On Fri, Feb 21, 2020 at 5:09 PM Lirong Yuan <yua...@google.com> wrote: > > This change allows us to set custom base address for guest programs. It is > needed to allow qemu to work with Thread Sanitizer (TSan), which has specific > boundary definitions for memory mappings on different platforms: > https://github.com/llvm/llvm-project/blob/master/compiler-rt/lib/tsan/rtl/tsan_platform.h > > Signed-off-by: Lirong Yuan <yua...@google.com> > --- > linux-user/main.c | 12 ++++++++++++ > linux-user/mmap.c | 3 ++- > linux-user/qemu.h | 5 +++++ > 3 files changed, 19 insertions(+), 1 deletion(-) > > diff --git a/linux-user/main.c b/linux-user/main.c > index fba833aac9..c01af6bfee 100644 > --- a/linux-user/main.c > +++ b/linux-user/main.c > @@ -336,6 +336,16 @@ static void handle_arg_guest_base(const char *arg) > have_guest_base = 1; > } > > +static void handle_arg_mmap_base(const char *arg) > +{ > + int err = qemu_strtoul(arg, NULL, 0, &mmap_base); > + if (err) { > + fprintf(stderr, "Invalid mmap_base: %s, err: %d\n", arg, err); > + exit(EXIT_FAILURE); > + } > + mmap_next_start = mmap_base; > +} > + > static void handle_arg_reserved_va(const char *arg) > { > char *p; > @@ -440,6 +450,8 @@ static const struct qemu_argument arg_table[] = { > "uname", "set qemu uname release string to 'uname'"}, > {"B", "QEMU_GUEST_BASE", true, handle_arg_guest_base, > "address", "set guest_base address to 'address'"}, > + {"mmap_base", "QEMU_MMAP_BASE", true, handle_arg_mmap_base, > + "", "begin allocating guest pages at this host address"}, > {"R", "QEMU_RESERVED_VA", true, handle_arg_reserved_va, > "size", "reserve 'size' bytes for guest virtual address space"}, > {"d", "QEMU_LOG", true, handle_arg_log, > diff --git a/linux-user/mmap.c b/linux-user/mmap.c > index 8685f02e7e..3f35543acf 100644 > --- a/linux-user/mmap.c > +++ b/linux-user/mmap.c > @@ -189,6 +189,7 @@ static int mmap_frag(abi_ulong real_start, > # define TASK_UNMAPPED_BASE 0x40000000 > #endif > abi_ulong mmap_next_start = TASK_UNMAPPED_BASE; > +abi_ulong mmap_base = TASK_UNMAPPED_BASE; > > unsigned long last_brk; > > @@ -299,7 +300,7 @@ abi_ulong mmap_find_vma(abi_ulong start, abi_ulong size, > abi_ulong align) > > if ((addr & (align - 1)) == 0) { > /* Success. */ > - if (start == mmap_next_start && addr >= TASK_UNMAPPED_BASE) { > + if (start == mmap_next_start && addr >= mmap_base) { > mmap_next_start = addr + size; > } > return addr; > diff --git a/linux-user/qemu.h b/linux-user/qemu.h > index 560a68090e..83c00cfea2 100644 > --- a/linux-user/qemu.h > +++ b/linux-user/qemu.h > @@ -161,6 +161,11 @@ void task_settid(TaskState *); > void stop_all_tasks(void); > extern const char *qemu_uname_release; > extern unsigned long mmap_min_addr; > +/* > + * mmap_base is minimum address to use when allocating guest pages. All guest > + * pages will be allocated at this (guest) address or higher addresses. > + */ > +extern abi_ulong mmap_base; > > /* ??? See if we can avoid exposing so much of the loader internals. */ > > -- > 2.25.0.265.gbab2e86ba0-goog >
Friendly ping~ Link to the page for the patch on patchwork: http://patchwork.ozlabs.org/patch/1242370/
