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arm32 unwind fix #1102

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merged 4 commits into from
Oct 13, 2016
Merged

arm32 unwind fix #1102

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7cd4334
arm32: unwind: fix incorrect return status
jforissier Oct 10, 2016
9c5e2f8
arm32: unwind: convert int to bool
jforissier Oct 10, 2016
e386996
arm32: unwind: mark tee_svc_do_call() with .cantunwind
jforissier Oct 10, 2016
18e8c53
arm32: unwind: print_stack(): fix unwind_state
jforissier Oct 10, 2016
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16 changes: 16 additions & 0 deletions core/arch/arm/include/arm32.h
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Original file line number Diff line number Diff line change
Expand Up @@ -558,6 +558,22 @@ static __always_inline uint32_t read_lr(void)
asm volatile ("mov %0, lr" : "=r" (val));
return val;
}

static __always_inline uint32_t read_fp(void)
{
uint32_t val;

asm volatile ("mov %0, fp" : "=r" (val));
return val;
}

static __always_inline uint32_t read_r7(void)
{
uint32_t val;

asm volatile ("mov %0, r7" : "=r" (val));
return val;
}
#endif /*ASM*/

#endif /*ARM32_H*/
12 changes: 8 additions & 4 deletions core/arch/arm/kernel/unwind_arm32.c
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Expand Up @@ -248,7 +248,7 @@ static bool unwind_exec_insn(struct unwind_state *state)

mask = unwind_exec_read_byte(state);
if (mask == 0 || (mask & 0xf0) != 0)
return 1;
return false;

/* Update SP */
update_vsp = 1;
Expand Down Expand Up @@ -283,7 +283,7 @@ static bool unwind_exec_insn(struct unwind_state *state)
}

/* Performs the unwind of a function */
static int unwind_tab(struct unwind_state *state)
static bool unwind_tab(struct unwind_state *state)
{
uint32_t entry;

Expand Down Expand Up @@ -367,10 +367,14 @@ void print_stack(int level)
{
struct unwind_state state;

memset(&state, 0, sizeof(state));
memset(state.registers, 0, sizeof(state.registers));
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maybe this is a stupid question: why zero-ing only the registers sub structure ?

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Because, that's the only part that contains input arguments. The rest is used internally by the unwinding code, so it doesn't look like it is the responsibility of the caller to initialize it (To which value BTW? Is zero acceptable for all fields?).

/* r7: Thumb-style frame pointer */
state.registers[7] = read_r7();
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for consistency, could you use a R7 label defined next to FP, SP and friends above ?

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I'd rather not for two reasons: (1) it does not improve legibility and (2) the above code is mostly copied from FreeBSD so the less we change it, the better.

/* r11: ARM-style frame pointer */
state.registers[FP] = read_fp();
state.registers[SP] = read_sp();
state.registers[LR] = read_lr();
state.registers[PC] = read_pc();
state.registers[PC] = (uint32_t)print_stack;

do {
switch (level) {
Expand Down
2 changes: 1 addition & 1 deletion core/arch/arm/tee/arch_svc_a32.S
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Expand Up @@ -42,8 +42,8 @@
*/
FUNC tee_svc_do_call , :
UNWIND( .fnstart)
UNWIND( .cantunwind)
push {r5-r9, lr}
UNWIND( .save {r5-r9, lr})
mov r7, sp
mov r8, r0
mov r9, r1
Expand Down