diff options
| author | H.J. Lu <hjl.tools@gmail.com> | 2017-06-16 14:32:02 -0700 |
|---|---|---|
| committer | H.J. Lu <hjl.tools@gmail.com> | 2017-06-17 06:15:23 -0700 |
| commit | 24a5df4d2540d59cb1395fb28d26a80dc861faef (patch) | |
| tree | 4351eca190a2b389c106f6b79cf98396fc16f32d | |
| parent | 32604815347b5316e46d481c2967bd526410a2c8 (diff) | |
| download | glibc-hjl/pr21598.tar.gz | |
i386: Update _dl_runtime_resolve/_dl_runtime_profilehjl/pr21598
To make symbol resolver compatible with Shadow Stack in Intel Control-flow
Enforcement Technology (CET) instructions:
https://software.intel.com/sites/default/files/managed/4d/2a/control-flow-enforcement-technology-preview.pdf
call resolved function indirectly with %ecx.
[BZ #21598]
* sysdeps/i386/dl-trampoline.S (_dl_runtime_resolve): Call
resolved function indirectly with %ecx.
(_dl_runtime_profile): Likewise.
| -rw-r--r-- | sysdeps/i386/dl-trampoline.S | 34 |
1 files changed, 16 insertions, 18 deletions
diff --git a/sysdeps/i386/dl-trampoline.S b/sysdeps/i386/dl-trampoline.S index 6e7f3aef92..d6c90a2d48 100644 --- a/sysdeps/i386/dl-trampoline.S +++ b/sysdeps/i386/dl-trampoline.S @@ -34,19 +34,17 @@ _dl_runtime_resolve: cfi_adjust_cfa_offset (8) pushl %eax # Preserve registers otherwise clobbered. cfi_adjust_cfa_offset (4) - pushl %ecx - cfi_adjust_cfa_offset (4) pushl %edx cfi_adjust_cfa_offset (4) - movl 16(%esp), %edx # Copy args pushed by PLT in register. Note - movl 12(%esp), %eax # that `fixup' takes its parameters in regs. + movl 12(%esp), %edx # Copy args pushed by PLT in register. Note + movl 8(%esp), %eax # that `fixup' takes its parameters in regs. call _dl_fixup # Call resolver. - popl %edx # Get register content back. - cfi_adjust_cfa_offset (-4) - movl (%esp), %ecx - movl %eax, (%esp) # Store the function address. - movl 4(%esp), %eax - ret $12 # Jump to function address. + movl (%esp), %edx # Get register content back. + movl %eax, %ecx # Store the function address. + movl 4(%esp), %eax # Get register content back. + addl $16, %esp # Adjust stack: PLT1 + PLT2 + %eax + %edx + cfi_adjust_cfa_offset (-16) + jmp *%ecx # Jump to function address. cfi_endproc .size _dl_runtime_resolve, .-_dl_runtime_resolve @@ -85,14 +83,14 @@ _dl_runtime_profile: movl (%esp), %edx testl %edx, %edx jns 1f - popl %edx - cfi_adjust_cfa_offset (-4) - popl %edx # Get register content back. - cfi_adjust_cfa_offset (-4) - movl (%esp), %ecx - movl %eax, (%esp) # Store the function address. - movl 4(%esp), %eax - ret $20 # Jump to function address. + movl 4(%esp), %edx # Get register content back. + movl %eax, %ecx # Store the function address. + movl 12(%esp), %eax # Get register content back. + # Adjust stack: PLT1 + PLT2 + %esp + %ebp + %eax + %ecx + %edx + # + free. + addl $32, %esp + cfi_adjust_cfa_offset (-32) + jmp *%ecx # Jump to function address. /* +32 return address |