OpenE2K/gcc
2
0
Fork 0
Code Issues Pull Requests Projects Releases Wiki Activity

[ARM/FDPIC v6 13/24] [ARM] FDPIC: Force LSB bit for PC in Cortex-M architecture

Browse Source 
Without this, when we are unwinding across a signal frame we can jump
to an even address which leads to an exception.

This is needed in __gnu_persnality_sigframe_fdpic() when restoring the
PC from the signal frame since the PC saved by the kernel has the LSB
bit set to zero.

2019-09-10  Christophe Lyon  <christophe.lyon@st.com>
	Mickaël Guêné <mickael.guene@st.com>

	libgcc/
	* config/arm/unwind-arm.c (_Unwind_VRS_Set): Handle thumb-only
	architecture.


Co-Authored-By: Mickaël Guêné <mickael.guene@st.com>

From-SVN: r275575
This commit is contained in:
Christophe Lyon 2019-09-10 09:58:44 +02:00 committed by Christophe Lyon
parent bb33a88e3d
commit 84818dbb70
2 changed files with 11 additions and 1 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

7
libgcc/ChangeLog
View File

@ -1,7 +1,12 @@
2019-09-10 Christophe Lyon <christophe.lyon@st.com>
Mickaël Guêné <mickael.guene@st.com>
libgcc/
* config/arm/unwind-arm.c (_Unwind_VRS_Set): Handle thumb-only
architecture.
2019-09-10 Christophe Lyon <christophe.lyon@st.com>
Mickaël Guêné <mickael.guene@st.com>
* unwind-arm-common.inc (ARM_SET_R7_RT_SIGRETURN)
(THUMB2_SET_R7_RT_SIGRETURN, FDPIC_LDR_R12_WITH_FUNCDESC)
(FDPIC_LDR_R9_WITH_GOT, FDPIC_LDR_PC_WITH_RESTORER)

5
libgcc/config/arm/unwind-arm.c
View File

@ -199,6 +199,11 @@ _Unwind_VRS_Result _Unwind_VRS_Set (_Unwind_Context *context,
return _UVRSR_FAILED;
vrs->core.r[regno] = *(_uw *) valuep;
#if defined(__thumb__)
/* Force LSB bit since we always run thumb code. */
if (regno == R_PC)
vrs->core.r[regno] |= 1;
#endif
return _UVRSR_OK;
case _UVRSC_VFP: