| Message ID | 20210314212724.1917075-4-richard.henderson@linaro.org (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | tcg: Workaround macOS 11.2 mprotect bug | expand |
On Sun, Mar 14, 2021 at 03:26:58PM -0600, Richard Henderson wrote: > Instead of delaying tcg_region_init until after tcg_prologue_init > is complete, do tcg_region_init first and let tcg_prologue_init > shrink the first region by the size of the generated prologue. > > Signed-off-by: Richard Henderson <richard.henderson@linaro.org> > --- > accel/tcg/tcg-all.c | 11 --------- > accel/tcg/translate-all.c | 3 +++ > bsd-user/main.c | 1 - > linux-user/main.c | 1 - > tcg/tcg.c | 52 ++++++++++++++------------------------- > 5 files changed, 22 insertions(+), 46 deletions(-) > > diff --git a/accel/tcg/tcg-all.c b/accel/tcg/tcg-all.c > index e378c2db73..f132033999 100644 > --- a/accel/tcg/tcg-all.c > +++ b/accel/tcg/tcg-all.c > @@ -111,17 +111,6 @@ static int tcg_init(MachineState *ms) > > tcg_exec_init(s->tb_size * 1024 * 1024, s->splitwx_enabled); > mttcg_enabled = s->mttcg_enabled; > - > - /* > - * Initialize TCG regions only for softmmu. > - * > - * This needs to be done later for user mode, because the prologue > - * generation needs to be delayed so that GUEST_BASE is already set. > - */ > -#ifndef CONFIG_USER_ONLY > - tcg_region_init(); Note that tcg_region_init() invokes tcg_n_regions() that depends on qemu_tcg_mttcg_enabled() that evaluates mttcg_enabled. Likely you need to move "mttcg_enabled = s->mttcg_enabled;" before tcg_exec_init() to keep existing behaviour. > -#endif /* !CONFIG_USER_ONLY */ > - > return 0; > } > > diff --git a/accel/tcg/translate-all.c b/accel/tcg/translate-all.c > index f32df8b240..b9057567f4 100644 > --- a/accel/tcg/translate-all.c > +++ b/accel/tcg/translate-all.c > @@ -1339,6 +1339,9 @@ void tcg_exec_init(unsigned long tb_size, int splitwx) > splitwx, &error_fatal); > assert(ok); > > + /* TODO: allocating regions is hand-in-glove with code_gen_buffer. */ > + tcg_region_init(); > + > #if defined(CONFIG_SOFTMMU) > /* There's no guest base to take into account, so go ahead and > initialize the prologue now. */ > diff --git a/bsd-user/main.c b/bsd-user/main.c > index 798aba512c..3669d2b89e 100644 > --- a/bsd-user/main.c > +++ b/bsd-user/main.c > @@ -994,7 +994,6 @@ int main(int argc, char **argv) > generating the prologue until now so that the prologue can take > the real value of GUEST_BASE into account. */ > tcg_prologue_init(tcg_ctx); > - tcg_region_init(); > > /* build Task State */ > memset(ts, 0, sizeof(TaskState)); > diff --git a/linux-user/main.c b/linux-user/main.c > index 4f4746dce8..1bc48ca954 100644 > --- a/linux-user/main.c > +++ b/linux-user/main.c > @@ -850,7 +850,6 @@ int main(int argc, char **argv, char **envp) > generating the prologue until now so that the prologue can take > the real value of GUEST_BASE into account. */ > tcg_prologue_init(tcg_ctx); > - tcg_region_init(); > > target_cpu_copy_regs(env, regs); > > diff --git a/tcg/tcg.c b/tcg/tcg.c > index 2991112829..0a2e5710de 100644 > --- a/tcg/tcg.c > +++ b/tcg/tcg.c > @@ -1204,32 +1204,18 @@ TranslationBlock *tcg_tb_alloc(TCGContext *s) > > void tcg_prologue_init(TCGContext *s) > { > - size_t prologue_size, total_size; > - void *buf0, *buf1; > + size_t prologue_size; > > /* Put the prologue at the beginning of code_gen_buffer. */ > - buf0 = s->code_gen_buffer; > - total_size = s->code_gen_buffer_size; > - s->code_ptr = buf0; > - s->code_buf = buf0; > + tcg_region_assign(s, 0); > + s->code_ptr = s->code_gen_ptr; > + s->code_buf = s->code_gen_ptr; Pardon me for asking a naive question, what's the difference between s->code_buf and s->code_gen_buf and, respectively, s->code_ptr and s->code_gen_ptr? Thanks, Roman > s->data_gen_ptr = NULL; > > - /* > - * The region trees are not yet configured, but tcg_splitwx_to_rx > - * needs the bounds for an assert. > - */ > - region.start = buf0; > - region.end = buf0 + total_size; > - > #ifndef CONFIG_TCG_INTERPRETER > - tcg_qemu_tb_exec = (tcg_prologue_fn *)tcg_splitwx_to_rx(buf0); > + tcg_qemu_tb_exec = (tcg_prologue_fn *)tcg_splitwx_to_rx(s->code_ptr); > #endif > > - /* Compute a high-water mark, at which we voluntarily flush the buffer > - and start over. The size here is arbitrary, significantly larger > - than we expect the code generation for any one opcode to require. */ > - s->code_gen_highwater = s->code_gen_buffer + (total_size - TCG_HIGHWATER); > - > #ifdef TCG_TARGET_NEED_POOL_LABELS > s->pool_labels = NULL; > #endif > @@ -1246,32 +1232,32 @@ void tcg_prologue_init(TCGContext *s) > } > #endif > > - buf1 = s->code_ptr; > + prologue_size = tcg_current_code_size(s); > + > #ifndef CONFIG_TCG_INTERPRETER > - flush_idcache_range((uintptr_t)tcg_splitwx_to_rx(buf0), (uintptr_t)buf0, > - tcg_ptr_byte_diff(buf1, buf0)); > + flush_idcache_range((uintptr_t)tcg_splitwx_to_rx(s->code_buf), > + (uintptr_t)s->code_buf, prologue_size); > #endif > > - /* Deduct the prologue from the buffer. */ > - prologue_size = tcg_current_code_size(s); > - s->code_gen_ptr = buf1; > - s->code_gen_buffer = buf1; > - s->code_buf = buf1; > - total_size -= prologue_size; > - s->code_gen_buffer_size = total_size; > + /* Deduct the prologue from the first region. */ > + region.start = s->code_ptr; > > - tcg_register_jit(tcg_splitwx_to_rx(s->code_gen_buffer), total_size); > + /* Recompute boundaries of the first region. */ > + tcg_region_assign(s, 0); > + > + tcg_register_jit(tcg_splitwx_to_rx(region.start), > + region.end - region.start); > > #ifdef DEBUG_DISAS > if (qemu_loglevel_mask(CPU_LOG_TB_OUT_ASM)) { > FILE *logfile = qemu_log_lock(); > qemu_log("PROLOGUE: [size=%zu]\n", prologue_size); > if (s->data_gen_ptr) { > - size_t code_size = s->data_gen_ptr - buf0; > + size_t code_size = s->data_gen_ptr - s->code_gen_ptr; > size_t data_size = prologue_size - code_size; > size_t i; > > - log_disas(buf0, code_size); > + log_disas(s->code_gen_ptr, code_size); > > for (i = 0; i < data_size; i += sizeof(tcg_target_ulong)) { > if (sizeof(tcg_target_ulong) == 8) { > @@ -1285,7 +1271,7 @@ void tcg_prologue_init(TCGContext *s) > } > } > } else { > - log_disas(buf0, prologue_size); > + log_disas(s->code_gen_ptr, prologue_size); > } > qemu_log("\n"); > qemu_log_flush(); > -- > 2.25.1 >
