The trampoline now properly restores the link register as well as the stack
pointer. As a minor optimisation, now only callee-saved registers are
restored: the scratch registers don't need that.
Tested on x86_64-pc-linux-gnu, committed on trunk
2018-05-22 Jerome Lambourg <lambo...@adacore.com>
gcc/ada/
* sigtramp-qnx.c: Properly restore link register in signal trampoline.--- gcc/ada/sigtramp-qnx.c
+++ gcc/ada/sigtramp-qnx.c
@@ -170,33 +170,20 @@ TCR("ret")
#define REG_OFFSET_GR(n) (n * 8)
#define REGNO_GR(n) n
-/* point to the ELR value of the mcontext registers list */
+/* ELR value offset withing the mcontext registers list */
#define REG_OFFSET_ELR (32 * 8)
-#define REGNO_PC 30
+/* The register used to hold the PC value to restore. We need a scratch
+ register. */
+#define REGNO_PC 9
#define CFI_DEF_CFA \
TCR(".cfi_def_cfa " S(CFA_REG) ", 0")
+/* This restores the callee-saved registers, the FP, the LR, and the SP.
+ A scratch register is used as return column to indicate the new value
+ for PC */
#define CFI_COMMON_REGS \
CR("# CFI for common registers\n") \
- TCR(COMMON_CFI(GR(0))) \
- TCR(COMMON_CFI(GR(1))) \
- TCR(COMMON_CFI(GR(2))) \
- TCR(COMMON_CFI(GR(3))) \
- TCR(COMMON_CFI(GR(4))) \
- TCR(COMMON_CFI(GR(5))) \
- TCR(COMMON_CFI(GR(6))) \
- TCR(COMMON_CFI(GR(7))) \
- TCR(COMMON_CFI(GR(8))) \
- TCR(COMMON_CFI(GR(9))) \
- TCR(COMMON_CFI(GR(10))) \
- TCR(COMMON_CFI(GR(11))) \
- TCR(COMMON_CFI(GR(12))) \
- TCR(COMMON_CFI(GR(13))) \
- TCR(COMMON_CFI(GR(14))) \
- TCR(COMMON_CFI(GR(15))) \
- TCR(COMMON_CFI(GR(16))) \
- TCR(COMMON_CFI(GR(17))) \
TCR(COMMON_CFI(GR(18))) \
TCR(COMMON_CFI(GR(19))) \
TCR(COMMON_CFI(GR(20))) \
@@ -209,6 +196,8 @@ TCR("ret")
TCR(COMMON_CFI(GR(27))) \
TCR(COMMON_CFI(GR(28))) \
TCR(COMMON_CFI(GR(29))) \
+ TCR(COMMON_CFI(GR(30))) \
+ TCR(COMMON_CFI(GR(31))) \
TCR(".cfi_offset " S(REGNO_PC) "," S(REG_OFFSET_ELR)) \
TCR(".cfi_return_column " S(REGNO_PC))
