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author | Ben Woodard <woodard@redhat.com> | 2022-01-24 10:46:18 -0300 |
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committer | Adhemerval Zanella <adhemerval.zanella@linaro.org> | 2022-02-01 14:49:46 -0300 |
commit | ce9a68c57c260c8417afc93972849ac9ad243ec4 (patch) | |
tree | adedf6275c170675cdd751e0d59f569f4b3c69ca /sysdeps/aarch64/bits | |
parent | 32612615c58b394c3eb09f020f31310797ad3854 (diff) | |
download | glibc-ce9a68c57c260c8417afc93972849ac9ad243ec4.tar.gz glibc-ce9a68c57c260c8417afc93972849ac9ad243ec4.tar.xz glibc-ce9a68c57c260c8417afc93972849ac9ad243ec4.zip |
elf: Fix runtime linker auditing on aarch64 (BZ #26643)
The rtld audit support show two problems on aarch64: 1. _dl_runtime_resolve does not preserve x8, the indirect result location register, which might generate wrong result calls depending of the function signature. 2. The NEON Q registers pushed onto the stack by _dl_runtime_resolve were twice the size of D registers extracted from the stack frame by _dl_runtime_profile. While 2. might result in wrong information passed on the PLT tracing, 1. generates wrong runtime behaviour. The aarch64 rtld audit support is changed to: * Both La_aarch64_regs and La_aarch64_retval are expanded to include both x8 and the full sized NEON V registers, as defined by the ABI. * dl_runtime_profile needed to extract registers saved by _dl_runtime_resolve and put them into the new correctly sized La_aarch64_regs structure. * The LAV_CURRENT check is change to only accept new audit modules to avoid the undefined behavior of not save/restore x8. * Different than other architectures, audit modules older than LAV_CURRENT are rejected (both La_aarch64_regs and La_aarch64_retval changed their layout and there are no requirements to support multiple audit interface with the inherent aarch64 issues). * A new field is also reserved on both La_aarch64_regs and La_aarch64_retval to support variant pcs symbols. Similar to x86, a new La_aarch64_vector type to represent the NEON register is added on the La_aarch64_regs (so each type can be accessed directly). Since LAV_CURRENT was already bumped to support bind-now, there is no need to increase it again. Checked on aarch64-linux-gnu. Co-authored-by: Adhemerval Zanella <adhemerval.zanella@linaro.org> Reviewed-by: Szabolcs Nagy <szabolcs.nagy@arm.com> Reviewed-by: Carlos O'Donell <carlos@redhat.com> Tested-by: Carlos O'Donell <carlos@redhat.com>
Diffstat (limited to 'sysdeps/aarch64/bits')
-rw-r--r-- | sysdeps/aarch64/bits/link.h | 26 |
1 files changed, 17 insertions, 9 deletions
diff --git a/sysdeps/aarch64/bits/link.h b/sysdeps/aarch64/bits/link.h index e64f36d3f3..2479abc4fb 100644 --- a/sysdeps/aarch64/bits/link.h +++ b/sysdeps/aarch64/bits/link.h @@ -20,23 +20,31 @@ # error "Never include <bits/link.h> directly; use <link.h> instead." #endif +typedef union +{ + float s; + double d; + long double q; +} La_aarch64_vector; + /* Registers for entry into PLT on AArch64. */ typedef struct La_aarch64_regs { - uint64_t lr_xreg[8]; - uint64_t lr_dreg[8]; - uint64_t lr_sp; - uint64_t lr_lr; + uint64_t lr_xreg[9]; + La_aarch64_vector lr_vreg[8]; + uint64_t lr_sp; + uint64_t lr_lr; + void *lr_vpcs; } La_aarch64_regs; /* Return values for calls from PLT on AArch64. */ typedef struct La_aarch64_retval { - /* Up to two integer registers can be used for a return value. */ - uint64_t lrv_xreg[2]; - /* Up to four D registers can be used for a return value. */ - uint64_t lrv_dreg[4]; - + /* Up to eight integer registers can be used for a return value. */ + uint64_t lrv_xreg[8]; + /* Up to eight V registers can be used for a return value. */ + La_aarch64_vector lrv_vreg[8]; + void *lrv_vpcs; } La_aarch64_retval; __BEGIN_DECLS |