On 3/15/21 5:37 PM, Roman Bolshakov wrote: >> tcg_exec_init(s->tb_size * 1024 * 1024, s->splitwx_enabled); >> mttcg_enabled = s->mttcg_enabled; >> - >> - /* >> - * Initialize TCG regions only for softmmu. >> - * >> - * This needs to be done later for user mode, because the prologue >> - * generation needs to be delayed so that GUEST_BASE is already set. >> - */ >> -#ifndef CONFIG_USER_ONLY >> - tcg_region_init(); > > Note that tcg_region_init() invokes tcg_n_regions() that depends on > qemu_tcg_mttcg_enabled() that evaluates mttcg_enabled. Likely you need > to move "mttcg_enabled = s->mttcg_enabled;" before tcg_exec_init() to > keep existing behaviour. Yes indeed. This gets fixed in patch 12, which is why I didn't notice breakage. Will adjust. >> - total_size = s->code_gen_buffer_size; >> - s->code_ptr = buf0; >> - s->code_buf = buf0; >> + tcg_region_assign(s, 0); >> + s->code_ptr = s->code_gen_ptr; >> + s->code_buf = s->code_gen_ptr; > > Pardon me for asking a naive question, what's the difference between > s->code_buf and s->code_gen_buf and, respectively, s->code_ptr and > s->code_gen_ptr? I don't remember. I actually had it in my mind to rename all of these, remove one or two that feel redundant, and document them all. But the patch set was large enough already. r~
diff --git a/accel/tcg/tcg-all.c b/accel/tcg/tcg-all.c index e378c2db73..f132033999 100644 --- a/accel/tcg/tcg-all.c +++ b/accel/tcg/tcg-all.c @@ -111,17 +111,6 @@ static int tcg_init(MachineState *ms) tcg_exec_init(s->tb_size * 1024 * 1024, s->splitwx_enabled); mttcg_enabled = s->mttcg_enabled; - - /* - * Initialize TCG regions only for softmmu. - * - * This needs to be done later for user mode, because the prologue - * generation needs to be delayed so that GUEST_BASE is already set. - */ -#ifndef CONFIG_USER_ONLY - tcg_region_init(); -#endif /* !CONFIG_USER_ONLY */ - return 0; } diff --git a/accel/tcg/translate-all.c b/accel/tcg/translate-all.c index f32df8b240..b9057567f4 100644 --- a/accel/tcg/translate-all.c +++ b/accel/tcg/translate-all.c @@ -1339,6 +1339,9 @@ void tcg_exec_init(unsigned long tb_size, int splitwx) splitwx, &error_fatal); assert(ok); + /* TODO: allocating regions is hand-in-glove with code_gen_buffer. */ + tcg_region_init(); + #if defined(CONFIG_SOFTMMU) /* There's no guest base to take into account, so go ahead and initialize the prologue now. */ diff --git a/bsd-user/main.c b/bsd-user/main.c index 798aba512c..3669d2b89e 100644 --- a/bsd-user/main.c +++ b/bsd-user/main.c @@ -994,7 +994,6 @@ int main(int argc, char **argv) generating the prologue until now so that the prologue can take the real value of GUEST_BASE into account. */ tcg_prologue_init(tcg_ctx); - tcg_region_init(); /* build Task State */ memset(ts, 0, sizeof(TaskState)); diff --git a/linux-user/main.c b/linux-user/main.c index 4f4746dce8..1bc48ca954 100644 --- a/linux-user/main.c +++ b/linux-user/main.c @@ -850,7 +850,6 @@ int main(int argc, char **argv, char **envp) generating the prologue until now so that the prologue can take the real value of GUEST_BASE into account. */ tcg_prologue_init(tcg_ctx); - tcg_region_init(); target_cpu_copy_regs(env, regs); diff --git a/tcg/tcg.c b/tcg/tcg.c index 2991112829..0a2e5710de 100644 --- a/tcg/tcg.c +++ b/tcg/tcg.c @@ -1204,32 +1204,18 @@ TranslationBlock *tcg_tb_alloc(TCGContext *s) void