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| author | Andrew Waterman <waterman@cs.berkeley.edu> | 2015-04-10 14:58:00 -0700 |
|---|---|---|
| committer | Andrew Waterman <waterman@cs.berkeley.edu> | 2015-04-10 14:58:00 -0700 |
| commit | e474878db4a406fb0bc7f6051314352f4406fcd2 (patch) | |
| tree | 3286da6cb52877f8d51f2346f0ec51bbb236f23a /pk/entry.S | |
| parent | 01fd29cb6ef8202ef6201f6f471dec9cbd1a4145 (diff) | |
| download | pk-e474878db4a406fb0bc7f6051314352f4406fcd2.zip pk-e474878db4a406fb0bc7f6051314352f4406fcd2.tar.gz pk-e474878db4a406fb0bc7f6051314352f4406fcd2.tar.bz2 | |
Fix stack discipline for recursive traps
Diffstat (limited to 'pk/entry.S')
| -rw-r--r-- | pk/entry.S | 24 |
1 files changed, 15 insertions, 9 deletions
@@ -37,13 +37,12 @@ STORE x31,31*REGBYTES(x2) # get sr, epc, badvaddr, cause - addi t0,sp,320 - csrrw t0,sscratch,t0 - csrr t1,sstatus + csrrw t0,sscratch,x0 + csrr s0,sstatus csrr t2,sepc csrr t3,scause STORE t0,2*REGBYTES(x2) - STORE t1,32*REGBYTES(x2) + STORE s0,32*REGBYTES(x2) STORE t2,33*REGBYTES(x2) STORE t3,35*REGBYTES(x2) @@ -57,15 +56,22 @@ .global trap_entry trap_entry: csrrw sp, sscratch, sp - + bnez sp, 1f + csrr sp, sscratch 1:addi sp,sp,-320 save_tf move a0,sp - j handle_trap + jal handle_trap + + mv a0,sp + # don't restore sstatus if trap came from kernel + andi s0,s0,SSTATUS_PS + bnez s0,start_user + addi sp,sp,320 + csrw sscratch,sp - .globl pop_tf -pop_tf: # write the trap frame onto the stack - # restore sstatus and epc + .globl start_user +start_user: csrc sstatus, SSTATUS_IE li t0, SSTATUS_PS LOAD t1, 32*REGBYTES(a0) |