diff options
Diffstat (limited to 'gdb/aarch64-linux-tdep.c')
| -rw-r--r-- | gdb/aarch64-linux-tdep.c | 205 |
1 files changed, 205 insertions, 0 deletions
diff --git a/gdb/aarch64-linux-tdep.c b/gdb/aarch64-linux-tdep.c index 1c45770..d573f06 100644 --- a/gdb/aarch64-linux-tdep.c +++ b/gdb/aarch64-linux-tdep.c @@ -30,6 +30,7 @@ #include "symtab.h" #include "tramp-frame.h" #include "trad-frame.h" +#include "target.h" #include "target/target.h" #include "expop.h" @@ -47,6 +48,9 @@ #include "arch/aarch64-mte-linux.h" +#include "arch-utils.h" +#include "value.h" + /* Signal frame handling. +------------+ ^ @@ -1503,6 +1507,182 @@ aarch64_linux_gcc_target_options (struct gdbarch *gdbarch) return {}; } +/* Helper to get the allocation tag from a 64-bit ADDRESS. + + Return the allocation tag if successful and nullopt otherwise. */ + +static gdb::optional<CORE_ADDR> +aarch64_mte_get_atag (CORE_ADDR address) +{ + gdb::byte_vector tags; + + /* Attempt to fetch the allocation tag. */ + if (!target_fetch_memtags (address, 1, tags, + static_cast<int> (memtag_type::allocation))) + return {}; + + /* Only one tag should've been returned. Make sure we got exactly that. */ + if (tags.size () != 1) + error (_("Target returned an unexpected number of tags.")); + + /* Although our tags are 4 bits in size, they are stored in a + byte. */ + return tags[0]; +} + +/* Implement the tagged_address_p gdbarch method. */ + +static bool +aarch64_linux_tagged_address_p (struct gdbarch *gdbarch, struct value *address) +{ + gdb_assert (address != nullptr); + + CORE_ADDR addr = value_as_address (address); + + /* Remove the top byte for the memory range check. */ + addr = address_significant (gdbarch, addr); + + /* Check if the page that contains ADDRESS is mapped with PROT_MTE. */ + if (!linux_address_in_memtag_page (addr)) + return false; + + /* We have a valid tag in the top byte of the 64-bit address. */ + return true; +} + +/* Implement the memtag_matches_p gdbarch method. */ + +static bool +aarch64_linux_memtag_matches_p (struct gdbarch *gdbarch, + struct value *address) +{ + gdb_assert (address != nullptr); + + /* Make sure we are dealing with a tagged address to begin with. */ + if (!aarch64_linux_tagged_address_p (gdbarch, address)) + return true; + + CORE_ADDR addr = value_as_address (address); + + /* Fetch the allocation tag for ADDRESS. */ + gdb::optional<CORE_ADDR> atag = aarch64_mte_get_atag (addr); + + if (!atag.has_value ()) + return true; + + /* Fetch the logical tag for ADDRESS. */ + gdb_byte ltag = aarch64_mte_get_ltag (addr); + + /* Are the tags the same? */ + return ltag == *atag; +} + +/* Implement the set_memtags gdbarch method. */ + +static bool +aarch64_linux_set_memtags (struct gdbarch *gdbarch, struct value *address, + size_t length, const gdb::byte_vector &tags, + memtag_type tag_type) +{ + gdb_assert (!tags.empty ()); + gdb_assert (address != nullptr); + + CORE_ADDR addr = value_as_address (address); + + /* Set the logical tag or the allocation tag. */ + if (tag_type == memtag_type::logical) + { + /* When setting logical tags, we don't care about the length, since + we are only setting a single logical tag. */ + addr = aarch64_mte_set_ltag (addr, tags[0]); + + /* Update the value's content with the tag. */ + enum bfd_endian byte_order = gdbarch_byte_order (gdbarch); + gdb_byte *srcbuf = value_contents_raw (address); + store_unsigned_integer (srcbuf, sizeof (addr), byte_order, addr); + } + else + { + /* Make sure we are dealing