tcg_prologue_init(TCGContext *s) { - size_t prologue_size, total_size; - void *buf0, *buf1; + size_t prologue_size; /* Put the prologue at the beginning of code_gen_buffer. */ - buf0 = s->code_gen_buffer; - total_size = s->code_gen_buffer_size; - s->code_ptr = buf0; - s->code_buf = buf0; + tcg_region_assign(s, 0); + s->code_ptr = s->code_gen_ptr; + s->code_buf = s->code_gen_ptr; s->data_gen_ptr = NULL; - /* - * The region trees are not yet configured, but tcg_splitwx_to_rx - * needs the bounds for an assert. - */ - region.start = buf0; - region.end = buf0 + total_size; - #ifndef CONFIG_TCG_INTERPRETER - tcg_qemu_tb_exec = (tcg_prologue_fn *)tcg_splitwx_to_rx(buf0); + tcg_qemu_tb_exec = (tcg_prologue_fn *)tcg_splitwx_to_rx(s->code_ptr); #endif - /* Compute a high-water mark, at which we voluntarily flush the buffer - and start over. The size here is arbitrary, significantly larger - than we expect the code generation for any one opcode to require. */ - s->code_gen_highwater = s->code_gen_buffer + (total_size - TCG_HIGHWATER); - #ifdef TCG_TARGET_NEED_POOL_LABELS s->pool_labels = NULL; #endif @@ -1246,32 +1232,32 @@ void tcg_prologue_init(TCGContext *s) } #endif - buf1 = s->code_ptr; + prologue_size = tcg_current_code_size(s); + #ifndef CONFIG_TCG_INTERPRETER - flush_idcache_range((uintptr_t)tcg_splitwx_to_rx(buf0), (uintptr_t)buf0, - tcg_ptr_byte_diff(buf1, buf0)); + flush_idcache_range((uintptr_t)tcg_splitwx_to_rx(s->code_buf), + (uintptr_t)s->code_buf, prologue_size); #endif - /* Deduct the prologue from the buffer. */ - prologue_size = tcg_current_code_size(s); - s->code_gen_ptr = buf1; - s->code_gen_buffer = buf1; - s->code_buf = buf1; - total_size -= prologue_size; - s->code_gen_buffer_size = total_size; + /* Deduct the prologue from the first region. */ + region.start = s->code_ptr; - tcg_register_jit(tcg_splitwx_to_rx(s->code_gen_buffer), total_size); + /* Recompute boundaries of the first region. */ + tcg_region_assign(s, 0); + + tcg_register_jit(tcg_splitwx_to_rx(region.start), + region.end - region.start); #ifdef DEBUG_DISAS if (qemu_loglevel_mask(CPU_LOG_TB_OUT_ASM)) { FILE *logfile = qemu_log_lock(); qemu_log("PROLOGUE: [size=%zu]\n", prologue_size); if (s->data_gen_ptr) { - size_t code_size = s->data_gen_ptr - buf0; + size_t code_size = s->data_gen_ptr - s->code_gen_ptr; size_t data_size = prologue_size - code_size; size_t i; - log_disas(buf0, code_size); + log_disas(s->code_gen_ptr, code_size); for (i = 0; i < data_size; i += sizeof(tcg_target_ulong)) { if (sizeof(tcg_target_ulong) == 8) { @@ -1285,7 +1271,7 @@ void tcg_prologue_init(TCGContext *s) } } } else { - log_disas(buf0, prologue_size); + log_disas(s->code_gen_ptr, prologue_size); } qemu_log("\n"); qemu_log_flush();
Instead of delaying tcg_region_init until after tcg_prologue_init is complete, do tcg_region_init first and let tcg_prologue_init shrink the first region by the size of the generated prologue. Signed-off-by: Richard Henderson <richard.henderson@linaro.org> --- accel/tcg/tcg-all.c | 11 --------- accel/tcg/translate-all.c | 3 +++ bsd-user/main.c | 1 - linux-user/main.c | 1 - tcg/tcg.c | 52 ++++++++++++++------------------------- 5 files changed, 22 insertions(+), 46 deletions(-)