From 69b46464badb01340a88d0ee57cdef0b7fdf545e Mon Sep 17 00:00:00 2001 From: Yvan Roux Date: Wed, 29 Jun 2022 14:01:45 +0200 Subject: gdb/arm: Only stack S16..S31 when FPU registers are secure MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit The FPCCR.TS bit is used to identify if FPU registers are considered non-secure or secure. If they are secure, then callee saved registers (S16 to S31) are stacked on exception entry or otherwise skipped. Signed-off-by: Torbjörn SVENSSON Signed-off-by: Yvan Roux --- gdb/arch/arm.h | 9 +++++++++ gdb/arm-tdep.c | 9 ++++++++- 2 files changed, 17 insertions(+), 1 deletion(-) diff --git a/gdb/arch/arm.h b/gdb/arch/arm.h index 4ad329f..3675749 100644 --- a/gdb/arch/arm.h +++ b/gdb/arch/arm.h @@ -109,6 +109,15 @@ enum arm_m_profile_type { ARM_M_TYPE_INVALID }; +/* System control registers accessible through an addresses. */ +enum system_register_address : CORE_ADDR +{ + /* M-profile Floating-Point Context Control Register address, defined in + ARMv7-M (Section B3.2.2) and ARMv8-M (Section D1.2.99) reference + manuals. */ + FPCCR = 0xe000ef34 +}; + /* Instruction condition field values. */ #define INST_EQ 0x0 #define INST_NE 0x1 diff --git a/gdb/arm-tdep.c b/gdb/arm-tdep.c index e36bde9..3a1b52c 100644 --- a/gdb/arm-tdep.c +++ b/gdb/arm-tdep.c @@ -3573,6 +3573,13 @@ arm_m_exception_cache (struct frame_info *this_frame) { int i; int fpu_regs_stack_offset; + ULONGEST fpccr; + + /* Read FPCCR register. */ + gdb_assert (safe_read_memory_unsigned_integer (FPCCR, + ARM_INT_REGISTER_SIZE, + byte_order, &fpccr)); + bool fpccr_ts = bit (fpccr,26); /* This code does not take into account the lazy stacking, see "Lazy context save of FP state", in B1.5.7, also ARM AN298, supported @@ -3592,7 +3599,7 @@ arm_m_exception_cache (struct frame_info *this_frame) cache->saved_regs[ARM_FPSCR_REGNUM].set_addr (unwound_sp + sp_r0_offset + 0x60); fpu_regs_stack_offset += 4; - if (tdep->have_sec_ext && !default_callee_register_stacking) + if (tdep->have_sec_ext && !default_callee_register_stacking && fpccr_ts) { /* Handle floating-point callee saved registers. */ fpu_regs_stack_offset = unwound_sp + sp_r0_offset + 0x68; -- cgit v1.1