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| author | Alexander Potapenko <glider@google.com> | 2025-09-30 11:02:37 +0200 |
|---|---|---|
| committer | Alexander Potapenko <glider@google.com> | 2025-10-17 06:51:20 +0000 |
| commit | 6ca4530067ac25a78291b176b6d3dbe6ba592d15 (patch) | |
| tree | 731490cefa5b43b5ccf48f83f77979a829da72c0 /executor/common_kvm.h | |
| parent | 554d3ef1c24ae1bc3c8c439e8c8f3a9006434244 (diff) | |
executor: introduce DEFINE_GUEST_FN_TO_GPA_FN()
DEFINE_GUEST_FN_TO_GPA_FN() allows to define helper functions to
calculate guest addresses in the host/guest code.
Diffstat (limited to 'executor/common_kvm.h')
| -rw-r--r-- | executor/common_kvm.h | 18 |
1 files changed, 18 insertions, 0 deletions
diff --git a/executor/common_kvm.h b/executor/common_kvm.h index fecd00922..b11e3e06b 100644 --- a/executor/common_kvm.h +++ b/executor/common_kvm.h @@ -5,6 +5,24 @@ // Common KVM-related definitions. +extern char *__start_guest, *__stop_guest; + +// Define a function that calculates the guest physical address for a guest function. +// Execute failure_action if the function does not belong to the guest section. +// This function is using volatile accesses, otherwise the compiler may attempt +// to store e.g. &__start_guest + offset as a constant in .rodata. +#define DEFINE_GUEST_FN_TO_GPA_FN(fn_name, offset, failure_action) \ + static inline uintptr_t fn_name(uintptr_t f) \ + { \ + volatile uintptr_t start = (uintptr_t)&__start_guest; \ + volatile uintptr_t stop = (uintptr_t)&__stop_guest; \ + if (f >= start && f < stop) { \ + return f - start + (offset); \ + } \ + (failure_action); \ + return 0; \ + } + #if SYZ_EXECUTOR || __NR_syz_kvm_assert_syzos_kvm_exit static long syz_kvm_assert_syzos_kvm_exit(volatile long a0, volatile long a1) { |