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authorRich Felker <dalias@aerifal.cx>2013-09-16 11:52:39 -0400
committerRich Felker <dalias@aerifal.cx>2013-09-16 11:52:39 -0400
commitcffb9e1ee2a5e8925845f0c9b79cb6c80487302c (patch)
tree06f35ba78ab45c5b209398aa0b0ef036d487fa6b /src/thread/mips
parent90710df5ccd405743d570dcb255fc28d952ba651 (diff)
downloadmusl-cffb9e1ee2a5e8925845f0c9b79cb6c80487302c.tar.gz
fix clobbering of caller's stack in mips __clone function
this was resulting in crashes in posix_spawn on mips, and would have affected applications calling clone too. since the prototype for __clone has it as a variadic function, it may not assume that 16($sp) is writable for use in making the syscall. instead, it needs to allocate additional stack space, and then adjust the stack pointer back in both of the code paths for the parent process/thread.
Diffstat (limited to 'src/thread/mips')
-rw-r--r--src/thread/mips/clone.s3
1 files changed, 3 insertions, 0 deletions
diff --git a/src/thread/mips/clone.s b/src/thread/mips/clone.s
index 6c2e7908..37dddf57 100644
--- a/src/thread/mips/clone.s
+++ b/src/thread/mips/clone.s
@@ -12,15 +12,18 @@ __clone:
lw $6, 16($sp)
lw $7, 20($sp)
lw $9, 24($sp)
+ subu $sp, $sp, 16
sw $9, 16($sp)
li $2, 4120
syscall
beq $7, $0, 1f
nop
+ addu $sp, $sp, 16
jr $ra
subu $2, $0, $2
1: beq $2, $0, 1f
nop
+ addu $sp, $sp, 16
jr $ra
nop
1: lw $25, 0($sp)