcg/tcg.h index 532d2a0710..2902a51505 100644 --- a/tcg/tcg.h +++ b/tcg/tcg.h @@ -852,7 +852,7 @@ static inline bool tcg_op_buf_full(void) * such that a RISC host can reasonably use a 16-bit signed * branch within the TB. */ - return tcg_ctx->nb_ops >= 8000; + return tcg_ctx->nb_ops >= 4000; } /* pool based memory allocation */ diff --git a/tcg/aarch64/tcg-target.inc.c b/tcg/aarch64/tcg-target.inc.c index be3192078d..4562d36d1b 100644 --- a/tcg/aarch64/tcg-target.inc.c +++ b/tcg/aarch64/tcg-target.inc.c @@ -1733,7 +1733,7 @@ static void tcg_out_op(TCGContext *s, TCGOpcode opc, tcg_out_insn(s, 3305, LDR, offset, TCG_REG_TMP); } tcg_out_insn(s, 3207, BR, TCG_REG_TMP); - s->tb_jmp_reset_offset[a0] = tcg_current_code_size(s); + set_jmp_reset_offset(s, a0); break; case INDEX_op_goto_ptr: diff --git a/tcg/arm/tcg-target.inc.c b/tcg/arm/tcg-target.inc.c index 56a32a470f..e1fbf465cb 100644 --- a/tcg/arm/tcg-target.inc.c +++ b/tcg/arm/tcg-target.inc.c @@ -1822,7 +1822,7 @@ static inline void tcg_out_op(TCGContext *s, TCGOpcode opc, tcg_out_movi32(s, COND_AL, base, ptr - dil); } tcg_out_ld32_12(s, COND_AL, TCG_REG_PC, base, dil); - s->tb_jmp_reset_offset[args[0]] = tcg_current_code_size(s); + set_jmp_reset_offset(s, args[0]); } break; case INDEX_op_goto_ptr: diff --git a/tcg/i386/tcg-target.inc.c b/tcg/i386/tcg-target.inc.c index 0d0ff524b7..e87b0d445e 100644 --- a/tcg/i386/tcg-target.inc.c +++ b/tcg/i386/tcg-target.inc.c @@ -2245,7 +2245,7 @@ static inline void tcg_out_op(TCGContext *s, TCGOpcode opc, tcg_out_modrm_offset(s, OPC_GRP5, EXT5_JMPN_Ev, -1, (intptr_t)(s->tb_jmp_target_addr + a0)); } - s->tb_jmp_reset_offset[a0] = tcg_current_code_size(s); + set_jmp_reset_offset(s, a0); break; case INDEX_op_goto_ptr: /* jmp to the given host address (could be epilogue) */ diff --git a/tcg/mips/tcg-target.inc.c b/tcg/mips/tcg-target.inc.c index ca5f1d4894..cff525373b 100644 --- a/tcg/mips/tcg-target.inc.c +++ b/tcg/mips/tcg-target.inc.c @@ -1744,7 +1744,7 @@ static inline void tcg_out_op(TCGContext *s, TCGOpcode opc, tcg_out_opc_reg(s, OPC_JR, 0, TCG_TMP0, 0); } tcg_out_nop(s); - s->tb_jmp_reset_offset[a0] = tcg_current_code_size(s); + set_jmp_reset_offset(s, a0); break; case INDEX_op_goto_ptr: /* jmp to the given host address (could be epilogue) */ diff --git a/tcg/ppc/tcg-target.inc.c b/tcg/ppc/tcg-target.inc.c index 86f7de5f7e..c2f729ee8f 100644 --- a/tcg/ppc/tcg-target.inc.c +++ b/tcg/ppc/tcg-target.inc.c @@ -2025,10 +2025,10 @@ static void tcg_out_op(TCGContext *s, TCGOpcode opc, const TCGArg *args, } tcg_out32(s, MTSPR | RS(TCG_REG_TB) | CTR); tcg_out32(s, BCCTR | BO_ALWAYS); - s->tb_jmp_reset_offset[args[0]] = c = tcg_current_code_size(s); + set_jmp_reset_offset(s, args[0]); if (USE_REG_TB) { /* For the unlinked case, need to reset TCG_REG_TB. */ - c = -c; + c = -tcg_current_code_size(s); assert(c == (int16_t)c); tcg_out32(s, ADDI | TAI(TCG_REG_TB, TCG_REG_TB, c)); } diff --git a/tcg/s390/tcg-target.inc.c b/tcg/s390/tcg-target.inc.c index 9af6dcef05..17c435ade5 100644 --- a/tcg/s390/tcg-target.inc.c +++ b/tcg/s390/tcg-target.inc.c @@ -1783,7 +1783,7 @@ static inline void tcg_out_op(TCGContext *s, TCGOpcode opc, /* and go there */ tcg_out_insn(s, RR, BCR, S390_CC_ALWAYS, TCG_REG_TB); } - s->tb_jmp_reset_offset[a0] = tcg_current_code_size(s); + set_jmp_reset_offset(s, a0); /* For