Hi Jakub, On 5/16/19 3:10 PM, Jakub Jermar wrote: > Hi, > > On 5/3/19 12:02 PM, Jakub Jermar wrote: >> Hi, >> >> On 4/23/19 4:58 PM, Jakub Jermar wrote: >>> Hi Philippe! >>> >>> On 4/23/19 3:48 PM, Philippe Mathieu-Daudé wrote: >>>> Hi Jakub, >>>> >>>> On 4/23/19 1:00 PM, Jakub Jermář wrote: >>>>> This commit addresses QEMU Bug #1825311: >>>>> >>>>> mips_cpu_handle_mmu_fault renders all accessed pages executable >>>>> >>>>> It allows finer-grained control over whether the accessed page should be >>>>> executable by moving the decision to the underlying map_address >>>>> function, which has more information for this. >>>>> >>>>> As a result, pages that have the XI bit set in the TLB and are accessed >>>>> for read/write, don't suddenly end up being executable. >>>>> >>>> >>>> Fixes: https://bugs.launchpad.net/qemu/+bug/1825311 >>>> >>>>> Signed-off-by: Jakub Jermář <jakub.jer...@kernkonzept.com> >>>>> --- >>>>> target/mips/helper.c | 17 ++++++++++------- >>>>> 1 file changed, 10 insertions(+), 7 deletions(-) >>>>> >>>>> diff --git a/target/mips/helper.c b/target/mips/helper.c >>>>> index c44cdca3b5..132d073fbe 100644 >>>>> --- a/target/mips/helper.c >>>>> +++ b/target/mips/helper.c >>>>> @@ -43,7 +43,7 @@ int no_mmu_map_address (CPUMIPSState *env, hwaddr >>>>> *physical, int *prot, >>>>> target_ulong address, int rw, int access_type) >>>>> { >>>>> *physical = address; >>>>> - *prot = PAGE_READ | PAGE_WRITE; >>>>> + *prot = PAGE_READ | PAGE_WRITE | PAGE_EXEC; >>>>> return TLBRET_MATCH; >>>>> } >>>>> >>>>> @@ -61,7 +61,7 @@ int fixed_mmu_map_address (CPUMIPSState *env, hwaddr >>>>> *physical, int *prot, >>>>> else >>>>> *physical = address; >>>>> >>>>> - *prot = PAGE_READ | PAGE_WRITE; >>>>> + *prot = PAGE_READ | PAGE_WRITE | PAGE_EXEC; >>>>> return TLBRET_MATCH; >>>>> } >>>>> >>>>> @@ -101,6 +101,9 @@ int r4k_map_address (CPUMIPSState *env, hwaddr >>>>> *physical, int *prot, >>>>> *prot = PAGE_READ; >>>>> if (n ? tlb->D1 : tlb->D0) >>>>> *prot |= PAGE_WRITE; >>>>> + if (!(n ? tlb->XI1 : tlb->XI0)) { >>>>> + *prot |= PAGE_EXEC; >>>>> + } >>>> >>>> This was indeed missed in commit 2fb58b73746e.
Aleksandar, if this patch is OK with you, can you amend this comment, and add the "Fixes:" tag too when applying? Thanks! Reviewed-by: Philippe Mathieu-Daudé <phi...@redhat.com> >>>> >>>>> return TLBRET_MATCH; >>>>> } >>>>> return TLBRET_DIRTY; >>>>> @@ -182,7 +185,7 @@ static int get_seg_physical_address(CPUMIPSState >>>>> *env, hwaddr *physical, >>>>> } else { >>>>> /* The segment is unmapped */ >>>>> *physical = physical_base | (real_address & segmask); >>>>> - *prot = PAGE_READ | PAGE_WRITE; >>>>> + *prot = PAGE_READ | PAGE_WRITE | PAGE_EXEC; >>>>> return TLBRET_MATCH; >>>>> } >>>>> } >>>>> @@ -913,8 +916,8 @@ int mips_cpu_handle_mmu_fault(CPUState *cs, vaddr >>>>> address, int size, int rw, >>>>> } >>>>> if (ret == TLBRET_MATCH) { >>>>> tlb_set_page(cs, address & TARGET_PAGE_MASK, >>>>> - physical & TARGET_PAGE_MASK, prot | PAGE_EXEC, >>>>> - mmu_idx, TARGET_PAGE_SIZE); >>>>> + physical & TARGET_PAGE_MASK, prot, mmu_idx, >>>>> + TARGET_PAGE_SIZE); >>>>> ret = 0; >>>>> } else if (ret < 0) >>>>> #endif >>>>> @@ -936,8 +939,8 @@ int mips_cpu_handle_mmu_fault(CPUState *cs, vaddr >>>>> address, int size, int rw, >>>>> address, rw, access_type, >>>>> mmu_idx); >>>>> if (ret == TLBRET_MATCH) { >>>>> tlb_set_page(cs, address & TARGET_PAGE_MASK, >>>>> - physical & TARGET_PAGE_MASK, prot | >>>>> PAGE_EXEC, >>>>> - mmu_idx, TARGET_PAGE_SIZE); >>>>> + physical & TARGET_PAGE_MASK, prot, mmu_idx, >>>>> + TARGET_PAGE_SIZE); >>>>> ret = 0; >>>>> return ret; >>>>> } >>>>> >>>> >>>> Your patch looks correct, but I'd like to test it. >>>> Do you have a reproducer? >>>> Can you describe the command line you used? >>> >>> I've just attached a reproducer image and script to the bug. It's a >>> 32-bit little-endian test binary running on top of the L4Re microkernel. I can't get the "TAP" output you described on launchpad. >>> Let me know if you also need a 64-bit version. 64-bit version is welcomed. >>> I tested both 32 and 64-bit versions of the reproducer and also checked >>> to see that the the other images I have lying around here (Linux 2.6.32 >>> big endian and HelenOS master little-endian, both 32-bit for 4Kc) >>> continue to run without regressions. Yes, definitively an improvement: Tested-by: Philippe Mathieu-Daudé <phi...@redhat.com> Regards, Phil.