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. >>> >>>> 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. >> Let me know if you also need a 64-bit version. >> >> 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. >> >> Best regards, >> Jakub > > (ping) > > Is there anything else I can do to help to get this merged? > > https://patchew.org/QEMU/20190423110034.1260142-1-jakub.jer...@kernkonzept.com/
Has anyone managed to have a look at this? Thanks, Jakub > > Thanks, > Jakub > -- Kernkonzept GmbH at Dresden, Germany, HRB 31129, CEO Dr.-Ing. Michael Hohmuth
