diff options
author | Linus Torvalds | 2022-03-11 12:28:21 -0800 |
---|---|---|
committer | Linus Torvalds | 2022-03-11 12:28:21 -0800 |
commit | 77fe1ba90241c2af6f14d53988bf0cd6b9586699 (patch) | |
tree | 51ec458e66f86ea5393a827d3eb1783045eef5cc /arch | |
parent | 878409ecde7c89c9f3db76ff1ef9486c6ceed02c (diff) | |
parent | 0966d385830de3470b7131db8e86c0c5bc9c52dc (diff) |
Merge tag 'riscv-for-linus-5.17-rc8' of git://git.kernel.org/pub/scm/linux/kernel/git/riscv/linux
Pull RISC-V fixes from Palmer Dabbelt:
- prevent users from enabling the alternatives framework (and thus
errata handling) on XIP kernels, where runtime code patching does not
function correctly.
- properly detect offset overflow for AUIPC-based relocations in
modules. This may manifest as modules calling arbitrary invalid
addresses, depending on the address allocated when a module is
loaded.
* tag 'riscv-for-linus-5.17-rc8' of git://git.kernel.org/pub/scm/linux/kernel/git/riscv/linux:
riscv: Fix auipc+jalr relocation range checks
riscv: alternative only works on !XIP_KERNEL
Diffstat (limited to 'arch')
-rw-r--r-- | arch/riscv/Kconfig.erratas | 1 | ||||
-rw-r--r-- | arch/riscv/Kconfig.socs | 4 | ||||
-rw-r--r-- | arch/riscv/kernel/module.c | 21 |
3 files changed, 19 insertions, 7 deletions
diff --git a/arch/riscv/Kconfig.erratas b/arch/riscv/Kconfig.erratas index b44d6ecdb46e..0aacd7052585 100644 --- a/arch/riscv/Kconfig.erratas +++ b/arch/riscv/Kconfig.erratas @@ -2,6 +2,7 @@ menu "CPU errata selection" config RISCV_ERRATA_ALTERNATIVE bool "RISC-V alternative scheme" + depends on !XIP_KERNEL default y help This Kconfig allows the kernel to automatically patch the diff --git a/arch/riscv/Kconfig.socs b/arch/riscv/Kconfig.socs index 6ec44a22278a..c112ab2a9052 100644 --- a/arch/riscv/Kconfig.socs +++ b/arch/riscv/Kconfig.socs @@ -14,8 +14,8 @@ config SOC_SIFIVE select CLK_SIFIVE select CLK_SIFIVE_PRCI select SIFIVE_PLIC - select RISCV_ERRATA_ALTERNATIVE - select ERRATA_SIFIVE + select RISCV_ERRATA_ALTERNATIVE if !XIP_KERNEL + select ERRATA_SIFIVE if !XIP_KERNEL help This enables support for SiFive SoC platform hardware. diff --git a/arch/riscv/kernel/module.c b/arch/riscv/kernel/module.c index 68a9e3d1fe16..4a48287513c3 100644 --- a/arch/riscv/kernel/module.c +++ b/arch/riscv/kernel/module.c @@ -13,6 +13,19 @@ #include <linux/pgtable.h> #include <asm/sections.h> +/* + * The auipc+jalr instruction pair can reach any PC-relative offset + * in the range [-2^31 - 2^11, 2^31 - 2^11) + */ +static bool riscv_insn_valid_32bit_offset(ptrdiff_t val) +{ +#ifdef CONFIG_32BIT + return true; +#else + return (-(1L << 31) - (1L << 11)) <= val && val < ((1L << 31) - (1L << 11)); +#endif +} + static int apply_r_riscv_32_rela(struct module *me, u32 *location, Elf_Addr v) { if (v != (u32)v) { @@ -95,7 +108,7 @@ static int apply_r_riscv_pcrel_hi20_rela(struct module *me, u32 *location, ptrdiff_t offset = (void *)v - (void *)location; s32 hi20; - if (offset != (s32)offset) { + if (!riscv_insn_valid_32bit_offset(offset)) { pr_err( "%s: target %016llx can not be addressed by the 32-bit offset from PC = %p\n", me->name, (long long)v, location); @@ -197,10 +210,9 @@ static int apply_r_riscv_call_plt_rela(struct module *me, u32 *location, Elf_Addr v) { ptrdiff_t offset = (void *)v - (void *)location; - s32 fill_v = offset; u32 hi20, lo12; - if (offset != fill_v) { + if (!riscv_insn_valid_32bit_offset(offset)) { /* Only emit the plt entry if offset over 32-bit range */ if (IS_ENABLED(CONFIG_MODULE_SECTIONS)) { offset = module_emit_plt_entry(me, v); @@ -224,10 +236,9 @@ static int apply_r_riscv_call_rela(struct module *me, u32 *location, Elf_Addr v) { ptrdiff_t offset = (void *)v - (void *)location; - s32 fill_v = offset; u32 hi20, lo12; - if (offset != fill_v) { + if (!riscv_insn_valid_32bit_offset(offset)) { pr_err( "%s: target %016llx can not be addressed by the 32-bit offset from PC = %p\n", me->name, (long long)v, location); |