On 2/10/22 01:00, Jinoh Kang wrote:
On 2/8/22 04:05, Rémi Bernon wrote:
Making sure stack pointer points to previous syscall / exit frame before entering a syscall, and restoring the PE frame information on return.
Wine-Bug: https://bugs.winehq.org/show_bug.cgi?id=52213 Signed-off-by: Rémi Bernon rbernon@codeweavers.com
dlls/ntdll/unix/signal_i386.c | 9 +++++++++ dlls/ntdll/unix/signal_x86_64.c | 9 +++++++++ 2 files changed, 18 insertions(+)
diff --git a/dlls/ntdll/unix/signal_i386.c b/dlls/ntdll/unix/signal_i386.c index d98a3b1d4bb..2f6e2fd4153 100644 --- a/dlls/ntdll/unix/signal_i386.c +++ b/dlls/ntdll/unix/signal_i386.c @@ -2492,6 +2492,9 @@ __ASM_GLOBAL_FUNC( __wine_syscall_dispatcher, "movl %esi,0x30(%ecx)\n\t" "movl %ebp,0x34(%ecx)\n\t" "leal 0x34(%ecx),%ebp\n\t"
__ASM_CFI(".cfi_def_cfa %ebp,0\n\t")This changes the value of CFA. By definition, the actual value of CFA (not the CFA register) may never change within the context of a subroutine activation [1]. If we desire to switch CFA to a different frame anyway (with EIP overriden), we must end the current FDE with ".cfi_endproc" and start another FDE with ".cfi_startproc simple". See [2] and [3] for how glibc achieves this.
__ASM_CFI(".cfi_rel_offset %eip,-0x2c\n\t")This is the system call return address, which would be in a PE module. I don't think this is very useful, since we will later switch to the exit frame anyway.
__ASM_CFI(".cfi_rel_offset %esp,-0x28\n\t")This makes GDB unhappy: "previous frame inner to this frame (corrupt stack)?" [4].
Oops, I forgot the link. It's at https://stackoverflow.com/questions/52518857/stackful-coroutines-gdb-previou.... My apologies.