From db634143224dc7cb985d996bed15257f5cb86b25 Mon Sep 17 00:00:00 2001 From: Pierre Langlois Date: Thu, 9 Jul 2015 16:35:11 +0100 Subject: [PATCH] [AArch64] Only access inferior registers when creating a frame cache This patch moves the address of the start of a function (func) and the address from which it was called (prev_pc) into aarch64_prologue_cache. The idea is to keep accesses to the inferior's registers into aarch64_make_prologue_cache and aarch64_make_stub_cache. gdb/ChangeLog: * aarch64-tdep.c (aarch64_prologue_cache) : New fields. (aarch64_scan_prologue): Set prev_pc. (aarch64_make_prologue_cache): Set func. (aarch64_make_stub_cache): Set prev_pc. (aarch64_prologue_this_id): Remove local variables id, pc and func. Read prev_pc and func from cache. (aarch64_stub_this_id): Read prev_pc from cache. --- gdb/ChangeLog | 11 +++++++++++ gdb/aarch64-tdep.c | 25 +++++++++++++++++-------- 2 files changed, 28 insertions(+), 8 deletions(-) diff --git a/gdb/ChangeLog b/gdb/ChangeLog index 73ee4d183e0..0cc42a378af 100644 --- a/gdb/ChangeLog +++ b/gdb/ChangeLog @@ -1,3 +1,14 @@ +2015-07-09 Pierre Langlois + + * aarch64-tdep.c (aarch64_prologue_cache) : New + fields. + (aarch64_scan_prologue): Set prev_pc. + (aarch64_make_prologue_cache): Set func. + (aarch64_make_stub_cache): Set prev_pc. + (aarch64_prologue_this_id): Remove local variables id, pc and + func. Read prev_pc and func from cache. + (aarch64_stub_this_id): Read prev_pc from cache. + 2015-07-09 Pierre Langlois * aarch64-tdep.c (aarch64_make_stub_cache): Update comment. New diff --git a/gdb/aarch64-tdep.c b/gdb/aarch64-tdep.c index b21182b2f81..fe1b71fe6aa 100644 --- a/gdb/aarch64-tdep.c +++ b/gdb/aarch64-tdep.c @@ -148,6 +148,15 @@ static const char *const aarch64_v_register_names[] = /* AArch64 prologue cache structure. */ struct aarch64_prologue_cache { + /* The program counter at the start of the function. It is used to + identify this frame as a prologue frame. */ + CORE_ADDR func; + + /* The program counter at the time this frame was created; i.e. where + this function was called from. It is used to identify this frame as a + stub frame. */ + CORE_ADDR prev_pc; + /* The stack pointer at the time this frame was created; i.e. the caller's stack pointer when this function was called. It is used to identify this frame. */ @@ -889,6 +898,8 @@ aarch64_scan_prologue (struct frame_info *this_frame, CORE_ADDR prev_pc = get_frame_pc (this_frame); struct gdbarch *gdbarch = get_frame_arch (this_frame); + cache->prev_pc = prev_pc; + /* Assume we do not find a frame. */ cache->framereg = -1; cache->framesize = 0; @@ -966,6 +977,8 @@ aarch64_make_prologue_cache (struct frame_info *this_frame, void **this_cache) if (trad_frame_addr_p (cache->saved_regs, reg)) cache->saved_regs[reg].addr += cache->prev_sp; + cache->func = get_frame_func (this_frame); + return cache; } @@ -978,21 +991,16 @@ aarch64_prologue_this_id (struct frame_info *this_frame, { struct aarch64_prologue_cache *cache = aarch64_make_prologue_cache (this_frame, this_cache); - struct frame_id id; - CORE_ADDR pc, func; /* This is meant to halt the backtrace at "_start". */ - pc = get_frame_pc (this_frame); - if (pc <= gdbarch_tdep (get_frame_arch (this_frame))->lowest_pc) + if (cache->prev_pc <= gdbarch_tdep (get_frame_arch (this_frame))->lowest_pc) return; /* If we've hit a wall, stop. */ if (cache->prev_sp == 0) return; - func = get_frame_func (this_frame); - id = frame_id_build (cache->prev_sp, func); - *this_id = id; + *this_id = frame_id_build (cache->prev_sp, cache->func); } /* Implement the "prev_register" frame_unwind method. */ @@ -1069,6 +1077,7 @@ aarch64_make_stub_cache (struct frame_info *this_frame, void **this_cache) cache->prev_sp = get_frame_register_unsigned (this_frame, AARCH64_SP_REGNUM); + cache->prev_pc = get_frame_pc (this_frame); return cache; } @@ -1082,7 +1091,7 @@ aarch64_stub_this_id (struct frame_info *this_frame, struct aarch64_prologue_cache *cache = aarch64_make_stub_cache (this_frame, this_cache); - *this_id = frame_id_build (cache->prev_sp, get_frame_pc (this_frame)); + *this_id = frame_id_build (cache->prev_sp, cache->prev_pc); } /* Implement the "sniffer" frame_unwind method. */ -- 2.30.2