Syscall thunks break stack alignment for dispatcher. Regardless of that, it is probably better not to assume aligned stack in syscall thunk entry.
Signed-off-by: Paul Gofman pgofman@codeweavers.com --- v2: - fix jump destination in error branch (last jump).
tools/winebuild/import.c | 16 +++++++++------- 1 file changed, 9 insertions(+), 7 deletions(-)
diff --git a/tools/winebuild/import.c b/tools/winebuild/import.c index 97191ca89ec..278de20522e 100644 --- a/tools/winebuild/import.c +++ b/tools/winebuild/import.c @@ -1497,23 +1497,25 @@ void output_syscalls( DLLSPEC *spec ) * depends on us returning to it. Adjust the return address accordingly. */ output( "\tsubq $0xb,0x8(%%rbp)\n" ); output( "\tcmpq $%u,%%rax\n", count ); - output( "\tjae 3f\n" ); + output( "\tjae 4f\n" ); output( "\tleaq .Lsyscall_args(%%rip),%%rcx\n" ); output( "\tmovzbl (%%rcx,%%rax),%%ecx\n" ); output( "\tsubq $0x20,%%rcx\n" ); - output( "\tjbe 1f\n" ); - output( "\tsubq %%rcx,%%rsp\n" ); + output( "\tja 1f\n" ); + output( "\tandq $~15,%%rsp\n\t" ); + output( "\tjmp 2f\n" ); + output( "1:\tsubq %%rcx,%%rsp\n" ); output( "\tshrq $3,%%rcx\n" ); output( "\tleaq 0x38(%%rbp),%%rsi\n" ); output( "\tandq $~15,%%rsp\n\t" ); output( "\tmovq %%rsp,%%rdi\n" ); output( "\tcld\n" ); output( "\trep; movsq\n" ); - output( "1:\tmovq %%r10,%%rcx\n" ); + output( "2:\tmovq %%r10,%%rcx\n" ); output( "\tsubq $0x20,%%rsp\n" ); output( "\tleaq .Lsyscall_table(%%rip),%%r10\n" ); output( "\tcallq *(%%r10,%%rax,8)\n" ); - output( "2:\tleaq -0x10(%%rbp),%%rsp\n" ); + output( "3:\tleaq -0x10(%%rbp),%%rsp\n" ); output( "\tpopq %%rdi\n" ); output_cfi( ".cfi_same_value %%rdi" ); output( "\tpopq %%rsi\n" ); @@ -1523,8 +1525,8 @@ void output_syscalls( DLLSPEC *spec ) output_cfi( ".cfi_adjust_cfa_offset -8" ); output_cfi( ".cfi_same_value %%rbp" ); output( "\tret\n" ); - output( "3:\tmovl $0x%x,%%eax\n", invalid_param ); - output( "\tjmp 2b\n" ); + output( "4:\tmovl $0x%x,%%eax\n", invalid_param ); + output( "\tjmp 3b\n" ); break; case CPU_ARM: output( "\tldr r1, 4f\n" );