the unlinked path of goto_tb, we need to reset TCG_REG_TB to the beginning of this TB. */ diff --git a/tcg/sparc/tcg-target.inc.c b/tcg/sparc/tcg-target.inc.c index bc673bd8c6..04bdc3df5e 100644 --- a/tcg/sparc/tcg-target.inc.c +++ b/tcg/sparc/tcg-target.inc.c @@ -1388,12 +1388,12 @@ static void tcg_out_op(TCGContext *s, TCGOpcode opc, tcg_out_arithi(s, TCG_REG_G0, TCG_REG_TB, 0, JMPL); tcg_out_nop(s); } - s->tb_jmp_reset_offset[a0] = c = tcg_current_code_size(s); + set_jmp_reset_offset(s, a0); /* For the unlinked path of goto_tb, we need to reset TCG_REG_TB to the beginning of this TB. */ if (USE_REG_TB) { - c = -c; + c = -tcg_current_code_size(s); if (check_fit_i32(c, 13)) { tcg_out_arithi(s, TCG_REG_TB, TCG_REG_TB, c, ARITH_ADD); } else { diff --git a/tcg/tcg.c b/tcg/tcg.c index 1d1dfd7f7c..f27b22bd3c 100644 --- a/tcg/tcg.c +++ b/tcg/tcg.c @@ -306,6 +306,14 @@ TCGLabel *gen_new_label(void) return l; } +static void set_jmp_reset_offset(TCGContext *s, int which) +{ + size_t off = tcg_current_code_size(s); + s->tb_jmp_reset_offset[which] = off; + /* Make sure that we didn't overflow the stored offset. */ + assert(s->tb_jmp_reset_offset[which] == off); +} + #include "tcg-target.inc.c" /* compare a pointer @ptr and a tb_tc @s */ @@ -3532,7 +3540,10 @@ int tcg_gen_code(TCGContext *s, TranslationBlock *tb) break; case INDEX_op_insn_start: if (num_insns >= 0) { - s->gen_insn_end_off[num_insns] = tcg_current_code_size(s); + size_t off = tcg_current_code_size(s); + s->gen_insn_end_off[num_insns] = off; + /* Assert that we do not overflow our stored offset. */ + assert(s->gen_insn_end_off[num_insns] == off); } num_insns++; for (i = 0; i < TARGET_INSN_START_WORDS; ++i) { diff --git a/tcg/tci/tcg-target.inc.c b/tcg/tci/tcg-target.inc.c index cc949bea85..62ed097254 100644 --- a/tcg/tci/tcg-target.inc.c +++ b/tcg/tci/tcg-target.inc.c @@ -574,7 +574,7 @@ static void tcg_out_op(TCGContext *s, TCGOpcode opc, const TCGArg *args, /* Indirect jump method. */ TODO(); } - s->tb_jmp_reset_offset[args[0]] = tcg_current_code_size(s); + set_jmp_reset_offset(s, args[0]); break; case INDEX_op_br: tci_out_label(s, arg_label(args[0]));
Also, assert that we don't overflow any of two different offsets into the TB. Both unwind and goto_tb both record a uint16_t for later use. Signed-off-by: Richard Henderson <richard.henderson@linaro.org> --- This fixes an arm-softmmu test case forwarded to me by Michael Tsirkin. There is a TB generated from that test case that runs to 7800 opcodes, and compiles to 96k on an x64 host. This overflows the 16-bit offset in which we record the goto_tb reset offset. Because of that overflow, we install a jump destination that goes to neverland. Boom. With this reduced op count, the same TB compiles to about 48k for both x64 and ppc64le hosts, and neither assertion fires. r~ --- tcg/tcg.h | 2 +- tcg/aarch64/tcg-target.inc.c | 2 +- tcg/arm/tcg-target.inc.c | 2 +- tcg/i386/tcg-target.inc.c | 2 +- tcg/mips/tcg-target.inc.c | 2 +- tcg/ppc/tcg-target.inc.c | 4 ++-- tcg/s390/tcg-target.inc.c | 2 +- tcg/sparc/tcg-target.inc.c | 4 ++-- tcg/tcg.c | 13 ++++++++++++- tcg/tci/tcg-target.inc.c | 2 +- 10 files changed, 23 insertions(+), 12 deletions(-) -- 2.17.1