MIPS: Fix get_frame_info() handing of function size

[1]: Commit b6c7a324df37b ("MIPS: Fix get_frame_info() handling of
                            microMIPS function size")
[2]: Commit 2b424cfc69728 ("MIPS: Remove function size check in
                            get_frame_info()")

First patch added a constant to check the number of iterations against.
Second patch fixed the situation that info->func_size is zero.

However, func_size member became useless after the second commit. Without
ip_end, the get frame_size operation may be out of range although KALLSYMS
enabled. Thus, check func_size first. Then make ip_end be the sum of ip
and a constant (512) if func_size is equal to 0. Otherwise make ip_end be
the sum of ip and func_size.

Signed-off-by: Jinyang He <hejinyang@loongson.cn>
Signed-off-by: Thomas Bogendoerfer <tsbogend@alpha.franken.de>

diff --git a/arch/mips/kernel/process.c b/arch/mips/kernel/process.c
index c2f9e18..9bf993f 100644 (file)
--- a/arch/mips/kernel/process.c
+++ b/arch/mips/kernel/process.c
@@ -373,10 +373,8 @@ static inline int is_sp_move_ins(union mips_instruction *ip, int *frame_size)
 static int get_frame_info(struct mips_frame_info *info)
 {
        bool is_mmips = IS_ENABLED(CONFIG_CPU_MICROMIPS);
-       union mips_instruction insn, *ip;
-       const unsigned int max_insns = 128;
+       union mips_instruction insn, *ip, *ip_end;
        unsigned int last_insn_size = 0;
-       unsigned int i;
        bool saw_jump = false;
 
        info->pc_offset = -1;
@@ -386,7 +384,9 @@ static int get_frame_info(struct mips_frame_info *info)
        if (!ip)
                goto err;
 
-       for (i = 0; i < max_insns; i++) {
+       ip_end = (void *)ip + (info->func_size ? info->func_size : 512);
+
+       while (ip < ip_end) {
                ip = (void *)ip + last_insn_size;
 
                if (is_mmips && mm_insn_16bit(ip->halfword[0])) {