Indeed, remove it entirely and remove the is_tcg_gen_code check from GETPC_EXT.
Fixes https://bugs.launchpad.net/qemu/+bug/1218098 wherein a call to a "normal" helper function performed a sequence of tail calls all the way into the memory helper functions, leading to a stack frame in which the memory helper function appeared to be called directly from tcg. Signed-off-by: Richard Henderson <r...@twiddle.net> --- include/exec/exec-all.h | 10 +++++----- 1 file changed, 5 insertions(+), 5 deletions(-) This is actually conclusive proof that using is_tcg_gen_code, and thus any scheme that requires GETPC_LDST, is fundamentally flawed. Thankfully, the follow-up patch sets that I've already posted give a framework for properly fixing this. I've already posted a cleanup for ARM to fix this. I have pending but unposted patch sets for AArch64 and PowerPC. In the meantime, please apply this fix for x86_64 asap. r~ diff --git a/include/exec/exec-all.h b/include/exec/exec-all.h index b70028a..ffb69a4 100644 --- a/include/exec/exec-all.h +++ b/include/exec/exec-all.h @@ -326,9 +326,7 @@ extern uintptr_t tci_tb_ptr; (6) jump to corresponding code of the next of fast path */ # if defined(__i386__) || defined(__x86_64__) -# define GETRA() ((uintptr_t)__builtin_return_address(0)) -/* The return address argument for ldst is passed directly. */ -# define GETPC_LDST() (abort(), 0) +# define GETPC_EXT() GETPC() # elif defined (_ARCH_PPC) && !defined (_ARCH_PPC64) # define GETRA() ((uintptr_t)__builtin_return_address(0)) # define GETPC_LDST() ((uintptr_t) ((*(int32_t *)(GETRA() - 4)) - 1)) @@ -349,7 +347,7 @@ static inline uintptr_t tcg_getpc_ldst(uintptr_t ra) not the start of the next opcode */ return ra; } -#elif defined(__aarch64__) +# elif defined(__aarch64__) # define GETRA() ((uintptr_t)__builtin_return_address(0)) # define GETPC_LDST() tcg_getpc_ldst(GETRA()) static inline uintptr_t tcg_getpc_ldst(uintptr_t ra) @@ -367,7 +365,9 @@ static inline uintptr_t tcg_getpc_ldst(uintptr_t ra) # error "CONFIG_QEMU_LDST_OPTIMIZATION needs GETPC_LDST() implementation!" # endif bool is_tcg_gen_code(uintptr_t pc_ptr); -# define GETPC_EXT() (is_tcg_gen_code(GETRA()) ? GETPC_LDST() : GETPC()) +# ifndef GETPC_EXT +# define GETPC_EXT() (is_tcg_gen_code(GETRA()) ? GETPC_LDST() : GETPC()) +# endif #else # define GETPC_EXT() GETPC() #endif -- 1.8.1.4