with a tagged address to begin with. */ + if (!aarch64_linux_tagged_address_p (gdbarch, address)) + return false; + + /* With G being the number of tag granules and N the number of tags + passed in, we can have the following cases: + + 1 - G == N: Store all the N tags to memory. + + 2 - G < N : Warn about having more tags than granules, but write G + tags. + + 3 - G > N : This is a "fill tags" operation. We should use the tags + as a pattern to fill the granules repeatedly until we have + written G tags to memory. + */ + + size_t g = aarch64_mte_get_tag_granules (addr, length, + AARCH64_MTE_GRANULE_SIZE); + size_t n = tags.size (); + + if (g < n) + warning (_("Got more tags than memory granules. Tags will be " + "truncated.")); + else if (g > n) + warning (_("Using tag pattern to fill memory range.")); + + if (!target_store_memtags (addr, length, tags, + static_cast<int> (memtag_type::allocation))) + return false; + } + return true; +} + +/* Implement the get_memtag gdbarch method. */ + +static struct value * +aarch64_linux_get_memtag (struct gdbarch *gdbarch, struct value *address, + memtag_type tag_type) +{ + gdb_assert (address != nullptr); + + CORE_ADDR addr = value_as_address (address); + CORE_ADDR tag = 0; + + /* Get the logical tag or the allocation tag. */ + if (tag_type == memtag_type::logical) + tag = aarch64_mte_get_ltag (addr); + else + { + /* Make sure we are dealing with a tagged address to begin with. */ + if (!aarch64_linux_tagged_address_p (gdbarch, address)) + return nullptr; + + gdb::optional<CORE_ADDR> atag = aarch64_mte_get_atag (addr); + + if (!atag.has_value ()) + return nullptr; + + tag = *atag; + } + + /* Convert the tag to a value. */ + return value_from_ulongest (builtin_type (gdbarch)->builtin_unsigned_int, + tag); +} + +/* Implement the memtag_to_string gdbarch method. */ + +static std::string +aarch64_linux_memtag_to_string (struct gdbarch *gdbarch, struct value *tag_value) +{ + if (tag_value == nullptr) + return ""; + + CORE_ADDR tag = value_as_address (tag_value); + + return string_printf ("0x%s", phex_nz (tag, sizeof (tag))); +} + static void aarch64_linux_init_abi (struct gdbarch_info info, struct gdbarch *gdbarch) { @@ -1560,6 +1740,31 @@ aarch64_linux_init_abi (struct gdbarch_info info, struct gdbarch *gdbarch) data associated with the address. */ set_gdbarch_significant_addr_bit (gdbarch, 56); + /* MTE-specific settings and hooks. */ + if (tdep->has_mte ()) + { + /* Register a hook for checking if an address is tagged or not. */ + set_gdbarch_tagged_address_p (gdbarch, aarch64_linux_tagged_address_p); + + /* Register a hook for checking if there is a memory tag match. */ + set_gdbarch_memtag_matches_p (gdbarch, + aarch64_linux_memtag_matches_p); + + /* Register a hook for setting the logical/allocation tags for + a range of addresses. */ + set_gdbarch_set_memtags (gdbarch, aarch64_linux_set_memtags); + + /* Register a hook for extracting the logical/allocation tag from an + address. */ + set_gdbarch_get_memtag (gdbarch, aarch64_linux_get_memtag); + + /* Set the allocation tag granule size to 16 bytes. */ + set_gdbarch_memtag_granule_size (gdbarch, AARCH64_MTE_GRANULE_SIZE); + + /* Register a hook for converting a memory tag to a string. */ + set_gdbarch_memtag_to_string (gdbarch, aarch64_linux_memtag_to_string); + } + /* Initialize the aarch64_linux_record_tdep. */ /* These values are the size of the type that will be used in a system call. They are obtained from Linux Kernel source. */ |