diff options
| author | Jean-Philippe Brucker <jean-philippe@linaro.org> | 2020-11-03 14:49:01 +0100 |
|---|---|---|
| committer | Will Deacon <will@kernel.org> | 2020-11-03 14:03:38 +0000 |
| commit | 7ee31a3aa8f490c6507bc4294df6b70bed1c593e (patch) | |
| tree | 901c9487d9137d2c88dcdb5f0e9100f323fc9e53 /arch/arm64/include/asm/brk-imm.h | |
| parent | 2a13c13b39a8aea4c69a31549e4cb0094f30103b (diff) | |
arm64: kprobes: Use BRK instead of single-step when executing instructions out-of-line
Commit 36dadef23fcc ("kprobes: Init kprobes in early_initcall") enabled
using kprobes from early_initcall. Unfortunately at this point the
hardware debug infrastructure is not operational. The OS lock may still
be locked, and the hardware watchpoints may have unknown values when
kprobe enables debug monitors to single-step instructions.
Rather than using hardware single-step, append a BRK instruction after
the instruction to be executed out-of-line.
Fixes: 36dadef23fcc ("kprobes: Init kprobes in early_initcall")
Suggested-by: Will Deacon <will@kernel.org>
Signed-off-by: Jean-Philippe Brucker <jean-philippe@linaro.org>
Acked-by: Masami Hiramatsu <mhiramat@kernel.org>
Link: https://lore.kernel.org/r/20201103134900.337243-1-jean-philippe@linaro.org
Signed-off-by: Will Deacon <will@kernel.org>
Diffstat (limited to 'arch/arm64/include/asm/brk-imm.h')
| -rw-r--r-- | arch/arm64/include/asm/brk-imm.h | 2 |
1 files changed, 2 insertions, 0 deletions
diff --git a/arch/arm64/include/asm/brk-imm.h b/arch/arm64/include/asm/brk-imm.h index e3d47b52161d..ec7720dbe2c8 100644 --- a/arch/arm64/include/asm/brk-imm.h +++ b/arch/arm64/include/asm/brk-imm.h @@ -10,6 +10,7 @@ * #imm16 values used for BRK instruction generation * 0x004: for installing kprobes * 0x005: for installing uprobes + * 0x006: for kprobe software single-step * Allowed values for kgdb are 0x400 - 0x7ff * 0x100: for triggering a fault on purpose (reserved) * 0x400: for dynamic BRK instruction @@ -19,6 +20,7 @@ */ #define KPROBES_BRK_IMM 0x004 #define UPROBES_BRK_IMM 0x005 +#define KPROBES_BRK_SS_IMM 0x006 #define FAULT_BRK_IMM 0x100 #define KGDB_DYN_DBG_BRK_IMM 0x400 #define KGDB_COMPILED_DBG_BRK_IMM 0x401 |