mirrors/qemu
1
0
Fork 0
Code Issues Pull Requests Packages Projects Releases Wiki Activity

tcg/ppc: Sanitize immediate shifts

Browse Source 
Sanitize shift constants so that shift operations with
large constants don't generate invalid instructions.

Signed-off-by: Catherine A. Frederick <chocola@animebitch.es>
Message-Id: <20200607211100.22858-1-agrecascino123@gmail.com>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
This commit is contained in:
Catherine A. Frederick 2020-06-07 17:10:59 -04:00 committed by Richard Henderson
parent eb6490f544
commit 94248cfc04
1 changed files with 10 additions and 5 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

15
tcg/ppc/tcg-target.inc.c
View File

@ -2610,21 +2610,24 @@ static void tcg_out_op(TCGContext *s, TCGOpcode opc, const TCGArg *args,
case INDEX_op_shl_i32:
if (const_args[2]) {
tcg_out_shli32(s, args[0], args[1], args[2]);
/* Limit immediate shift count lest we create an illegal insn. */
tcg_out_shli32(s, args[0], args[1], args[2] & 31);
} else {
tcg_out32(s, SLW | SAB(args[1], args[0], args[2]));
}
break;
case INDEX_op_shr_i32:
if (const_args[2]) {
tcg_out_shri32(s, args[0], args[1], args[2]);
/* Limit immediate shift count lest we create an illegal insn. */
tcg_out_shri32(s, args[0], args[1], args[2] & 31);
} else {
tcg_out32(s, SRW | SAB(args[1], args[0], args[2]));
}
break;
case INDEX_op_sar_i32:
if (const_args[2]) {
tcg_out32(s, SRAWI | RS(args[1]) | RA(args[0]) | SH(args[2]));
/* Limit immediate shift count lest we create an illegal insn. */
tcg_out32(s, SRAWI | RS(args[1]) | RA(args[0]) | SH(args[2] & 31));
} else {
tcg_out32(s, SRAW | SAB(args[1], args[0], args[2]));
}
@ -2696,14 +2699,16 @@ static void tcg_out_op(TCGContext *s, TCGOpcode opc, const TCGArg *args,
case INDEX_op_shl_i64:
if (const_args[2]) {
tcg_out_shli64(s, args[0], args[1], args[2]);
/* Limit immediate shift count lest we create an illegal insn. */
tcg_out_shli64(s, args[0], args[1], args[2] & 63);
} else {
tcg_out32(s, SLD | SAB(args[1], args[0], args[2]));
}
break;
case INDEX_op_shr_i64:
if (const_args[2]) {
tcg_out_shri64(s, args[0], args[1], args[2]);
/* Limit immediate shift count lest we create an illegal insn. */
tcg_out_shri64(s, args[0], args[1], args[2] & 63);
} else {
tcg_out32(s, SRD | SAB(args[1], args[0], args[2]));
}