diff options
author | Richard Henderson <richard.henderson@linaro.org> | 2023-08-15 19:31:38 -0700 |
---|---|---|
committer | Richard Henderson <richard.henderson@linaro.org> | 2023-09-16 14:57:16 +0000 |
commit | 5826a0dbf097c50c5b6db71054cffed972c7e9e6 (patch) | |
tree | b3462c19f84c07e238f08e19cff65b0a8fc004d8 /tcg/aarch64/tcg-target.c.inc | |
parent | 095859e5d97284dd3ea666c337845dc63f6ba5e7 (diff) | |
download | qemu-5826a0dbf097c50c5b6db71054cffed972c7e9e6.zip qemu-5826a0dbf097c50c5b6db71054cffed972c7e9e6.tar.gz qemu-5826a0dbf097c50c5b6db71054cffed972c7e9e6.tar.bz2 |
tcg/aarch64: Emit BTI insns at jump landing pads
The prologue is entered via "call"; the epilogue, each tb,
and each goto_tb continuation point are all reached via "jump".
As tcg_out_goto_long is only used by tcg_out_exit_tb, merge
the two functions. Change the indirect register used to
TCG_REG_TMP1, aka X17, so that the BTI condition created
is "jump" instead of "jump or call".
Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Diffstat (limited to 'tcg/aarch64/tcg-target.c.inc')
-rw-r--r-- | tcg/aarch64/tcg-target.c.inc | 54 |
1 files changed, 39 insertions, 15 deletions
diff --git a/tcg/aarch64/tcg-target.c.inc b/tcg/aarch64/tcg-target.c.inc index a0b6502..06ea3c7 100644 --- a/tcg/aarch64/tcg-target.c.inc +++ b/tcg/aarch64/tcg-target.c.inc @@ -602,6 +602,10 @@ typedef enum { DMB_ISH = 0xd50338bf, DMB_LD = 0x00000100, DMB_ST = 0x00000200, + + BTI_C = 0xd503245f, + BTI_J = 0xd503249f, + BTI_JC = 0xd50324df, } AArch64Insn; static inline uint32_t tcg_in32(TCGContext *s) @@ -843,6 +847,17 @@ static void tcg_out_insn_3313(TCGContext *s, AArch64Insn insn, | rn << 5 | (rd & 0x1f)); } +static void tcg_out_bti(TCGContext *s, AArch64Insn insn) +{ + /* + * While BTI insns are nops on hosts without FEAT_BTI, + * there is no point in emitting them in that case either. + */ + if (cpuinfo & CPUINFO_BTI) { + tcg_out32(s, insn); + } +} + /* Register to register move using ORR (shifted register with no shift). */ static void tcg_out_movr(TCGContext *s, TCGType ext, TCGReg rd, TCGReg rm) { @@ -1351,18 +1366,6 @@ static void tcg_out_goto(TCGContext *s, const tcg_insn_unit *target) tcg_out_insn(s, 3206, B, offset); } -static void tcg_out_goto_long(TCGContext *s, const tcg_insn_unit *target) -{ - ptrdiff_t offset = tcg_pcrel_diff(s, target) >> 2; - if (offset == sextract64(offset, 0, 26)) { - tcg_out_insn(s, 3206, B, offset); - } else { - /* Choose X9 as a call-clobbered non-LR temporary. */ - tcg_out_movi(s, TCG_TYPE_I64, TCG_REG_X9, (intptr_t)target); - tcg_out_insn(s, 3207, BR, TCG_REG_X9); - } -} - static void tcg_out_call_int(TCGContext *s, const tcg_insn_unit *target) { ptrdiff_t offset = tcg_pcrel_diff(s, target) >> 2; @@ -1947,12 +1950,28 @@ static const tcg_insn_unit *tb_ret_addr; static void tcg_out_exit_tb(TCGContext *s, uintptr_t a0) { + const tcg_insn_unit *target; + ptrdiff_t offset; + /* Reuse the zeroing that exists for goto_ptr. */ if (a0 == 0) { - tcg_out_goto_long(s, tcg_code_gen_epilogue); + target = tcg_code_gen_epilogue; } else { tcg_out_movi(s, TCG_TYPE_I64, TCG_REG_X0, a0); - tcg_out_goto_long(s, tb_ret_addr); + target = tb_ret_addr; + } + + offset = tcg_pcrel_diff(s, target) >> 2; + if (offset == sextract64(offset, 0, 26)) { + tcg_out_insn(s, 3206, B, offset); + } else { + /* + * Only x16/x17 generate BTI type Jump (2), + * other registers generate BTI type Jump|Call (3). + */ + QEMU_BUILD_BUG_ON(TCG_REG_TMP0 != TCG_REG_X16); + tcg_out_movi(s, TCG_TYPE_I64, TCG_REG_TMP0, (intptr_t)target); + tcg_out_insn(s, 3207, BR, TCG_REG_TMP0); } } @@ -1970,6 +1989,7 @@ static void tcg_out_goto_tb(TCGContext *s, int which) tcg_out32(s, I3206_B); tcg_out_insn(s, 3207, BR, TCG_REG_TMP0); set_jmp_reset_offset(s, which); + tcg_out_bti(s, BTI_J); } void tb_target_set_jmp_target(const TranslationBlock *tb, int n, @@ -3074,6 +3094,8 @@ static void tcg_target_qemu_prologue(TCGContext *s) { TCGReg r; + tcg_out_bti(s, BTI_C); + /* Push (FP, LR) and allocate space for all saved registers. */ tcg_out_insn(s, 3314, STP, TCG_REG_FP, TCG_REG_LR, TCG_REG_SP, -PUSH_SIZE, 1, 1); @@ -3114,10 +3136,12 @@ static void tcg_target_qemu_prologue(TCGContext *s) * and fall through to the rest of the epilogue. */ tcg_code_gen_epilogue = tcg_splitwx_to_rx(s->code_ptr); + tcg_out_bti(s, BTI_J); tcg_out_movi(s, TCG_TYPE_REG, TCG_REG_X0, 0); /* TB epilogue */ tb_ret_addr = tcg_splitwx_to_rx(s->code_ptr); + tcg_out_bti(s, BTI_J); /* Remove TCG locals stack space. */ tcg_out_insn(s, 3401, ADDI, TCG_TYPE_I64, TCG_REG_SP, TCG_REG_SP, @@ -3137,7 +3161,7 @@ static void tcg_target_qemu_prologue(TCGContext *s) static void tcg_out_tb_start(TCGContext *s) { - /* nothing to do */ + tcg_out_bti(s, BTI_J); } static void tcg_out_nop_fill(tcg_insn_unit *p, int count) |