diff options
author | Chris Metcalf <cmetcalf@tilera.com> | 2010-08-13 08:40:57 -0400 |
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committer | Chris Metcalf <cmetcalf@tilera.com> | 2010-08-13 08:40:57 -0400 |
commit | 1fcbe027b5d29ec9cd0eeb753c14fb366ae852ac (patch) | |
tree | b0d80646567ac71238cf2ffb33e29ad33d758816 /arch/tile/kernel/backtrace.c | |
parent | 32020effaf713c0c669864301bcd5dac6b9bb9e0 (diff) | |
download | linux-1fcbe027b5d29ec9cd0eeb753c14fb366ae852ac.tar.bz2 |
arch/tile: support backtracing on TILE-Gx
This functionality was stubbed out until recently. Now we support our
normal backtracing API on TILE-Gx as well as on TILE64/TILEPro.
This change includes a tweak to the instruction encoding caused by
adding addxli for compat mode.
Signed-off-by: Chris Metcalf <cmetcalf@tilera.com>
Diffstat (limited to 'arch/tile/kernel/backtrace.c')
-rw-r--r-- | arch/tile/kernel/backtrace.c | 137 |
1 files changed, 99 insertions, 38 deletions
diff --git a/arch/tile/kernel/backtrace.c b/arch/tile/kernel/backtrace.c index 77265f3b58d6..d3c41c1ff6bd 100644 --- a/arch/tile/kernel/backtrace.c +++ b/arch/tile/kernel/backtrace.c @@ -19,9 +19,6 @@ #include <arch/chip.h> -#if TILE_CHIP < 10 - - #include <asm/opcode-tile.h> @@ -29,6 +26,27 @@ #define TREG_LR 55 +#if TILE_CHIP >= 10 +#define tile_bundle_bits tilegx_bundle_bits +#define TILE_MAX_INSTRUCTIONS_PER_BUNDLE TILEGX_MAX_INSTRUCTIONS_PER_BUNDLE +#define TILE_BUNDLE_ALIGNMENT_IN_BYTES TILEGX_BUNDLE_ALIGNMENT_IN_BYTES +#define tile_decoded_instruction tilegx_decoded_instruction +#define tile_mnemonic tilegx_mnemonic +#define parse_insn_tile parse_insn_tilegx +#define TILE_OPC_IRET TILEGX_OPC_IRET +#define TILE_OPC_ADDI TILEGX_OPC_ADDI +#define TILE_OPC_ADDLI TILEGX_OPC_ADDLI +#define TILE_OPC_INFO TILEGX_OPC_INFO +#define TILE_OPC_INFOL TILEGX_OPC_INFOL +#define TILE_OPC_JRP TILEGX_OPC_JRP +#define TILE_OPC_MOVE TILEGX_OPC_MOVE +#define OPCODE_STORE TILEGX_OPC_ST +typedef long long bt_int_reg_t; +#else +#define OPCODE_STORE TILE_OPC_SW +typedef int bt_int_reg_t; +#endif + /** A decoded bundle used for backtracer analysis. */ struct BacktraceBundle { tile_bundle_bits bits; @@ -41,7 +59,7 @@ struct BacktraceBundle { /* This implementation only makes sense for native tools. */ /** Default function to read memory. */ static bool bt_read_memory(void *result, VirtualAddress addr, - size_t size, void *extra) + unsigned int size, void *extra) { /* FIXME: this should do some horrible signal stuff to catch * SEGV cleanly and fail. @@ -106,6 +124,12 @@ static bool bt_has_addi_sp(const struct BacktraceBundle *bundle, int *adjust) find_matching_insn(bundle, TILE_OPC_ADDI, vals, 2); if (insn == NULL) insn = find_matching_insn(bundle, TILE_OPC_ADDLI, vals, 2); +#if TILE_CHIP >= 10 + if (insn == NULL) + insn = find_matching_insn(bundle, TILEGX_OPC_ADDXLI, vals, 2); + if (insn == NULL) + insn = find_matching_insn(bundle, TILEGX_OPC_ADDXI, vals, 2); +#endif if (insn == NULL) return false; @@ -190,13 +214,52 @@ static inline bool bt_has_move_r52_sp(const struct BacktraceBundle *bundle) return find_matching_insn(bundle, TILE_OPC_MOVE, vals, 2) != NULL; } -/** Does this bundle contain the instruction 'sw sp, lr'? */ +/** Does this bundle contain a store of lr to sp? */ static inline bool bt_has_sw_sp_lr(const struct BacktraceBundle *bundle) { static const int vals[2] = { TREG_SP, TREG_LR }; - return find_matching_insn(bundle, TILE_OPC_SW, vals, 2) != NULL; + return find_matching_insn(bundle, OPCODE_STORE, vals, 2) != NULL; +} + +#if TILE_CHIP >= 10 +/** Track moveli values placed into registers. */ +static inline void bt_update_moveli(const struct BacktraceBundle *bundle, + int moveli_args[]) +{ + int i; + for (i = 0; i < bundle->num_insns; i++) { + const struct tile_decoded_instruction *insn = + &bundle->insns[i]; + + if (insn->opcode->mnemonic == TILEGX_OPC_MOVELI) { + int reg = insn->operand_values[0]; + moveli_args[reg] = insn->operand_values[1]; + } + } } +/** Does this bundle contain an 'add sp, sp, reg' instruction + * from a register that we saw a moveli into, and if so, what + * is the value in the register? + */ +static bool bt_has_add_sp(const struct BacktraceBundle *bundle, int *adjust, + int moveli_args[]) +{ + static const int vals[2] = { TREG_SP, TREG_SP }; + + const struct tile_decoded_instruction *insn = + find_matching_insn(bundle, TILEGX_OPC_ADDX, vals, 2); + if (insn) { + int reg = insn->operand_values[2]; + if (moveli_args[reg]) { + *adjust = moveli_args[reg]; + return true; + } + } + return false; +} +#endif + /** Locates the caller's PC and SP for a program starting at the * given address. */ @@ -227,6 +290,11 @@ static void find_caller_pc_and_caller_sp(CallerLocation *location, int next_bundle = 0; VirtualAddress pc; +#if TILE_CHIP >= 10 + /* Naively try to track moveli values to support addx for -m32. */ + int moveli_args[TILEGX_NUM_REGISTERS] = { 0 }; +#endif + /* Default to assuming that the caller's sp is the current sp. * This is necessary to handle the case where we start backtracing * right at the end of the epilog. @@ -380,7 +448,11 @@ static void find_caller_pc_and_caller_sp(CallerLocation *location, if (!sp_determined) { int adjust; - if (bt_has_addi_sp(&bundle, &adjust)) { + if (bt_has_addi_sp(&bundle, &adjust) +#if TILE_CHIP >= 10 + || bt_has_add_sp(&bundle, &adjust, moveli_args) +#endif + ) { location->sp_location = SP_LOC_OFFSET; if (adjust <= 0) { @@ -427,6 +499,11 @@ static void find_caller_pc_and_caller_sp(CallerLocation *location, sp_determined = true; } } + +#if TILE_CHIP >= 10 + /* Track moveli arguments for -m32 mode. */ + bt_update_moveli(&bundle, moveli_args); +#endif } if (bt_has_iret(&bundle)) { @@ -502,11 +579,10 @@ void backtrace_init(BacktraceIterator *state, break; } - /* The frame pointer should theoretically be aligned mod 8. If - * it's not even aligned mod 4 then something terrible happened - * and we should mark it as invalid. + /* If the frame pointer is not aligned to the basic word size + * something terrible happened and we should mark it as invalid. */ - if (fp % 4 != 0) + if (fp % sizeof(bt_int_reg_t) != 0) fp = -1; /* -1 means "don't know initial_frame_caller_pc". */ @@ -547,9 +623,16 @@ void backtrace_init(BacktraceIterator *state, state->read_memory_func_extra = read_memory_func_extra; } +/* Handle the case where the register holds more bits than the VA. */ +static bool valid_addr_reg(bt_int_reg_t reg) +{ + return ((VirtualAddress)reg == reg); +} + bool backtrace_next(BacktraceIterator *state) { - VirtualAddress next_fp, next_pc, next_frame[2]; + VirtualAddress next_fp, next_pc; + bt_int_reg_t next_frame[2]; if (state->fp == -1) { /* No parent frame. */ @@ -563,11 +646,9 @@ bool backtrace_next(BacktraceIterator *state) } next_fp = next_frame[1]; - if (next_fp % 4 != 0) { - /* Caller's frame pointer is suspect, so give up. - * Technically it should be aligned mod 8, but we will - * be forgiving here. - */ + if (!valid_addr_reg(next_frame[1]) || + next_fp % sizeof(bt_int_reg_t) != 0) { + /* Caller's frame pointer is suspect, so give up. */ return false; } @@ -585,7 +666,7 @@ bool backtrace_next(BacktraceIterator *state) } else { /* Get the caller PC from the frame linkage area. */ next_pc = next_frame[0]; - if (next_pc == 0 || + if (!valid_addr_reg(next_frame[0]) || next_pc == 0 || next_pc % TILE_BUNDLE_ALIGNMENT_IN_BYTES != 0) { /* The PC is suspect, so give up. */ return false; @@ -599,23 +680,3 @@ bool backtrace_next(BacktraceIterator *state) return true; } - -#else /* TILE_CHIP < 10 */ - -void backtrace_init(BacktraceIterator *state, - BacktraceMemoryReader read_memory_func, - void *read_memory_func_extra, - VirtualAddress pc, VirtualAddress lr, - VirtualAddress sp, VirtualAddress r52) -{ - state->pc = pc; - state->sp = sp; - state->fp = -1; - state->initial_frame_caller_pc = -1; - state->read_memory_func = read_memory_func; - state->read_memory_func_extra = read_memory_func_extra; -} - -bool backtrace_next(BacktraceIterator *state) { return false; } - -#endif /* TILE_CHIP < 10 */ |