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From: Alistair Francis <alistair.francis@opensource.wdc.com>
To: qemu-devel@nongnu.org
Cc: alistair23@gmail.com, Nicolas Pitre <nico@fluxnic.net>,
	Alistair Francis <alistair.francis@wdc.com>
Subject: [PULL 19/31] target/riscv/pmp: fix NAPOT range computation overflow
Date: Thu, 21 Apr 2022 16:36:18 +1000	[thread overview]
Message-ID: <20220421063630.1033608-20-alistair.francis@opensource.wdc.com> (raw)
In-Reply-To: <20220421063630.1033608-1-alistair.francis@opensource.wdc.com>

From: Nicolas Pitre <nico@fluxnic.net>

There is an overflow with the current code where a pmpaddr value of
0x1fffffff is decoded as sa=0 and ea=0 whereas it should be sa=0 and
ea=0xffffffff.

Fix that by simplifying the computation. There is in fact no need for
ctz64() nor special case for -1 to achieve proper results.

Signed-off-by: Nicolas Pitre <nico@fluxnic.net>
Reviewed-by: Alistair Francis <alistair.francis@wdc.com>
Message-Id: <rq81o86n-17ps-92no-p65o-79o88476266@syhkavp.arg>
Signed-off-by: Alistair Francis <alistair.francis@wdc.com>
---
 target/riscv/pmp.c | 14 +++-----------
 1 file changed, 3 insertions(+), 11 deletions(-)

diff --git a/target/riscv/pmp.c b/target/riscv/pmp.c
index 81b61bb65c..151da3fa08 100644
--- a/target/riscv/pmp.c
+++ b/target/riscv/pmp.c
@@ -141,17 +141,9 @@ static void pmp_decode_napot(target_ulong a, target_ulong *sa, target_ulong *ea)
        0111...1111   2^(XLEN+2)-byte NAPOT range
        1111...1111   Reserved
     */
-    if (a == -1) {
-        *sa = 0u;
-        *ea = -1;
-        return;
-    } else {
-        target_ulong t1 = ctz64(~a);
-        target_ulong base = (a & ~(((target_ulong)1 << t1) - 1)) << 2;
-        target_ulong range = ((target_ulong)1 << (t1 + 3)) - 1;
-        *sa = base;
-        *ea = base + range;
-    }
+    a = (a << 2) | 0x3;
+    *sa = a & (a + 1);
+    *ea = a | (a + 1);
 }
 
 void pmp_update_rule_addr(CPURISCVState *env, uint32_t pmp_index)
-- 
2.35.1



  parent reply	other threads:[~2022-04-21  7:26 UTC|newest]

Thread overview: 33+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2022-04-21  6:35 [PULL 00/31] riscv-to-apply queue Alistair Francis
2022-04-21  6:36 ` [PULL 01/31] hw/ssi: Add Ibex SPI device model Alistair Francis
2022-04-21  6:36 ` [PULL 02/31] riscv: opentitan: Connect opentitan SPI Host Alistair Francis
2022-04-21  6:36 ` [PULL 03/31] target/riscv: Define simpler privileged spec version numbering Alistair Francis
2022-04-21  6:36 ` [PULL 04/31] target/riscv: Add the privileged spec version 1.12.0 Alistair Francis
2022-04-21  6:36 ` [PULL 05/31] target/riscv: Introduce privilege version field in the CSR ops Alistair Francis
2022-04-21  6:36 ` [PULL 06/31] target/riscv: Add support for mconfigptr Alistair Francis
2022-04-21  6:36 ` [PULL 07/31] target/riscv: Add *envcfg* CSRs support Alistair Francis
2022-04-21  6:36 ` [PULL 08/31] target/riscv: Enable privileged spec version 1.12 Alistair Francis
2022-04-21  6:36 ` [PULL 09/31] target/riscv: cpu: Fixup indentation Alistair Francis
2022-04-21  6:36 ` [PULL 10/31] target/riscv: Allow software access to MIP SEIP Alistair Francis
2022-04-21  6:36 ` [PULL 11/31] target/riscv: Add initial support for the Sdtrig extension Alistair Francis
2022-04-21  6:36 ` [PULL 12/31] target/riscv: optimize condition assign for scale < 0 Alistair Francis
2022-04-21  6:36 ` [PULL 13/31] target/riscv: optimize helper for vmv<nr>r.v Alistair Francis
2022-04-21  6:36 ` [PULL 14/31] target/riscv: misa to ISA string conversion fix Alistair Francis
2022-04-21  6:36 ` [PULL 15/31] target/riscv: Add isa extenstion strings to the device tree Alistair Francis
2022-04-21  6:36 ` [PULL 16/31] target/riscv: fix start byte for vmv<nf>r.v when vstart != 0 Alistair Francis
2022-04-21  6:36 ` [PULL 17/31] target/riscv: Use cpu_loop_exit_restore directly from mmu faults Alistair Francis
2022-04-21  6:36 ` [PULL 18/31] hw/riscv: virt: Exit if the user provided -bios in combination with KVM Alistair Francis
2022-04-21  6:36 ` Alistair Francis [this message]
2022-04-21  6:36 ` [PULL 20/31] hw/riscv: virt: fix DT property mmu-type when CPU mmu option is disabled Alistair Francis
2022-04-21  6:36 ` [PULL 21/31] hw/intc: Add .impl.[min|max]_access_size declaration in RISC-V ACLINT Alistair Francis
2022-04-21  6:36 ` [PULL 22/31] hw/intc: Support 32/64-bit mtimecmp and mtime accesses " Alistair Francis
2022-04-21  6:36 ` [PULL 23/31] hw/intc: Make RISC-V ACLINT mtime MMIO register writable Alistair Francis
2022-04-21  6:36 ` [PULL 24/31] hw/intc: riscv_aclint: Add reset function of ACLINT devices Alistair Francis
2022-04-21  6:36 ` [PULL 25/31] target/riscv: debug: Implement debug related TCGCPUOps Alistair Francis
2022-04-21  6:36 ` [PULL 26/31] target/riscv: cpu: Add a config option for native debug Alistair Francis
2022-04-21  6:36 ` [PULL 27/31] target/riscv: csr: Hook debug CSR read/write Alistair Francis
2022-04-21  6:36 ` [PULL 28/31] target/riscv: machine: Add debug state description Alistair Francis
2022-04-21  6:36 ` [PULL 29/31] target/riscv: cpu: Enable native debug feature Alistair Francis
2022-04-21  6:36 ` [PULL 30/31] hw/core: tcg-cpu-ops.h: Update comments of debug_check_watchpoint() Alistair Francis
2022-04-21  6:36 ` [PULL 31/31] hw/riscv: boot: Support 64bit fdt address Alistair Francis
2022-04-21 15:03 ` [PULL 00/31] riscv-to-apply queue Richard Henderson

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